technical handbook 1kw dme station ldb-102
DESCRIPTION
Technical Handbook 1kW DME STATION LDB-102TRANSCRIPT
Technical Handbook
1kW DME STATION LDB-102
Handbook HA72500
HA72500_Revisions.doc
HA72500 REVISION RECORD
REVISION No. AUTHORITY DATE INSERTED INITIALS1-3 Included in Issue 1 25/6/93 R S Reid
4 Included in Issue 2 13/4/94 R S Reid
5 Editorial 18/6/94 R S Reid
6 Editorial 31/10/94 R S Reid
7 Editorial 23/11/94 R S Reid
8 ECO 901695, 901687, 901695, 901701, 901702, 901704, 1901705, 101709, 901727, 901775, 901777, 901787, 901788, 901798, 901799, 901800, 901877, 901887, 901891, 901911, 901934, 901936, 901947, 901953, 901996, 901997, 902000, 902006,
Editorial
2/5/95 R S Reid
9 ECO 902169, 902181, 902309, 902449, 902499
6/3/96 R S Reid
10 ECO 901940, 902157, 902422, 902731 9/7/96 R S Reid
11 ECO 902011, 903033, 903044, 903233, 903296, 903516, 903757
18/12/96 R S Reid
12 ECO 903757 19/12/96 R S Reid
13 ECO 903915 1/7/97 R S Reid
14 ECO E1389 11/5/98 C O’Hara
15 ECO E1575 11/5/98 C O’Hara
16 ECO E1636 11/5/98 C O’Hara
17 ECO E1708 12/5/98 C O’Hara
18 ECO E1713 12/5/98 C O’Hara
19 ECO E1764 25/5/98 C O’Hara
20 ECO E2261 25/2/00 C O’Hara
21 ECO E2286 5/7/00 C O’Hara
22 ECO E10006 4/6/01 C O’Hara
23 ECO E3003, E3004, E3005, E3006, E3007, E3008, E3025, E3035, E3048
25/7/05 C O’Hara
24 E3101 17/8/06 C O’Hara
25 ECO E3146 2/12/08 A.Cain
26 ECO E3188 23/7/09 A.Cain
© Copyright Interscan Navigation Systems Pty Ltd
This publication is copyright and all rights pertaining to it are reserved. No part may be reproduced by any process without written permission.
HA72500
HANDBOOK HA72500
VOLUME ARRANGEMENT
VOLUME 1 SECTION 1 BRIEF SPECIFICATION AND SPECIFICATION
2 TECHNICAL DESCRIPTION
VOLUME 2 3 ALIGNMENT AND ADJUSTMENT
VOLUME 3 4 MAINTENANCE PROCEDURES
APPENDIX PHYSICAL DIMENSIONS AND MASSES
C POWER AND REMOTE CONTROL
D SYSTEM INSTALLATION
E TEST EQUIPMENT
VOLUME 4 A OPERATING INSTRUCTIONS
VOLUME 5 F COMPONENTS SCHEDULE
G AGENTS
H CTU SOFTWARE
I COMPONENT LAYOUT DIAGRAMS
J AC POWER SUPPLY 3A71130
K DEPOT TEST FACILITY
L CHANNEL FREQUENCY AND SPACING SPECIFICATION
M PROGRAMMABLE LOGIC DEVICE DESCRIPTIONS
N CRYSTAL SPECIFICATIONS
VOLUME 6 DRAWINGS
HA72500
WARNINGS
The warning information Included below should be made known to all personnel engaged in operation and maintenance of the
DME LDB-102 equipment
RADIATION EXPOSURE HAZARD The LDB-102 DME has been tested to determine the levels of microwave radiation existing around various parts of the equipment. These tests were performed in Australia by the Environmental Protection Authority of the New South Wales State Government. The only significant levels of radiation are those close to the 1kW Power Amplifier when its cover is removed, and the measured power density is less than 1.0 milliwatt per square centimetre (mW/cm2) in all cases.
The DME therefore meets the requirements of Australian Standard AS2772-1985, which sets an occupational exposure limit of 1 mW/cm2, over an 8-hour day, for these frequencies. The equipment also meets the requirements of the American National Standards Institute (ANSI) Standard C95.1-1982, which sets a limit of 3 mW/cm2.
On the basis of these measurements, maintenance personnel are in no danger of hazardous radiation while working on an operating DME.
Despite the low level of radiation from the equipment, it is recommended that the DME be always operated with the cover fitted to the 1kW Power Amplifier. When servicing procedures require DME operation with this cover removed, personnel should exercise care not to unnecessarily expose sensitive body tissue (such as eyes or gonads) to areas of radiation for an extended time period.
ELECTRIC SHOCK HAZARD Maintenance or other tasks which require access to the equipment during operation should be performed only by suitable qualified personnel who are aware of the precautions to be taken when working on equipment in which hazardous operating voltages may be present.
All personnel should be conversant with emergency cardiopulmonary resuscitation procedures. An illustrated procedure authorised by the National Heart Foundation of Australia is included in this manual for reference.
TOXIC SUBSTANCES Beryllium Oxide Beryllium oxide in the sintered (ceramic) form is safe to handle whilst it remains intact in its original manufactured form, but if it is broken or pulverised the resulting dust particles are highly toxic.
The sintered form of beryllium oxide is a component in the manufacture of thermally conductive washers as used in transistor heat sink applications, and in the manufacture of chip resistors. These SHOULD NOT be broken, filed, drilled, sandpapered, or abraded in any way.
The sintered form of beryllium oxide is also used in the manufacture of high-frequency (VHF and UHF) transistors; these can usually be identified by a white ceramic-looking circumferential band. These transistors SHOULD NOT be opened 'in any circumstances.
HA72500
Beryllium oxide is also used as a greasy-looking paste inside certain types of metal can transistors; these SHOULD NOT be opened in any circumstances.
Because of the difficulty in identifying those transistors which may contain beryllium oxide, NO TRANSISTORS SHOULD EVER BE CUT OPEN FOR INTERNAL INSPECTION. Also, used or replaced transistors should be disposed of in a manner consistent with the potential hazard that they may present.
Beryllium oxide should not be confused with beryllium copper, which is safe to handle.
Polytetrafluoroethylene (PTFE) Thermal degradation of PTFE will commence at temperatures above 200 degrees Celsius; toxic vapours will be evolved at such temperatures.
This characteristics of PTFE must be taken into account when repair or replacement of components may involve heating of PTFE. Adequate ventilation should be provided in the event that processes (such as soldering) may submit PTFE to temperatures above 200 degrees Celsius.
LIGHTNING PROTECTION The design of the DME LDB-102 minimises hazard from lightning strike effect up to the order of a few hundred volts. In installations where external wiring is connected to the equipment and extends over significant distances, suitable protection devices should be fitted at the point where the external wiring enters the equipment shelter.
CAUTION
The precautionary Information included below should be made known to all personnel engaged in maintenance of the DME LDB-
102 equipment
STATIC-SENSITIVE DEVICES All metal oxide semiconductor (MOS) devices and the FET family of transistors can potentially be damaged by electrostatic discharge voltages occurring during handling, or during testing or installation into a circuit board.
Some types of devices incorporate in-built circuitry to provide protection against the effects of electrostatic discharge voltages. Other types do not, and are potentially susceptible to damage. These latter types are referred to as static-sensitive devices (SSDs).
The DME LDB-102 equipment contains SSDs. Personnel involved in testing and repair of the equipment should be aware of the causes and effects of potential damage to SSDs, and of the proper practices to be observed in order to obviate such damage.
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V19_in_progress\NHF-CPR.doc
EMERGENCY CARDIOPULMONARY RESUSCITATION FOR UNCONSCIOUS PATIENT. STAY WITH VICTIM – CALL FOR HELP AND COMMENCE RESUSCITATION.
AIRWAY: Clear the airway. Quickly turn victim on side and remove foreign material from mouth. Place neck and jaw in correct positions.
Check breathing and listen to breath, watch for chest movement. If breathing, leave victim on side and keep the airway clear.
BREATHING: If not breathing, quickly turn the victim on his back and commence expired air resuscitation. mouth or mouth to nose, using
jaw lift method to open airway. Give 5 full ventilations in ten seconds.
Check circulation, carotid pulse. If present, continue expired air resuscitation at a rate of 15 per minute.
Check the circulation after 1 minute and then every 2 minutes. If breathing returns, place the victim on side and keep the airway clear.
CIRCULATION: Check carotid pulse. If absent, begin external cardiac compression. Place the heel of one hand on the lower half of the sternum and lock the other hand to the first by grasping wrist or interlocking fingers. Keep fingers off the chest.
One Operator: 2 ventilations, 15 compressions, 4 cycles per minute.
Two Operators: 1 ventilation, 5 compressions, 12 cycles per minute.
CHECK PROGRESS - If effective • Carotid pulse felt with each
compression. • Skin will become pinker.
GET HELP In metropolitan areas, dial 000 and ask for ambulance service. In country areas, contact your local ambulance service.
National Heart Foundation of Australia PE3 (rev) 1984
HA72500
ACRONYMS AND ABBREVIATIONS The major acronyms and abbreviations used throughout this handbook, and their meanings, are listed below. Unless shown otherwise these apply to indicate both noun and verb forms, and to singular and plural cases. Examples:
AM may indicate either amplitude modulation
or amplitude modulated
LED may indicate either light emitting diode
or light emitting diodes
ABBREVIATION MEANING
AC Alternating current
AFC Automatic frequency control
AGC Automatic gain control
AH Ampere-hour
AM Amplitude modulation
ATIS Airport terminal information service
BCD Binary coded decimal
CMOS Complementary metal oxide semiconductor
CPU Central processing unit
CVOR Conventional VHF omni-range
CW Carrier wave
DAC Digital-to-analogue converter
DC Direct current
DIL Dual in line
DIP Dual in line package
DME Distance measuring equipment
DVOR Doppler VHF omni-range
EPROM Electrically programmable read only memory
FET Field effect transistor
FM Frequency modulation
ISEP International standard equipment practice
LED Light emitting diode
LRU Line replaceable unit
LSB Lower sideband
MOS Metal oxide semiconductor
MOSFET Metal oxide semiconductor field effect transistor
PIN P-type/intrinsic/N-type
PPM Parts per million
PRF Pulse repetition frequency
PROM Programmable read only memory
PTFE Polytetrafluoroethane
PVC Polyvinyl chloride
HA72500
ABBREVIATION MEANING
PWB Printed wiring board
RAM Random access memory
R/C Resistor/capacitor
RF Radio frequency
RMS Root-mean-square
ROM Read only memory
SCR Silicon controlled rectifier
USB Upper sideband
SSD Static-sensitive device
UV Ultraviolet
VCO Voltage controlled oscillator
VHF Very high frequency
VOR VHF omni-range
VSWR Voltage standing wave ratio
WPM Words per minute
COMPONENT DESIGNATORS The system of letter codes used for the designation of electronic component items of the equipment described in this handbook conforms to Australian Standard AS1103.2 (1982). This system is as follows:
Letter Code Kind of Item
A Assemblies, subassemblies
B Transducers, from non-electrical to electrical quantity or vice versa
C Capacitors
D Binary elements, delay devices, storage devices
E Miscellaneous
F Protective devices
G Generators, power supplies
H Signalling devices
K Relays, contactors
L Inductors, reactors
M Motors
N Analogue integrated circuits
P Measuring equipment, testing equipment
O Mechanical switching devices for power circuits
R Resistors
S Switches, selectors
T Transformers, regulators (power)
U Modulators, changes
V Tubes, semiconductors (discrete)
W Transmission paths, waveguides, aerials (antennas)
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HA72500
Letter Code Kind of Item
X Terminals, plugs, sockets, links, joints (also see below)
Y Electrically operated mechanical devices
Z Networks, hybrid transformers, filters, equalisers, limiters
COMPONENT DESIGNATOR SUFFIXES All connectors (terminals, plugs, sockets. jacks) are identified by the designator letter 'X'; additionally, suffix letters are used to further identify the type or location of connectors. Connector designators used are:
Letter Code Type of Connector
XA A connection point mounted on the face panel of an equipment module and accessible during normal operation of the equipment; example - a front panel test jack.
XC A coaxial connector.
XN A multiway connector with either male or female contacts.
XT A test point mounted on a printed wiring board assembly, accessible only when access panels are removed and/or the board assembly is extended for maintenance or adjustment
TERMINAL/PIN DESIGNATION The system used for identification of terminal designations conforms to Australian Standard AS1103.2 (1982), Section 6.5. Under this system, a terminal number is prefixed with the qualifying symbol ':'. Thus, for example:
XN4:13 Identifies pin 13 of connector XN4.
N161:3 Identifies pin 3 of analogue integrated circuit N161.
D5:2 Identifies pin 2 of digital integrated circuit D5.
HA72500 SECTION 1
SECTION 1
BRIEF DESCRIPTION AND SPECIFICATION
1-i
HA72500 SECTION 1
TABLE of CONTENTS
1. BRIEF DESCRIPTION AND SPECIFICATION........................................... 1-1 1.1 FUNCTIONAL DESCRIPTION 1-1
1.1.1 Introduction.................................................................................................. 1-1 1.1.2 Application ................................................................................................... 1-1
1.2 SYSTEM OPERATION 1-1 1.2.1 Introduction.................................................................................................. 1-1 1.2.2 Distance Measuring Function ...................................................................... 1-1 1.2.3 DME Pulse Generation................................................................................ 1-2 1.2.4 System Squitter ........................................................................................... 1-2 1.2.5 Maximum Reply Rate .................................................................................. 1-2 1.2.6 Identification Message................................................................................. 1-3 1.2.7 Range and Echo.......................................................................................... 1-3 1.2.8 Remote Control and Monitoring System...................................................... 1-3
1.3 PERFORMANCE SPECIFICATION 1-3 1.4 DOCUMENTATION 1-10
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HA72500 SECTION 1
LIST of FIGURES
Figure 1-1 DME Principle.........................................................................................1-2
LIST of TABLES
Table 1-1 Performance Characteristics Summary......................................................1-4 Table 1-2 Controls and Indicators...............................................................................1-7
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HA72500 SECTION 1
1. BRIEF DESCRIPTION AND SPECIFICATION 1.1 FUNCTIONAL DESCRIPTION
1.1.1 Introduction This document describes the Distance Measuring Equipment (DME) series LDB-102 type A72500. It contains information which includes equipment description, alignment procedures, installation and operation instructions, component parts lists, and circuit diagrams.
The LDB-102 is designed and manufactured to meet the requirements laid down by the International Civil Aviation Organisation (ICAO) authority for this type of equipment. The LDB-102 is fully solid state, and uses digital techniques to minimise the number of adjustable controls.
1.1.2 Application The DME system is a navigational system which provides slant-range distance information between aircraft and a ground station.
The system consists of a transmitter/receiver (interrogator) in the aircraft, and a receiver/transmitter (transponder) ground station. The interrogator transmits interrogation pulses to the transponder, which on receipt of the interrogation pulses is triggered to transmit a sequence of reply pulses which have a predetermined time delay. The time difference between interrogation and reply is measured in the interrogator and translated into a distance measurement which is presented on a digital display in the aircraft cockpit; this display is continuously updated.
1.2 SYSTEM OPERATION
1.2.1 Introduction This section describes the operating principles of the DME and the options available for remote control of the equipment.
1.2.2 Distance Measuring Function The DME system provides each aircraft with up-to-date information regarding the slant-range distance between the aircraft and the selected DME ground station. By using the correct airborne equipment h is also possible for the interrogating aircraft to establish the rate of closure and the flight time to a ground station.
The DME system has a transmitter/receiver (interrogator) in the aircraft and a receiver/transmitter (transponder) operating as the ground beacon. The UHF DME operates in the L band, from 962 MHz to 1213 MHz. This band is divided into 126 1-MHz channels for interrogation, and 126 1-MHz channels for transponder replies with the interrogation frequency and reply frequency always differing by 63 MHz. The number of channels available is doubled by the use of X and Y channels which define the pulse separation for the interrogation and reply pulses.
Initially, the airborne equipment is set to the correct frequency for the desired ground station. The interrogator transmits pairs of pulses at the interrogation frequency at a repetition rate of approximately 120 pulse-pairs per second (pp/s) (this is called 'searching' mode). The transponder, having identified these pulses as valid interrogations, introduces a 50 microsecond delay after each interrogating pulse-pair and transmits reply pulse-pairs at the reply frequency. The airborne interrogator automatically compares the lapsed time between transmission and reception, subtracts the 50 microsecond delay, and displays the result in nautical miles. Once the
1-1
HA72500 SECTION 1
interrogator receives replies to its interrogations, the interrogator 'locks' onto the reply pulses and reduces its transmitted repetition rate to approximately 30 pp/s (this is called 'tracking' mode).
Figure 1-1 DME Principle
1.2.3 DME Pulse Generation The RF pulses transmitted by both the interrogator and the ground transponder consist of a pair of 'Gaussian-shaped' pulses; the separation between pulses depends on whether an X channel or a Y channel has been selected. The duration of the pulses is in all cases a nominal 3.5 microseconds as measured at the half-amplitude point. The pulse separation for X channels, for both interrogation and reply pulses, is 12 microseconds; for Y channels the pulse separation is 36 microseconds for interrogation pulses, and 30 microseconds for reply pulses. The channel frequencies and spacings for all channels are shown in Appendix L.
1.2.4 System Squitter Airborne DME receivers require a continuous stream of random pulses to ensure correct operation; however, unless there are interrogating aircraft present, the airborne receivers may not receive the required minimum pulse rate. To ensure that the airborne receivers always receive at least a minimum pulse rate, the DME transponder will generate 'extra' pulses in a random fashion at a minimum pulse rate of 945 pp/s. These extra random pulse-pairs are called squitter. At the time when no aircraft are interrogating, only the squitter is being transmitted, at an average rate of 945 pp/s; however, as the number of authentic interrogations increases the squitter rate is reduced, and becomes zero when the live interrogation rate reaches 945 pp/s.
1.2.5 Maximum Reply Rate As the pulse rate of the interrogations increases, a limit is reached where the transponder will not allow further interrogations to be serviced. This limit is reached at a reply rate of approximately 2800 pp/s, above which the transponder would become overloaded. To avoid overloading, the transponder detects the high rate of replies and
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HA72500 SECTION 1
causes the receiver automatic gain control to limit the gain of the receiver until the weaker, more distant, aircraft are excluded from the transponder, thus lowering the transponder loading. Should the system reply rate still exceed the 2800 pp/s limit, video output pulses are randomly suppressed to limit the maximum reply rate to 2800 pp/s.
1.2.6 Identification Message Each operational DME is identified by a 2-character or 3-character Morse code message which is transmitted every 40 seconds. Each identification code (ident) is unique and identifies a specific DME site. The identification message code is programmed by preset controls within the equipment, and can be readily altered if the ident is required to be changed.
Frequently, DME is collocated with ILS or VOR equipment and for this reason the DME may operate either as a master or as a slave for the generation and transmission of the station identification message. When the DME is operating as a slave unit, any failure of the external ident generator will cause the DME to internally generate and transmit the ident in place of the failed unit.
1.2.7 Range and Echo The normal slant range for a DME system operating in the ultra high frequency band is approximately 200 nautical miles (370 km) for good conditions at maximum transponder sensitivity. This maximum range may be seriously degraded, however, by the terrain surrounding the installation and by the maximum demands of interrogating aircraft.
A major contributing factor to distance accuracy degradation is the effect of echoes on the interrogation pulses arriving at the transponder. The shortest path is the direct line between the aircraft and ground transponder and thus the wave front taking this path arrives first. Other wave fronts may reflect off the terrain, buildings, and other objects, and thus arrive at any indeterminate time after the arrival of the direct pulse. Should the first pulse of a pulse-pair suffer such echo conditions it is possible that a reflection could arrive at the DME antenna at the same time as the direct second pulse of the interrogating pulse-pair; and the two pulses may arrive in any phase relationship. It is possible under these conditions for the second pulse of a pulse-pair to undergo distortion leading either to cancellation or to a shift in timing such that the transponder cannot recognise the receipt of a valid pulse-pair.
Short distance echo suppression is included within the LDB-102 to minimise the problems associated with such reflections. As well, long distance echo suppression is included to eliminate recognition of echoes that are synchronised with the interrogation pulses but arrive in the order of up to 320 microseconds late.
1.2.8 Remote Control and Monitoring System The Remote Control and Monitoring System (RCMS) has a relay-based interface to the DME, providing on/off control and operational status monitoring. The operator console at the central she permits control of the DME in the same manner as that provided on the DME control panel.
1.3 PERFORMANCE SPECIFICATION The performance parameters of the major system functions and the location and functions of all system controls and indicators are given in Table 1-1 and Table 1-2 following.
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HA72500 SECTION 1
Table 1-1 Performance Characteristics Summary
CHARACTERISTIC PARAMETER VALUE/LIMITS Voltage 21 to +28 volts Current drain (normal operation, 27.0 volts DC)
Single 1 kW, Single Monitor at 945 Hz (squitter rate) 6 amperes
at 2800 Hz (maximum traffic) 12 amperes Dual 1 kW, Dual Monitor
at 945 Hz (squitter rate) 7 amperes
Power Supply Requirements
at 2800 Hz (maximum traffic) 13 amperes
Temperature (indoor equipment) -10 to 60 degrees C Relative humidity (indoor equipment) 95% (to 45 degrees C) 50% (45 to 60 degrees C)
Environmental Condition Limits
Antenna -40 to 70 degrees C (100% RH)
Operating frequency (set by installed crystals)
Can be set to any of 252 channels in the 962-1213 MHz band
Pulse spacing (microseconds) Transmit X channels 12.0±0.1 Y channels 30.0±0.1 Decode X channels 12.0±1.0
Frequency and Pulse Characteristics
Y channels 36.0±1.0
Transmitter power (measured at rack connector)
Low power > 150 watts peak High power > 1 kW peak
Frequency accuracy ±0.002% Transmitter pulse count Minimum 945 pulse-pairs/second Maximum 2800 pulse-pairs/second Note that interrogation has precedence over squitter. Squitter pulses are only generated if the reply rate to authentic interrogation is less than 945 pulse-pairs per second
Pulse shape Width 3.5 ±0.5 microseconds Rise time 2.25 ±0.75 microseconds Fall time 2.5 ±1.0 microseconds Spectrum DME (N) Ident Rate 1350 ±25 pulse-pairs/second Internal generator Repeat interval 40 seconds nominal Dot duration 0.13 seconds nominal Dash duration Equals 3 dots
Transmitter
Transmitted ident Every 4th internally generated or externally provided from associated navaid
1-4
HA72500 SECTION 1
CHARACTERISTIC PARAMETER VALUE/LIMITS
Receiver triggering level -91 dBm at cabinet connector Adjacent channel rejection
80 dB
Spurious rejection 80 dB IF rejection 80 dB Frequency stability ±0.002% kHz System time delay X channel 35 to 50 microseconds Y channel 50 to 56 microseconds Timing reference First interrogation pulse
Receiver
Accuracy For interrogation signal levels between -81 dBm and -10 dBm at cabinet connector and throughout the range of service conditions the bias error shall not exceed ±0.5 microseconds
These modules continuously interrogate the transponder and monitor its reply and initiate an alarm for the following fault conditions:
REPLY DELAY Alarm limits can be set in 0.1 microseconds steps up to ±1.0 microseconds
SPACING Alarm limits can be set in 0.1 microseconds steps up to ±1.0 microseconds
EFFICIENCY Alarms when efficiency drops to 60% REPLY RATE Alarms when reply rate fails below 833 pulse-pairs per
second or exceeds 3000 pulse-pairs per second PULSE WIDTH Alarms if not in range 3.0 to 4.0 microseconds PULSE RISE TIME Alarms if greater than 3.0 microseconds PULSE FALL TIME Alarms if greater than 3.5 microseconds POWER OUTPUT Alarm point can be set to between 1 dB and 6 dB below
nominal level IDENT Alarms when ident is absent for more than a period which
can be set to be between 2 and 128 seconds in 1 second steps
Test Interrogator and Monitor
MONITOR The monitor checks its failure circuitry on reply delay and reply spacing parameters. It initiates an alarm if it passes a faulty reply
Injection levels of test interrogations into receiver
Efficiency monitoring: -85 dBm Reply delay monitoring: -70 dBm
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HA72500 SECTION 1
CHARACTERISTIC PARAMETER VALUE/LIMITS Output voltage range
Normal operation 21-28 volts, adjustable
Test operation 18-33 volts. adjustable Output current rating 30 amperes maximum input voltage 200, 210, 220, 230, 240, 250,
260 volts ±10% Input frequency 50Hz ±10% Line regulation 1% for ±15% variation Load regulation 0.45V over range 0 to 30 amperes Noise and ripple 200 mV peak to peak Variation of output voltage with temperature Within 0.2V over temperature range
0-20 amperes Less than 2 volts; 50 milliseconds recovery Transient response 20-0 amperes Less than 2 volts; 200 milliseconds recovery
Efficiency 70% at 27 volts, 10 amperes Overcurrent protection Current limits can be set over the range
20 amperes to 30 amperes Reverse voltage protection Fuse
AC Mains Power Supply
Ambient temperature range -10 to +60 degrees C Voltage 24 volts nominal Capacity (discharged at 10-hour rates to 1.85 volts per cell - AS1981)
105 AH (for specified operating time)
Operating time At maximum transponder reply rate
6.5 hours - dual DME 7.0 hours - single DME
Battery Supply
At squitter reply rate 12 hours minimum - dual DME 14 hours minimum - single DME
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HA72500 SECTION 1
Table 1-2 Controls and Indicators UNIT/MODULE CONTROLTYPE FUNCTION SETTINGS or INDICATION
OFF/RESET (Alarms) Yellow NO1 Green
SELECT MAIN (3 buttons)
NO2 Green INHIBIT Red MONITOR ALARM
(toggle action) (NORMAL) ON Red MAINTENANCE (mode)
(toggle action) (OFF) LOCAL Yellow SOURCE (of control)
(2 buttons) REMOTE Green ON Green
Control Panel Pushbutton with LED indicators
RECYCLE (after shutdown) (toggle action) (OFF)
Rotary switch 10 positions 1…10
ALARM DELAY Delay in seconds from fault appearing until the CTU takes action.
NO 1 ON Green NO 2 ON Green NORMAL Green TRANSFER Yellow SHUTDOWN Red
STATUS
MAINTENANCE Red DELAY Red SPACING Red EFFICIENCY Red TX RATE Red RF POWER Red IDENT Red PULSE SHAPE Red ANTENNA Red PRIMARY Red SECONDARY Red MONITOR Red
ALARM REGISTER (indicates alarm status at last TRANSFER/ SHUTDOWN action by the equipment)
CTU Red AC PWR NORM Green BATT CHG 1 Green BATT CHG 2 Green
POWER
BATT LOW Red MODULES Red
LED indicators
TEST (switches not in NORMAL position)
ANT RELAY Red
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HA72500 SECTION 1
UNIT/MODULE CONTROLTYPE FUNCTION SETTINGS or INDICATION Test Facility Pushbuttons Five pushbuttons, the functions of which are definable by the bottom line
of the TEST FACILITY display. Through a menu of options, the following information can be selected by these pushbuttons to be displayed on the top line of the TEST FACILITY display.
Parameters Spacing Transmitter pulse spacing
Delay Reply delay PwrOut RF power out Effncy Reply efficiency, when
maintenance mode is OFF. When maintenance mode is ON, a sub-menu under this choice gives access to
(Reply) Efficiency (normal levels) (Reply) Efficiency (high level) (Reply) Efficiency (low level)
D.Rate Decoded pulse rate Tx.Rate Transmitted pulse rate Width Transmitted pulse width Rise Transmitted pulse rise time Fall Transmitted pulse fall time Vcal Voltage measurement calibration Rcal Rate measurement calibration Tcal Time measurement calibration Signal Levels RV.Osc Receiver video local oscillator RV.RF Receiver video transmitter RF drive TD.Drv Transmitter driver RF output TD.Mod Transmitter driver modulation PA.Mod 1 kW RF amplifier modulator output PA.Drv 1 kW RF amplifier driver output PA.0ut 1 kW RF amplifier final output TI RF Test interrogator interrogation Power Supply Voltages Aux.24V Auxiliary 24 volts supply
PA.HT Power amplifier high tension supply TP.15V Transponder power supply:
15 volts output TP.18V Transponder power supply:
18 volts output Drv.HT Transponder power supply:
high tension output Status MON PS Monitor power supply status RV PS Receiver video power supply status Tl PS Test interrogator power supply
status RV TRIG Receiver video trigger signal to
transmitter driver
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HA72500 SECTION 1
UNIT/MODULE CONTROLTYPE FUNCTION SETTINGS or INDICATION
Reset Restart count set to zero Alarm1 Modifies alarm register display so
that only those alarms due to Transponder 1 are displayed
Alarm2 Modifies alarm register display so that only those alarms due to Transponder 2 are displayed
LEDTst Turns on all LEDs on the CTU front panel
Version CTU software version identity Ident Source (for speaker) Mon1 Monitor module 1 Mon2 Monitor module 2 2440 Hz 2240 Hz tone
Miscellaneous (only available if MAINTENANCE mode not selected)
OFF Off Ch1 Source Selection
(only available if MAINTENANCE mode is selected)
Ch2 Selects the test interrogator/monitor module to use for parameter, level and power supply voltage measurements
Delay Delay upper and lower limits Spacing Spacing upper and lower limits Effncy Efficiency lower limit Tx.Rate Transmitted pulse rate upper and
lower limits
Pushbuttons (continued)
Fault Limits (only available if MAINTENANCE mode is selected)
Ant.Pwr Antenna power lower limit Pushbutton ESC(APE) Returns to topmost menu
Sets interrogation rate of test interrogator. Selected rate is displayed on top right hand corner of the TEST FACILITY display. 1 kHz Toggle action between rates of
1 kHz and the normal rate (50 Hz for dual, 100 Hz for single)
Test Facility (continued)
Pushbutton TI RATE (only available if MAINTENANCE mode is selected)
10 kHz Rate of 10 kHz while button held pressed.
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HA72500 SECTION 1
1.4 DOCUMENTATION Equipment Serial Numbers All equipment assemblies have individual serial numbers allocated. These are used to record the history of the equipment.
Modification Records The modification status of all equipment is controlled with a modification register, and a modification record is attached to each item of equipment. Navaid users are not normally notified of any change of modification status as equipments with differing modification status are functionally interchangeable.
Modification Bulletins During the production life of equipment, design changes may be made to alter or improve particular performance characteristics. These changes are documented on a Technical Service Bulletin (TSB) which will be forwarded to users as appropriate.
Type Numbering System All manufactured equipments; and subassemblies are identified by a 7-digit type number.
For navaid equipments the type number has the form YAXXXXX, in which:
• 'XXXXX is a 5-figure number which is unique to the particular assembly.
• ‘Y’ is a prefix digit which identifies a particular variant of assembly type 'XXXXX’.
• ‘A’ signifies that the equipment is avionics equipment.
All correspondence relating to manufactured items should quote the applicable, complete type number.
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HA72500 SECTION 2
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SECTION 2
TECHNICAL DESCRIPTION
HA72500 SECTION 2
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TABLE of CONTENTS
2. TECHNICAL DESCRIPTION...................................................................... 2-1 2.1 SYSTEM DESCRIPTION 2-1
2.1.1 Principles of Operation ..............................................................................2-1 2.1.2 Signal Flow................................................................................................2-2 2.1.3 Mechanical Description .............................................................................2-5 2.1.4 Rack Wiring ...............................................................................................2-7
2.2 SUBSYSTEM DESCRIPTIONS 2-7 2.2.1 Introduction................................................................................................2-7 2.2.2 Transponder Subsystem ...........................................................................2-7 2.2.3 Control and Test Subsystem .....................................................................2-9 2.2.4 Power Supply Subsystem........................................................................2-10 2.2.4.1 Single DME Power Distribution.........................................................2-10 2.2.4.2 Dual DME Power Distribution ...........................................................2-11
2.3 MODULE DESCRIPTIONS 2-12 2.3.1 Introduction..............................................................................................2-12 2.3.2 RF Panel Single DME 1A72545 and RF Panel Dual DME 2A72545 ......2-12 2.3.2.1 Preselector Filter 1A72546 ...............................................................2-13 2.3.2.2 Directional Coupler 1A69755............................................................2-13 2.3.2.3 Directional Coupler 2A69755............................................................2-14 2.3.2.4 50 Ohm Termination 1A69757 .........................................................2-14 2.3.2.5 RF Panel PWB Assembly Single DME 1A72547..............................2-14 2.3.2.6 RF Panel PWB Assembly Dual DME 2A72547 ................................2-15 2.3.3 Receiver Video 1A72520.........................................................................2-16 2.3.3.1 Main PWB Assembly Receiver Video 1A72521 ...............................2-17 2.3.3.2 RF Source 1A72522 .........................................................................2-25 2.3.3.3 IF Amplifier 1A72523 ........................................................................2-26 2.3.3.4 RF Amplifier 1A72524 ......................................................................2-27 2.3.3.5 RF Filter 1A72517 ............................................................................2-27 2.3.4 Transmitter Driver 1A72530 ....................................................................2-30 2.3.4.1 2.3.4.1 Pulse Shaper PWB Assembly 1A72531...............................2-31 2.3.4.2 Exciter 1A72532 ...............................................................................2-36 2.3.4.3 Medium Power Driver 1A72533........................................................2-37 2.3.4.4 Power Modulation Amplifier 1A72534...............................................2-37 2.3.5 Transponder Power Supply 1A72525......................................................2-40 2.3.5.1 Main PWB Assembly Transponder Power Supply 1A72526 ............2-40 2.3.6 1kW RF Power Amplifier Assembly 1A72535 .........................................2-43 2.3.6.1 Power Divider 1A72536....................................................................2-44 2.3.6.2 Power Combiner 1A72537 ...............................................................2-44 2.3.6.3 250W RF Amplifier 1A69873 ............................................................2-45 2.3.6.4 Power Modulation Amplifier 1A72534...............................................2-45 2.3.6.5 1kW PA Connector PWB Assembly 1A72544..................................2-45 2.3.7 1kW PA Power Supply 1A72540 .............................................................2-46 2.3.7.1 DC-DC Converter PWB Assembly 1A72542 ....................................2-46 2.3.7.2 Control and Status PWIB Assembly 1A72541..................................2-47 2.3.8 Test Interrogator 1A72514.......................................................................2-49 2.3.8.1 Main PWB Assembly Test Interrogator 1A72515 .............................2-50 2.3.8.2 RF Generator 1A72516 ....................................................................2-57 2.3.8.3 Attenuator 1A69737..........................................................................2-58 2.3.8.4 Modulator and Detector 1A72518.....................................................2-58 2.3.8.5 Reply Detector 1A72519 ..................................................................2-60 2.3.9 Monitor Module 1A72510 ........................................................................2-63 2.3.9.1 Main PWB Assembly Monitor Module 1A72511...............................2-65
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2.3.9.2 Peak Power Monitor 1A72512..........................................................2-88 2.3.10 Control and Test Unit 1A72550 ...............................................................2-92 2.3.10.1 General .............................................................................................2-92 2.3.10.2 Mechanical .......................................................................................2-92 2.3.10.3 CTU Processor PWB Assembly 1A72552........................................2-93 2.3.10.4 CTU Front Panel PWB Assembly 1A72553....................................2-101 2.3.10.5 RCMS Interface MB Assembly 1A722555......................................2-104 2.3.11 Power Distribution Panel Single DME 1A72549 and Power Distribution
Panel Dual DME 2A72549.....................................................................2-106 2.3.12 AC Power Supply 3A71130 ...................................................................2-107 2.3.13 Power Supply System Dual AC 2A/3A69758 ........................................2-108 2.3.14 Transponder Subrack 1A72513.............................................................2-109 2.3.15 CTU Subrack 1A72506..........................................................................2-109 2.3.16 External I/O PWB Assembly 1A72557 ..................................................2-109 2.3.17 1kW PA Power Supply Frame 1A72503................................................2-110
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LIST of FIGURES
Figure 2-1 Block Diagram Single 1kW DME...............................................................2-3 Figure 2-2 Block Diagram Dual 1kW DME..................................................................2-4 Figure 2-3 Layout of DME LDB-102 Single 1kW Rack ...............................................2-5 Figure 2-4 Layout of DME LDB-102 Dual 1kW Rack..................................................2-6 Figure 2-5 Transponder Subsystem Diagram.............................................................2-8 Figure 2-6 Control and Test Subsystem Diagram.......................................................2-9 Figure 2-7 Single 1kW DME Power Distribution .......................................................2-10 Figure 2-8 Dual 1kW DME Power Distribution..........................................................2-11 Figure 2-9 Directional Coupler 1A69755...................................................................2-13 Figure 2-10 Directional Coupler 2A69755................................................................2-14 Figure 2-11 Waveforms for Interrogation Pulse Processing ....................................2-18 Figure 2-12 Ident Keyer Waveforms ........................................................................2-22 Figure 2-13 Transmitter Driver Block Diagram ........................................................2-30 Figure 2-14 Shaped Pulse Generation Waveforms .................................................2-33 Figure 2-15 1kW RF Power Amplifier Block Diagram ..............................................2-43 Figure 2-16 CTU Bus Timing - Read .......................................................................2-51 Figure 2-17 CTU Bus Timing - Write........................................................................2-51 Figure 2-18 Modulator and Detector Waveforms.....................................................2-59 Figure 2-19 Delay Monitor .......................................................................................2-65 Figure 2-20 Delay Monitor Waveforms ....................................................................2-66 Figure 2-21 Spacing Monitor....................................................................................2-67 Figure 2-22 Spacing Monitor Waveforms ................................................................2-68 Figure 2-23 Efficiency Monitor .................................................................................2-70 Figure 2-24 Rate Monitor .........................................................................................2-71 Figure 2-25 Ident Monitor.........................................................................................2-73 Figure 2-26 Effective Radiated Power Monitor ........................................................2-75 Figure 2-27 Antenna Integrity Monitor .....................................................................2-77 Figure 2-28 Width Monitor Waveforms ....................................................................2-79 Figure 2-29 Pulse Shape Monitor ............................................................................2-80 Figure 2-30 Rise Time Monitor Waveforms .............................................................2-81 Figure 2-31 Fall Time Monitor Waveforms...............................................................2-82 Figure 2-32 Level Monitor ........................................................................................2-84 Figure 2-33 Fault Line Driver ...................................................................................2-85 Figure 2-34 CTU Block Diagram..............................................................................2-92 Figure 2-35 CTU Processor Board Block Diagram ..................................................2-94 Figure 2-36 CTU Front Panel Board Block Diagram..............................................2-101 Figure 2-37 RCMS Interface Board Block Diagram ...............................................2-104 Figure 2-38 Single Power Distribution Panel Block Diagram.................................2-107 Figure 2-39 Dual Power Distribution Panel Block Diagram ...................................2-107 Figure 2-40 Power Supply System Dual AC 2A69758 Layout...............................2-108
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LIST of TABLES
Table 2-1 Summary of Controls and Indicators: RF Panel (Dual) ...........................2-15 Table 2-2 Summary of Front Panel Controls and Indicators : Receiver
Video Module .......................................................................................................2-28 Table 2-3 Summary of Internal Controls : Receiver Video Module..........................2-29 Table 2-4 Pulse Shaper Board Test Points .............................................................2-35 Table 2-5 Summary of Front Panel Controls and Indicators : Transmitter Driver....2-38 Table 2-6 Summary of Internal Controls : Transmitter Driver ..................................2-39 Table 2-7 Summary of Front Panel Controls and Indicators : Transponder
Power Supply .......................................................................................................2-42 Table 2-8 Summary of Internal Controls : Transponder Power Supply ...................2-42 Table 2-9 Summary of Front Panel Controls and Indicators : PA Power Supply.....2-48 Table 2-10 Summary of Internal Controls : PA Power Supply................................2-48 Table 2-11 Summary of Front Panel Controls and Indicators : Test Interrogator
Module ..............................................................................................................2-61 Table 2-12 Summary of Internal Controls: Test Interrogator Module .....................2-62 Table 2-13 Summary of Front Panel Controls and Indicators : Monitor Module.....2-89 Table 2-14 Summary of Internal Controls : Monitor Module ...................................2-90 Table 2-15 Ident PLD Outputs: MA_IDENT_IN_1,2, MA_IDENT_OUT,
IDENT_TONE_TRANSFORMER, DET_IDENT_KEY..........................................2-97 Table 2-16 Ident PLD Output: IDENT+ CPU_TONE ..............................................2-97 Table 2-17 Ident PLD Output: IDENT_ON..............................................................2-97 Table 2-18 CTU Processor Board LED Indicators..................................................2-98 Table 2-19 CTU Processor Board Links .................................................................2-98 Table 2-20 CTU Processor Board D19 and D24 Inputs .........................................2-99 Table 2-21 CTU Processor Board D18 and D23 Outputs.....................................2-100 Table 2-22 CTU Front Panel Address Map ..........................................................2-102 Table 2-23 CTU Front Panel Switch Scanner and Coder Output .........................2-103 Table 2-24 RCMS Interface Address Map............................................................2-105
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2. TECHNICAL DESCRIPTION 2.1 SYSTEM DESCRIPTION
2.1.1 Principles of Operation The LDB-102 series DME equipment is available in several standard configurations, depending on RF power, duplication and primary power requirements.
It is available as either a single equipment or dual equipment configuration; each of these may be fitted with either low power or high power RF amplifiers. The basic transponder provides modulation and RF drive to a power amplifier assembly which raises the power output to either 200 watts or 1kW
Single Transponder - Single Monitor The basic transponder assembly consist of five modules, a control panel, an RF distribution panel (mounted behind the control panel), and a DC distribution panel. Low power and high power amplifier assemblies fed by a driver amplifier boosts the peak power to more than 200 watts for the low power version and more than 1kW for the high power version.
Aircraft interrogation signals from the antenna pass through the RF panel to the receiver and video circuits which process the signals. If the signals are valid interrogations, then a reply is initiated through the RF power amplifiers and RF panel back to the antenna for transmission.
A test interrogator, in conjunction with a monitor, continuously interrogates the transponder to check that it is performing correctly. These signals pass through the transponder in the same manner as those from aircraft, but now the replies are coupled from the beacon output and processed by the monitor to verify that the DME signal parameters are within tolerance. The monitor itself is automatically checked for correct operation.
An AC mains power supply, which converts the incoming AC supply voltage to a nominal 24 volts DC suitable for the rack as well as charging and standby battery bank, can be included.
Dual Transponder - Dual Monitor To provide this configuration, a second transponder assembly of five modules is added along with a second RF power amplifier (200 watts or 1kW).
Additionally, a single RF panel is replaced by a dual version. A dual 1kW DME has the AC power supply/battery charger located outside the basic equipment rack.
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2.1.2 Signal Flow REFER Figure 2-1 for Single 1kW DME
Figure 2-2 for Dual 1kW DME Block Diagram 72500-2-26
The following description refers to a 1kW single system, the signal flow in a dual system being essentially the same for each of the transponders in the system.
Figure 2-1 and Figure 2-2 show simplified block diagrams of the basic single and dual configurations. A more detailed block diagram is shown in Drawing 72500-2-26
Interrogation signals from an aircraft are received by the DME antenna which is connected to the RF panel in the DME equipment. In this assembly, the signals pass through a directional coupler and circulator to the preselector filter. The circulator prevents the transmitter output from coupling directly into the receiver. The preselector, comprising three coupled resonant cavities tuned to the receive frequency, reject the IF image frequency, rejects unwanted spurious frequencies and gives further attenuation to the transmitter output frequency. The interrogation signals then pass to the receiver video module.
The receiver video module detects and decodes on-channel interrogations and encodes the synchronous reply trigger pulse pair. Random reply pulse pairs are added, if necessary, to the synchronous replies to maintain a minimum reply rate of 945 Hz. The maximum reply rate is limited to a nominal 2800 Hz by reducing receiver sensitivity. The keyed identification signal (ident) occurs every 40 seconds, the 'mark' of the ident replacing normal reply pulses with a 1350 Hz pulse train.
Receiver output reply pulse pairs trigger the modulation generator in the transmitter driver module, producing RF pulses which are connected to the 1kW RF power amplifier module. The excitation frequency for the transmitter driver is provided by the local oscillator in the receiver video module.
The output from the power amplifier is connected back to the RF panel, where it passes through the circulator and directional coupler to the antenna for the reply transmission to the aircraft. In a dual system, the RF panel includes a coaxial transfer relay to connect either of the transponders to the antenna, the other being terminated in a dummy load.
The equipment also has a test interrogator and a monitor. These units are used together to check the performance of the DME. The test interrogator continuously interrogates the DME in a similar manner to an aircraft. This invokes the transponder to generate reply pulses; these are detected and processed by the monitor to verity that the signal parameters of the replies being generated by the transponder are within acceptable limits.
The test interrogators inject monitoring interrogating signals via a directional coupler in the main antenna line, and operate at a combined PRF of 100 Hz. In a dual system, two test interrogators are interconnected to prevent the interrogation of one falling in the transponder dead-time produced by the other. Efficiency is monitored at an RF level of -85 dBm, and transponder delay and reply pulse separation at an RF level of -70 dBm by successive interrogations. The signals pass through the circulator and preselector to the receiver video, where they are processed.
Transponder output pulses are sampled in the directional coupler and detected in the reply detector of the test interrogator module. Processing within the test interrogator separates out the synchronous replies from all other non-synchronous replies and squitter.
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The monitor module processes output signals from the test interrogator and provides a pass or fail signal to the control and test unit for each monitored parameter. The monitor itself is periodically checked by a self-test function initiated by the control and test unit; this confirms that the monitor is capable of registering a fault for the two primary parameters of reply delay and pulse spacing.
Figure 2-1 Block Diagram Single 1kW DME
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Figure 2-2 Block Diagram Dual 1kW DME
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2.1.3 Mechanical Description The LDB-102 DME is designed to be mounted in a standard 483 mm (19-inch) rack type rack. The dimensions of the rack for both single and dual DME racks are 1800 mm high by 560 mm wide by 560 mm deep.
The bulk of the electronics is contained within five modules each of 6 rack units height (267 mm) which plug into the transponder subrack and are secured by holding screws to the rack frame.
Figure 2-3 Layout of DME LDB-102 Single 1kW Rack
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Figure 2-4 Layout of DME LDB-102 Dual 1kW Rack
The CTU Subrack (1A72506) houses the Control and Test Unit (1A72550) and the Power Distribution Panel (1A72549). The CTU subrack is screwed to the rack and is 6 rack units (267 mm) high.
Behind the CTU subrack is the RF Panel (1A72545 for single configuration or 2A72545 for dual), on which is mounted the directional coupler(s), preselector(s), circulators and other RF circuitry.
In 1kW transponders the 1kW RF Power Amplifier (1A72535) and the 1kW PA Power Supply (1A72540) are both screwed to the rack. They together occupy a 6-unit (267 mm) high space, with the 1kW power amplifier at the back of the rack and the 1kW PA power supply at the front of the rack. The 1kW PA power supply is located on hinges which swing down to give easy access to the unit. The 1kW amplifier, consisting of a modulating 180-watt stage and ten 250W RF amplifiers together with their associated splitters and combiners, is mounted on a heat sink which is screwed to the rear of the rack. A DC-DC converter, which supplies the power amplifier, is mounted on the inside of the front panel, which swings back to give access to the components.
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The AC power supply/battery charger, when fitted, occupies 8 rack units (356 mm) height, and is 437 mm deep. In a single transponder station, this supply is normally mounted in the bottom part of the main equipment rack. In a dual transponder, two of these supplies are mounted in a separate rack as Dual AC Power Supply 2A/3A69758.
If standby batteries are used, these are housed in a separate, ventilated enclosure which may be either inside or outside the main equipment shelter.
The physical layout of the 1kW single transponder, single monitor, AC supply version is shown in Figure 2-3. The physical layout of the 1kW dual transponder, dual monitor, AC supply version is shown in Figure 2-4.
2.1.4 Rack Wiring REFER Rack Interwiring (Single 1kW DME) 72505-2-06
Rack Interwiring (Dual 1kW DME) 72505-2-17
Rack interwiring is shown in these drawings, which each consist of three sheets:
• Sheet 1 shows RF cable interwiring.
• Sheet 2 shows signal interwiring.
• Sheet 3 shows power interwiring.
2.2 SUBSYSTEM DESCRIPTIONS
2.2.1 Introduction To enable easier understanding of the LDB-102 DME system the description is split into three subsections - Transponder Subsystem, Control and Test Subsystem and the Power Supply Subsystem. For further information on any individual modules, refer to Section 2.3 of this handbook.
2.2.2 Transponder Subsystem REFER Interwiring Diagram 72505-2-37
The Transponder Subsystem consists of five modules mounted in the Transponder Subrack (1A72513); these are the Receiver/Video (1A72520), Transmitter Driver (1A72530), Transponder Power Supply (1A72525), Test Interrogator (1A72514) and the Monitor Module (1A72510), the 1kW RF Amplifier (1A72535); and the RF Panel (1A72545 for single, 2A72545 for dual). The transponder subrack interwiring is shown in Drawing 72505-2-37, and is identical for both single and dual configurations.
The basic transponder functions are provided by the receiver/video, transmitter driver and the 1kW RF power amplifier.
The receiver/video module receives and decodes interrogations and encodes replies. When a valid interrogation is decoded, a pair of ‘TX Modulation Trigger’ signals is sent to the transmitter driver. In a 1kW station, for each ‘TX Modulation Trigger’ sent to the transmitter driver a shaped modulation pulse and a square pulse of RF, at the station frequency, are generated in the transmitter driver and both fed to the 1kW RF power amplifier. In a 250W transponder, for each ‘TX Modulation Trigger’ a shaped pulse of RF, at the station frequency, is generated in the transmitter driver and fed to the 250W RF amplifier.
The transponder power supply generates +15 volts, +18 volts and +HT to power the transmitter driver.
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The RF panel provides filtering of the input interrogation signals, coupling of the transmit and receive paths to the antenna, and connection of the test interrogation and reply signals of the test interrogator. In a dual system, it also provides for switching of the active transponder to the antenna.
Figure 2-5 Transponder Subsystem Diagram
The test interrogator operates as an independent unit simulating aircraft interrogation pulses. The transponder treats these pulses as normal interrogations and responds accordingly, allowing the test interrogator to extract operational parameters from the transponder. The test interrogator can measure each of the parameters for display on the CTU.
The monitor accepts from the test interrogator signals representing the operational parameters of the transponder and compares them to preset values stored on the monitor module main board. If any of the parameters are found to be in error, the fault is indicated to the CTU, which takes appropriate action.
The test interrogator also contains the monitor fault limit test circuitry which (under control from the CTU) can measure the range over which parameters measured by the monitor indicate acceptance or failure.
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2.2.3 Control and Test Subsystem The Control and Test Subsystem of the LDB-102 DME monitors, controls and tests various functions within the DME.
The Control and Test Unit (CTU) monitors the operation of the active transponder. If a fault is indicated in any of the monitored parameters, then the CTU can shut down the beacon (or cause a transfer to the second transponder in the case of a dual transponder beacon).
The CTU also contains a comprehensive test facility to allow rapid assessment of performance. By keypad selection, each of the main DME parameters, including important signal levels and status conditions can be displayed. The CTU controls the test interrogator and monitor module(s) in performing the tests.
The CTU also controls and monitors the Remote Control and Monitoring System (RCMS) interface which interfaces outside equipment to the DME. The RCMS interface is accessible on the External I/O PWB (1A72557) for ease of connection.
Figure 2-6 Control and Test Subsystem Diagram
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2.2.4 Power Supply Subsystem
2.2.4.1 Single DME Power Distribution The single DME is supplied with nominal 240 volts 50 Hz mains AC which powers a battery charger (Power Supply 3A71130) mounted at the bottom of the transponder rack. This supplies a regulated +27 volts to the rack's battery terminals, to which batteries may be connected and charged. The battery terminals are also connected to the distribution panel (through a diode to protect against battery reversal) which distributes the supply through circuit breakers to the rest of the DME circuitry.
The CTU and the transponder are powered through a 5A circuit breaker. The CTU power (+24V_AUX) is routed via the external I/O board. The transponder power (+24V_D) is connected directly to the transponder through the main power wiring loom.
The CTU converts the incoming +24 volts to +5 volts by use of a DC/DC converter, which is mounted on the CTU module metalwork. The CTU +5 volts is distributed to the CTU Main PWB Assembly 1A72552, CTU Front Panel PWB Assembly 1A72553, RCMS Interface PWB Assembly 1A72555.
The transponder draws its power from the +24V_D. The Test Interrogator 1A72514, Monitor Module 1A72510, and the Receiver Video 1A72520 all have separate linear voltage regulators converting the +24V_D to +15 volts and +5 volts. The Transmitter Driver 1A72530, however, is powered from the Transponder Power Supply 1A72525 which consists of a +15 volts and a +18 volts linear regulator and a DC/DC converter to generate +HT. The +24V_AUX is used for switching and test mode indication.
The 1kW PA Power Supply 1A72540 has its own circuit breaker (20A). This power supply generates 1kW_HT by use of a DC/DC converter. 1kW_HT is fed to the 1kW Power Amplifier 1A72535.
Figure 2-7 Single 1kW DME Power Distribution
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2.2.4.2 Dual DME Power Distribution The dual DME is supplied by a Dual AC Power Supply 2A69758 or 3A69758. This consists of two AC Power Supplies 3A71130 mounted in a rack adjacent to the transponder rack. The two separate +27 volts DC outputs of these supplies are connected to the rack's battery terminals, to which batteries may be connected and charged.
The battery terminals are also connected to the distribution panel (through diodes to protect against battery reversal) which distributes the supply through circuit breakers to the rest of the DME transponder circuitry.
The CTU is powered through a 5A circuit breaker as described in Section 2.2.4.1.
Each transponder has its own 5A circuit breaker, so a fault in one transponder does not affect the other. Each transponder is connected to the distribution panel through the main power wiring loom as described in Section 2.2.4.1.
Each 1kW PA Power Supply 1A72540 has its own 20A circuit breaker so a fault in one does not affect the other. +24V_AUX is supplied to the 1kW PA power supplies for switching and indication purposes.
Figure 2-8 Dual 1kW DME Power Distribution
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2.3 MODULE DESCRIPTIONS
2.3.1 Introduction Section 2.3 contains functional and circuit descriptions for the modules and other assemblies comprising the DME. The material is arranged in hierarchical fashion, with each description at module level being immediately followed by sub-sections describing the elements of that module.
2.3.2 RF Panel Single DME 1A72545 and RF Panel Dual DME 2A72545
REFER Circuit Diagram 72545-3-04 (Single DME) Circuit Diagram 72545-3-05 (Dual DME)
The RF panel is physically mounted behind the CTU at the back of the rack. Unrestricted access to the panel can be gained by opening the back door of the rack.
The RF panel mounts all the antenna feed and coupling components permitting short feeder lengths from the output RF amplifier to maintain low RF loss and leakage. All fixed coaxial wiring is accomplished in semirigid or flexible semirigid cable which also assists in low RF leakage and low loss.
In the case of a single transponder DME (see drawing 72545-3-04), the RF panel has mounted upon it a directional coupler (W3), a circulator (W1), and a receiver preselector filter (Z1). For a dual transponder system an extra preselector filter, circulator, directional coupler and transfer relay are added to enable independent operation of transponders with antenna and dummy load changeover facilities (see drawing 72545-3-05). Switch S1 (on the RF panel board in a dual DME) permits local operation of the changeover relay (No. 2 to antenna), no operation (No. 1 to antenna) or remote operation under control of the changeover logic in the CTU (normal).
Reply signals from the transmitter travel via a circulator and directional coupler to the antenna. The circulator (W1 or W2), prevents the high power from the transmitter from damaging the input circuitry of the receiver. The circulator also directs received interrogation signals from the antenna to the receiver.
The directional coupler (W3 in the single system, W4 in the dual system) couples power from the transmitter into the reply detector section of the test interrogator where the reply pulses are measured for their critical parameters. In addition, the directional coupler injects test interrogator interrogation pulses into the transponder receiver.
An extra pair of connections is available on the directional coupler, labelled FWD PORT A and REV PORT A, which may be used for observing the conditions on the antenna line.
In the case of a dual system (see drawing 72545-3-05), there is a further pair of connectors on W4 to enable both test interrogators to test the on-air system. The second directional coupler W3 and the 50 ohm load enable one transponder to be isolated and tested off-air while the other transponder is fully operational. The test interrogator associated with the transponder under test may have its reply detector and signal generator cables removed from W4 and re-connected to the appropriate positions on W3, thus allowing independent operation and testing of the two transponders.
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2.3.2.1 Preselector Filter 1A72546 REFER Circuit Diagrams 72545-3-04 or 72545-3-05
The preselector filter is located on the RF panel in the receiver signal path between the antenna circulator and connector to the receiver video. The filter consists of three quarter-wave cavity sections of high Q and having an insertion loss of typically 1.5 dB at the receive frequency.
As well as rejecting image and intermediate frequency signals, the filter also rejects any reflections from the transmitter which may occur due to antenna system mismatches. Within the pass-band, the filter presents a 50 ohms load to the circulator, and at the transmit frequency the attenuation is at least 70 dB.
It is tunable over the frequency band 950 to 1220 MHz.
2.3.2.2 Directional Coupler 1A69755 REFER Circuit Diagram 72545-3-04
This four coupled port directional coupler is used for monitoring and test signal injection into the antenna feeder of a single DME beacon. It is also used in a dual beacon to interrogate and monitor the off-line transponder for test purposes. It is mounted on the RF panel.
The 50 ohms stripline design involves the through-line, one forward and reverse unterminated coupled line and two forward only coupled lines internally resistively terminated. Each coupler is designed for a 30 dB nominal coupling with at least 15 dB directivity over the DME frequency band.
Figure 2-9 Directional Coupler 1A69755
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2.3.2.3 Directional Coupler 2A69755 REFER Circuit Diagram 72545-3-05
This six coupled port directional coupler is used for monitoring and test signal injection into the antenna feeder of a dual DME beacon and is mounted on the RF panel with the 1A69755 type.
The 50 ohms stripline design is essentially the same as the four-port 1A69755, with two more forward coupled ports added.
In the dual DME system there are two test interrogator test signals to be injected into the antenna feeder and two replies to be monitored, hence the extra coupler ports.
Figure 2-10 Directional Coupler 2A69755
2.3.2.4 50 Ohm Termination 1A69757 This is a component of the RF Panel Dual DME 2A72545 and is fitted to provide a termination for the RF output of the second transponder when the second transponder is in maintenance.
Physically, it is a 50 ohms 150 watts (average) resistor fixed to a base plate and which terminates a short length of semirigid cable; the loose end of the cable has a SMA connector fitted. A protection cover is fitted over the unit and the base plate is bolted to the RF panel, which acts as a heat dissipator.
2.3.2.5 RF Panel PWB Assembly Single DME 1A72547 REFER Circuit Diagram 72547-1-01
The RF Panel PWB Assembly Single DME 1A72547 is used in the RF Panel Single DME 1A72545 to allow connection of the antenna integrity input to the DME. This input is protected from lightning primarily by the gas discharge tube V3, with secondary protection provided by R1 and V2. R2 provides the reference resistance for the antenna integrity circuit on the monitor module.
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2.3.2.6 RF Panel PWB Assembly Dual DME 2A72547 REFER Circuit Diagram 72547-1-01
The RF Panel PWB Assembly Dual DME 2A72547 is used in the RF Panel Dual DME 2A72545 to allow connection of the antenna integrity device to the DME. This input is protected from lightning primarily by the gas discharge tube V3, with secondary protection provided by R1 and V2. R2 provides the reference resistance for the antenna integrity circuit on the monitor module.
It is also used in control of the antenna relay K1 (see circuit diagram 72545-3-05) by setting the position of S1. This switch can be set to one of three positions:
a. If switch S1 is in the up (TPNDR 2) position, relay K1 on the RF Panel 2A72545 is energised and the output of Transponder 2 RF power amplifier is connected to the antenna. The output of Transponder 1 RF power amplifier is connected to the 50 Ohm Load 1A69757.
b. If switch S1 is in the centre (TPNDR 1) position, relay K1 is not energised and the output of Transponder 1 RF power amplifier is connected to the antenna. The output of Transponder 2 RF power amplifier is connected to the 50 Ohm Load 1A69757.
c. If S1 is in the down position (NORMAL) the setting of the relay K1 is determined by the input Antenna_Relay_Control from the CTU. If this input is high (+ 24 volts) then Transponder 1 is connected to the antenna with Transponder 2 terminated, and if this input is low (0 volts) then Transponder 2 is connected to the antenna as in with Transponder 1 terminated.
Table 2-1 Summary of Controls and Indicators: RF Panel (Dual)
CONTROL/INDICATION FUNCTION DETAILS TYPE LEGEND FUNCTION/SETTING/INDICATION
TPNDR2 The output of Transponder 2 is fed directly to the antenna. The output of Transponder 1 is terminated in the 50 ohms load.
TPNDR1 The output of Transponder 1 is fed directly to the antenna. The output of Transponder 2 is terminated in the 50 ohms load.
Toggle switch, centre off
NORMAL The CTU controls which transponder output is fed to the antenna.
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2.3.3 Receiver Video 1A72520 REFER Interwiring Diagram 72520-3-04
The Receiver Video module provides the main receiver functions and contains the Main PWB Assembly Receiver Video 1A72521, RF Source 1A72522, RF Filter 1A72517, IF Amplifier 1A72523 and RF Amplifier 1A72524.
The received signal is passed from the antenna into the RF panel and preselector filter on to the receiver. A circulator in the RF panel is used to isolate the receiver from the transmitter while allowing the use of a common antenna. The cavity-tuned preselector rejects the image signal and provides initial selectivity for the receiver.
The receiver video module amplifies and detect on-channel interrogations and provides trigger pulse-pairs for the transmitter modulator for International Morse Code identification, interrogation replies and squitter. A continuous wave (CW) RF output at the local oscillator frequency is provided as excitation for the transmitter.
The RF source generates the RF signal required for both the receiver local oscillator and the transmitter. A single-crystal oscillator operating at a frequency of one-twelfth of the DME transmit channel frequency generates a signal which is buffered and then frequency multiplied in three stages to produce the required signal frequency.
The RF amplifier is designed as a broadband micro-stripline amplifier system. It amplifies the low level signal received from the antenna and, in a separate stage, amplifies and splits the local oscillator signal into two signals each at an approximate level of +11 dBm. One of these signals is used as the local oscillator injection frequency for the receiver mixer, while the other is fed to the transmitter driver as the excitation signal. The mixer stage utilises a double balanced diode mixer circuit and produces an intermediate frequency signal at 63 MHz.
The IF amplifier board provides the main 63 MHz IF amplifier which consists of a dual-gate FET amplifier stage followed by a successive detection logarithmic output amplifier chain. Gain control is provided by developing a DC bias to control the FET amplifier stage. This controlling DC bias is manually and automatically set to reduce CW response and to reduce the transponder sensitivity during over-interrogation.
The demodulated video output of the logarithmic amplifier stages is broadband and does not discriminate against adjacent channels.
A second mixer circuit converts the amplified 63 MHz RF signal to 9.25 MHz where it is amplified and passed through narrowband tuned circuits which provide rejection to all adjacent channel signals. This narrowband signal is AM-demodulated and is used both as an on-channel gating pulse and to develop the AGC voltages to control the dual-gate FET amplifier stage.
Both the logarithmic output pulse and the on-channel pulse are fed into the receiver video main PWB assembly for decoding and processing.
In the main PWB assembly the signals from the IF amplifier detectors are detected and processed. Pulses arriving at the logarithmic pulse input without corresponding on-channel pulses are ignored as spurious or adjacent channel noise. The remaining on-channel logarithmic pulses are passed on to a half-amplitude finder circuit for accurate time referencing. The pulses are then decoded for correct pulse spacing.
On receiving and detecting a valid pulse-pair the transponder then enters a programmable wait period before generating an appropriate pulse-pair for transmission as reply pulses. Transponder delay time is referenced to the 50% amplitude point on the leading edge of the first interrogation pulse.
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As a result of reflection, genuine interrogation pulses which appear to be valid may be received, having been delayed due to a longer transmission path. These signals could trigger a misleading reply; to prevent this happening a dead time is introduced, following a successful interrogation, to block out any such signals.
All pulses for transmission are generated in the receiver video. All critical pulse durations and time delays are produced by programmable counters and shift registers for which the clocking frequency is derived from a crystal oscillator. Site-dependent programming is set by switches.
The ident message is stored on four 8-way DIL switches on the main board. Depending on the appropriate external connections the ident may act as either master or slave. When operating as a slave to an associated VHF navaid, the external ident has priority. If the external ident should fail the internal ident generator automatically takes over.
Squitter is generated in a pseudo-random time sequence at an average frequency of 945 Hz and is transmitted as standard pulse-pairs with random time spacing.
For all transmissions, replies to interrogation have priority over squitter and the ident message has priority over reply pulses, however reply pulses may occur in the 'space' period of the ident message.
Short distance echo suppression is selected by an ON/OFF switch mounted on the board. Its function is to allow decoding of an interrogation when the inter-pulse space is filled with signals which are reflections of the first pulse. It operates by removing video signals from the input of the amplitude finder just prior to the arrival of the second interrogation pulse thereby effectively clearing a space for the second pulse.
Long distance echo suppression is also selected by an ON/OFF switch mounted on the board. Its function is to inhibit decoding of an interrogation pulse-pair which is produced by a distant reflector such that it arrives after the dead time has expired. It operates by increasing the dead time to an adjustable value for those interrogations which exceed a preset signal level. This provides a better compromise in traffic handling capability than would be achieved by simply increasing the dead time for all interrogation signal levels.
2.3.3.1 Main PWB Assembly Receiver Video 1A72521 REFER Circuit Diagram 72521-1-01
2.3.3.1.1 Pulse Processing Delayed interrogation pulses from the log video input at XN2:5 and the on-channel video pulses at XN2:2 arrive at D50 in a phase relationship that permits the on channel pulses to change the address of the analogue multiplexer in time to allow the log video pulse to pass through to the follower-amplifier N7b. In the process, the arriving log video pulse is added on to a DC pedestal voltage of approximately 0.5 volts; N7a clamps the baseline of the log input signal to +1.5 volts (at the junction of R49 and R36) which is 0.5 volts above the reference input to D50.
If the log video input pulse is a result of noise or adjacent channel signals, there will be no accompanying on-channel pulse and D50 will ignore the log video input. This method recognises valid input pulses and maintains the logarithmic shape of these pulses as they are passed to the half-height and timing detectors.
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2.3.3.1.2 Half-height and Timing Detection An adjustable (R45, 6 dB OFFSET) constant current source V15 feeds into the output of N7b. This current flowing through R44 produces an input to N6:5 which is DC offset with respect to the waveform applied to N5:4 input. Amplifier N6:7 and delay line D38 provide a unity-gain time-delayed signal to the other input of N5:5. Thus the signal at XT6 has been offset by a DC voltage equivalent to 6 dB pulse amplitude, as well as being delayed by a period equal to half the duration of the standard input pulse.
Due to the offset in amplitude and the delay applied to the pulse at XT6 the half-height point of the delayed pulse corresponds to the maximum point of the original pulse at XT13. This will always occur for all logarithmic-shaped pulses of standard duration regardless of amplitude and thus the comparator output N5:12 will always identify the half-height point by going low at this time.
As N5:12 goes low, the D-type flip-flop D26:3 is clocked with the D input pin 5 high due to the on-channel pulse still being present. D26:1 generates a pulse of 2.5 microseconds duration which is determined by the 14-stage shift register D25, clocked at 5.5296 MHz. The pulse at D26:1 is loaded into the shift registers D21, D22, D23, D24. This window, 2.5 microseconds wide, passes down the shift registers to coincide with the next valid input pulse. The shift registers are varied in length depending upon X or Y channel selection. In the case of X channel operation it will take approximately 13.2 microseconds for a pulse to arrive at D20:5, whereas in the case of Y channel operation the shift registers are configured to delay the pulse by approximately 37.2 microseconds before operating D20:5. The SELECT DECODER MODE switch S5 is used to select X or Y channel operation and is set on installation for the type of operation required.
Figure 2-11 Waveforms for Interrogation Pulse Processing
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At the time when a valid first pulse of a pulse-pair is emerging from the shift register, the second pulse will have operated D26:1 and enabled D20:3 via the gate D41:4 thus triggering the monostable at D20:5 by the leading edge of the delayed first pulse. The positive-going pulse generated at XA3 indicates that a valid interrogation pulse-pair has been decoded. Because D20:5 is enabled for 2.5 microseconds, coincidence can occur at 12.0 ±1.2 microseconds for X channels, and at 36.0 ±1.2 microseconds for Y channels.
2.3.3.1.3 Dead Time After a valid pulse-pair has been received (as indicated by the pulse generated at XA3) the counter D40 is loaded with the binary number set in to the SET DEAD TIME switch S7. D40 will count to zero at the clock rate of 86.4 kHz determined by D49 and the 5.5296 MHz clock. During the down-count of D40, pulse-pair decoder pulses are inhibited by the output of D41:3, thus creating the beacon dead time. Switch S7 sets the dead time in multiples of the 86.4 kHz clock period; that is, 11.57 microseconds. Due to the random timing of the interrogation pulses in relation to the 86.4 kHz clock, the dead time will vary between approximately (2.5 + (n-1) x 11.57) microseconds and (2.5 + n x 11.57) microseconds where 'n' is the number set on switch S7.
2.3.3.1.4 Short Distance Echo Suppression The purpose of the SDES is to allow the decoding of an interrogation when the space between the pulses is filled with signals which are echoes of the first pulse. This may be used at sites which have large nearby reflectors which cause strong echo signals with amplitude comparable to that of the direct signal. The echo suppression operates by removing signals from the half-amplitude detector just prior to the arrival of the second pulse. This allows the decoder to recognise the presence of the second pulse and thereby initiate a reply to the interrogation.
When SDES is selected, by switch S8, the delayed first pulse produced at D22:10 (2.5 microseconds duration) is used to disable D50. Following the trailing edge of the SDES pulse, D50 is again enabled to allow decoding of the second pulse. For X channels the SDES pulse trailing edge occurs approximately 10 microseconds down the shift register. After a further delay of approximately 1.8 microseconds in the half-amplitude finder, a pulse is generated with the correct separation to form a decodable pair. For Y channels, the pulse trailing edge occurs approximately 34 microseconds down the shift register.
The fast-attack slow-release time constant provided by V20, R55 and C79 disables the 2.5 microsecond pulse at D26:1 for approximately 1.5 microseconds after each pulse terminates. This prevents the generation of SDES pulses with zero gap between them, which situation could cause inhibiting decoding if the trailing edge of one SDES pulse was about to generate the artificial second pulse only to be inhibited by a following SDES pulse.
2.3.3.1.5 Long Distance Echo Suppression In a similar fashion to SDES, the long distance echo suppression (LDES) function will eliminate echo pulses with long delays. LDES is only initiated after receiving a valid pulse-pair and with the LDES switch S9 set ON, Counter D39 will be set by the pulse from D20:6 and will count the LDES PERIOD set on switch S6. D39 derives its clock, 43.2 kHz, from the divider D49 and the 5.5296 MHz crystal oscillator. The function of LDES is to inhibit decoding of an interrogation pulse-pair which is produced by a distant reflector such that it arrives after the dead time has expired. It operates by increasing the dead time by (if set to be longer than the normal dead time) an adjustable period (determined by switch S6) for those interrogations which exceed a preset level set by R46, LDES LEVEL and compared in N5:10. This provides a better compromise in traffic
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handling capability than would be achieved by simply increasing the dead time for all interrogation signal levels.
Switch S6 sets the LDES period in multiples of the 43.2 kHz clock; that is, 23.15 microseconds. Due to the random timing of the interrogation pulses in relation to the 43.2 kHz clock, the LDES period will vary between approximately (2.5 + (n-1) x 23.15) microseconds and (2.5 + n x 23.15) microseconds where 'n' is the number set on switch S6.
2.3.3.1.6 Beacon Delay On recognition of a valid pulse-pair, monostable INPUT D2:a is enabled by DOUBLE PULSE DECODER OUT pulse (observable on XA3) and D2:6 changes state at the next falling edge of the 5.5296 MHz clock pulse, synchronising this pulse with the 5.5296 MHz clock. The SET BEACON DELAY COARSE switch S1 and the SET BEACON DELAY FINE switch S2 set the beacon delay time by adjusting the length of the shift register D13, D42 and D31. Both of these switches are mounted on the front panel of the receiver video module, and are operator accessible. Monostable output D2:10 assists to re-adjust the phase of the shift register output pulses to be coincident with the clock. The output pulse from the beacon delay timer chain comes from D31:10 and appears at the multiplexer D12 which is configured as a priority selection gate.
2.3.3.1.7 Reply Pulse-pair Generation The dual 4-channel analogue multiplexer D12 has two outputs (pins 13 and 3) each of which can be switched to be connected to one of four inputs, depending on the selection logic. As pin 6 is tied permanently low, the address (selection) conditions at pins 10 and 9 determine which inputs are connected to the outputs.
These two address selection lines are controlled by D11:12 (Address 0, pin 10) which is the select interrogation counter, and by D47:3 (Address 1, pin 9) which is the ident input control. These two inputs then determine which of the three output conditions will occur - interrogation reply, squitter, or ident.
Address 01 selects squitter pulses, 00 selects interrogation pulses, and 11 selects ident pulses. When a double pulse decode occurs, D11 is asynchronously loaded to a count of 12. D11 counts down to 0 at a clock rate of approximately 173 kHz, and clamps at a count of 0 by feedback from pin 12 to pin 4. The interrogation select pulse applied to D12:10 is approximately 70 microseconds in duration and drives D12 to accept the output pulse, D31:10, from the beacon delay timer.
Reply pulses have a lower priority than ident pulses, but a higher priority than squitter. Thus, provided that there is no ident mark transmission in progress and D11 is counting, the multiplexer D12 will have address 00 selected, which will allow the delay timer pulse from D31:10 to enable D3:13 and the delay shift registers D32, D33 and D34. These shift registers generate the reply pulse separation time. The pulse generated by D3:10 is used as the first pulse of the pulse-pair and passes via V1 and D4:12 as the trigger pulse to the transmitter driver. The same pulse from D3:10 is delayed by the shift registers D32, D33 and D34 to create the second pulse in D35:10 at the falling edge of the clock. The time delay created by the shift registers may be varied by the switches S3 and S4. The REPLY PULSE SEPARATION switch S3 allows the delay to be altered in steps of approximately 180 nanoseconds, whereas the SELECT ENCODER MODE switch S4 provides for the selection of a 12-microsecond delay for X channel operation or a 30-microsecond delay for Y channel operation.
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2.3.3.1.8 Identification Message (Ident) The ident message is a 2-character or 3-character Morse code signal with a 1350 Hz tone and having a 'dot' period of 0.125 seconds. The tone frequency is derived from the 5.5296 MHz clock, thus assuring accuracy of the tone frequency. The ident message is set by four 8-bit SPST switches (S13, S14, S15, S16).
The counter D49 divides the 5.5296 MHz clock to produce the 1350 Hz clocking frequency which is used as the Morse code tone as well as a clock for the ident timing circuits.
The ident keyer circuit generates a repeated Morse code identification signal of up to three characters. The characters are built up by setting switches to place the 'dot' and 'dash' elements in the required sequence.
The speed at which the identification signal is transmitted is set by the frequency of the oscillator circuit associated with D44:5. The frequency can be varied by altering the CODE SPEED preset R37.
The repetition rate of the ident signal is determined by the frequency of the oscillator circuit associated with D44:9. The rate can be varied by altering the REPTN RATE preset, R39.
The required sequence of dots and dashes is provided by circuitry associated with D36, D45 and D37. The arrangement of common binary lines to the demultiplexers D45 and D37 in conjunction with the steering circuitry implemented with D51 and D53 enables one of the demultiplexers D45 and D37 in turn, while inhibiting the other demultiplexer. The 4-bit binary counter D36 generates the binary code corresponding to decimal 0 through 15. Thus a high (15 volts) is stepped along first from D45:4 through to D45:13, and then through D37 and, depending on the settings of switches S13 to S16, the high is applied to either the 'dots' bus or the 'dashes' bus.
The detailed operation of the keyer can be seen with reference to Figure 2-12 which shows the signals present at various circuit points for the generation of the letters UN (dot-dot-dash dash-dot). The sequence is started by the asynchronous start pulse which is produced at D29:12 by dividing the frequency of the repetition oscillator D44:9 by 15. The start pulse initialises the sequence by setting D51:1 high and by loading counter D36 with a count of 15. This enables the first output D45:4 which may be switched by S15/S16 to the dot or dash line to give the first desired code element. With a dot selected, a high level will be produced at the code output for one full clock cycles when D51:2 goes high.
When D51:2 is clocked low on the next clock pulse the generation of a 'dot-length' space is automatically inserted after the first element.
The next clock pulse from D44:5 clocks D36 to its next state for the generation of the next code element, and the sequence is repeated.
With a dash selected by closure of S16 to the dash position, the dash bus will be high, which will preload the dash timer D43 with a decimal 3 causing the output to remain high for three dot periods.
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Figure 2-12 Ident Keyer Waveforms
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The space between letters (see line labelled STATE in Figure 2-12) is formed by leaving both the dot and dash switches in the 'off' position. This allows a space equivalent to three dot elements to be generated between letters of the code word.
The line labelled COUNTER D36 STATE in Figure 2-12 traces the counter zero 15,14, etc, states and the progression of the high along the demultiplexer output.
At the end of the character generation sequence D37:13 is activated and an inhibit signal is applied to D43:4, stopping the operation of the keyer until the next start pulse is received.
Where a VOR and a DME beacon are collocated they may be operated in either 'independent' mode or 'associated' mode. D30 is a divide-by-4 counter controlling the switching of D19 such that three consecutive ident code sequences from D52:3 are switched to MASTER IDENT OUT and the fourth ident code sequence is switched to D48:9 for INTERNAL IDENT.
2.3.3.1.9 Squitter Squitter is generated as a pseudo-random set of pulses at an average rate of 945 Hz and is transmitted at the lowest priority, being preceded by the ident message and reply pulses. As the interrogation pulse rates increase to 945 Hz, the squitter becomes totally inhibited.
Squitter is generated by the action of D15 and D16 operating at different clock rates (from D49:12 and D49:1 respectively) and the arranged 'disorder` of the parallel load lines into D15. D16 is a 5-stage Johnson counter clocked at 1.35 kHz. The10 outputs go high, in turn, for one clock period. D15, an 8-bit, parallel-in, serial-out shift register, is clocked at 10.8 kHz and is loaded at a rate of 1350 Hz with the end bit always being zero, and with the other inputs loaded no bit (3/10 of the time) with 1 bit (7/10 of the time), in the disordered pattern, from D16. This produces the required pseudo-random pulse rate.
2.3.3.1.10 Minimum Reply Rate D14:11 is enabled by the absence of decoded interrogation pulses in D20:7 and D2:7 and on receipt of a random pulse (squitter) causes D5 to output a pulse via D17:10 to D12.
In the absence of both a select interrogation pulse and an ident mark, D12 will automatically select the squitter input and enable the reply pulse generator logic to transmit the squitter pulse.
As reply pulses are detected on D2:3, D5 will increment its count with each pulse, requiring one squitter pulse to occur to decrement the count to zero before transmitting the next squitter pulse. In this way each reply pulse will replace a squitter pulse and, at a reply rate of 945 Hz, no squitter will be transmitted. In the case where a reply pulse occurs simultaneously with a squitter pulse, D14:9 will be inhibited and the reply pulse will be transmitted; one squitter pulse will be lost to the counter D5.
2.3.3.1.11 Over Interrogation Accepted interrogation pulses trigger D2:6, and its inverted output D2:7 is used as a clock for D6 which is configured as a self-reloading divide-by-three counter. D18 is also self-loaded, each time a terminal count is reached, inhibiting a 'roll-over' of the count. D18 counts up with each squitter pulse and down with each third reply pulse; thus if the reply rate exceeds three times the squitter rate, reply pulses are inhibited by D3:6 and the beacon delay registers are reset. Both D6 and D18 remain jammed at a count of 0, inhibiting reply pulses until a squitter pulse from D14:9 increments D18 to a count of 1.
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Three more reply pulses are then transmitted. In this situation the squitter pulses are used as a reference pulse rate only, and the maximum reply rate is held at a nominal 3 times 945 Hz, or 2835 per second.
When this over-interrogation condition exists the output pulses from D18:7 provide two output signals; one, via buffer D4:9 and XN1:9a, to the test interrogator to switch to high signal level interrogation for monitoring, and another via XN2:7 to the IF amplifier to desensitise the receiver, thus discriminating against weaker interrogations from distant aircraft. Once the receiver gain reduction has achieved control of the interrogation rate the video inhibiting via D3a, as described above, ceases. If XT22 and XT21 are bridged the receiver gain reduction is prevented and maximum response rate control is provided by the video inhibit method. This latter method treats all aircraft equally, giving each the maximum possible response rate for the interrogating conditions.
2.3.3.1.12 Output Inhibit The TX MODULATOR TRIGS output at XN1:8c is suppressed at power switch-on, during transfer relay operate time, and (if the non-active transponder) during warm standby.
Suppression is provided by a 5 volts logic level applied to XN1:29b which tristates the output, inhibiting the trigger pulses to the modulator and stopping transmitter output pulses.
The primary fault signals REPLY_DEL_FLT_1/2 and PULSE_SPAC_FLT_1/2, when low, indicate that there is a fault in the primary parameters. If both REPLY_DEL_FLT_1 and REPLY_DEL_FLT_2 or both PULSE_SPAC_FLT_1 and PULSE_SPAC_FLT_2 are low, then the counter D8 begins counting the clock pulses produced by the RC oscillator of D8:9, 10, 11. When output 9, D8:15, goes high (after about 70 seconds) the oscillator of D8 is disabled, causing D8 counter to hold its count. The high input on D4:15 inhibits TX_MODULATION_TRIGS. The action of the inhibit will be disabled when the input signal INHIBIT_DISABLE is low.
This inhibited state will hold until power is removed from the module. XN1:9c is a disable for this circuit and is connected to the TRANSPONDER DC POWER switch in the power supply module. When this switch is in the ON position, which is the usual position during maintenance, the inhibit circuit is disabled.
2.3.3.1.13 Replies Inhibited Indicator This front panel LED indicator lights to indicate whenever replies are inhibited. For no replies the LED is on continuously. As an indicator of over-interrogation it flashes at a rate of eight flashes per second, driven by the square wave connected via V5 modulating the output from the ident speed generator D18:7.
2.3.3.1.14 Miscellaneous The RF level and the local oscillator level are buffered and scaled by N10 before being fed to the monitor for measurement. Each of the RF levels is also available for monitoring on the front panel.
The +15V rail is monitored by a window comparator consisting of N2 and, N4. RV_PS is high when +15 V is between 13.0 and 16.5 volts, and low when +15V is outside these limits.
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2.3.3.2 RF Source 1A72522 REFER Circuit Diagram 72522-3-01
This unit is designed to produce the signal required for excitation of the transmitter stages and the first mixer stage of the receiver. It provides an output of approximately +4 dBm to the receiver RF amplifier board where further amplification and signal splitting occurs, as described in Section 2.3.3.4.
The signal generation is accomplished by the use of a crystal oscillator operating in the frequency range of 80 to 101.5 MHz, one-twelfth of the required signal frequency. The crystal oscillator output is buffered and then multiplied in three stages to produce the operating signal frequency.
The oscillator stage V1 incorporates a fifth-overtone crystal G1 in series resonance in the feedback path.
Feedback from V1 emitter is passed through the series resonant crystal to create self-excitation to the transistor via a damped base tank circuit comprising of L1, C2 and C11.
The tuned circuit L1, C2 and C11, as well as correcting phase shifts around the feedback loop, also ensures that the fifth-overtone crystal operates without any tendency to change mode.
An inductor, L6, is connected across the crystal and is selected to resonate with the crystal holder and crystal stray capacitances to form a parallel tuned circuit at the operating frequency. This prevents the stray capacitance acting as a separate feedback path which could cause parasitic oscillation and instability.
Base bias for the oscillator stage V1 is derived by the resistor chain R2, R23 and R3 and L1. The transistor is operated at a low level of drive to enhance overall stability.
The output from the oscillator is taken from the collector of V1 via C6 to the emitter of the grounded-base buffer-amplifier stage V2 which isolates the loading effects of the following multiplier stage from affecting the operation of the crystal oscillator. Capacitor C8 is adjusted for maximum drive into V3.
The first stage of multiplication is a self-biased multiply-by-three circuit using a heavily driven transistor V3 with its collector tuned by C12 to three times the oscillator frequency. Self biasing reduces the conduction angle and raises the efficiency of this stage.
Transistor V4 operates as a multiply-by-two circuit with its collector circuit tuned to twice its input frequency or six times the oscillator frequency. This stage uses a small forward bias voltage on the base circuit which is reduced automatically as drive is increased due to the increased voltage drops occurring across R15 and R16 as drive increases. Capacitor C18 tunes the collector circuit of V4.
The final multiplier stage operates in a similar fashion to the previous stage; however, the final stage uses a microwave transistor (V5) as a multiply-by-two and produces the required operating frequency in its collector circuit. Tuning of this stage is accomplished by capacitor C26.
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2.3.3.3 IF Amplifier 1A72523 REFER Circuit Diagram 72523-1-01
The 63 MHz intermediate frequency signal originates in the RF amplifier mixer stage and is connected to the input of the IF amplifier at XC1 via a 50 ohms coaxial cable. The low-noise dual-gate FET stage of the IF amplifier V2 operates as an AGC-controlled amplifier with the two tuned circuits of L7 and L5 providing the necessary bandwidth for rejecting large out-of-band signals, increasing the signal-to-noise ratio, and providing inter-stage impedance matching.
Manual gain control is applied to the input stage via a preset gain control R29, which is adjusted to give a threshold sensitivity of -94 dBm. In addition, delayed AGC is applied via N9 in such a manner as to reduce the transponder gain when the interrogation rate exceeds the preset limit of 2800 per second or in the presence of in-band high-level-carrier received signal. The AGC threshold for CW signals is set by the SET AGC control R15. The range of automatic gain control is in excess of 50 dB and the receiver functions normally over this range of gain reduction provided the pulse signal level is sufficiently above the CW level.
Following the input amplifier stage the signal is amplified and successively detected in a cascaded set of logarithmic (log) intermediate frequency amplifiers. The eight amplifiers are divided into two groups of three, coupled via a single parallel resonant circuit which serves to increase the overall signal-to-noise ratio by restricting the bandwidth and a group of two (N1, N2) in parallel. To match the amplifier chain to the dynamic range of the input signal (-90 dBm to -10 dBm), N1 has its input attenuated so that it provides its required contribution to the log detection law at high signal levels without increasing the overall gain at low signal levels. Amplifier N1 provides amplifier N3 with the required bias potential from its pin 7 connection; N6 supplies the bias potential for the second group of amplifiers; each amplifier is DC coupled. The detected log output from the amplifiers is then amplified in the transistor stage V5 and then delayed 1.6 microseconds in the delay line D1 before reaching the video output of the IF amplifier. The value of the delay compensates for the additional delay to the on-channel pulses in passing through the narrowband filter L3 and L6.
The 63 MHz output from the log amplifier chain at N8:3 is mixed in the dual-gate FET mixer circuit of V1 with a 53.75 MHz signal generated by the third-overtone crystal oscillator circuit of V4.
The output of the mixer circuit is a 9.25 MHz signal which is filtered by a narrowband filter comprising L3 and L6. L6 includes an inbuilt amplitude detector, and the video output pulses are applied to the input of a voltage comparator N10a. The reference input to this stage is a voltage set by the ON CHANNEL THRESHOLD preset R50. R50 is set to slice the signal just above the noise level, and 15 volts logic pulses are produced at the ON CHANNEL OUT terminal.
As the 63 MHz intermediate frequency amplifier has a bandwidth of several MHz, adjacent channel signals could be mistaken as valid interrogation pulses; however, the narrowband 9.25 MHz circuit will only pass signals that are on-channel and although the demodulated video pulses do not carry easily definable timing information, these pulses are used to identity the valid log interrogation pulses by coincidence.
Linear regulator N11 derives +6 volts DC for log amplifier operation from the 15 volts supply.
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2.3.3.4 RF Amplifier 1A72524 REFER Circuit Diagram 72524-3-01
The RF amplifier is a broadband micro-stripline amplifier system which:
• amplifies the signal received by the DME antenna via the Preselector Filter 1A72546;
• amplifies and splits the signals from the RF Source 1A72522 into two +11 dBm signals; and
• mixes the amplified received signal with an amplified signal from the RF source to produce a 63 MHz intermediate frequency signal.
The RF signal stage uses V1 in a common-emitter amplifier in a micro-stripline matching network. The AC-coupled input from the preselector filter, at XC1, feeds a tee-impedance transformer comprising a series micro-strip inductance and chip capacitor C2 to ground to achieve matching of the base input impedance.
Base bias current is supplied via a quarter-wave micro-strip inductance from the collector voltage source and is zener referenced to maintain a constant collector current. The collector also draws its current via a length-tuned inductor and the collector impedance is matched to the load impedance presented by the mixer by a series length of micro-stripline. Capacitor C5 AC-couples the double-balanced mixer load to V1.
The signal from the RF source, which is input via connector XC3, is used as a local oscillator injection signal for the mixer as well as the low power signal for exciting the transmitter stages. The RF source input from XC3 is fed through a 50 ohms microstrip track. A level detector provides a signal for monitoring purposes. A tee-impedance transformer matches the base input impedance of V4. Bias is applied to V4 in the same manner as for V1, via a quarter-wave choke.
The collector circuit incorporates a parallel micro-strip inductor pre-tuned by the bypass chip capacitor C11 and the impedances are transformed by a series capacitor into the 50 ohms wireline hybrid 3 dB coupler, W1. W1 splits the RF power between the outputs XC4 (RF output to the transmitter) and the micro-stripline feed to the mixer U1. Both output levels are approximately +11 dBm, and are sensed by the level detector circuit V8 to provide a signal for monitoring purposes.
The double-balanced mixer U1 is supplied as a module and is not field repairable. The input RF signal from V1 and the RF signal from the RF source are mixed in U1 to produce the 63 MHz IF signal which is fed out via XC2 into the IF amplifier at a nominal 50 ohms impedance.
2.3.3.5 RF Filter 1A72517 REFER Circuit Diagram 72517-4-02
The RF filter is a lumped element filter used to reduce spurious frequency outputs from the RF source, before the signal is used as local oscillator for the receiver and source for the transmitter; it is tunable from 950 to 1220 MHz.
The filter is a two-stage, high Q, parallel tuned circuit with, 50 ohms auto transformer input and output matching and inductive inter-stage coupling. The inductors are formed as short tinned copper wire elements and the tuning capacitor is a glass dielectric concentric type.
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Table 2-2 Summary of Front Panel Controls and Indicators : Receiver Video Module
CONTROL/INDICATION FUNCTION DETAILS TYPE LEGEND FUNCTION/SETTING/INDICATION
Flashes on and off when the receiver video is being over-interrogated.
Yellow LED REPLIES INHIBITED
On continuously when replies are inhibited. Red LED TEST Indicates that the IDENT switch is not in the NORMAL position. Green LED DC POWER ON Indicates that DC power is applied to the module.
COARSE Sets the Delay parameter of the receiver video. 16-position switches
BEACON DELAY FINE
16-position switch
REPLY PULSE SEPARATION
Sets the Spacing parameter of the receiver video.
NORMAL Normal mode of operation. OFF No ident is generated.
Toggle switch, centre off
IDENT
CONTINUOUS Ident is generated continuously. INHIBIT INTERROGATIONS
All interrogations are inhibited. Toggle switch, spring loaded to centre off TEST REPLY RATE
MONITOR Transponder replies are inhibited and squitter reduced to 810 Hz.
Test jack SDES PULSE Buffered output from the double pulse decoder, which gives the short distance echo suppression pulse to the on-channel gating logic (15 volts, 2.5 microseconds wide. one pulse per correctly decoded pulse pair).
Test jack LDES PULSE Buffered output from the dead time suppressor showing the period of long distance echo suppression and when it is active (15 volts, selectable length, selectable trigger level).
Test jack DOUBLE PULSE DECODER OUT
Buffered output of the double pulse decoder indicating a pulse pair has been correctly decoded (15 volts, 2.5 microseconds wide, one pulse per each valid interrogation).
Test jack DEAD TIME Buffered output from the dead time generator, shows the period of dead time and when it is active (15 volts. selectable length).
Test jack TRIGS TO MODULATOR
Buffered output from the double pulse encoder buffer to the transmitter driver This output is normally high, and goes low during TX MODULATION TRIGGERS (0-15 volts, 2.5 microseconds wide pulses in pulse pairs separated by 12 or 36 microseconds; minimum rate 945 PPPS, maximum rate 3000 PPPS).
Test jack LOCAL OSC LEVEL DC output proportional to the drive level out of the RF source. Test jack +15V Buffered output from the +15V regulator. Test jack EARTH Common earth of all supply voltages and outputs. Test jack EARTH Common earth of all supply voltages and outputs. Test jack RFLEVEL DC output proportional to the output TX RF DRIVE. Test jack ON CHANNEL
VIDEO Buffered output of the narrow band detected on-channel gate from the IF amplifier (15 volts pulses forming an envelope around the detected log video pulses, normally 3 microseconds wide).
Test jack EARTH Common earth of all supply voltages and outputs. Test jack DETECTED LOG
VIDEO Buffered output from the wideband logarithmic amplifiers of the IF amplifier.
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Table 2-3 Summary of Internal Controls : Receiver Video Module
CONTROL FUNCTIONS SUBASSY TYPE REF LEGEND FUNCTION/SETTING/INDICATION
Preset resistor
R37 CODE SPEED Varies the ident code speed, which is set to 8 Hz.
Preset resistor
R39 CODE REPTN Varies the ident repetition rate, which is set to 1.5 Hz.
1A72521 Main PWB Assembly, Receiver Video Preset
resistor R45 ADJUST 6 dB
OFFSET Set to 0.24 volts during factory test, but may need to be varied at module test level (see Sections 3.3.8, 3.4.17).
Preset resistor
R46 LONG DISTANCE ECHO SUPP LEVEL
Varies the LDES DC level.
X Selects X mode operation for the encoder. Slide switch S4 SELECT ENCODER MODE Y Selects Y mode operation for the encoder.
X Selects X mode operation for the decoder. Slide switch S5 MODE SELECT DECODER Y Selects Y mode operation for the decoder.
16-way rotary switch
S6 SET LDES PERIOD Sets the LDES period in multiples of 12.15 microseconds.
16-way rotary switch
S7 SET DEAD TIME Sets the dead time period in multiples of 11.57 microseconds ON Enables SDES operation. Slide switch S8 SDES OFF Disables SDES operation. ON Enables LDES operation. Slide switch S9 LDES OFF Disables LOES operation.
8-way switch S13 to S16
CODE ELEMENT Set the ident Morse code characters.
Variable capacitors
C8, 12. 18. 26 1A72522 RF Source
Variable inductor
L1
Used to align the RF source to the operating reply frequency (see Section 3.4.18)
Variable capacitor
C1 1A72523 IF Amplifier
Preset resistors
R15, 29, 50
Used to align the IF amplifier (see Section 3.4.19).
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2.3.4 Transmitter Driver 1A72530 REFER Interwiring Diagram 72530-3-03
The transmitter driver mounts the pulse shaper and RF amplifier stages. When used as a driver for the 1kW RF power amplifier it produces rectangular reply pulses generated in response to trigger pulses from the receiver video module.
Front-panel test jacks are available for measurement of selected pulse shaper parameters and indicators are provided for TEST and DC POWER ON status.
The interconnections of the subassemblies within the module are shown in Drawing 72530-3-03. The subassemblies, each with its own circuit diagram, are described individually in the following sections.
Within the transmitter driver there are four subunits; these are the exciter, the medium power amplifier, the power modulation amplifier, and the pulse shaper.
The three amplifiers form an amplifier chain; the RF output from the RF amplifier in the receiver video module is input to the exciter section of this amplifier chain at a level of 10 mW. This signal is successively amplified and modulated by the amplifier chain to produce the required pulse shape and timing characteristics. The final output from the power modulation amplifier consists of RF pulses, produced in response to trigger pulses from the receiver video module, at a level of 50 watts.
Figure 2-13 Transmitter Driver Block Diagram
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2.3.4.1 2.3.4.1 Pulse Shaper PWB Assembly 1A72531 REFER Circuit Diagram 72531-1-01
The pulse shaper controls the modulation characteristics of the transmitter amplifiers. It does this by producing modulation pulses that are accurately controlled in shape, duration, and time. Pulse production and timing are both controlled by the receiver video, which produces modulation trigger pulses to initiate pulse generation and a 5.5296 MHz signal which is used as the pulse shaper clock signal. The second major function of the pulse shaper is to provide control and adjustment of high tension and bias supplies to the three amplifier assemblies.
The inputs to the pulse shaper are:
a. Modulation trigger signal from the receiver video (XN1:8c).
b. 5.5296 MHz clock signal from the receiver video (XN1:8a, XN1:8b).
c. Provision for input from an external temperature sensor, which could be used to determine the DC pedestal level of the high level modulation pulse outputs (XN1:26c, XN1:27a). The external temperature sensor would be a forward biased diode thermally joined to the power transistor heat sink and connected in parallel with V13. (This external sensor is not used in this equipment; adequate temperature compensation is achieved by the on-board sensor V13 responding to ambient temperature changes only.)
d. Provision for a detected RF input to be switch-selected to be the source from which the automatic level control of the high level modulation pulses is derived (XN1:26a, XN1:26b).
e. Modulated detected signal from the power modulation amplifier at X2:16, which is used to derive the driver pulse level reference voltage.
f. Supply voltages for the transmitter driver stages, all routed from the transponder power supply: high tension supply (XN1:2a,b,c); +18 volts supply (XN1:6a,b,c); +15 volts supply (XN1:9a,b,c).
g. Auxiliary +24 volts supply (XN1:3a,b,c).
The outputs of the pulse shaper are of two main types - modulation pulses, and adjustable supply voltages for the amplifier assemblies. The outputs are:
a. A receiver suppression pulse, which is supplied to the receiver video to suppress receive functions during pulse transmission from the transmitter (XN1:10b).
b. To the exciter:
1. A rectangular modulation pulse signal 1W PULSE which provides the low-level modulation of the transmitter (XN2:10).
2. Adjustable DC voltage EXCITER DC which supplies the collector voltage for V5 and V6 (XN2:8).
3. DC supplies for Class A operation of V1; these are collector voltage VC1 (XN2:6) and bias voltage BIAS 1 (XN2:2).
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c. To the medium power driver:
1. High tension supply +HT (XN2:14).
2. V1 collector voltage MED PD COLL; this can be switch-selected to be either an adjustable DC level or a shaped modulation pulse signal (XN2:12). In configurations which do not use the 1kW amplifier, this latter arrangement provides for the high-level modulation in the system.
d. To the power modulation amplifier:
1. High tension supply +HT (XN2:20).
2. Adjustable DC voltage POWER MOD AMP DC which supplies the collector voltage for V1 (XN2:18).
e. In system configurations having 1kW outputs, high-level shaped pulse signal supplied to the modulating stages in the associated 1kW RF amplifiers (XN1:25a, XN1:25b).
f. Reference voltage TO_TX_LVL (XN1:28b) which is fed to the monitor module and CTU for measurement and comparison purposes.
The leading edge of the shaped modulation pulse is generated by a six-segment adjustable-slope integrator. The durations of the segments are timed by a 5.5296 MHz clock derived from the receiver video. The trailing edge is symmetrically generated by discharging the integrator in reverse order. Because the same generator is used for both pulses of a pair, reply separation of the RF pulses is equal to that determined by the receiver video. Further, the timing of segments by the transponder clock ensures the stability of the beacon reply.
Automatic peak pulse level control is applied as a slow acting feedback loop derived either from the detected RF envelope of the 1kW output pulses of the transmitter or direct from the high-level output of the pulse shaper.
In the quiescent state, awaiting the arrival of a modulator trigger pulse, the output of the monostable D6:7 is high. This is the reset state of the pulse generating circuit. The high output at D6:7:
a. sets the output of the D7, D4:12 divide-by-four flip-flops to low;
b. turns the bilateral switch D4:1, 2 on, thus setting the integrator output N1:1 to zero;
c. inhibits the analogue multiplexer D1 from operating; and
d. sets the up/down flip-flop D5:2 output to high, which turns the bilateral switch D4:10. 11 on, grounding the input to the multiplexer, and resets the up/down counter D2 to the count up mode.
The carry out signal from D2:7 is high in the reset state when counting up. This signal is applied to D6:3, and sets the monostable D6:6 in the ready state for a trigger pulse.
On receipt of a negative-going trigger pulse at XN1:8c, D6:7 goes low. When D6:7 goes low:
a. the reset signal is removed from D7:7;
b. the reset is removed from the BCD counter D2:9, enabling it to begin counting;
c. the reset is removed from the up/down flip-flop D5:4;
d. the inhibit is removed from the analogue multiplexer D1:6; and
e. the initialisation bilateral switch D4:1, 2 is turned off, enabling integration to begin.
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Figure 2-14 Shaped Pulse Generation Waveforms
During the period that the D6:7 is low, the flip-flops D7 inject a 1.3824 MHz signal into the BCD counter D2:15 which in turn feeds the BCD signal into the analogue multiplexer D1. The D1 output levels that drive the integrator are individually adjustable to give the required slope for each segment of the pulse; the first segment (produced by D1:14, 15) is adjusted by the BASE level adjustment R3, the second segment by R5, through to the sixth segment (produced by D1:4) which is adjusted by the APEX level adjustment R13.
When the counter D2 reaches a count of 7, the AND gate D3:1 changes state to high which places a high on the preset enable (D2:1) of the BCD counter D2 and also places a high on the J input of the up/down flip-flop D5:6. The next positive-going edge of the D7:15 flip-flop output causes the up/down flip-flop D5:2 to change state. D5:2 goes low and sends D2:10 low; this sets the counter D2 to the count down mode.
The state change of D5:2 also turns the bilateral switches D4:10, 11 off and D4:8, 9 on and removes the preset signal from D2:1, allowing D2 to count down on the next clock pulse.
When the D5:2 state change occurred, after the 7 count, D3:1 went low, which latched the D5:2 up/down flip-flop output by putting a low on D5:6.
The bilateral switch D4:8, 9 turning on places approximately +10 volts on the multiplexer D1:3 input. As the counter counts down it addresses the multiplexer in the reverse order, discharging the integrating capacitor and producing a symmetrical waveform. When a count of zero is reached D2:7 goes low, which places a low on the clear of the monostable D6:3. The output D6:7 then goes high, and the system resets awaiting another trigger pulse.
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The falling edge of the modulator pulse is determined by the discharge of the integrator, and the relationship between leading edge charge and falling edge discharge characteristics can be set by the INTEGRATOR BALANCE adjustment R17.
Following the integrator, the pulse is injected into a two-stage filter network. The pulse amplitude is variable by the MOD PULSE AMPLITUDE adjustment R58. Because the RF amplifiers require a threshold voltage before modulation occurs, a pedestal voltage is added which is variable by the PEDESTAL VOLTAGE adjustment R53. Provision is made for the pedestal level to be determined by an input from an external temperature sensor (XN1:26c, XN1:27a) consisting of a forward biased diode thermally joined to the power transistor heat sink in parallel with V13; this is not employed in this equipment and the reference voltage for N4:3 is derived from the voltage divider R63, R65, V13 which is on-board mounted and compensates for ambient temperature variations only. The pulse and the pedestal voltage are added together in V16. The pulse and pedestal voltage is then amplified in the modulation amplifier comprising V10, V11, V5. The modulation pulse output is accessible at test point XA3 and can be applied either to the associated 1kW RF amplifier (in high-power systems) via XN1:25a, XN1:25b, or to the medium power driver (in low-power systems) via XN2:12. The modulation input to the medium power driver is controlled by the MED COLL switch S4, and can be either the modulation pulse or a variable DC voltage as set by the MED POWER DRIVER DC adjustment R115.
The circuitry comprising N2 and associated components forms a video detector and automatic level control circuit. The level is adjustable using ALC LEVEL R62. The ALC source selection switch S3 allows the level control voltage to be derived either from the modulator pulse output at N3:1, or from an external pulse detection circuit. The level control voltage is accessible at test point XT3. The loop can be disabled by the ALC LOOP switch S2; in the OPEN position this applies a +10 volts to the integrator, N1, input via R40.
The two monostables D8 turn off the bilateral switch D4:3, 4 to induce a reduction in the gain of the modulator amplifier for the second of the X channel pulses because the effective gain of the RF transistors increases slightly for the second pulse when the pulses are of 12 microseconds spacing. The gain reduction does not function on a Y channel, because the pulses are spaced at 30 microseconds and the RF transistors treat each pulse as an isolated event.
The rectangular RECTANGULAR MODULATION PULSE pulse signal is derived from theD6 monostable. The two-stage common emitter amplifier V20 and V19 drives a complementary pair of transistors V18 and V17 which operate together as buffers to isolate the driver circuitry from the capacitive input of the FET transistor V23. The transistor V18 conducts during the rising edge of the pulse and V17 conducts on the falling edge providing a path to ground. C30 and R82 decouple the load of V23 from the HT supply; R73 reduces the Q of the gate circuit to prevent oscillation, and R83 references the gate to 0V whenever V17 and V18 are both OFF. The RECTANGULAR MODULATION PULSE is accessible at test point XT4 and at test jack XA1, and is output to drive the second stage of the exciter via XN2:10. Components V31, C48 and R136 comprise a pulse stretching circuit, to extend the rectangular waveform pulse for use in the receiver video module as receiver suppression.
Transistor V29 and associated components supply base and collector bias to the exciter input stage V1. V21, V22, V25 and V30 provide the adjustable collector voltage supplies for the amplifiers; R97 is the EXCITER DC adjustment for the collector voltage supplied to V5 and V6 in the exciter; R115 is the MED POWER DRIVER DC adjustment for the control voltage supplied to the medium power driver; R69 is the POWER MOD AMP DC adjustment for the control voltage supplied to the power modulation amplifier.
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Board test points are provided as shown in Table 2-4. The test points mounted on the edge of the board are positioned to be accessible as front panel jacks on the transmitter driver.
Table 2-4 Pulse Shaper Board Test Points
LOCATION REF LEGEND SIGNAL XT1, 2 (EARTH) Earth XT3 (ALC) Loop control voltage XT4 SQUARE MODULATION Pulse to exciter via XN2:10 XT5 (PWR MOD AMP DC) DC control voltage to power modulation amplifier
via XN2:18 XT6, 8 (EARTH) Earth XT7 (EXCITER DC) Supply voltage to exciter via XN2:8 XT9 (MED PWR DRV DC) DC control voltage for medium power driver XT10 (VC1) Collector voltage to exciter, first stage, via XN2:6XT11 (TD_TX_LVL) Detected RF output level from the transmitter
driver
On Pulse Shaper Board
XT12 (TD_MOD_LVL) Detected modulation pulse level XA1 SQUARE MODULATION Modulation pulse to exciter XA2 FUNCTION GENERATOR Output to the pulse-shaping integrator XA3 SHAPED MODULATION Shape modulation pulse XA4 +15 VOLTS Supply input to board XA5 DRIVER LEVEL Detected RF output from transmitter driver XA6 EARTH
Board edge (front panel jacks on Transmitter Driver)
XA7 EARTH
The DRIVER DC POWER switch S1 is mounted as a front-panel control, in the NORMAL position it connects the +8 volts supply to V29 to generate the bias and collector voltages for the input stage of the exciter; in the OFF position the supply is disconnected, and the amplifier chain is disabled.
The green POWER ON indicator H1 is lit whenever the +15 volts board supply is present. The red TEST indicator H2 is supplied from the +24 volts auxiliary voltage line; this indicator lights when the DRIVER DC POWER switch S1 is set to the OFF position. Both indicators are mounted to be visible as front-panel indicators on the transmitter driver.
The output levels of the shape modulation pulse and the detected driver in are fed to peak rider circuitry which holds the peak value of the pulse. This DC level is fed to the monitor module for measurement by the CTU.
Detected driver in has its own bootstrap return to negate the capacitance in the line between the detector and the pulse shaper.
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2.3.4.2 Exciter 1A72532 REFER Circuit Diagram 72532-2-01
The exciter employs three cascaded stages. The first stage (V1) operates in class A condition, and is maintained in this condition by a regulator located on the pulse shaper board. The regulator circuit measures the collector current of V1 and maintains it at approximately 100 mA by controlling the base bias of V1. The base bias for V1 enters at XN1:9 and the collector current enters at XN1:5. The base bias circuit is decoupled and reaches the base via RF choke L1. The collector current is similarly decoupled and reaches the collector via L2. Microstrip circuits match the 50 ohms input at XC1 to the transistor base, and match the output impedance of the transistor to the 50 ohms load presented by the input of the 90-degree hybrid coupler W1.
The input power level to the class A stage V1 is 10 mW and it delivers to W1 typically 100 mW. The ferrite beads on L1 and L2 keep the Q of the decoupling circuits low over a broad band of frequencies.
The transistors of the next two stages each operate between pairs of 90 degree couplers. Operated in this way, both the input and output impedances of these stages approximate to 50 ohms. The transistors V3 and V4 of the second stage operate in class AB condition, their biases being supplied via the RF chokes L5 and L7.
The collectors of V3 and V4 are supplied with a rectangular pulse from a common pulse source of adjustable amplitude located on the pulse shaper. This pulse amplitude may be adjusted from 8 volts to 18 volts. The pulsing of the collectors results in the second stage delivering RF pulses of approximately 1 watt peak power to the input of the 90 degree hybrid coupler W2.
The third stage operates in class C condition, the bases of transistors V5 and V6 being returned to ground through L9 and L11. In this third stage microstrip circuits are again used to match the transistors V5 and V6 to their 90 degree hybrid couplers. The output impedance of the 90 degree coupler W3 appears as a 50 ohms source to the third stage, and the input impedance of the 90 degree hybrid W4 appears as a 50 ohms load. The common DC collector supply voltage to the transistors V5 and V6 is adjustable on the pulse shaper board from 15 volts to 30 volts. The third stage being driven by pulsed RF at its input delivers corresponding pulses at its output. As used in the transmitter chain of stages, the peak pulse power output from the exciter is typically 4 watts at XC2.
Wire loops labelled CURRENT TEST POINT on the circuit diagram allow the magnitude and shape of the current pulses to be measured or observed on an oscilloscope using a current probe. Adjustable trimmer capacitors are provided for the input circuits of all three stages and for the output circuits of the first and the third stages. These trimmer capacitors are adjusted at the factory to give an essentially flat response over the DME frequency band (960 to 1220 MHz). The alignment procedure for the exciter, involving the setting of the pulse amplitude to the second stage and the DC supply voltage to the third stage, are carried out at the assigned operating frequency.
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2.3.4.3 Medium Power Driver 1A72533 REFER Circuit Diagram 72533-3-01
The medium power driver consists of two parts - an RF amplifier section and a modulator section - and is mounted in a metal diecast box. The input signal to the medium power driver comes from the Exciter 1A72532. A microstrip circuit matches the 50 ohms PULSE IN circuit at XC1 to the input impedance of the transistor V1. A second microstrip circuit matches the output impedance of the transistor to the 50 ohms PULSE OUT XC2. The transistor operates in class C.
The transistor collector is supplied with either a DC supply or a pulsed voltage, depending on the role of the amplifier. In a 1kW transponder this stage operates with DC on its collector, whereas in a 100 watt transponder this stage is the high-level modulated stage. If DC is used its level may be adjusted from 15 volts to 30 volts. If pulse modulation is used the pulse amplitude may be adjusted up to 30 volts.
The transistor V3 in the modulating circuit is a source follower. The transistors V4 and V5 buffer the circuits on the pulse shaper against the input capacitance of V3 when the medium power driver is used in the pulse modulated role. The inductors L1 and L2 function as RF chokes.
The amplifier operates over the frequency range 962 to 1213 MHz without retuning. The output power at the operating frequency is controlled by setting the DC collector supply or the peak voltage of the modulation pulse.
The capacitors C15, C16 and the resistors R6, R7, R8 act to fitter the current pulses from the HT supply. The peak pulse power of the input pulse is approximately 4 watts, and the pulse power at the output XC2 is typically 20 watts.
2.3.4.4 Power Modulation Amplifier 1A72534 REFER Circuit Diagram 72534-3-01
The RF pulse input to the power modulation amplifier at XC1 from the medium power driver is via a short length of semirigid transmission line which operates as a balun converting the unbalanced input coaxial circuits at the module connector to a balanced circuit at the entry points on the microstrip circuit. The amplifier uses a balanced transistor. Microstrip circuits together with some fixed and variable capacitors match the input and output impedances of the transistor to the 50 ohms balanced impedances presented by the baluns.
A modulator detected signal, derived from a coupling and detector circuit (V2) is output via XN1:A to the pulse shaper, where it is used to derive a driver pulse level reference voltage.
The transistor V3 in the modulation circuit is a source follower. The transistors V4 and V5 buffer the circuits on the pulse shaper against the input capacitance of V3 when used in the pulse modulated role. The inductors L2 and L3 function as RF chokes.
When used as a modulator its output power is set by adjustment of the input rectangular pulse power and the amplitude of the video modulation pulse, applied to its collector.
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Table 2-5 Summary of Front Panel Controls and Indicators : Transmitter Driver CONTROL/INDICATION FUNCTION DETAILS
TYPE LEGEND FUNCTION/SETT1NG/INDICATION Green LED DC POWER ON Indicates that 15 volts output from the transponder power supply is
applied to the module. Red LED TEST Indicates that the DRIVER DC POWER switch is not in the NORMAL
position or that internal switches S2 and S3 are not in the correct positions.
Variable resistor
RF OUTPUT Adjusts the RF output from the DME, when the ALC loop is closed.
OFF Turns off the pulse modulation to the second stage of the exciter.
Toggle switch DRIVER DC POWER
NORMAL Normal operation. Test jack SQUARE PULSE
MODULATION A buffered low-level modulation pulse output representing the signal from the pulse shaper to the second stage of the exciter.
Test jack FUNCTION GENERATOR
The buffered output of the pulse-shaping integrator on the pulse shaper.
Test jack SHAPED PULSE MODULATION
A buffered high-level modulation output representing the signal from the pulse shaper to the modulation stage.
Test jack +15V The buffered input +15V supply. Test jack DRIVER LEVEL A buffered signal representing the output RF pulses from the
module. Test jack EARTH Common earth of all supply voltages and outputs. Test jack EARTH Common earth of all supply voltages and outputs.
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Table 2-6 Summary of Internal Controls : Transmitter Driver
CONTROL FUNCTIONS SUBASSY TYPE REF LEGEND FUNCTION/SETTING/INDICATION
Preset resistors
R3. 5, 7, 9, 11, 13
PULSE SHAPE These vary the slope of the segments of the function generator output from base (R3) to apex (R13).
1A72531 Pulse Shaper PWB Assembly R17 INTEGRATOR
BALANCE Adjusts the balance of the function generator integrator.
R36 BACK PORCH Adjusts the spacing between the modulation pulses. R52 PEDESTAL
VOLTAGE Adjusts the DC level of the shaped modulation pulse.
R54 2ND PULSE EOUALISING
Adjusts the height of the second pulse of the pulse pair to equalise it with the height of the first pulse.
R58 MOD PULSE AMPLITUDE
Adjusts the amplitude of the shaped modulation pulse.
R62 ALC LEVEL With S2 (ALC LOOP) in its closed position, adjusts the shaped modulation pulse amplitude.
R69 POWER MOD AMP DC
Adjusts the power modulation amplifier DC level.
R85 1W PULSE Adjusts the pulse modulation amplitude. R97 EXCITER DC Adjusts the exciter DC level. R115 MED POWER
DRIVER DC Adjusts the medium power driver DC level.
OFF Power supply to exciter is off. Toggle switch
S1 DRIVER DC POWER NORMAL Power supply to the exciter is under
CTU control. CLOSED Automatic level control is enabled. Slide switch S2 ALC LOOP OPEN Automatic level control is disabled. VIDEO ALC maintains shaped modulation
pulse amplitude. Slide switch S3 ALC
DETECTED RF
ALC maintains output level from the 1kW RF power amplifier.
Slide switch S4 MED PD COLL DC Selects a DC voltage as the collector supply for the medium power driver in high power (1kW) mode.
MODULATION Selects the shaped modulation pulse as the collector supply for the medium power driver in low power (250 W) mode.
1A72532 Exciter
Variable capacitors
C5, 15, 17. 21, 26, 30, 33, 34.
Used to align the exciter (see Section 3.4.25),
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2.3.5 Transponder Power Supply 1A72525 This assembly comprises the Main PWB Assembly Transponder Power Supply 1A72526 mounted on a supporting frame; the board functions are described in the following section.
2.3.5.1 Main PWB Assembly Transponder Power Supply 1A72526 REFER Circuit Diagram 72526-1-01
This power supply is used to generate the voltage supplies required by the Transmitter Driver 1A72530. These voltages are +15 volts, +18 volts, and HT (42-50 volts). The front panel TRANSPONDER DC POWER switch enables the transponder (transmitter driver and receiver video) to be turned ON, OFF, or to NORMAL; in this latter condition the transponder is controlled by the CTU via XN1:30b.
Commands to turn the power supply on, either from the control panel or the front panel switch, will result in the relay K1 being operated by the action of V11 being turned on.
With K1 operated, contacts K1a and K1b will close, supplying the transponder with +24 volts and supplying +24 volts to the internal regulators and inverter.
The ON position on the front panel TRANSPONDER DC POWER switch is provided so that power may be applied to a failed system for maintenance. Normally, if a primary fault has occurred and the power has remained on, circuitry in the monitor module(s) will (after a time delay) inhibit pulse-pairs from leaving the receiver video module. However, the ON position of TRANSPONDER DC POWER activates INHIBIT DISABLE line at XN1:9c to enable the faulty system to be operated for fault diagnosis.
The input +24 volts supply is available for monitoring on the front panel using a high impedance voltmeter between the test jacks +24V IN (XA1) and EARTH (XA4). Also the input +24 volts supply current may be monitored, again with a high impedance voltmeter connected across + SUPPLY CURRENT (XA7) and - SUPPLY CURRENT (XA8). In this case a measured voltage of 100 mV corresponds to a supply current of 1 ampere.
The HT, +18 volts, and +15 volts supplies may be monitored at the front panel, at test jacks HT (XA2), +18V (XA5) and +1 5V (XA3) respectively.
The +15 volts supply is produced by a 3-terminal regulator V1, with its input supplied from the switched +24 volts rail. The 3-terminal regulator is current limited. Its output is used within the power supply as a reference voltage for generating the +18 volts supply and for powering N1.
The +18 volts supply is designed using discrete components. V3 and V4 are connected as a differential error amplifier with the reference voltage, derived from the +15 volts supply via R7 and R11, connected to the base of V4. The +18 volts output voltage is sensed by V3 via the resistive divider R16 and R10. These two resistive dividers determine the output voltage from the regulator. The output voltage of this regulator is within the range 17.5 to 18.5 volts.
Zener diode V6 provides a regulated 5 volts to the current-limiting transistor V8.
The current limiter operates in the following manner. In the normal working condition of the supply (non-overload state), V8 is forward biased and the voltage drop across V8 (0.3 volts), applied to the emitter-base junction of V5, is not sufficient to turn it on. When the regulator output current reaches the predetermined overload value (approximately 170 mA), the voltage drop across R20, R21 added to the 0.3 volts already present turns V5 on and its collector current raises the base voltage of V7, overriding the normal voltage regulating action, to limit the output current from the supply.
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The HT supply is developed by a switched mode inverter which steps up the voltage from the switched +24 volts supply. A power MOSFET V22 is used as a pulse-width-modulated switch operating into a transformer whose output is rectified, filtered and controlled at a constant voltage.
A constant switching frequency is generated by N1, the frequency (40 kHz) being determined by R34 and C24. A sample of the output voltage presented at pin 1 of N1 is compared with the reference sample at pin 2. The circuit automatically adjusts the width of the on-pulse at pins 11, 14 so that the energy delivered from the secondary of the transformer is just sufficient to maintain a consistent DC out voltage. The HT voltage is set using the HT VOLTAGE adjustment R26.
Input current overload protection is provided as follows. An override control on the pulse width generated in N1 is available through pin 9. When pin 9 is open circuit, control of the pulse width is through pin 1 only. As the resistance to ground at pin 9 is lowered, the maximum length of the pulse is progressively shortened, until it drops below 1 microsecond. As the input current increases from the supply, so does the magnitude of the current pulses through V22. The resistor R40 is chosen so that at a predetermined overload current, the peaks of the voltage pulses across R40 just turn off V26. As V26 turns off, V25 turns on to provide a current path from pin 9 to ground, bringing the current limiting action of the circuit into play.
The transistors V20 and V18 charge and discharge respectively the input capacitance of V22, while the turn-off spike at its drain is controlled at a safe level by V12, V19 in combination, by V13, C16 and R28 in combination, and by C15 and R25 in combination.
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Table 2-7 Summary of Front Panel Controls and Indicators : Transponder Power Supply
CONTROL/INDICATION FUNCTION DETAILS TYPE LEGEND FUNCTION/SETTING/INDICATION
Green LED POWER ON Indicates that power is applied to the module. Red LED TEST Indicates that the TRANSPONDER DC POWER switch is not in the
NORMAL position. ON All supply outputs are on, regardless of CTU commands.
This is required during testing and maintenance. OFF All power supply outputs are off.
Toggle switch, centre off
TRANSPONDER DC POWER
NORMAL Power supply outputs are under CTU control. Test jack +24V IN The input voltage from the power supply/battery. Test jack HT HT output to the Transmitter Driver 1A72530. Test jack +15V +15 volts output to the Transmitter Driver 1A72530. Test jack EARTH Ground reference for +24V IN, HT, +18V and +15V, which is connected
to the power +24V IN return. Test jack +18V +18 volts output to the Transmitter Driver 1A72530. Test jack SWITCHED +24V The switched +24 volts output. Test jack SUPPLY
CURRENT+ Test jack SUPPLY
CURRENT-
These test jacks are connected to either side of a resistor in series with the input +24V IN. The + jack is connected to the higher voltage side of the resistor, and the - jack to the lower voltage side (100 mV/ampere).
Table 2-8 Summary of Internal Controls : Transponder Power Supply
CONTROL FUNCTIONS SUBASSY
TYPE REF LEGEND FUNCTION/SETTING/INDICATION 1A72526 Main PWB Assembly, Transponder Power Supply
Preset resistor
R26 HT VOLTAGE Sets the HT output voltage to the transmitter driver.
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2.3.6 1kW RF Power Amplifier Assembly 1A72535 REFER Circuit Diagram 72535-1-07
The 1kW RF power amplifier assembly is located at the rear of the rack behind the 1kW PA power supply which provides the power amplifier's HT supply.
The elemental electrical operations of the 1kW power amplifier are:
• Formation of the initial shaped pulse by the power modulation amplifier.
• The first power amplification of the shaped pulses by the broadband amplifier pair A1, A2.
• Eight-way power division of the output of the A1, A2 pair by the power divider.
• A second broadband amplification of each eighth-part of power by the amplifiers A3, A4 .... A10, which form the output amplifier.
• Recombination of the amplified outputs by the power combiner.
• Passage of the power through the circulator to the output point XC2.
• Containment of the RF energy to within the amplifier metal housing by the filters on the 1kW PA connector assembly.
• Provision of the main component of the supply current pulse to the amplifier from a reservoir capacitor bank.
Figure 2-15 1kW RF Power Amplifier Block Diagram
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The pulses leaving the power modulation amplifier consist of a shaped portion above a pedestal. The pedestal provides the turn-on power for the following broadband amplification. The initial pulse is modified by passage through the amplifier to emerge at XC2 with the characteristic DME Gaussian shape.
Formation of the initial shaped pulse takes place in the following manner. A rectangular RF power pulse of typically 50 watts enters the Power Modulation Amplifier 1A72534 at XC1 and drives the emitter of the transistor in the modulation amplifier. The collector voltage pulse enters the amplifier at XN1:C and modulates the power modulation amplifier to deliver at its output a pulse consisting of a shaped portion on a rectangular pedestal. The pulse power drive, the collector pulse shape and amplitude, are all adjusted to produce the required initial pulse shape. These adjustments are made from the transmitter driver.
The first power amplification of the pulse takes place in the amplifier pair A1, A2 in the 1kW RF power amplifier. Here the 250W amplifiers A1, A2 are connected between 90-degree hybrid couplers on the combiner and divider assemblies. This arrangement has the property of providing a near 50 ohms resistive input impedance to the hybrid coupler W5 and a near 50 ohms resistive output impedance from the hybrid coupler W1, provided always that the impedances of the two transistors remain the same, even though the actual match at each transistor may deteriorate.
2.3.6.1 Power Divider 1A72536 REFER Circuit Diagram 72535-1-07
In the power divider, power division by four is obtained as a division by two, using the Wilkinson divider circuit shown schematically on the power divider in Drawing 72535-1-07, followed by the two further divisions again using the Wilkinson circuit. The division by eight is completed using the 90-degree hybrid circuits labelled W2, W3, W4 and W5 on the power divider. The resistors R1, R2 and R3 provide isolation between the output ports of the Wilkinson circuits; the resistors R5, R6, R7 and R8 on the 90-degree hybrids absorb reflected power from the transistor circuits.
A coupling and detector circuit creates a driver detected signal output at XC11.
The second broadband amplification of each eighth-part of power is obtained by pairs of amplifiers A3, A4; A5, A6; A7, A8, A9 and A10 which operate between 90 degree hybrids in the same way as just described for the amplifier pair A1, A2, though at a higher power level.
2.3.6.2 Power Combiner 1A72537 REFER Circuit Diagram 72535-1-07
The recombining of the powers is accomplished in the power combiner circuit, through processes which are the reverse of those described for the power divider.
A coupling circuit and detector creates an output detected signal output at XC12.
The combined power is passed to the output through the circulator W1. The resistive load Rl connected to the circulator provides a 50 ohms resistive load for the 1kW amplifier in the event of a fault effectively removing its load - for example, disconnection of the DME antenna.
A group of 20 capacitors form the capacitor bank which provides a reservoir from which the current pulse requirements of the amplifier are supplied, thus largely confining the current pulse paths to the amplifier ground plane.
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2.3.6.3 250W RF Amplifier 1A69873 REFER Circuit Diagram 69873-3-09
This amplifier is the basic building block of the 1kW RF power amplifier, and operates with a constant DC collector supply of 50 volts to raise the peak input power pulse of 50 watts to, typically, a 250 watts peak output power pulse. It is a microstrip design which covers the frequency range 962 to 1213 MHz without the need for circuit adjustment; input and output impedances are each 50 ohms.
The amplifiers are used in pairs between 90-degree couplers, so that each pair presents a generally better input/output match than either amplifier would show if operated separately.
2.3.6.4 Power Modulation Amplifier 1A72534 The function and operation of this unit is described in Section 2.3.4.4.
2.3.6.5 1kW PA Connector PWB Assembly 1A72544 REFER Circuit Diagram 72544-1-01
The 1kW PA connector assembly provides a method of connection for the power and signals to and from the 1kW power amplifier.
To reduce RF leakage through the connector assembly the PWB is covered on all non-track areas with ground plane and each of the inputs is decoupled through a surface mount 22 pF capacitor which is self resonant in the DME frequency band.
Each signal output (PWR AMP MOD, PWR AMP DRV, PWR AMP OUTPUT) is supplied with a return connection (R-PWR AMP MOD, R-PWR-AMP-DRV, R-PWR AM OUTPUT) which follows the signal waveform. This reduces the effect of line capacitance in the cables from the 1kW power amplifier detectors to the control and status board.
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2.3.7 1kW PA Power Supply 1A72540 REFER Interwiring Diagram 72540-1-03
This unit consists of the DC-DC Converter Assembly 1A72542 and attached Regulator Assembly 1A72543, the Control and Status PWB Assembly 1A72541, relay K1 and filter components.
A front panel switch AMPLIFIER DC POWER mounted from the control and status board allows the 1kW RF power amplifier to be powered ON or OFF through the relay K1 for test purposes.
2.3.7.1 DC-DC Converter PWB Assembly 1A72542 REFER Circuit Diagram 72542-1-01
The DC-DC converter changes the 24 volts DC supply to the DME beacon to a regulated 50 volts supply to power the 1kW RF power amplifier. The converter is protected against output short circuits and includes circuitry to prevent over-voltage supply to the 1kW power amplifier.
The converter circuit consists of a power switching section and a switching signal generating section. The power switching section comprises four power FET switches, V1 through V4, associated with the ferrite-cored transformer T6. This is followed by a bridge rectifier and smoothing circuit built around L2. A second filter associated with L3 reduces the level of switching hash present on the output voltage from the supply.
The switching signal generation section of the converter, located on the Regulator PWB Assembly 1A72543, is shown in Drawing 72542-1-01 within a dotted surround. The heart of this circuit is the CA1524 (V101) which generates pulses of controlled width at a constant rate (30 kHz) determined by R105 and C103. A pulse from V101 is delivered alternately at pins 12 and 13. These pulses drive the gates of the FET pair V1, V2 via the buffer amplifiers V118 and the gates of the FET pair V3, V4 via the buffers V119.
An adjustable fraction of the output voltage taken across C11 is applied to pin 1 of V101. This voltage is compared within V101 to the reference voltage applied at pin 2. The on-time of the switching pulses to the FETs is adjusted by V101 so as to deliver just sufficient energy at the secondary of the transformer to meet the current demand on the converter at the set output voltage. The output voltage from the converter is varied by changing the fraction of it which is applied at pin 1, by altering the value of the variable resistor R112.
If the output voltage rises above 50 volts, the emitter voltage of V116 increases more rapidly than its base voltage. At an over-voltage of typically 55 volts the transistor V116 turns on, the SCR V117 is triggered on, and as a consequence the 15 volts supply to the buffers is removed and the converter remains shut down until the primary supply is removed to allow the SCR to extinguish.
For current overload protection, the primary current sensing circuit is set to respond at a lower overload current than the direct output current overload sensing circuit. The primary sensing circuit peak rectifies the stream of primary current pulse samples across the secondary of transformer T1, to produce a positive voltage across R115. When this voltage is sufficient to turn off V106, V107 turns on, the voltage at pin 9 falls and the pulses generated by V101 shorten to restrict the further increase of the output current while the fault condition exists. In the event of the primary current overload not operating, then at a higher secondary overload current; the voltage drop across R12 is sufficient to turn on V110; this turns on V112 and, as for the primary current pulse sensing circuit, the voltage at pin 9 falls and V101 output pulses are shortened to limit the overload current.
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Snubber circuits and zener diodes limit the positive voltage turn-off spike at the FET drains to typically 80 volts. Zener diodes limit the gate voltages of the FETs to 18.4 volts. The variable resistor R16 is set for 1 mV between XP:4 and XP:3 per ampere of primary current. The pulse transformers T2, T3, T4 and T5 produce 0.1 volts per ampere of FET source pulse current; these allow the performance of the individual FETs of either pair to be measured or compared.
2.3.7.2 Control and Status PWIB Assembly 1A72541 REFER Circuit Diagram 72541-1-01
A sample of the converter voltage, taken at XP:5a on that unit goes to the control and status board where it causes the front panel green POWER ON indicator H3 to light if the voltage is between 48.5 volts and 51.9 volts. This result is achieved as follows; the variable resistor R45 is adjusted so that the two voltages at the imaginary centre of R46 is equal to the zener reference voltage (5.6 volts) of V12. A window comparator formed by two comparators of N7 monitors the voltage sample against upper and lower limits allowing H3 to light when between these two limits.
A 15 volts supply is derived from the 24 volts supply via a linear voltage regulator N9 and provides the IC supply on the board.
The AMPLIFIER DC POWER test switch S1, when in the NORMAL position, allows the relay K1 coil to be energised by a 5 volts signal on XN1:8. If the switch is in the ON or OFF positions then the front panel red TEST indicator H2 is lit, the test line XN1:2 is at 0 volts and this condition is signalled to the CTU.
The power amplifier signals, output, driver and modulator are buffered and then level detected. The detected output level of the power amplifier output, power amplifier driver, power amplifier modulator from the 1kW RF power amplifier are fed to the control and status board.
Each detected output level has its own bootstrap return to negate the capacitance in the line between the 1kW PA and the control and status board. The bootstrap trigger also provides the detected output level test jack output (XA1, XA2, XA3).
PA_OP_LVL, PA_DRV_LVL, PA_MOD_LVL are the detected outputs peak levels. These DC voltages are held and fed to the monitor module for measurement by the CTU.
RF DET IN is fed to the pulse shaper (in the transmitter driver) and is the feedback level for the ALC loop.
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Table 2-9 Summary of Front Panel Controls and Indicators : PA Power Supply
CONTROL/INDICATION FUNCTION DETAILS TYPE LEGEND FUNCTION/SETTING/INDICATION
Green LED POWER ON Indicates that DC power is supplied to the module. Red LED TEST Indicates that the AMPLIFIER POWER switch is not in the NORMAL position.Green LED HT ON Indicates that the HT supply is available, and within limits.
ON HT output voltage is supplied to the 1kW RF power amplifier regardless of the power control signal state. This is required only during testing and maintenance.
OFF There is no power output from the 1kW PA power supply.
Toggle switch, centre off
AMPLIFIER DC POWER
NORMAL There is HT output from the module while the power control signal from the CTU is active (high); if it is inactive (low) the HT output is set to 0 volts.
Test jack POWER AMP MODULATOR OUT
Buffered output signal from the modulation stage of the 1kW RF power amplifier.
Test jack POWER AMP OUTPUT OUT
Buffered output signal from the output stage of the 1kW RF power amplifier.
Test jack POWER AMP DRIVER OUT
Buffered output signal from the driver stage of the 1kW RF power amplifier.
Test jack +15V Internally generated +15V supply (15 volts). Test jack SUPPLY
CURRENT - Test jack SUPPLY
CURRENT+
These jacks are connected to either side of a resistor in series with the +24V IN supply. The + jack is buffered to the higher voltage side of the resistor, and the - jack to the lower voltage side (1 mV/ampere).
Test jack EARTH A ground reference for the +24V IN, HT OUT and +15V OUT supplies, which is connected to the +24V IN return.
Test jack +24V IN Buffered +24V IN power supply input. Test jack HT OUT Buffered HT output of 48 to 52 volts. Test jack SHAPED
PULSE MODULATION
Buffered signal modulation pulse.
Table 2-10 Summary of Internal Controls : PA Power Supply
CONTROL FUNCTIONS SUBASSY
TYPE REF FUNCTION/SETTING/INDICATION 1A72541 Control and Status PWB Assembly
Preset resistor
R45 Varies the centre of the HT ON window between approximately 48.5 and 51.9 volts.
1A72542 DC-DC Converter Assembly
Preset resistor
R16 Calibrates the input circuit monitoring of the DC-DC converter see Section 3.4.33).
A72543 Regulator PWB Assembly
Preset resistor
R112 Sets the HT output voltage to the 1kW RF power amplifier.
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2.3.8 Test Interrogator 1A72514 REFER Interwiring Diagram 72514-3-04
The test interrogator module contains the Test Interrogator Main PWB Assembly (1A72515), RF Generator (1A72516), Modulator and Detector (1A72518), Reply Detector (1A72519) and Attenuator (1A69737), plus fixed 30 dB and 20 dB attenuators The interconnection of these subassemblies is shown in Drawing 72514-3-04. The front panel has a number of test jack connectors and test switches by which various operating parameters of the module can be set and checked.
The test interrogator operates as an independent unit simulating aircraft interrogation pulses. The DME transponder treats these pulses as normal interrogations and responds accordingly, allowing the test interrogator to measure and display the critical transponder parameters such as transponder delay, pulse separation and efficiency.
Interrogation pulses are alternately generated at two predetermined power levels, to allow different parameters to be measured. The lower level of interrogation into the transponder receiver is at -85 dBm and permits a measurement of transponder efficiency to be made. The level into the transponder receiver is then switched to -70 dBm to allow transponder delay to be measured. To enable these changes in signal level out of the test interrogator into the DME receiver, a switched PIN diode Attenuator (type 1A69737) is used.
The actual levels from the test interrogator are nominally 30.5 dB higher than the levels stated above, because of the attenuation provided by the directional coupler in the RF panel, and the attenuation in the rack cabling.
The measured parameter values are presented in digital form to the control and test unit where each parameter value may be displayed as required. As well as real-time testing of the transponder, the test interrogator may also be used as a built-in test unit for system alignment.
A directional coupler mounted in the RF panel connected in-line with the antenna feeder is used for injecting the test interrogator interrogation pulses into the transponder. Another port on the directional coupler is used to sample the transponder reply pulses and to feed them through to the test interrogator module for detection and parameter testing.
The RF generator uses a crystal-controlled oscillator as its signal source, operating at a frequency of one-twelfth of the DME receive frequency. A total of five crystals are used to allow shifting of the RF generator frequency for testing the band pass and adjacent channel rejection characteristics of the transponder. The five crystals correspond to frequencies of nominal operating frequency; nominal ±160 kHz, for pass band testing; nominal ±900 kHz for adjacent channel rejection testing.
The crystal oscillator is followed by a buffer stage and three stages of frequency multiplication to produce the required operating channel frequency. Following the multipliers a micro-stripline amplifier stage raises the signal level to approximately +11.5 dBm.
The output circuit of the RF generator includes a video amplitude demodulator from which the video output pulses are fed out to the modulator and detector for automatic level control.
After receiving a pulse from the test interrogator main board, the modulator and detector will generate the correct modulation waveforms, MOD OUT and DRIVE OUT, to produce the required pulse shape at the output of the RF generator.
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RF pulses from the RF generator are passed to a 20 dB 50 ohms attenuator pad; the output of the pad is connected directly to the input of the PIN diode stripline attenuator.
The stripline attenuator is arranged such that when the PIN diode is off the attenuator loss approaches zero, and when the diode is switched on the attenuator loss increases by 15 dB. The output of the stripline attenuator is fed through a 30 dB 50 ohms attenuator pad to the directional coupler in the RF panel.
With 1 dB residual loss in the module interconnections, pulse-pairs leaving the RF generator are alternatively attenuated by 51 and 66 dB by switching the diode attenuator between each pulse-pair; these signals are further attenuated by 30 dB in the directional coupler.
Transponder output pulses, extracted by the directional coupler in the antenna transmission line, are demodulated and processed, in the reply detector, to provide logic-level trigger pulses timed at the 50% amplitude points on the leading edge of each pulse. These trigger pulses are used as timing points for measuring the transponder critical time-dependent parameters.
The reply detector uses a half-height pulse detector-processor identical to the one used in the modulator and detector so that the inherent delays in each detector will be equal and not affect the measurement of transponder delay. A front-panel pushbutton switch connects both the reply detector and the modulator detector circuits to the RF generator so that the detector pulses may be checked for coincidence.
As the test interrogator relies heavily on time period and rate measurements, a stable 10 MHz crystal oscillator is used as a master clock. All pulse generation and timing waveforms are derived from this stable source.
For normal transponder interrogation and monitoring, pulse-pairs for transmission are generated at a frequency of 100 Hz in a single DME, or 50 Hz in a dual. This rate may be varied for other testing purposes by the appropriate switching of a multiplexer to select an alternative clocking frequency. The demodulated RF pulses from the RF generator are fed back into the test interrogator main board where the signal processing is begun.
2.3.8.1 Main PWB Assembly Test Interrogator 1A72515 REFER Circuit Diagram 72515-1-01
The following description of the test interrogator main board functions is related to the five main functions provided by the board - - CTU bus, power, normal mode, counter/timer and monitor fault limit test (MFLT) mode.
2.3.8.1.1 CTU Bus The CTU bus is the control interface between the Control and Test Unit (CTU) and the test interrogator. Control information is sent from the CTU to control the MFLT, counter/timer and other functions of the test interrogator. D15, D25 and D27 buffer the incoming signals from the CTU. The CTU control signals (RD, WR, XDT_R, XDEN, ADDR) are decoded in D26 and the selected latch or buffer is enabled as shown in the timing diagrams - Figure 2-16 and Figure 2-17.
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Figure 2-16 CTU Bus Timing - Read
Figure 2-17 CTU Bus Timing - Write
The MFLT and counter/timer chips D34 and D35 have their own internal address decoders, but their chip select signals MEAS_CT_CS and M_FLT_CT_CS are derived from D26.
2.3.8.1.2 Power The test interrogator can be powered in one of three ways:
a. The CTU can switch the test interrogator power on or off via the CTU bus when the test interrogator front panel switch TEST INTERROGATOR AND MONITOR POWER is in the NORMAL position. The test interrogator module is then powered from the switched +24 volts supply +24V_SW.
b. When the test interrogator front panel switch TEST INTERROGATOR AND MONITOR POWER is in the ON position CTU control is bypassed, and the module is powered on directly from the +24V_AUX supply.
c. When the Transponder Power Supply 1A72525 (located in the transponder subrack) is on, either by the power supply front panel switch TRANSPONDER DC POWER or by CTU control.
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2.3.8.1.3 Normal Mode Operation Normal mode is the situation when the test interrogator interrogates the transponder and extracts parameter information from the received reply pulses. In this mode the counter/timer functions may be used to measure the parameters for display on the CTU.
The 10 MHz crystal oscillator is formed with D51, G1 and associated components. This 10 MHz is divided down to 1 MHz in D39 and is fed to the divider chain D43, D44, D45 and D46. From the divider chain the four test interrogation pulse repetition frequencies (TIPRF) are derived. The TIPRFs (10 kHz, 1 kHz, 100 Hz and 50 Hz) are fed to D28 where one of the TIPRFs is selected. The selected TIPRF initiates an interrogation of the transponder as shown below.
The signal TO_SIG_GEN is the signal which triggers an interrogation from the RF Generator (1A72516) and the Modulator and Detector (1A72518). The pulse spacing can be either 12 or 36 microseconds depending on whether an X mode or a Y mode interrogation is being made. X or Y mode is selected by S4. The interrogation pulse spacing may be altered by ±1 or ±2 microseconds by S2 or S3 to test the transponder double pulse decoder.
The TIPRF also initiates a pair of reply accept gates, after a time delay selected by switches S6 and S5, which ensures that non-synchronous replies from the receiver video do not corrupt any parameters, as shown in the timing diagram below. The operation of D18, D17. , D1 and D19:4 is similar to that described above for D3 and D4.
Synchronous first reply pulses are detected by the DETECTED TX PULSE signal at D2:5 clocking D2:7, enabled by D17:11. Following the first pulse, D5:7 is set low, enabling D5:10 to be clocked by the second synchronous DETECTED TX PULSE, provided it falls within the second reply accept gate from D1:11.
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The Delay parameter (DELAY_DUR_PULSE) D2:10 is set by the signal FROM_SIG_GEN_DETECTOR and is reset by the first pulse of the signal WIDTH_PULSE coincident with REPLY_ACCEPT_GATES D2:7. If there is no WIDTH_PULSE coincident with the reply gate pulses then the monostable D2:10 times out (after approximately 180 microseconds).
The Spacing parameter (SPAC_DUR_PULSE) D5:6 is set by the first WIDTH_PULSE coincident with the REPLY_ACCEPT_GATES from D2:7 and reset by a second WIDTH_PULSE coincident with the REPLY_ACCEPT_GATES from D5:9. If there is no second WIDTH_PULSE coincident with the REPLY_ACCEPT_GATES the monostable D5:6 will time out (after approximately 60 microseconds).
If a reply pulse pair is correctly decoded (that is, a WIDTH_PULSE is coincident with both REPLY_ACCEPT_GATES) then a REPLY_PULSE is generated (from D5:9).
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The RF output of the RF generator is attenuated every second output pulse so the monitor can measure Efficiency at low RF signal levels. The signal TI_ATTENUATOR (at XN2:20) controls the RF output attenuator which can be set permanently high or low under CTU control. The output signal DEL_SPAC_MON_EN (XN1:22c), when high, indicates that the Interrogation taking place is a high level interrogation. The output pulse EFF_MON_ENABLE (XN1:25a), when high, indicates that a low level interrogation is taking place. Signals AC0, AC1 (under control from the CTU), when high, cause EFF_MON_ENABLE and DEL_SPAC_MON_ENABLE to stay low.
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2.3.8.1.4 Counter/Timer The counter/timer section of the test interrogator counts and times parameters by use of the type 82C54 counter/timer chip D35. This device is controlled by the CTU via the CTU bus. For information on the programming of the 82C54, refer to manufacturer data sheets.
The counter section uses two of the three counters in D35. Counter 2 is loaded with a number from the CTU bus and when COUNT_EN is set high by the CTU, a single pulse (COUNTER_STATUS) of 1, 2 or 4 seconds is generated to set the measurement period from Counter 1. COUNTER_STATUS opens the gate of counter 1 of D35 allowing the required parameter to be counted. When COUNTER_STATUS goes low this is an indication to the CTU that the count has finished and valid data is waiting in counter 1 to be read. The parameters to be counted (transmitted pulses, decoded interrogations, synchronous replies and calibration signal) are selected in the multiplexer D42.
The timer section consists of counter 0 of D35 and the PLD (programmable logic device) D33. When the signal TIMER_EN is set high by the CTU, this input to D33:2 causes circuitry in D33 to select one complete pulse from the pulse trains selected in D8 and input to D33:11. It achieves this by detecting a falling edge on the input to D33:11 to set TIMER_STATUS high. An internal signal selects the next pulse input to D33:11 and passes it to the gate of counter 0 of D35. The duration of this pulse is measured by counter 0 using the 10 MHz clock at D35:9. The falling edge of the selected pulse sets TIMER_STATUS LOW to signal the CTU that valid timer parameter data is waiting in counter 0 to be read.
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2.3.8.1.5 Monitor Fault Limit Test Mode Monitor Fault Limit Test (MFLT) mode is a mode in which the test interrogator is used to test the Monitor Module (1A72510). In this mode, the test interrogator creates the parameters normally derived from the output of the transponder and feeds these to the monitor module. The value of the parameter is varied by control from the CTU to determine the point at which the monitor indicates a fault. To simulate the reply the type 82C54 counter/timer D34 is used. Each of the counters is loaded with a number which gives the required TIPRF (Counter 0), Delay (Counter 1) and Spacing (Counter 2) - see figure below.
When the signal M_FLT_EN is set high, the test interrogator no longer interrogates the transponder and ignores any WIDTH_PULSEs produced by the reply detector. D28:13 is switched so the selected TIPRF is M_FLT_TIPRF (from D34:10). The signal M_FLT_REPLY produced at D29:7 (see figure below) and selected by D6 is processed like any other reply and the parameters are extracted as described in normal mode operation. To prevent interfering with beacon operation, signal TO_SIG_GEN is inhibited during these tests. D6:14 also selects a replacement detected interrogation signal from D52:10 since no signal is available on FROM_SIGN_GEN_DETECT. This signal is required for the measurement of delay.
To test Efficiency the signal M_FLT_EFF_EN is set high, via the CTU bus. This switches the MON_TIPRF signal to the monitor module to 10 kHz, while retaining separate CTU control of REPLY_PULSES.
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2.3.8.2 RF Generator 1A72516 REFER Circuit Diagram 72516-2-01
The RF generator signal source consists of a crystal oscillator operating at a nominal frequency of one-twelfth of the transponder receiver frequency.
Any one of five crystals G1-G5 may be selected to provide the output frequency of the test interrogator. One crystal corresponds to the transponder receive frequency while the other four correspond to frequencies either side of the nominal receive frequency at ±160 kHz and ±900 kHz.
The crystals may be selected by operating the dual-in-line switch S1 mounted on the printed board. Access to the switch is made by withdrawing the module from the rack and then operating the switch through the access hole in the cover of the RF generator diecast box. An extra switch position is included to provide a CW TEST condition for receiver AGC tests. This adds a CW signal 10 dB below the interrogation pulses.
The selected fifth-overtone crystal is connected in series resonance in an in-phase feedback path between the emitter and base circuit of V1. Inductor L7 is used to resonate with the stray crystal, socket and switch capacitances creating a high series impedance and thus avoiding feedback via the stray capacitive coupling which could cause parasitic oscillation or instability. Inductor L1 is tuned to optimise the operation of the oscillator. Test point XT1 provides a DC level which indicates oscillator output when monitored with a high impedance voltmeter.
Transistor V2 is configured as a grounded-base buffer amplifier and isolates the effects of the non-linear and abrupt loading changes of the following multiplier stage from the oscillator, as well as providing sufficient gain to drive the multiplier stages.
Each of the three multiplier stages V4 (tripler), V5 (doubler), V6 (doubler) and the following class-A amplifier stage, V7, are pulse modulated to create the required RF pulse envelope at the output as well as obtaining the required on/off output signal ratios. There are two types of modulation inputs to the unit, both supplied from the pulse shape circuitry on the modulator and detector. One is DRIVE PULSE, a square wave pulse input at XS4 that activates V4, V6, and V7 by an on/off action; the other is a SHAPED PULSE at input XS2 which shapes, in V5, the RF envelope.
The DRIVE IN pulse turns switch V3 and bias amplifier V8 on and supplies bias drive to V6. V3 switches on V4, and V8 switches on V7, so that the frequency multipliers V4 and V6 and the amplifier V7 are operating normally, ready for the shaped modulation to develop.
The SHAPED PULSE input pulse has a constant DC pedestal voltage of approximately 1 volt and, on top of this, the trapezoidal modulation pulse will be positioned and aligned in the centre of the DRIVE PULSE pulse.
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2.3.8.3 Attenuator 1A69737 REFER Circuit Diagram 69737-3-24
Interrogation pulses at the RF generator output are at a level of +11.5 dBm and pass through a 20 dB, 50 ohms attenuator before reaching the input of the switched attenuator connector XMA. Capacitors C1 and C2 provide DC blocking and L1 provides a high impedance choke feed for the DC bias for the PIN diode V1. L2, C3 and C4 form a filter section to reduce RF leakage into the DC supply lines. Resistors R1 and R2 are selected to match the characteristics of the PIN diode such that the DC voltage applied to XFB:1 produces an increase of 15 dB RF attenuation above the attenuation when the potential at XFB:1 is off.
The output of the switched attenuator at XFA is then passed through a 30 dB, 50 ohms fixed attenuator to the 30 dB directional coupler in the transponder antenna feed.
2.3.8.4 Modulator and Detector 1A72518 REFER Circuit Diagram 72518-2-01
The modulator and detector operates in conjunction with the RF generator to produce trapezoidal interrogation pulses of the correct duration and amplitude. Each pulse is initiated by a modulation pulse coming from the test interrogator main board.
In the quiescent state, the output at N6:7 is high; the analogue multiplexer D2 is enabled with a zero address input; N6:12 output is low and N4A is configured as a follower, having an output voltage equal to the pulse pedestal voltage set by R37.
On arrival of a square wave pulse at XS7, the address presented to D2 changes from 00 to 11 by the direct connection of the pulse to D2:9 (A in Figure 2-18) and the action of D1d and D1c operating on D2:10 (B in Figure 2-18). D2 now reconfigures N4A as an integrator with C11 coupling the negative voltage step at D2:13 to drive the integrator output up at a rate controlled by R19, R20 and C17. Simultaneously the XS8 signal, which follows the integrator N4A output, causes the RF generator to produce an RF pulse which increases in amplitude as the integrator output goes up. N6A changes state as the integration voltage exceeds the offset voltage across R36 so that the N6A output goes high.
A video amplitude-demodulated pulse from the RF generator, at XS1, follows the shape of the RF pulse and operates as feedback into the modulator and detector to provide automatic level control. When the RF pulse amplitude reaches the level preset by the PULSE AMPLITUDE control R13, the video pulse amplitude will cause the comparator N6B to change state and its output will go from a high to a low state, disabling D2 and causing the integrator N4A to maintain a constant output voltage until the end of the input pulse on XS7. This is shown in Figure 2-18 waveforms.
At the time when the input pulse at XS7 returns to 0 volts, D2 is again enabled and the address presented to D2 is now 01. Now N4A is configured to integrate down at a rate determined by R19, R20 and C17 and the positive voltage step at D2:13.
N4A will now continue to integrate down until the output of N4A reaches the pedestal voltage plus the offset voltage across C17, and at that time the comparator N6A will change its output state from high to low, which changes the address presented to D2 to 00 again, clamping the output of N4A at the pedestal voltage.
In this fashion a complete test interrogation pulse is produced, and is repeated at the pulse spacing and repetition rate determined by the test interrogator main board inputting modulation pulses to the modulator and detector.
As each pulse is produced it is necessary to establish a time reference for each pulse to enable time periods to be measured and checked. The circuit comprising N5A and V2
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acts as a peak follower and generates a DC voltage which closely follows the amplitude of the pulse. N2A acts as a buffer for the DC voltage and this DC voltage, after amplification by N3A, is available at XS3 as an indicator of the RF level. Half the DC voltage is also fed to the comparator N5B, the other input of which is the detector pulses, and N5 generates a logic level pulse whose width is equal to the half-height width of the interrogation pulses. These pulses appear at XS4 for use in the main board.
Transistor V3 is used as a constant current load for N4A to increase its sinking capability while V11 and V12 are emitter-follower buffer amplifiers.
To enable RF alignment of the RF generator a TEST position on switch SA is provided to allow the square-wave modulation pulses direct from the test interrogator main board to modulate the RF generator via V10 and with the ALC loop inoperative.
Figure 2-18 Modulator and Detector Waveforms
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2.3.8.5 Reply Detector 1A72519 REFER Circuit Diagram 72519-3-01
The reply detector consists of an amplitude-modulated video detector, a peak rider circuit, an analogue multiplexer and circuitry to generate pulse representing the rise time, fall time and width of the detected pulses.
A sample of the RF power in the antenna feeder system is coupled into the RF input connector XC1 of the reply detector via the directional coupler in the RF panel. The received RF power is demodulated by an envelope detector V1, and the resultant video pulses are amplified by N1a. Resistors R3 and R4 are used to provide a small DC bias to the detector diode V1; this enables the detector to recover signals at very low levels. The detected signal is buffered by N3a and appears on connector XS2.
The detected video pulses as well as the detector bias voltage on V1 are fed into the analogue 2:1 multiplexer D1. Also input to D1 are detected interrogations and the detector bias from the RF Generator 1A72516; these signals enter the reply detector via XS7 and XS8 respectively. A signal from a pushbutton switch TEST DETECTOR COINCIDENCE on the front panel of the test interrogator module is used by the multiplexer to switch between the detected replies and detector bias of either the reply detector or the RF generator.
The TEST DETECTOR COINCIDENCE check is used to ensure that the half-height detector in the reply detector has the same timing delay as the half-height detector in the RF generator. Any difference in timing delay will introduce inaccuracies in the transponder delay time measurements. The half-height signal in the reply detector appears on connector XS4 as signal WIDTH; an alternative designation for this signal is REPLY TIMING.
The detected signal at the output of N1a is fed into N1b where it is buffered to create the signal REPLIES, before being passed to the peak rider circuit and the rise, fall and width time detectors.
The peak rider consists of N5a and V3, and produces a DC voltage level representing the peak of the detected video pulses. The peak level is buffered by N2b and amplified by N3b and appears on connector XS3 as signal REPLY_LVL.
The buffered peak level output from N2b is fed into a resistor divider chain consisting of R11, R12, R13 and R14. These resistors are used to create reference levels of 90% of peak level, 50% of peak level and 10% of peak level which are fed into comparators N4a, N4b and N5b respectively.
The other input to the comparators is the buffered video pulse signal REPLIES. Comparator N4a produces a pulse that is low when any part of the video pulse is greater than 90% of the peak of the pulse. Comparator N4b produces a pulse that is low when any part of the video pulse is greater than 50% of the peak of the pulse; it is N4b that is the half-height detector. N5b produces a pulse that is low when any part of the pulse is greater than 10% of the peak of the pulse.
D2 and D3 are used to create three pulses named RISE, FALL and WIDTH. These pulses represent the rise time, fall time and half-height width of the detected video pulses. RISE is measured between 10% and 90% of pulse peak on the rising edge, FALL is measured between 90% and 10% of the pulse peak on the falling edge, and WIDTH is measured between consecutive 50% levels. The signals RISE, FALL and WIDTH appear on connectors XS4, XS5 and XS6 respectively.
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Table 2-11 Summary of Front Panel Controls and Indicators : Test Interrogator Module
CONTROL/INDICATION FUNCTION DETAILS TYPE LEGEND FUNCTION/SETTING/INDICATION
Red LED TEST Indicates that the MONITOR AND INTERROGATOR DC POWER switch is not in the NORMAL position.
Green LED DC POWER ON Indicates that DC power is applied to the monitor and test interrogator.
Pushbutton switch
CHECK DETECTOR COINCIDENCE
Connects the output of the RF generator into the reply detector, bypassing the transponder. Is used to check that the detector stages in the transponder have the same delay. The signals at the INTERROGATIONS TIMING and REPLY TIMING test jacks should match each other when this switch is pressed. This switch will interfere with the normal operation of the monitor module connected to the test interrogator under test.
+2us Toggle Switch, centre off
REJECT -2us
Alters the interrogating pulse spacing outside acceptable limits to test the transponder pulse decoder rejection.
+1us Toggle switch, centre off
TEST TRANSPONDER DECODING
ACCEPT-1us
Alters the interrogating pulse spacing within acceptable limits to test the transponder pulse decoder acceptance
Sets accept gate timing; variable between 0 and 60 microseconds. 16-way rotary switch COARSE 16 microseconds increments. 16-way rotary switch
REPLY GATE DELAY
FINE 1 microsecond increments.
ON The power supply output is connected to the test interrogator and monitor regardless of other power sources.
OFF The power supply is disconnected from the test interrogator and monitor.
Toggle switch, centre off
MONITOR AND INTERROGATOR DC POWER
NORMAL The test interrogator circuitry is connected to the power supply if the input signal TI_ON from the CTU is active (high) or TRANSPONDER POWER on the transponder power supply is switched ON. Otherwise, the module's circuitry is isolated from the power supply.
Test jack TRIGGER Buffered version of test interrogator output TI_PRF; can be used to trigger an oscilloscope.
Test jack EARTH Common earth of all supply voltages and outputs. Test jack REPLY ACCEPT
GATES Buffered pulse from the parameter extractor circuitry, defining a time slot in which the received reply pulse should be present (15 volts, 6 microseconds wide).
Test jack 1 us MARKERS Buffered output from the timer circuitry (5 volts, 1 microsecond period).
Test jack +15V Buffered +15V internal supply (15 volts). Test jack +5V Protected +5V internal supply (5 volts). Test jack DETECTED
REPLIES Buffered output of the reply detector, which is a detected pulse envelope representing the RF pulses transmitted from the transponder.
Test jack DETECTED INTERROGATIONS
Buffered detected pulse envelope representing the RF pulse generated by the test interrogator for test interrogation.
Test jack EARTH Common earth of all supply voltages and outputs. Test jack EARTH Common earth of all supply voltages and outputs. Test jack INTERROGATIONS
TIMING Output pulses from the RF generator detector.
Test jack EARTH Common earth of all supply voltages and outputs. Test jack REPLY TIMING Buffered output pulses of the reply detector.
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Table 2-12 Summary of Internal Controls: Test Interrogator Module
CONTROL/INDICATION FUNCTION DETAILS SUBASSY
TYPE REF LEGEND FUNCTION/SETTING/INDICATION X Sets pulse spacing for X channel operation. Slide
switch S4 mode
Y Sets pulse spacing for Y channel operation. 1A72515 Main PWB Assembly, Test Interrogator
Preset resistor
R7 TPNDR OP LVL CAL
Used to calibrate the transmitted pulse peak power.
Variable capacitors
C 10, 10, 14, 18, 22 Used to align the RF generator to the operating interrogator frequencies (see Section 3.4.12).
Inductor L1 6-way DIL switch
S1 SW1 Selects interrogations at the nominal interrogation frequency.
SW2 Selects interrogations at 160 kHz above the nominal interrogation frequency.
SW3 Selects interrogations at 160 kHz below the nominal interrogation frequency.
SW4 Selects interrogations at 900 kHz above the nominal interrogation frequency.
SW5 Selects interrogations at 900 kHz below the nominal interrogation frequency.
1A72516 RF Generator
SW6 Adds a CW signal to the interrogation pulse at -10 dB. 1A72517 RF Filter
Variable capacitors
C1, C2
Used to align the RF filter (see Section 3.4.13).
R13 Pulse amplitudeR20 Pulse shape
1A72518 Modulator and Detector
Preset resistors
R37 Pulse pedestal
Used to align the pulse shape of the interrogations produced by the RF generator (see Section 3.4.14).
Normal Position for normal operation. Slide switch
S1 Test Used during testing.
Test point XT1 Bias voltage Bias voltage for level detector circuitry. Test point XT2 Pk amp lvl DC voltage proportional to the peak amplitude of the
transmitted pulses. Test point XT3 Timing pulse Timing reference for the transmitted pulse. Test point XT4 Mod out Modulation pulse to RF generator. Test point XT5 Ground 0 volts reference. Test point XT6 Ground 0 volts reference.
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2.3.9 Monitor Module 1A72510 REFER Interwiring Diagram 72510-3-06
The monitor module receives input signals from the associated test interrogator module and from the antenna pickup. These signals represent operational parameters, and the monitor applies a pass/fail check on each one. A pass/fail result is able to be read by the control and test unit (CTU) which indicates an alarm or control action as required. A number of voltage levels from other modules in the transponder are also input to the monitor module where they are measured and eventually read by the CTU.
The eight monitored parameters are divided into primary and secondary categories, with primary parameters being defined as those which could, if at fault, give rise to false guidance information. The parameters are:
Transponder delay PRIMARY PARAMETERS Transponder pulse spacing
Transponder efficiency Transponder reply rate Transponder power output effective radiated power (ERP) Transponder ident Transponder antenna integrity
SECONDARY PARAMETERS
Transponder pulse shape
The individual monitor circuits are designed to be failsafe. As an added safeguard, the CTU regularly initiates a test routine to check that the primary parameter monitors are operative. If one or both primary monitor circuits do not return a fault indication in response to this test, the CTU diagnoses a monitor fault and, because the failure involves a primary parameter, it also initiates the control action appropriate for a primary parameter fault.
The criteria for the pass/fail decisions for delay, spacing, efficiency, reply rate and pulse shape measurements are essentially the same. The frequency of success is compared with a predetermined frequency; hence each of those circuits involves an up/down counter that determines the higher frequency.
The monitors are independent of interrogating pulse repetition frequency, and exhibit no drift error. The desired fault limits are either pre-wired or programmable by switches.
The ident monitor extracts ident messages from the transponder output pulses by means of a continuous pulse spacing decoder. This decoder produces a pulse (called the ident spacing pulse) which is measured and checked to see if the spacing is within a window centred on the period of the 1350 Hz ident pulse train. An ident fault will be indicated if:
a. continuous ident keying extends for more than 10 seconds; or
b. the ident message extends for more than 10 seconds; or
c. an ident message is absent for more than a preset 45 to 75 seconds interval.
The recovered 1350 Hz ident tone is used for an audible check of ident message integrity. The recovered ident mark keying waveform is used to inhibit the delay and efficiency monitors, thus preventing them indicating spurious faults during ident.
Real-time fault indicators (light emitting diodes) are included for each monitored parameter. Two LED indicators and associated output lines are provided to show if a real-time primary and/or secondary fault exists.
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The transponder output pulses sensed by the antenna pickup probe are detected and their peak value obtained; this peak value is then compared with a DC level preset to the required fault level. The value of this fault level setting can be checked under the control of the CTU.
A check of antenna integrity is made by the antenna integrity monitor. This check involves two fault parameters. "Antenna integrity 1 " fault indicates two or more open circuit antenna elements, an antenna short circuit or an antenna not connected. "Antenna integrity 2" fault indicates a single open circuit antenna element. These signals are read by the CTU to take action as appropriate.
Voltage levels representing monitored parameters from various other stages in the transponder are input to the monitor. These levels are converted by an analogue-to-digital converter into digital numbers that are read and processed by the CTU.
The following circuit features ensure failsafe monitoring:
• The choice of primary fault line outputs as zero volts.
• The inclusion of timeout monostables to ensure that a failure in any stage of a parameter monitor will signal a fault in that parameter. Delay, spacing, efficiency, rate, ident and pulse shape monitors involve counters that are continually checked for operation. Failure to count results in a fault output.
• Inputs from other boards are buffered and level shifted where appropriate. Input pull-down resistors ensure that floating inputs will be driven to a state that will produce a fault.
• An automatic test routine is applied to the delay and spacing monitors to check that they are capable of producing a fault.
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2.3.9.1 Main PWB Assembly Monitor Module 1A72511 REFER Circuit Diagram 72511-1-01
The monitor main board receives pulses from the test interrogator main board, each pulse having a duration proportional to the parameter being tested. Each parameter is tested for certain limits and is accepted or rejected in accordance with preset conditions. The monitor main board indicates alarms as appropriate, and signals the CTU for the relevant indications and actions.
2.3.9.1.1 Delay Monitor
Figure 2-19 Delay Monitor
The transponder delay is continuously being represented in the test interrogator by a positive going pulse with a duration equal to the delay time. This pulse appears as DLY_DUR_PULSE, and it is accessible at test point XT6.
A test of the transponder delay time is initiated by the PRF pulse (XT9) loading presettable counter D30 with the binary values held on S12. During the course of a test a second window count is loaded from switch S9.
The values held on switches S12 and S9 are indicative of the reject limits on the transponder delay. Each count on the switches represents 0.1 microseconds actual time.
The signal DLY_COUNT appears on test point XT5 and the signal DLY_DUR_PULSE appears on XT6. These two test points can be used in conjunction with an oscilloscope to check the accuracy of the switch settings. Figure 2-20 illustrates this check.
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Figure 2-20 Delay Monitor Waveforms
For an X channel the transponder delay can be between 35 and 50 microseconds and for a Y channel between 50 and 56 microseconds. The description which follows assumes a nominal transponder delay of 50 microseconds
When the counter D30 has been loaded with the preset values held on switch S12 it waits for the arrival of DLY_DUR_PULSE. The rising edge of this pulse initiates the first down count that will continue while DLY_DUR_PULSE is present. It takes one clock cycle (100 nanoseconds) to initiate the first down count. If the counter reaches zero and DLY_DUR_PULSE is still present the preset value on switch S9 is loaded into the counter D30 and a second down count is initiated after 1 clock cycle. If the falling edge of the DLY_DUR_PULSE occurs before the first count has reached zero no delay_OK flag is set and the second count is not started.
The signal DLY_COUNT at test point XT5 gives an indication of the lengths of the first and second down counts. If and only if the falling edge of DLY_DUR_PULSE occurs after the end of the first count and before the end of the second count will a delay_OK flag be set. The delay_OK flag is set on the falling edge of DLY_DUR_PULSE and a non-zero second count and is reset when the second count goes to zero. If the second down count reaches zero and DLY_DUR_PULSE is still asserted then no delay_OK flag is set. The existence of the delay_OK flag indicates that the DLY_DUR_PULSE is within the window of acceptable delay limits.
The primary error counter D37 is made up of two 3-bit up/down counters D37a and D37b. In a non-fault state the delay_OK flag and PRF pulses are fed into D37a. Within D37 the PRF rate is reduced to 33% of the original PRF rate. The PRF/3 rate is used to count the 3-bit counter toward zero. The delay_OK flags are used to count the 3-bit counter towards 7. If the delay_OK flag rate exceeds PRF/3 rate then the primary error counter will count to 7 and give no fault indications. If the delay_OK rate is exceeded by PRF/3 rate the counter will count to zero and a fault indication will be given.
The delay_OK rate will be exceeded by PRF/3 if the DLY_DUR_PULSEs are continually outside the window of acceptable delay limits or no valid DLY_DUR_PULSEs are returned from the test interrogator due to low beacon efficiency. In either case a DELAY fault must be raised. If a fault is to be raised the signal delay_fault_indication from D37a is asserted. This signal is input to the timeout monostable D41b.
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Timeout monostable D41b is used to ensure that the counter device D30 is operating. The signal DLY_COUNT (XT5) is used to continually retrigger D41b. In the event of a delay_fault_indication being asserted from counter D37a the monostable D41b is reset and a positive going DELAY FAULT is output from D41b:9. This timeout monostable also has the effect that if the DLY_DUR_PULSE is not encountered then the retriggering signal DLY_COUNT will not be produced and so the monostable will timeout and the DELAY FAULT signal from D41b:9 will be asserted.
The DELAY FAULT signal from D41b is then fed into the fault line driver circuitry D13.
Delay is monitored on every second interrogation when the RF level is -69 dBm. The delay monitor circuit is therefore enabled by a 50 Hz square wave (25 Hz in a dual system) from the test interrogator called DELAY_MON_EN. This signal is applied to the inhibit driver device D51:7 and fed to the primary error counter D37:23 as a delay_inhibit signal. When this signal is asserted the primary error counter is frozen so that counting is only permitted during the time when the RF signal is high.
During the transmission of an ident mark an ident_inhibit signal is fed into D51:5. This signal will also cause the delay_inhibit to be asserted and prevent D37a counting. By using the delay_inhibit signal from D51 a delay_fault will only be registered when this signal is not asserted so that false fault indications will not be given during efficiency testing and ident mark.
2.3.9.1.2 Spacing Monitor
Figure 2-21 Spacing Monitor
A test of the transponder spacing time is initiated by the PRF pulse (XT9) loading presettable counter D31 with the binary values held on S13. During the course of a test a second window count is loaded from switch S10.
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Figure 2-22 Spacing Monitor Waveforms
The SPACING FAULT signal from D41a is then fed into the fault line driver circuitry D13.
A signal from the binary switch S13, called CODING_MODE_MON is used by the CTU to determine the operating mode of the beacon, either X or Y channel.
The signal SPAC_COUNT appears on test point XT14 and the signal SPAC_DUR_PULSE appears on XT8. These two test points can be used in conjunction with an oscilloscope to check the accuracy of the switch settings. Figure 2-22 illustrates this check.
The values held on switches S13 and S10 are indicative of the reject limits on the transponder spacing. Each count on the switches represents 0.1 microseconds actual time.
For an X channel the nominal window of acceptable transponder spacing is between 11.5 microseconds and 12.5 microseconds. For a Y channel the nominal accept window is between 29.5 microseconds and 30.5 microseconds.
A measurement of spacing duration is initiated by the rising edge of a TIPFIF pulse input to spacing counter D31. This edge causes the counter to reset to zero regardless of the state of the counter before the edge. Within D31 the TIPRF pulse is delayed by 1 clock cycle (100 nanoseconds) and then used to load the counter with the preset value held on switch S13. By clearing the counter before loading the preset values the initial count value can be guaranteed.
When the counter D31 has been loaded with the preset values held on switch S13 it waits for the arrival of SPAC_DUR_PULSE. The rising edge of this pulse initiates the first down count that will continue while SPAC_DUR_PULSE is present. It takes one clock cycle (100 nanoseconds) to initiate the first down count. If the counter reaches zero and SPAC_DUR_PULSE is still present the preset value on switch S10 is loaded into the counter D31 and a second down count is initiated after 1 clock cycle. If the falling edge of the SPAC_DUR_PULSE occurs before the first count has reached zero no spacing_OK flag is set and the second count is not started.
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The signal SPAC_COUNT at test point XT14 gives an indication of the lengths of the first and second down counts. If and only if the falling edge of SPAC_DUR_PULSE occurs after the end of the first count and before the end of the second count will a spacing_OK flag be set. The spacing_OK flag is set on the falling edge of SPAC_DUR_PULSE and a non-zero second count and is reset when the second count goes to zero. If the second down count reaches zero and SPAC_DUR_PULSE is still asserted then no spacing_OK flag is set. The existence of the spacing_OK flag indicates that the SPAC_DUR_PULSE is within the window of acceptable spacing limits.
The primary error counter D37 is made up of two 3-bit up/down counters D37a and D37c. In a non-fault state the spacing_OK flag and PRF pulses are fed into D37b. Within D37 the PRF rate is reduced to 33% of the original PRF rate. The PRF/3 rate is used to count the 3-bit counter toward zero. The spacing_OK flags are used to count the 3-bit counter towards 7. If the spacing_OK flag rate exceeds PRF/3 rate then the primary error counter will count to 7 and give no fault indications. If the spacing_OK rate is exceeded by PRF/3 rate the counter will count to zero and a fault indication will be given.
The spacing_OK rate will be exceeded by PRF/3 if the SPAC_DUR_PULSEs are continually outside the window of acceptable spacing limits or no valid SPAC_DUR_PULSES are returned from the test interrogator due to low beacon efficiency. In either case a SPACING fault must be raised. If a fault is to be raised the signal spacing_fault_indication from D37c is asserted. This signal is input to the timeout monostable D41a.
Timeout monostable D41a is used to ensure that the counter device D31 is operating. The signal SPAC_COUNT (XT14) is used to continually retrigger D41a. In the event of a spacing_fault_indication being asserted from counter D37c, the monostable D41a is reset and a positive going SPACING FAULT is output from D41a:7. This timeout monostable also has the effect that if the SPAC_DUR_PULSE is not encountered then the retriggering signal SPAC_COUNT will not be produced and so the monostable will timeout and the SPACING FAULT from D41a:7 will be asserted.
2.3.9.1.3 Monitor Self Test An automatic test routine is applied to both the delay and spacing monitors to check that fault outputs can be obtained. A positive going signal is written to the monitor main board from the CTU and is applied to MON_TEST input D51:5. This signal has the effect of altering the value set on the preset switches S12 and S13 which are loaded into the counters D30 and D31 respectively. The value loaded into each counter is altered by 32 counts (3.2 microseconds) which is sufficient to cause both delay and spacing monitors to fail. The CTU reads faults from both monitors indicating each parameter has failed and terminates the test, thereby restoring normal operation. The test is repeated every 16 seconds, and at monitoring PRF takes approximately 0.1 seconds to complete.
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2.3.9.1.4 Efficiency Monitor
Figure 2-23 Efficiency Monitor
The efficiency monitor maintains a running count of each decoded reply and the PRF, and indicates when the decoded reply rate falls below 60% of the PRF count. This indication is signalled as an efficiency fault.
The buffered signal representing PRF pulses called XTIPRF is input to a rate multiplier D36, configured to pass 60% of its input pulses to its output. Counter D49 uses these signals as an up count pulse.
The buffered signal representing decoded replies called XREPLY_PULSES is used by counter D49 as a down count pulse. Provided the down count pulse rate is greater than the up count pulse rate the count value will stay at zero. If the decoded reply rate falls below 60% the up count rate will be greater than the down count rate, D49 will count up and be held at a maximum value of 15. At this point an efficiency_error flag will be asserted.
After an efficiency_error flag has been raised it will be reset by an increase in the reply rate to greater than 60% of PRF. At this time D49 will begin to count down from the maximum count of 15. When D49 has a count value of 0 the efficiency_error flag is reset.
To ensure fail-safe operation a clock signal created in counter D49 from the input XREPLY_PULSES is used to retrigger a timeout monostable D35a. If counter D49 should fail or XREPLY_PULSES not be present this monostable will timeout and will assert an EFFICIENCY FAULT D35a:7. In the event of the efficiency_error flag being asserted from counter D49:8, the monostable D35a is reset and a positive going EFFICIENCY FAULT is output from D35a:7.
The EFFICIENCY FAULT signal from D35a is then fed into the fault line driver circuitry D13.
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Efficiency is monitored on every second interrogation when the RF level is -84 dBm. The efficiency monitor circuit is therefore enabled by a 50 Hz square wave (25 Hz in a dual system) from the test interrogator called EFF_MON_EN. This signal is applied to the inhibit driver device D51:8 and fed into counter D49:10 as an EFF_INHIBIT signal. When this signal is asserted the counter D49 is frozen so that counting is only permitted during the time when the RF signal is low.
During the transmission of an ident mark an ident_inhibit signal is fed into D51:5. This signal will also cause EFF_INHIBIT to be asserted and prevent D49 counting. By using the EFF_INHIBIT signal from D51, efficiency faults will only be registered when this signal is not asserted so that false fault indications will not be given during delay testing and ident mark.
2.3.9.1.5 Reply Rate Monitor This section of the monitor detects if the transponder reply rate falls below a preset limit of 833 Hz or rises above a preset limit of 3 kHz. The reply rate monitor consists of two parts. The first part checks the minimum reply rate and the second checks the maximum reply rate. The buffered signal representing all replies called XDETD_TX_PULSES is used as input to both parts. The counter D45 consist of parts D45a and D45b. Each part functions identically.
Figure 2-24 Rate Monitor
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2.3.9.1.5.1 Minimum Reply Rate Monitor The signal XDETD_Tx_PULSES is input to a rate multiplier D34, configured to pass 60% of its input pulses to its output. Since XDETD_Tx_PULSES consists of pulse pairs its frequency is twice the reply rate. The down count pulse rate used by counter D45a is calculated according to the following formula:
(reply rate) x 2 x 0.6 = down count pulse rate.
Example: for reply rate = 833 Hz, the down count pulse rate = 1 kHz.
The clock signal 1kHz_CLK is used by counter D45a as an up count pulse. Provided the reply rate is greater than 833 Hz, the down count pulse rate will be greater than the up count pulse rate of 1 kHz. This will cause D45a to count down to and be held at zero. If the reply rate falls below 833 Hz the up count rate will be greater than the down count rate, D45a will count up and be held at a maximum value of 15. At this point a rate_error flag will be asserted.
2.3.9.1.5.2 Maximum Reply Rate Monitor The clock signal 1kHz_CLK is input to rate multiplier D39, configured to pass 60% of its input pulses to its output. This output used by counter D45b as a down count pulse of frequency 600 Hz.
The signal XDETD_Tx_PULSES is input to a rate multiplier D43, configured to pass 10% of its input pulses to its output. The up count pulse rate used by counter D45b is calculated as:
(reply rate) x 2 x 0.1 = up count pulse rate.
Example: for reply rate = 3 kHz, the up count pulse rate = 600 Hz.
Provided the reply rate is less than 3 kHz, the down count pulse rate from D39 of 600 Hz will be greater than the up count pulse rate. This will cause D45b to count down to and be held at zero. If the reply rate rises above 3 kHz the up count rate will be greater than the down count rate and D45b will count up and be held at a maximum value of 15. At this point a rate_error flag will be asserted.
2.3.9.1.5.3 Fault Processing After a rate_error flag has been raised it will be reset by the rate returning to a non-fault condition. This means that if the rate_error flag was raised by the reply rate falling below 833 Hz the rate must increase to above 833 Hz to reset the flag. If the rate_error flag was raised by the reply rate exceeding 3 kHz it must fall below 3 kHz to reset the flag. In either case a return to a non-fault state will cause D45a or D45b to count down from the maximum count of 15. When D45a or D45b has a count value of 0 the rate_error flag is reset.
To ensure fail-safe operation a clock signal created in counter D45 from the input XDETD_Tx_PULSES is used to retrigger a timeout monostable D35b. If counter D45 should fail or XDETD_Tx_PULSES not be present this monostable will timeout and will assert a RATE FAULT from D35b:9. In the event of the rate_error flag being asserted from counter D45b:8, triggering of the monostable is prevented, and a positive going RATE FAULT is output from D35b:9, after the timeout period.
The RATE FAULT from D35b is then fed into the fault line driver circuitry D13.
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2.3.9.1.6 Ident Monitor
Figure 2-25 Ident Monitor
Each ident message transmitted by the transponder consists of pulse pairs sent at a rate of 1350 Hz for the duration of each Morse code 'mark'.
The ident monitor scans all reply pulse pairs to identify the trains of pulse pairs at the ident pulse rate. Once an ident message has been identified the monitor checks that the messages are occurring within preset timing limits.
During the transmission of an ident mark the normal delay and efficiency monitoring is suspended as no replies are being sent by the transmitter during this period. Measuring these parameters at this time would result in a false error indication.
The ident monitoring circuitry consists of three main devices. D33 extracts a single pulse representing the spacing between pulse pairs from the incoming XDETD_Tx_PULSES signal; this pulse is called ident_pulse. During ident message transmission the spacing between pulse pairs is 1/1350 Hz or 741 microseconds. D40 uses ident_pulse in the same way as the delay and spacing monitors and ensures that the period of this pulse falls within a specific range of values called ident_window.
The ident window is centred around 741 microseconds with a variation of ±4 microseconds. If ident_pulse falls within the ident_window an ident_keying signal is passed to D47, which ensures that the Morse code marks do not violate any ident timing limits. These limits are:
1. Ident messages shall occur within a preset interval (adjustable from 2 to 128 seconds by S8 - connected to D33).
2. An ident mark shall not last more than 10 seconds.
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3. An ident mark shall not inhibit delay and efficiency measurement for more than 2 seconds.
4. An ident message shall not last for longer than 10 seconds.
If any of the above limits are violated an ident_error is indicated.
All ident message information is extracted from the buffered signal XDETD_Tx_PULSES. When the rising edge of the first pulse of an XDETD_TX_PULSES pulse pair is encountered on input D33:2 a pulse of 1 clock cycle duration is created and output from D33:10. This pulse is called IDENT_DECIDE. The clock input to D33 for ident message extraction is 1 MHz.
The pulse IDENT_DECIDE is input to monostable D38a:4 which produces a pulse, IDENT_GATE, of 40 microseconds duration to be fed back into D33:14. This gating pulse is used to gate out the second pulse in the XDETD_Tx_PULSE pulse pair. If this pulse is not gated out another IDENT_DECIDE pulse will be created on the rising edge of the second pulse. If this occurs, erroneous information about the pulse pair spacing will be output from D33 as IDENT_PULSE.
The pulse IDENT_DECIDE generates the signals IDENT_LOAD and IDENT_PULSE within D33. IDENT_PULSE, at D33:18, is a 3 microseconds negative-going pulse, with a pulse spacing equal to the spacing between the pulses XDETD_TX_PULSE. It is used by D40 to determine if the spacing between transmitter output pulse pairs falls within the ident window.
The IDENT_DECIDE pulse is used by D40 to determine if IDENT_PULSE from the previous measurement is still high during the ident window generated within D40. If this is the case then the XDETD_Tx_PULSES pulse pair spacing is at the ident rate of 1350 Hz and output D40:18 is held high. D40:18 is called IDENT_KEYING and represents the envelope of the ident message pulse pairs.
IDENT_DECIDE is also used to create the pulse IDENT_CLEAR in D33. This pulse, output from D33:22, is of 1 clock cycle duration and is used by D40 to reset its internal counter to zero after the previous ident spacing measurement.
IDENT_CLEAR is used to create the pulse IDENT_LOAD in D33. This pulse, output from D33:15, is of 1 clock cycle duration and is used by D40 to preload its internal counter to the preset value representing the ident rate pulse pair spacing of 741 microseconds (the number actually loaded into the counter is 738 since three clock periods are used in creating the control pulses IDENT_DECIDE, IDENT_CLEAR and IDENT_LOAD).
IDENT_KEYING from D40:18 will be high during a Morse code 'mark' and low during a Morse code 'space'. This signal is input to D47.
To prevent random squitter pulse pairs of the correct ident spacing being recognised as valid IDENT_KEYING a digital fitter is used in D47. This filter requires at least three pulse pairs at the correct ident spacing before it will recognise an ident message. Valid ident keying is output at D47:7 as the signal REC_IDENT_KEY to the CTU. Valid ident keying is also output from D47:21 to the inhibit driver device D51:6 as IDENT_INHIBIT, to disable the monitoring of delay and efficiency during an ident mark. Once valid ident keying has been recognised by D47 an internal counter of 10 seconds is started. If valid ident keying extends beyond the 10 second limit an IDENT_ERROR flag is raised. After 2 seconds of continuous valid ident keying the signal IDENT_INHIBIT is disabled. This enables delay and efficiency measurements to resume.
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The signal REC_IDENT_TONE is output from D47:10 and used by the CTU to give an audible check of the ident message being transmitted by the beacon. This signal is created by gating the valid ident keying signal with the IDENT_GATE pulse from D38a:6. IDENT_GATE represents a 1350 Hz tone. The REC_IDENT_TONE signal is also input to D38b:12.
D38b is used to create a pulse called IDENT_CODE which will remain high during an entire ident message. The output of this pulse from D38b:10 is input to D47 where it initiates a count of 10 seconds. If this count reaches 10 the ident message has extended beyond the specified limit of 10 seconds and an IDENT_ERROR flag is raised.
The inverse of IDENT_CODE is output from D38:9 and input to D33:11. This signal, IDENT_MESSAGE_SPACING, represents the spacing between ident messages. Preloading of the binary value held on switch S8 is initiated by a count of zero in D33 (the power on condition) or the rising edge of IDENT_MESSAGE_SPACING. After preloading the counter in D33 a down count is immediately started. The value held on S8 represents the maximum spacing between ident messages in seconds. If the count reaches zero a valid ident message has not been received within the maximum time and an IDENT_SPACING_ERROR flag is raised in D33:21. This flag is input to D47. Switch S8 can be set for a maximum ident message spacing of 2 to 128 seconds (although it would normally be set in the range 45 to 75 seconds).
To ensure fail safe operation the signal IDENT_LOAD is used to retrigger a timeout monostable D42a. If D33 should fail or XDETD_Tx_PULSES not be present this monostable will timeout and will assert an ident fault signal from D42a:7. In the event of the IDENT_ERROR flag being asserted from counter D47:18, the monostable D42a is reset and a positive going IDENT FAULT is output from D42a:7.
The IDENT FAULT from D42a is then fed into the fault line driver circuitry D13.
2.3.9.1.7 Effective Radiated Power Monitor
Figure 2-26 Effective Radiated Power Monitor
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The effective radiated power (ERP) monitor receives from the Peak Power Monitor 1A72512 a DC level representing the transponder ERP. This circuitry also incorporates an ERP monitor fault limit check controlled by the CTU.
The input from the Peak Power Monitor 1A72512 is called POWER_LEVEL and appears on test point XT2. At commissioning, the variable resistor R87 is used to adjust the voltage on XT2 to be equal to 2.50 +0.01 volts. The voltage on XT2 is input to 8:1 multiplexer, D5:13, and to quad 2:1 multiplexer D1:12. In normal operation the control signal PWR_TESTEN from the CTU will cause POWER_LEVEL to be output from D1:14. This output is fed into comparator N9:10.
The switch S7 is used to set the ERP monitor fault alarm level on an accumulative basis. Each additional switch setting reduces the fault alarm level a further 1 dB. The 0 dB level is set at commissioning by R87. The input that appears on N9:11 is a voltage that represents the fault alarm level.
The power level at N9:10 and the fault alarm level at N9:11 are compared. While the power level is greater than the fault alarm level no POWER FAULT is indicated. Should the power level fall below the fault alarm level a POWER FAULT will be indicated and the output sent to the fault line driver D13.
During ERP monitor fault limit test operation the control lines PWR_TEST0 … 2 from the CTU are used to control D5. The software on the CTU will cycle through the inputs to D5. These inputs represent the following monitor fault levels:
• The power level set by R87. This is the 0 dB level.
• Voltages representing -0.5 dB to -6.5 dB levels in -1 dB steps.
The monitor fault level output of D5:3 is fed into D1. The control signal from the CTU PWR_TESTEN selects the monitor fault level input to D1 to be output to N9, instead of the power level.
By cycling through the monitor fault levels and comparing these to the fault alarm level, the CTU can determine the fault alarm level set on the ERP monitor. The CTU will continue to cycle through the inputs to D5 until a POWER FAULT is indicated. When the POWER FAULT is indicated the input monitor fault level to D5 that forced the POWER FAULT is read by the CTU and returned as the ERP monitor fault limit.
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2.3.9.1.8 Antenna Integrity Monitor
Figure 2-27 Antenna Integrity Monitor
The antenna integrity monitor is used to ensure that all of the elements in the antenna of the transponder are operational. If elements are faulty an indication of the fault is given by this monitor. Two antenna integrity faults are indicated:
• Antenna integrity 1 fault is indicated if the antenna is not present, if the antenna is short circuited or if two or more elements have failed open circuit.
• Antenna integrity 2 fault is indicated if one element of the antenna has failed open circuit.
The antenna can be represented by 10 parallel 10 kilohm loads, one load for each element. This represents an equivalent load seen by the antenna integrity monitor of 1 kilohm. As each element in the antenna fails the effective load increases. A constant current source made from transistors V6 and V4 and associated components ensures that a current of less than 4 mA is fed into this effective load. An identical current produced by V2 is fed into an external 1 kilohm reference resistor. This produces a set of reference voltages that are input to the comparator network formed by quad comparator N2.
The external reference resistor of 1 kilohm is located on the RF Panel PWB Assembly 1A/2A72547. A reference resistor of 1 kilohm is fed by the same current source as feeds the effective antenna load. The voltage produced across the reference resistor is buffered and multiplied by 1.18 in amplifier N1. The output from this amplifier is fed into the comparator network formed by N2.
The reference input to comparator N2a:7 represents a voltage 1.18 times the voltage produced by the effective antenna load of a fully functioning antenna. Should a multiple element failure occur then the effective antenna load, connected to N2a:6, will increase and the current source will produce a voltage across this load greater than the reference voltage. This will cause an ANTENNA_INTEGRITY_1 FAULT.
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The reference input to comparator N2b:5 represents a voltage 1.06 times the voltage produced by the effective antenna load of a fully functioning antenna. Should a single element failure occur, the effective antenna load, connected to N2b:4, will increase and the current source will produce a voltage across this load greater than the reference voltage. This will cause an ANTENNA_INTEGRITY_2 FAULT.
The reference input to comparator N2c:8 represents a voltage 0.2 times the voltage produced by the effective antenna load of a fully functioning antenna. Should the antenna be short circuited the effective antenna load, connected to N2c:9, is less than 200 ohms and the current source will produce a voltage across this load less the reference voltage. This will cause an ANTENNA_INTEGRITY_1 FAULT.
If the antenna is not connected the current source has no load and the voltage will be pulled up by the power supply to greater than the reference voltage in N2a. This will cause an ANTENNA_INTEGRITY_1 FAULT.
The output of N2a and N2c are wired ORed together so that a fault indication on either will cause an ANTENNA_INTEGRITY_1 FAULT.
Both fault lines ANTENNA_INTEGRITY_1 FAULT and ANTENNA_INTEGRITY_2 FAULT are input to fault line driver D13.
2.3.9.1.9 Pulse Shape Monitor REFER Figure 2-29
The pulse shape monitor takes its inputs as a series of positive going pulses representing rise, fall and width times of the transponder output pulses. These pulses are created in the test interrogator.
The width pulse is monitored to ensure that the width of the transponder output pulses is within a preset range of values. The width pulse is measured from the 50% points on the transponder output pulses.
The rise pulse and the fall pulse are monitored to ensure that the rise time and fall time of the transponder output pulses are less than preset values. Both rise pulse and fall pulse are measured between 10% and 90% points on the transponder output pulses.
Width pulse monitoring is achieved with the same circuit configuration used in the delay and spacing monitors. A similar procedure is used to preset the switches S1 and S4.
A test of the transponder pulse width is initiated by the PRF pulse (XT9) loading presettable counter D9 with the binary values held on S1. During the course of a test a second window count is loaded from switch S4.
The values held on switches S1 and S4 are indicative of the reject limits on the transponder width. Each count on the switches represents 0.1 microseconds actual time.
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Figure 2-28 Width Monitor Waveforms
The signal WIDTH_COUNT appears on test point XT7 and the signal WIDTH_PULSE appears on XT11. These two test points can be monitored with an oscilloscope to check the accuracy of the switch settings. Figure 2-28 illustrates this check.
When the counter D9 has been loaded with the preset values held on switch S1 it waits for the arrival of WIDTH_PULSE. The rising edge of this pulse initiates the first down count that will continue while WIDTH_PULSE is present. It takes one clock cycle (100 nanoseconds) to initiate the first down count. If the counter reaches zero and WIDTH_PULSE is still present the preset value on switch S4 is loaded into the counter D9 and a second down count is initiated after 1 clock cycle. If the falling edge of the WIDTH_PULSE occurs before the first count has reached zero no width_OK flag is set and the second count is not started.
The signal WIDTH_COUNT at test point XT7 gives an indication of the lengths of the first and second down counts. If and only K the falling edge of WIDTH_PULSE occurs after the end of the first count and before the end of the second count will a width_OK flag be set. The width_OK flag is set on the falling edge of WIDTH_PULSE and a non-zero second count and is reset when the second count goes to zero. If the second down count reaches zero and WIDTH_PULSE is still asserted then no width_OK flag is set. The existence of the width_OK flag indicates that the WIDTH_PULSE is within the window of acceptable width limits.
The pulse-shape error counter D23 is made up of two 3-bit up/down counters D23a and D23b. In a non-fault state the width_OK flag and PRF pulses are fed into D23a. Within D23 the PRF rate is reduced to 33% of the original PRF rate. The PRF/3 rate is used to count the 3-bit counter toward zero. The width_OK flags are used to count the 3-bit counter towards 7. If the width_OK flag rate exceeds PRF/3 rate then the pulse - shape error counter will count to 7 and give no fault indications. If the width_OK rate is exceeded by PRF/3 rate the counter will count to zero and a fault indication will be given.
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Figure 2-29 Pulse Shape Monitor
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The width_OK rate will be exceeded by PRF/3 if the WIDTH_PULSEs are continually outside the window of acceptable width limits or no valid WIDTH_PULSEs are returned from the test interrogator due to low beacon efficiency. In either case a WIDTH fault must be raised. If a fault is to be raised the signal width_fault_indication from D23a is asserted. This signal is input to the timeout monostable D18b.
Timeout monostable D18b is used to ensure that the counter device D9 is operating. The signal WIDTH_COUNT (XT7) is used to continually retrigger D18b. In the event of a width_fault_indication being asserted from counter D23a the monostable D18a is reset and a positive going WIDTH FAULT is output from D18b:9. This timeout monostable also has the effect that if the WIDTH_PULSE is not encountered then the retriggering signal WIDTH_COUNT will not be produced and so the monostable will timeout and the WIDTH FAULT signal from D18b:9 will be asserted.
The WIDTH FAULT signal from D18b is then fed into the fault line driver circuitry D13.
A test of the transponder pulse rise time is initiated by the PRF pulse (XT9) loading presettable counter D10 with the binary values held on S3.
The value held on switch S3 is indicative of the maximum rise time of the transponder pulse. Each count on the switches represents 0.1 microseconds actual time.
Figure 2-30 Rise Time Monitor Waveforms
When the counter D11 has been loaded with the preset values held on switch S3 it waits for the arrival of RISE_PULSE. The rising edge of this pulse initiates a down count that will continue while RISE_PULSE is present. It takes one clock cycle (100 nanoseconds) to initiate the down count. If the falling edge of the RISE_PULSE occurs before the first count has reached zero a rise_OK flag is set.
The signal RISE_COUNT at test point XT15 gives an indication of the lengths of the down count. If and only if the falling edge of RISE_PULSE occurs before the end of the count will a rise_OK flag be set. The rise_OK flag is set on the falling edge of RISE_PULSE and a non-zero count and is reset when the count goes to zero. If the down count reaches zero and RISE_PULSE is still asserted then no rise_OK flag is set. The existence of the rise_OK flag indicates that the RISE_PULSE is less than the maximum rise time limit.
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The pulse_shape error counter D23 is made up of two 3-bit up/down counters D23a and D23b. Only D23b is used for rise time measurements. In a non-fault state the rise_OK flag and PRF pulses are fed into D23b. Within D23 the PRF rate is reduced to 33% of the original PRF rate. The PRF/3 rate is used to count the 3-bit counter toward zero. The rise_OK flags are used to count the 3-bit counter towards 7. If the rise_OK flag rate exceeds PRF/3 rate then the pulse_shape error counter will count to 7 and give no fault indications. If the rise_OK rate is exceeded by PRF/3 rate the counter will count to zero and a fault indication will be given.
The rise_OK rate will be exceeded by PRF/3 if the RISE_PULSEs are continually greater than the maximum rise time limit or no valid RISE_PULSEs are returned from the test interrogator due to low beacon efficiency. In either case a PULSE SHAPE fault must be raised. If a fault is to be raised the signal rise_fault_indication from D23b is asserted. This signal is input to the timeout monostable D42b.
Timeout monostable D42b is used to ensure that the counter device D10 is operating. The signal RISE_COUNT is used to continually retrigger D42b. In the event of a rise_fault_indication being asserted from counter D23b the monostable D42b is reset and a positive going RISE FAULT is output from D42b:9. This timeout monostable also has the effect that if the RISE_PULSE is not encountered then the retriggering signal RISE_COUNT will not be produced and so the monostable will timeout and the RISE FAULT signal from D42b:9 will be asserted.
The RISE FAULT signal from D42b is then fed into the fault line driver circuitry D13.
Monitoring of rise pulses and fall pulses is accomplished using identical circuitry.
A test of the transponder pulse fall time is initiated by the PRF pulse (XT9) loading presettable counter D11 with the binary values held on S2.
Figure 2-31 Fall Time Monitor Waveforms
The values held on switches S2 are indicative of the maximum fall time of the transponder pulse. Each count on the switches represents 0.1 microseconds actual time.
When the counter D10 has been loaded with the preset values held on switch S2 it waits for the arrival of FALL_PULSE. The rising edge of this pulse initiates a down count that will continue while FALL_PULSE is present. It takes one clock cycle (100 nanoseconds) to initiate the down count. If the falling edge of the FALL_PULSE occurs before the first count has reached zero a fall_OK flag is set.
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The signal FALL_COUNT at test point XT16 gives an indication of the lengths of the down count. If and only if the falling edge of FALL_PULSE occurs before the end of the count will a fall_OK flag be set. The fall_OK flag is set on the falling edge of FALL_PULSE and a non-zero count and is reset when the count goes to zero. If the down count reaches zero and FALL_PULSE is still asserted then no fall_OK flag is set. The existence of the fall_OK flag indicates that the FALL_PULSE is less than the maximum fall time limit.
The pulse-shape error counter D17 is made up of two 3-bit up/down counters D17a and D17b. Only D17a is used for fall time measurements. In a non-fault state the fall_OK flag and PRF pulses are fed into D17a. Within D17 the PRF rate is reduced to 33% of the original PRF rate. The PRF/3 rate is used to count the 3-bit counter toward zero. The fall_OK flags are used to count the 3-bit counter towards 7. If the fall_OK flag rate exceeds PRF/3 rate then the pulse_shape error counter will count to 7 and give no fault indications. If the fall_OK rate is exceeded by PRF/3 rate the counter will count to zero and a fault indication will be given.
The fall_OK rate will be exceeded by PRF/3 if the FALL_PULSEs are continually greater than the maximum fall time limit or no valid FALL_PULSEs are returned from the test interrogator due to low beacon efficiency. In either case a PULSE SHAPE fault must be raised. If a fault is to be raised the signal fall_fault_indication from D17a is asserted. This signal is input to the timeout monostable D18a.
A timeout monostable D18a is used to ensure that the counter device D11 is operating. The signal FALL_COUNT is used to continually retrigger D18a. In the event of a fall_fault_indication being asserted from counter D17a the monostable D18a is reset and a positive going FALL FAULT is output from D18a:7. This timeout monostable also has the effect that if the FALL_PULSE is not encountered then the retriggering signal FALL_COUNT will not be produced and so the monostable will timeout and the FALL FAULT signal from D18a:7 will be asserted.
The FALL FAULT signal from D18a is then fed into the fault line driver circuitry D13.
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2.3.9.1.10 Level Monitor
Figure 2-32 Level Monitor
A number of DC voltage levels are input to the level monitor circuit from other modules within the transponder. Each of these levels is buffered and under CTU control converted to a digital value that can be read by the CTU.
The following signal levels are read:
SOURCE MODULE SIGNAL NAME SOURCE MODULE SIGNAL NAME
RV_LOCAL_OSC_LVL TI_INT_RF_LVL Receiver Video
RV_Tx_LVL Test Interrogator
TPNDR_OP_LVL
TD_MOD_LVL PS_15V_LVL Transmitter Driver
TD_Tx_LVL_ PS_18V_LVL
PA_DRV_LVL
Transponder Power Supply
PS_HT_LVL
PA_MOD_LVL MON_24V_LVL
PA_OP_LVL CALIBRATE Power Amplifier
PA_HT_LVL
Monitor
GND
The two monitor signals CALIBRATE and GND are used by the CTU to calibrate the other level measurements.
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D22 and D27 are 8:1 multiplexers which are used to choose the level signal to be monitored and also provide a degree of buffering. The CTU controlled signal lines AMUX0:3 are used by D22 and D27 to choose the level to be monitored.
The chosen level is buffered by N1 and fed to analogue-to-digital converter D28. The output of D28 is read under CTU control.
2.3.9.1.11 Fault Line Driver
Figure 2-33 Fault Line Driver
The fault line driver circuitry combines all of the faults from the various parameter monitors to give primary and secondary fault indications.
The faults are combined in device D13 according to the following table. From this device the combined faults are directed to the CTU bus and to LED drivers. D8 and D4 are used to buffer the fault lines and drive the LEDs on the front panel. A pair of signal lines representing a DELAY fault and a SPACING fault are directed to the receiver video to inhibit beacon operation, following a primary Fault, if the CTU fails to shut the beacon down.
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The faults are combined as follows:
FAULT TYPE FAULT FAULT GROUP DELAY FAULT PRIMARY SPACING FAULT
EFFICIENCY FAULT
RATE FAULT
IDENT FAULT
POWER FAULT
WIDTH FAULT
RISE FAULT
FALL FAULT
PULSE SHAPE FAULT
ANTENNA INTEGRITY 1 FAULT
SECONDARY
ANTENNA INTEGRITY 2 FAULT ANTENNA FAULT
Each of the faults shown in italics above are able to be read by the CTU, which then takes the appropriate course of action for the indicated fault.
The following front panel indicators are used to give a real-time indication of the fault status of each of the monitored parameters. With the exception of the PRIMARY and SECONDARY fault indicators, a lit indicator signifies normal operation. If the indicator is unlit a fault has occurred in that parameter. If the PRIMARY or SECONDARY indicators are lit a primary fault or a secondary fault has occurred. An unlit indicator for these parameters signifies normal transponder operation.
FAULT INDICATOR DELAY FAULT GREEN SPACING FAULT GREEN
EFFICIENCY FAULT GREEN
RATE FAULT GREEN
IDENT FAULT GREEN
POWER FAULT GREEN
PULSE SHAPE FAULT GREEN
ANTENNA FAULT GREEN
PRIMARY FAULT RED
SECONDARY FAULT AMBER
When the front panel switch MONITOR OUTPUTS (S16) is set to FAILED, all of the front panel indicators will indicate faults. All fault lines read by the CTU will also indicate faults.
To allow the transponder operation to be inhibited should the CTU fail to respond to primary faults a pair of fault lines indicating DELAY FAULT and SPACING FAULT are hardwired to the receiver video module. If these faults are indicated the receiver video module will inhibit all replies after about 70 seconds.
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2.3.9.1.12 Miscellaneous Circuitry A buffered 10 MHz crystal oscillator is fed into clock device D24. This device produces clocks of 1 MHz and 1 kHz. The 1 kHz signal is fed into clock device D19 and this device produces a clock of 1 Hz. These four clock frequencies are used for timing circuits throughout the monitor main board. D48 is used to buffer all of the clock signals before distribution around the board.
Two power supplies are required on the monitor main board. These are +15 volts for buffering analogue signals from other transponder modules and +5 volts for all of the digital logic. The +5 volts supply is created by taking the +24 volts from the test interrogator and first regulating this to +15 volts via ballast resistor R1 and 3-terminal regulator N4. This +15 volts is then further regulated to +5 volts using ballast resistor R89 and 3-terminal regulator N8. The +15 volts supply is created by directly regulating the +24 volts from the test interrogator using the adjustable three terminal regulator N6.
A power supply monitor is used to provide an indication to the CTU that the two power supplies used on the monitor main board are operating. The circuit consists of a pair of window comparators that indicate if the voltages on the +5 volts supply and the +15 volts supply fall with hardwired limits. These limits are set to be 4.75 volts to 5.25 volts and 14.5 volts and 15.5 volts respectively. Should the power supplies fall outside these limits then a signal line to the CTU called MON_PS_FLT will fall to zero volts indicating that the monitor power supplies have failed. The CTU will then take an appropriate action.
From the +15 volts supply two precision +5 volts references N3 and N6 are used to provide accurate +5.00 volts levels for use in ERP monitor and level monitor.
The MONITOR OUPUTS switch S16 is used to determine the operational mode of the monitor module. When S16 is in NORMAL mode all parameter monitors are operational. In FAILED mode all parameter monitors are forced into the failed condition, Primary and Secondary faults are forced and the TEST LED H12 is lit to indicate that the monitor is no longer in normal mode. When S16 is set to FAILED a hardwired TI_MON_TEST signal line is grounded. This test line gives indications on both the test interrogator and the CTU.
Precision resistors R76 and R77 are used to provide a calibrated voltage level to the level monitor circuitry so that, on request from the CTU, a measurement can be made of the +24 volts supply from the test interrogator.
A number of signals from the test interrogator representing parameters to be measured are buffered on the monitor board before distribution to the respective parameter monitors. This buffering is done with 74HC4050 buffers D29 and D32. HC CMOS is used for these buffers to ensure that the parameters to be measured are not changed by the buffering process. Input pulldown resistors are used on all lines to ensure that the lines are at a known state should a failure of the test interrogator occur.
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2.3.9.2 Peak Power Monitor 1A72512 REFER Circuit Diagram 72512-3-01
The RF power in the antenna is sampled by a coupler situated within the antenna housing, and a separate coaxial cable is used to feed this power into the peak power monitor board at RF input connector XC1.
The peak power monitor consists of an amplitude-modulated video detector and a peak rider circuit. The detected pulse envelope of the signal at XC1 is output to the monitor main board via connector XN2:9 as DET_REPLIES. A DC level representing the peak pulse amplitude of the detected DET_REPLIES signal is also output to the monitor main board via XN2:14 as REPLY_LVL.
The received RF power is demodulated by an envelope detector V1 and the resultant video pulses are amplified and buffered by N1a and N1b respectively. Resistors R3 and R4 are used to provide a small DC bias to the detector diode V1; this enables the detector to recover signals at very low levels.
The output of N1a at N1:1 is buffered by N3a, producing the signal DET_REPLIES.
The output of N1b at N1:7 is fed into a peak rider circuit consisting of N4a and V3. The peak amplitude of the pulse envelope is buffered by N2b and amplified by N3b, producing the signal REPLY_LVL.
The peak power monitor is capable of producing a DC level of greater than 2.5 volts for input RF power levels of +10 dBm to +20 dBm. This DC level is used by the monitor main board to determine RF power fault levels.
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Table 2-13 Summary of Front Panel Controls and Indicators : Monitor Module
CONTROL/INDICATION FUNCTION DETAILS TYPE LEGEND FUNCTION/SETTING/INDICATION
Toggle switch
MONITOR OUTPUTS
FAILED All monitor outputs are set to their fault condition (high) which invokes a FAILED condition for all front panel indicators and all fault lines read by the CTU. The TEST indicator is turned on.
NORMAL Monitor module operates normally and TEST indicator is off.
Green LED DELAY Green LED SPACING Green LED EFFICIENCY Green LED RATE Green LED POWER Green LED IDENT Green LED ANTENNA Green LED SHAPE
When on, indicates that the named parameter is within preset limits.
Yellow LED SELF TEST Indicates that the CTU is performing a Monitor Self Test, during which the CTU will look for the two primary parameters in the fault state.
Red LED PRIMARY Indicates that one or both of the primary parameters (Delay, Spacing) are outside preset limits.
Yellow LED SECONDARY Indicates that one or more of the six secondary parameters (Efficiency, Rate, RF Power, Ident, Antenna, Shape) are outside preset limits.
Red LED TEST Indicates that the MONITOR OUTPUTS switch is not in the NORMAL position.
Green LED POWER ON Indicates that DC power is applied to the monitor. Test jack ERP PULSE Detected pulse waveform of transmitted pulse - sampled near the
antenna and fed into the ERP IN connector. Test jack ERP EARTH Earth reference for the ERP PULSE test jack signal. Test jack +1 5V Buffered output of the internally generated +15 volts. Test jack +5V Buffered output of the internally generated +5 volts. Test jack EARTH Common earth of the power supplies, the internally generated supplies,
and all input and output signals.
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Table 2-14 Summary of Internal Controls : Monitor Module
CONTROL FUNCTIONS SUBASSY TYPE REF LEGEND FUNCTIONISETTING/INDICATION
Preset resistor
R87 Sets the ERP monitor fault alarm reference level to 0 dB at commissioning. 1 2 3 4 5 6 7 8 ON
1A72511 Main PWB Assembly, Monitor Module 8-way DIL
switch S1 PULSE WIDTH
LOWER REJECT LIMIT OFF
Multiply the required lower reject limit (in microseconds) by 10 and subtract 1. Encode the switches for this value. For a lower reject limit of 2.9 microseconds the switches are encoded for a number of 28, as shown above. 1 2 3 4 5 6 7 8 ON
8-way DIL switch
S2 FALL TIME UPPER REJECT LIMIT OFF
Multiply the required upper reject limit (in microseconds) by 10 and subtract 2. Encode the switches for this value. For an upper reject limit of 3.6 microseconds the switches are encoded for a number of 34, as shown above. 1 2 3 4 5 6 7 8 ON
8-way DIL switch
S3 RISE TIME UPPER REJECT LIMIT OFF
The Monitor Fault Limit switches S1-4 and S7-10, S12 and S13 are binary coded, with switch 1 of the DIL switches the least significant and switch 8 (or 10) the most significant. They use inverted logic, with the OFF position of the switch being active.
Multiply the required upper reject limit (in microseconds) by 10 and subtract 2. Encode the switches for this value. For an upper reject limit of 3.1 microseconds the switches are encoded for a number of 29, as shown above. 1 2 3 4 5 6 7 8 ON
8-way DIL switch
S4 PULSE WIDTH REJECT WINDOW OFF
Multiply the difference between the required upper and lower reject limits (in microseconds) by 10 and subtract 1. Encode the switches for this value. For an upper reject limit of 4.1 microseconds the difference between the limits is 1.2 microsecond and the switches are encoded for a number of 11, as shown above. 1 2 3 4 5 6 7 8 ON
8-way DIL switch
S7 POWER LEVEL LOWER REJECT LIMIT OFF
The power level corresponds to the switch setting, from -1 to -8 dB. For a lower reject limit of -3 dB the switches are set as shown above.
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CONTROL FUNCTIONS SUBASSY
TYPE REF LEGEND FUNCTIONISETTING/INDICATION 1 2 3 4 5 6 7 8 ON
1A72511 Main PWB Assembly, Monitor Module
8-way DIL switch
S8 IDENT GAP UPPER REJECT LIMIT OFF
Subtract 2 from the required upper reject limit (in seconds). Encode the switches for this value. For an upper reject limit of 62 seconds the switches are encoded for a number of 60, as shown above. 1 2 3 4 5 6 7 8 ON
8-way DIL switch
S9 DELAY REJECT WINDOW
OFF Multiply the difference between the required upper
and lower reject limits (in microseconds) by 10 and subtract 1. Encode the switches for this value. For an upper reject limit of 50.5 microseconds the difference between the limits is 1.0 microsecond and the switches are encoded for a number of 9, as shown above. 1 2 3 4 5 6 7 8 ON
8-way DIL switch
S10 SPACING REJECT WINDOW OFF
Multiply the difference between the required upper and lower reject limits (in microseconds) by 10 and subtract 1. Encode the switches for this value. For an upper reject limit of 12.5 microseconds the difference between the limits is 1.0 microsecond and the switches are encoded for a number of 9, as shown above. 1 2 3 4 5 6 7 8 9 10 ON
10-way DIL switch
S12 DELAY LOWER REJECT LIMIT
OFF Multiply the required lower reject limit
(in microseconds) by 10 and subtract 1. Encode the switches for this value. For a lower reject limit of 49.5 microseconds the switches are encoded for a number of 494, as shown above. 1 2 3 4 5 6 7 8 9 10 ON
10-way DIL switch
S13 SPACING LOWER REJECT LIMIT OFF
Multiply the required lower reject limit (in microseconds) by 10 and subtract 1. Encode the switches for this value. For a lower reject limit of 11.5 microseconds the switches are encoded for a number of 114, as shown above.
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2.3.10 Control and Test Unit 1A72550
2.3.10.1 General The Control and Test Unit (CTU) monitors, controls and tests various functions within the LDB-102 DME. The CTU contains a comprehensive test facility to allow rapid assessment of performance. By keypad selection, each of the main DME parameters, including signal levels and status conditions, can be measured and displayed. The CTU is used in conjunction with the test interrogator module(s) to perform the measurements and tests.
The CTU controls the operation of a single or dual transponder configuration LDB-102 DME, both locally and remotely. It also performs data acquisition and control functions for the Remote Control and Monitoring System (RCMS).
A detailed description of the controls and indicators of the CTU is given in Appendix A.3.
2.3.10.2 Mechanical The CTU comprises three boards, namely the CTU Processor PWB Assembly (1A72552), the CTU Front Panel PWB Assembly (1A72553) and the RCMS Interface PWB Assembly (1A72555). The boards are mounted on an aluminium frame and connected using ribbon cables. A DC/DC converter is also mounted on the aluminium frame and connects to the CTU processor board. The CTU is installed in the CTU subrack.
A block diagram of the CTU is shown in Figure 2-34. Details of the individual boards are given in following sections.
Figure 2-34 CTU Block Diagram
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2.3.10.3 CTU Processor PWB Assembly 1A72552 REFER Circuit Diagram 72552-1-02
2.3.10.3.1 General The CTU processor board provides the microprocessor and memory for the CTU. It provides interfaces with the CTU front panel board, the RCMS interface board, and Transponders 1 and 2. The CTU also has a serial port, and controls the sourcing of the ident signals.
A block diagram of the CTU processor board is shown in Figure 2-35.
2.3.10.3.2 Microprocessor The microprocessor, D9, is a CMOS 80C186 which operates at 10 MHz. The processor provides a clock generator, an interrupt controller, three 16-bit timers, memory and peripheral chip select logic, and a wait state generator.
The microprocessor supervisory chip, N2, acts as a watchdog for the processor and as a 24 volts monitor. If the watchdog input (WDI), pin 11, is not toggled within 1.6 seconds, RESET, pin 15, pulses low causing the processor to be reset. N2 monitors the 24 volts line via the power fail comparator input (PFI), pin 9. If the 24 volts line voltage drops below a preset value then the voltage at PFI drops below its threshold. This in turn causes PFO, pin 10, to go low, which activates the LOW_TPNDR_BAT alarm. The preset value may be adjusted by R32 to be anywhere in the range 18 to 23 volts.
The wait state generator and address decoder, D13, is implemented using an EP610 programmable logic device (PLD). D13 generates external CTU bus signals for the interfaces with the front panel board, RCMS interface board and the transponders. It also produces the SRDY signal for the processor. The SRDY signal causes the processor to insert wait states during input/output operations to slower devices. All devices selected by PCS0, PCS1, PCS2, MCS1 and MCS2 require seven wait states. All other devices require zero wait states.
D7, D8 and D10 are address latches.
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Figure 2-35 CTU Processor Board Block Diagram
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2.3.10.3.3 Memory The memory on the CTU processor board comprises 8Kx8 EEPROM, 64Kx16 EPROM, and 32Kx16 RAM.
The EEPROM, D16, is a 28C65. It is used to store the state of the CTU front panel at power down so that it can be restored to the same state at the next power-up; it also stores the number of restarts.
The EPROM, D17, is a 27C210. It is used to store the CTU program, operating system, applications code, built-in tests and production test code.
The RAM is divided between two chips; D15 stores the low bytes, and D14 stores the high bytes.
2.3.10.3.4 Serial Port The RS-422 serial port comprises two differential bus transceivers, N4 and N5, as well as a universal asynchronous receiver/transmitter (UART), D6. This arrangement allows the serial port to operate in full-duplex mode.
The serial port is used to communicate with a remote maintenance monitoring system.
2.3.10.3.5 RCMS and Front Panel Interface The interface to the RCMS interface board and the front panel board is implemented using D29, D30 and D31.
D29 is an octal bus transceiver used to transfer data between the CTU processor board and the other two boards. DT/R from the processor controls the direction of data flow through the transceiver. Resistor networks RN20 and RN21 reduce noise susceptibility on input data to D29.
D30 is the address buffer, and its outputs are enabled when PCS0 is low. A0 from the processor is not buffered since it is used as an enable signal rather than an address signal by the processor (analogous to BHE for the low data byte). Hence ADDR0 to the front panel and RCMS interface boards connects to A1, ADDR1 connects to A2, and so on up to ADDR6.
D31 is the control byte buffer. Its outputs are always enabled.
The interrupt input (XINT) from the front panel and RCMS interface enters the CTU board on XN3:34. It is ANDed with the RDY/BSY signal from the EEPROM. This has the effect of disabling XINT while the EEPROM is being written to.
2.3.10.3.6 Transponder Interfaces The Transponder 1 interface comprises D35, D36 and D37, and connects to Transponder 1 via XN2. The Transponder 2 interface comprises D32, D33 and D34, and connects to the RCMS interface board via XN3. (The RCMS interface board directs the signals to Transponder 2.).
The arrangement and operation of these interfaces is similar to the RCMS and front panel interface in Section 2.3.10.3.5.
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2.3.10.3.7 Ident Selection of the ident signals is performed by the ident tone and keying PLD, D2. The ident PLD has the following inputs and outputs:
a. Sources of ident signal (inputs):
1. ASSOC_IDENT_IN;
2. MA_IDENT_OUT_1;
3. MA_IDENT_OUT_2;
4. REQ_IDENT_KEYING_1;
5. REC_IDENT_KEYING_2;
6. REC_IDENT_TONE_1; and
7. REC_IDENT_TONE_2.
b. Clock inputs:
1. 2440 Hz; and
2. TMROUT.
c. Select inputs:
1. ASSOC_IDENT_SEL_1;
2. ASSOC_IDENT_SEL_2;
3. REC_IDENT_SEL_1; and
4. REC_IDENT_SEL_2.
d. Ident signal outputs:
1. IDENT_ON;
2. MA_IDENT_IN_1;
3. MA_IDENT_IN_2;
4. MA_IDENT_OUTPUT;
5. DET_IDENT_KEY;
6. IDENT_TONE_TRANSFORMER; and
7. IDENT and CPU TONE.
The relationship between these is shown in Table 2-15 to Table 2-17.
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Table 2-15 Ident PLD Outputs: MA_IDENT_IN_1,2, MA_IDENT_OUT, IDENT_TONE_TRANSFORMER, DET_IDENT_KEY
INPUTS OUTPUTS
ASSOC_IDENT_SEL MA_IDENT_IN
2 1 2 1 MA_IDENT_OUT IDENT_TONE_
TRANSFORMER DET_IDENT_KEY
0 0 0 ASSOC_IDENT_IN MA_IDENT_OUT_1 REC_IDENT_TONE_1 REC_IDENT_KEYING_1
0 1 ASSOC-DENT_IN 0 MA_IDENT_OUT_2 REC_IDENT_TONE_2 REC_IDENT_KEYING_2
1 0 0 0 0 0 0
1 1 0 0 0 0 0
Table 2-16 Ident PLD Output: IDENT+ CPU_TONE
INPUTS OUTPUTS
REC_IDENT_SEL
2 1 IDENT +CPU_TONE
0 0 REC_IDENT_TONE_1
0 1 REC_IDENT_TONE_2
1 0 2240 Hz
1 1 TMROUT
Table 2-17 Ident PLD Output: IDENT_ON
INPUTS OUTPUTS
ASSOC_IDENT_SEL REC_IDENT_SEL
2 1 2 1 2240 Hz IDENT_ON
x x 1 1 x 0
0 x 0 0
x 0 ↑ REC_IDENT_KEYING_1
0 x 0 1
x 0 ↑ REC_IDENT_KEYING_2
0 x 1 x
x 0 ↑ q
x = Don't care ↑ = Low-to-high transition q = State of IDENT_ON at previous low-to-high transition of 2440 Hz
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The MA_IDENT_OUTPUT signal is produced by N1 which is an optically coupled MOSFETV relay. This signal appears as either an open circuit or as a contact closure. The DET_IDENT_KEY output appears as either +24 volts or ground. The other five IDENT outputs are TTL level signals.
The recovered ident signal at D2:9 activates buzzer B1 for monitoring purposes. The level of the signal may be adjusted using the variable resistor R33.
2.3.10.3.8 Switches There are two 8-position DIP switches on the board, S1 and S2, which are read via buffers D20 and D25 and are used to configure the CTU. The setting details for these switches are given in Appendix A.
2.3.10.3.9 Indicators There are eight green LEDs on the CTU board, H1-8. H1 and H2 are driven by one of the address latches, D10, and the remaining six LEDs are driven by octal latch D26. The meaning of the LED states is summarised in Table 2-18.
Table 2-18 CTU Processor Board LED Indicators
LED INDICATES H1 A19 activity H2 A16 activity
H3 -
H4 ROM Test OK
H5 -
H6 Heartbeat
H7 -
H8 RAM Test OK
2.3.10.3.10 Links The CTU board has six links, XN5-10, the functions of which are summarised in Table 2-19.
Table 2-19 CTU Processor Board Links
LED FUNCTION XN5 Ground one leg of MA_IDENT_OUTPUT XN6 Watchdog disable
XN7 Select signature analysis
XN8 Ident Test
XN9 Watchdog Test
XN10 Pullup ASSOC.IDENTIN input to +24 volts
NOTE: The function is enabled when the link is fitted
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2.3.10.3.11 Miscellaneous Inputs and Outputs There are 13 bits read by D19 and D24. Their source and signal type are summarised in Table 2-20.
Table 2-20 CTU Processor Board D19 and D24 Inputs
BIT NAME SOURCE DESCRIPTION 15 LOW_TPNDR_BATT N2:10 High if battery voltage < preset 14 Spare
13 Spare
12 ANT_REL_TEST External I/O Board Ground or open circuit
11 TI_MON_TEST_2 RCMS (Transponder 2) Ground or open circuit
10 TI_MON_TEST_1 Transponder 1 Ground or open circuit
9 TPNDR_TEST_2 RCMS (Transponder 2) Ground or open circuit
8 TPNDR_TEST_1 Transponder 1 Ground or open circuit
7 EEPROM_RDY D16:1 Low if EEPROM engaged in write cycle
6 IDENT_ON D2:6 Ident output
5 Spare
4 TRNS_CB_OFF External I/O Board Ground or open circuit
3 BAT_CHG_NORM_1 External I/O Board 24 volts or open circuit
2 BAT_CHG_NORM_2 External I/O Board 24 volts or open circuit
1 AC_PWR_NORM_1 External I/O Board 24 volts or open circuit
0 AC_PWR_NORM_2 External I/O Board 24 volts or open circuit
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There are 16 bits output via D18 and D23. Their destination and signal type are summarised in Table 2-21.
Table 2-21 CTU Processor Board D18 and D23 Outputs
BIT NAME DESTINATION DESCRIPTION 15 ASSOC_IDENT_SEL_2 D2:19 +24 volts or ground 14 ASSOC_IDENT_SEL_1 D2:23 +24 volts or ground
13 ANT_RELAY_CONTROL External I/O Board +24 volts or ground
12 RV_IDENT_INH_2 RCMS (Transponder 2) +5 volts or ground
11 RV_TX_INH_2 RCMS (Transponder 2) +5 volts or ground
10 RV_RF_ON_2 RCMS (Transponder 2) +5 volts or ground
9 TPDR_PWR_ON_2 RCMS (Transponder 2) +5 volts or ground
8 PA_PWR_ON_2 RCMS (Transponder 2) +5 volts or ground
7 REC_IDENT_SEL_2 D2:10 +24 volts or ground
6 REC_IDENT_SEL_1 D2:14 +24 volts or ground
5 MAINT_FNS_EN RCMS (Transponder 2) and Transponder 1 +24 volts or ground
4 RV_IDENT_INH_1 Transponder 1 +5 volts or ground
3 RV_TX_INH_1 Transponder 1 +5 volts or ground
2 RV_RF_ON_1 Transponder 1 +5 volts or ground
1 TPDR_PWR_ON_1 Transponder 1 +5 volts or ground
0 PA_PWR_ON_1 Transponder 1 +5 volts or ground
2.3.10.3.12 Counter D12 is a binary ripple counter. The clock input (pin 10) is 10 MHz clock output from the processor. The three D12 outputs used are 610 Hz (pin 3), 1220 Hz (pin 2) and 2440 Hz (pin 1). Either 610 Hz or 1220 Hz can be selected to be a clock input for the processor (D9:20, 21) and the UART (D6:5). The selection is made by fitting either R30 or R31 as required. The 2440 Hz output of D12 is an input to the ident PLD (D2:2).
2.3.10.3.13 Power 24 volts from the main power supply enters the CTU board via XN1:3a and XN1:3c. This is distributed around the board and to XN3:43 and XN3:44 for distribution to the front panel and RCMS interface boards. 24 volts is also connects to XN11:1. From here it is fed to the CTU DC/DC converter which returns 5 volts via XN11:4. The DC/DC converter is a switching power supply which is mounted on the CTU metalwork.
5 volts from the DC/DC converter is used on the CTU processor board; it is distributed to the front panel board and RCMS interface board via XN3:39 and 40; and it is distributed to the external I/O board via XN1:2c and it is distributed for general use by other modules mounted in the CTU subrack via XN1:12a,c, 13a,c and 14a,c.
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2.3.10.3.14 External 5 Volts Circuit The external 5 volts circuit comprises V7, R50-52, C53-54, and N3. This circuit provides a 5 volts supply for Transponder 1 which is independent of the CTU 5 volts supply. This ensures that any problem which brings down the transponder 5 volts supply will not adversely affect CTU 5 volts.
Diode V7 protects the linear regulator N3 from any accidental reverse polarity voltages which may be applied to the 24 volts line. R52 restricts the maximum current drawn to about 150 mA. During normal operation the current supplied by N3 is typically less than 60 mA.
R50 and R51 set the output voltage of N3 to be in the range 5.3 to 5.7 volts.
2.3.10.4 CTU Front Panel PWB Assembly 1A72553 REFER Circuit Diagram 72553-1-02
2.3.10.4.1 General The front panel board provides the CTU user interface. It has switches, LEDs and a 2-line by 40-character LCD which allow the user to:
a. display operational parameters and test results; and
b. exercise local control and monitoring of the DME.
The LCD displays a menu of functions available to the user on the function keys, while other keys have dedicated functions.
A block diagram of the front panel board is shown in Figure 2-36.
Figure 2-36 CTU Front Panel Board Block Diagram
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2.3.10.4.2 Interface with CTU Processor PWB Assembly The interface with the CTU processor board comprises D7, D9, RN1-6 and RN12-14. Resistor networks RN1, RN2, RN4, RN5, RN12 and RN13 reduce noise effects on the incoming fines. D9 is an EP610 PLD which is programmed as the address decoder for the front panel. The address map for the board is shown in Table 2-22. D7 is a 74HC245 data transceiver which is used to transfer data bits D0-7 between the front panel and the processor board. The XDT/R signal from the processor is used to control the direction of data flow through the transceiver.
Table 2-22 CTU Front Panel Address Map
A6 A5 A4 A3 A2 A1 PCS0 XWR XRD SELECTS 0 x x x x x 0 0 1 Data transceiver D7 (Write) 0 x x x x x 0 1 0 Data transceiver D7 (Read)
0 0 0 0 0 0 0 0 1 LCD control/address (Write)
0 0 0 0 0 1 0 0 1 LCD data (Write)
0 0 0 0 0 1 0 1 0 LCD data (Read)
0 0 0 0 1 0 0 1 0 Switch scanner and coder D5 (Read)
0 0 0 0 1 1 0 1 0 Alarm inhibit/delay D3 (Read)
0 0 0 1 0 0 0 0 1 Alarm register 1 D11 (Write)
0 0 0 1 0 1 0 0 1 Alarm register 2 D10 (Write)
0 0 0 1 1 0 0 0 1 Control status 1 D12 (Write)
0 0 0 1 1 1 0 0 1 Control status 2 D12 (Write)
0 0 1 0 0 0 0 0 1 Miscellaneous status D8 (Write)
2.3.10.4.3 Liquid Crystal Display The liquid crystal display (LCD) is 40-character by 2-line display. The view angle of the LCD may be adjusted by varying R1, which changes the feedback of the drive voltage to the LCD display provided by N1. V1 and V2 in the operational amplifier circuit provide temperature compensation. The forward voltage drop across diodes V1 and V2 varies with temperature, resulting in the positive input to the amplifier also varying with temperature; this helps to maintain good LCD contrast.
2.3.10.4.4 Indicators There are 33 LEDs visible to the CTU user. These LEDs provide information on DME control status, test functions, power status, alarms and miscellaneous status. Another LED, the heartbeat LED (H14) is not visible to the user. It is used as a diagnostic aid to make sure that the CTU processor software is writing to the front panel. During normal operation the heartbeat LED will flash about once a second.
The octal latches D6, D8 and D10-12 are used to control the LEDs. A high level on the XRES line from the CTU processor will force all latch outputs high, turning the LEDs off. Also during reset, transistors V7 and V8 will turn on, causing the PRIMARY alarm LED (H30) and the CTU alarm LED (H33) to be on.
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2.3.10.4.5 Pushbutton Switches The front panel has 16 pushbutton switches which are read by the switch scanner and coder PLD, D5. This divides the keys into two groups, those with dedicated inputs and outputs, and those read as part of a four-by-four matrix and coded to form a four-bit output.
The TI RATE switches, 1 kHz (S6) and 10 kHz (S7) have dedicated inputs and outputs. The D5 outputs for these switches, pins 20 and 21, are enabled by the select signal from the address decoder which enters D5:4. R11-12, C9-10 and D4 make up the debounce circuitry for these switches.
Switches S1-5, S10 and S13-20 are read as part of a 4x4 array. D5 senses switch closures by driving the COL1-4 outputs low, one at a time, and reading the ROW1-4 inputs. When D5 recognises a switch closure, the VALID output (pin 19) goes high, and the code corresponding to the pressed pushbutton is output on pins 15-18 as shown in Table 2-23. If more than one of the pushbuttons is pressed at any one time, no switch closure is recognised by D5, R10, C8 and D4 debounce switch closures and openings from the switch matrix.
No switches are fitted in the S8 and S9 locations.
Table 2-23 CTU Front Panel Switch Scanner and Coder Output
I013 I014 I015 I016 SWITCH RECOGNISED 0 0 0 0 S20 0 0 0 1 S19 0 0 1 0 S18 0 0 1 1 S17 0 1 0 0 S16 0 1 0 1 S15 0 1 1 0 S14 0 1 1 1 S13 1 0 0 0 S1 1 0 0 1 S2 1 0 1 0 S3 1 0 1 1 S4 1 1 0 0 S5 1 1 0 1 S10 1 1 1 0 S9 1 1 1 1 S8
2.3.10.4.6 Rotary Switches There are two rotary switches, ALARM POWER ON INHIBIT (S11) and ALARM DELAY (S12). The outputs of these binary coded decimal (BCD) switches are read via buffer D3. S11 is not accessible to the operator, as it is set only by a technician. S12 is mounted on the front panel and is accessible to the user.
2.3.10.4.7 Charge-pump Voltage Inverter -5 volts for the front panel is obtained from +5 volts by using two 74HC04 inverter chips, D1 and D2, in a charge-pump voltage inverter circuit.
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2.3.10.5 RCMS Interface MB Assembly 1A722555 REFER Circuit Diagram 72555-1-02
2.3.10.5.1 General The RCMS interface board provides opto-isolators to read remote control relay inputs, and relays to control remote lamp outputs. All of the RCMS interface relays are fitted with surge protection. This board also extends the Transponder 2 interface signals from the CTU processor board to a backplane connector.
A block diagram of the RCMS interface board is shown in Figure 2-37.
Figure 2-37 RCMS Interface Board Block Diagram
2.3.10.5.2 Interface with CTU Processor MB Assembly The interface with the CTU processor board comprises D1, D2 and RN1-9. Resistor networks RN2, RN3, RN4, RN5, RN8 and RN9 reduce noise effects on the incoming lines. D1 is a PLD which is programmed as the address decoder for the RCMS interface board. The address map for the board is shown in Table 2-24 D2 is a 74HC245 data transceiver which is used to transfer data bits D0-7 between the RCMS interface board and the processor board. The XDT/R signal from the processor is used to control the direction of data flow through the transceiver.
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Table 2-24 RCMS Interface Address Map
A6 A5 A4 A3 A2 A1 PCS0 XWR XRD SELECTS 1 x x x x x 0 0 1 Data transceiver D2 (Write) 1 x x x x x 0 1 0 Data transceiver D2 (Read)
1 0 0 0 1 0 0 0 1 Miscellaneous status D3 (Write)
1 0 0 0 1 1 0 0 1 RCMS status 2 D4 (Write)
1 0 0 1 0 1 0 0 1 Bit out 3 D5 (Write)
1 0 0 1 1 1 0 1 0 Bit feedback 2 D6 (Read)
1 0 1 0 0 0 0 1 0 RCMS control 1 D7 (Read)
2.3.10.5.3 Input/Output Feedback The latch D5 and buffer D6 form an input/output feedback circuit. An RCMS interface board may not be fitted to all CTUs, and so this circuit is used to check for the presence of the board. If a byte written to the latch can be read back, the RCMS interface board is fitted.
2.3.10.5.4 Relays The RCMS interface board is fitted with 15 relays, K1-15. The relays have changeover contacts fitted with varistors, F2-31, to provide surge protection. The relays are controlled via octal latches D3 and D4.
2.3.10.5.5 Heartbeat Indicator The heartbeat LED, H1, is used as a diagnostic aid to make sure that the CTU processor software is writing to the RCMS interface board. During normal operation the LED will flash about once a second.
2.3.10.5.6 Opto-isolator Inputs The RCMS interface board is fitted with six opto-isolator inputs. Each input comprises an opto-isolator, a diode, a 3.9 volts zener diode, a 1 uF capacitor and a 4.75 kilohms resistor. The resistor limits current to the opto-isolator; the capacitor filters the applied voltage; the zener ensures that low voltage inputs do not activate the opto-isolator; and the diode protects the opto-isolator against reverse polarity voltages. The inputs are read via buffer D7. The inputs to the buffer are normally pulled high by RN11 and go low when the opto-isolator is switched on.
2.3.10.5.7 Ident Tone Transformer The ident tone transformer, T1, is a 600 ohms balanced transformer used to send ident to a remote location via XN1:32a,c. The ident input is sourced from the CTU processor board via XN3:46. The variable resistor R1 may be used to adjust the level of the ident signal.
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2.3.10.5.8 External 5 Volts Circuit The external 5 volts circuit comprises V13, R10, R15-16, C18, C23, and N7. This circuit provides a 5 volts supply for Transponder 2 which is independent of the CTU 5 volts supply. This ensures that any problem which brings down the transponder 5 volts supply will not adversely affect CTU 5 volts.
Diode V13 protects the linear regulator N7 from any accidental reverse polarity voltages which may be applied to the 24 volts line. R10 restricts the maximum current drawn to about 150 mA. During normal operation the current supplied by N7 is typically less than 60 mA.
R15 and R16 set the output voltage of N7 to be in the range 5.3 to 5.7 volts.
2.3.10.5.9 External 24 Volts Circuit The external 24 volts circuit comprises R9 and F1, and is fitted if required to provide 24 volts to remote equipment via XN1:2a,c. R9 is a 10 ohms resistor and F1 is an RXE050 polyswitch thermistor. During normal operation the current drawn through R9 and F1 is less than 180 mA. In the event of a short circuit to ground at the remote equipment, R9 restricts the current to 2.4 amperes. At this current, F1 switches off in about 1.5 seconds, reducing the current to a negligible level until the remote fault is rectified. R9 (which is 10 watts rating) can comfortably withstand the overcurrent for the short period.
2.3.10.5.10 Transponder 2 Interface The RCMS interface board extends Transponder 2 signals between XN2 and XN3. XN2 is a backplane connector which connects to the transponder. XN3 connects via ribbon cable to the CTU processor board which controls the interface to the transponder.
2.3.11 Power Distribution Panel Single DME 1A72549 and Power Distribution Panel Dual DME 2A72549
REFER 1A72549 Circuit Diagram 72549-3-06 2A72549 Circuit Diagram 72549-3-16
The power distribution panels terminate and distribute the primary 24 volts supplies and provide circuit protection for DME circuits. The Power Distribution Panel for a single DME is a type 1A72549; a block diagram for this is shown in Figure 2-38. For a dual DME the Power Distribution Panel is a type 2A72549; a block diagram for this is shown in Figure 2-39.
The circuit breakers used have a second set of contacts which are electrically isolated from the trip contacts. These secondary contacts are connected in series and tied to ground at one end. The other end is connected to the CTU as the TRNS_CB_OFF line. If all circuit breakers are on, the TRNS_CB_OFF signal to the CTU will be ground. If one or more of the circuit breakers are off, the TRANS_CB_OFF signal will appear as an open circuit at the CTU.
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Figure 2-38 Single Power Distribution Panel Block Diagram
Figure 2-39 Dual Power Distribution Panel Block Diagram
2.3.12 AC Power Supply 3A71130 Manufacturer documentation for the power supply, including circuit and components schedule, is identified in Appendix J.
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2.3.13 Power Supply System Dual AC 2A/3A69758 REFER Circuit Diagram 69758-3-28
The Dual AC Power Supply Systems 2A69758 and 3A69758 each consist of two AC Power Supplies 3A71130 mounted in an equipment rack. The two types are electrically and functionally identical but they are mounted in different rack sizes; the type supplied depends on the installation requirements. The layout of a type 2A69758 is shown in Figure 2-40, as an example.
Each AC power supply positive and negative output is connected independently to the DME racks +ve and -ve battery terminals.
The AC power supplies' status outputs (AC Power Normal 1 and 2, Bty Charger Normal 1 and 2 and Mains OK) are connected to terminal blocks for ease of connection. It should be noted that 'Mains OK' is from AC power supply 1 only.
For detail on AC Power Supply 3A71130, refer to the handbook detail in Appendix J.
Figure 2-40 Power Supply System Dual AC 2A69758 Layout
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2.3.14 Transponder Subrack 1A72513 REFER Circuit Diagram 72556-2-01
The transponder subrack consists of a standard Eurocard 6 unit by 280 mm deep card frame which accepts the five transponder plug-in modules. The card frame is fitted with a Transponder Subrack Motherboard (1A72556) in the upper three units, and an RF connector mounting panel in the lower three units to make the coaxial connections when the modules are plugged in.
The chassis of the plug-in modules are grounded to the subrack through securing screws fitted to the front panels of the modules.
2.3.15 CTU Subrack 1A72506 REFER Interwiring Diagrams 72550-1-03, 72505-2-06, 72505-2-17
The CTU subrack consists of a standard Eurocard 6 unit by 220 mm deep card frame which accepts the Control and Test Unit (1A72550) and the Power Distribution Panel (1A/2A72549); a number of spare monitors are available for expansion (for remote maintenance monitoring, for example).
All modules are of the plug-in type. The CTU plugs into DIN type IDC connectors in the card frame.
The power distribution panel plugs into a 15-way DIN connector in the card frame, which is connected directly to the main power loom.
The chassis of the plug-in modules are grounded to the subrack through securing screws fitted to the front panels of the modules.
2.3.16 External I/O PWB Assembly 1A72557 REFER Circuit Diagram 72557-1-01
The External I/O PWB Assembly 1A72557 is mounted on the side of the rack frame at the rear of the transponder subrack. It provides the interface for external connections to the DME unit. These are made using the terminal block connectors XB1 to XB11.
Connections to the CTU and the Remote Control and Monitoring System (RCMS) are made by two 64-way ribbon cable connectors XN6 and XN8.
XN1 connects to the RF panel and provides the RF relay signals and +24 volts to the CTU. XN2 connects the battery charger signals (Mains OK, AC Normal and Battery Charger Normal) to the CTU.
Amplifier N2 and transistor V1 provide a protected power supply, for external use with the status signalling relays. Should the external load current exceed the rated load for the circuit, the output voltage will fall and the output current will 'fold-back', reducing the dissipation in transistor V1.
Voltage divider R1 and R9 establish a reference voltage at the non-inverting input, N2:3, of amplifier N2. The voltage at the inverting input, N2:2, is determined by resistors R2, R7 and R8. Under normal load conditions, this voltage is slightly above the voltage at N2:3, so the output at N2:6 is close to ground and transistor V1 is turned on.
When the load current approaches the limiting value, the voltage drop across R4 and R5 causes the voltage at N2:2 to fall slightly below the voltage at N2:3 The voltage at the output, N2:6, therefore starts to rise, turning off V1 and causing V1 collector voltage to fall. At the same time, positive feedback is applied through R8, which pulls the voltage at N2:2 even lower, causing V1 collector voltage to fall further so that the load current decreases. This creates the so-called 'fold-back' characteristic, where the short-circuit current is significantly less than the current at the onset of limiting.
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Voltage regulator N1 provides a remote supply for the modem connector XN3 (for use by a remote maintenance monitoring system).
2.3.17 1kW PA Power Supply Frame 1A72503 This is designed to carry the 1kW PA Power Supply (1A72540).
The frame occupies 6 units of rack space, and has a front panel which hinges forward and down to provide access to the 1kW PA power supply, which is fitted to this panel.
The front panel has two straps to stop it approximately horizontally when open. It is fitted with two captive screws to secure it in the closed position. When fitted to the rack the 1kW RF Power Amplifier (1A72535) is located directly behind the 1kW PA power supply frame.
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3-i
SECTION 3
ALIGNMENT AND ADJUSTMENT
HA72500 SECTION 3
3-ii
TABLE of CONTENTS
3. ALIGNMENT AND ADJUSTMENT ............................................................. 3-1 3.1 INTRODUCTION 3-1 3.2 FIELD PERFORMANCE CHECKS AND ALIGNMENT 3-2
3.2.1 Introduction.................................................................................................. 3-2 3.2.2 Test Equipment ........................................................................................... 3-2 3.2.3 General Requirements ................................................................................ 3-2 3.2.4 Test Procedures .......................................................................................... 3-3
3.2.4.1 Preliminaries 3-3 3.2.4.2 Module Presets 3-4 3.2.4.3 Procedural Requirements 3-10 3.2.4.4 Test Interrogator Alignment 3-11 3.2.4.5 RF Source and RF Amplifier Alignment and Tests 3-14 3.2.4.6 RF Panel Preselector Filter Alignment and Tests 3-15 3.2.4.7 Receiver Video Alignment 3-16 3.2.4.8 Transmitter Driver RF Output Alignment 3-16 3.2.4.9 1kW RF Power Amplifier Alignment 3-18 3.2.4.10 Transmitter Pulse Parameters 3-20 3.2.4.11 Receiver Performance Tests 3-23 3.2.4.12 Echo Suppression 3-27 3.2.4.13 Transponder Delay 3-29 3.2.4.14 Ident 3-30 3.2.4.15 Monitor Fault Limits 3-31 3.2.4.16 Control System - PART 1 - SINGLE DME 3-38 3.2.4.16 Control System - PART 2 - DUAL DME 3-43 3.2.4.17 Rack Current Drain 3-52 3.2.4.18 Final Check 3-53
3.2.5 Test Interrogator Alignment ....................................................................... 3-54 3.2.6 Receiver Video Alignment ......................................................................... 3-56 3.2.7 Transmitter Driver Alignment..................................................................... 3-57
3.2.7.1 Preparation 3-57 3.2.7.2 RF Alignment 3-59
3.2.8 Function Generator Alignment................................................................... 3-60 3.2.9 IF Amplifier Alignment ............................................................................... 3-61
3.2.9.1 Preliminary Adjustments 3-61 3.2.9.2 Preamplifier Tuning 3-61 3.2.9.3 Local Oscillator Tuning 3-61 3.2.9.4 Narrowband Detector Tuning 3-62
3.2.10 Y-channel Operation.................................................................................. 3-62 3.3 DEPOT PERFORMANCE CHECKS AND ALIGNMENT 3-66
3.3.1 Introduction................................................................................................ 3-66 3.3.2 Test Equipment Required.......................................................................... 3-66 3.3.3 Module Presets.......................................................................................... 3-67
3.3.3.1 Power Distribution Panel Presets 3-67 3.3.3.2 1kW RF Power Amplifier Presets 3-67 3.3.3.3 Control and Test Unit Presets 3-67 3.3.3.4 Receiver Video Presets 3-68 3.3.3.5 Transmitter Driver Presets 3-70 3.3.3.6 Transponder Power Supply Presets 3-70 3.3.3.7 Test Interrogator Presets 3-70 3.3.3.8 Monitor Module Presets 3-71 3.3.3.9 RF Panel Presets - Single DME 3-72 3.3.3.10 RF Panel Presets - Dual DME 3-73
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3.3.3.11 AC Power Supply Presets 3-73 3.3.4 Preliminary Check and Setup .................................................................... 3-76
3.3.4.1 Inspection 3-76 3.3.4.2 Switching On 3-76 3.3.4.3 Procedural Requirements 3-76
3.3.5 Test Interrogator Alignment ....................................................................... 3-77 3.3.5.1 RF Generator Alignment 3-77 3.3.5.2 RF Generator at Nominal Interrogation Frequency 3-78 3.3.5.3 RF Generator at 160 kHz Above Nominal Frequency 3-79 3.3.5.4 RF Generator at 160 kHz Below Nominal Frequency 3-79 3.3.5.5 RF Generator at 900 kHz Above Nominal Frequency 3-79 3.3.5.6 RF Generator at 900 kHz Below Nominal Frequency 3-80 3.3.5.7 Spacing Offset Control 3-80 3.3.5.8 RF Generator Output Frequencies 3-80 3.3.5.9 Test Interrogator Levels 3-81 3.3.5.10 Test Interrogator System Timing Parameters 3-82
3.3.6 RF Source and RF Filter Alignment and Tests.......................................... 3-82 3.3.7 RF Panel Preselector Filter Alignment and Tests...................................... 3-83 3.3.8 Receiver Video Alignment ......................................................................... 3-84
3.3.8.1 6 dB Offset 3-84 3.3.8.2 Receiver On-channel Threshold 3-85
3.3.9 Transmitter Driver Alignment..................................................................... 3-85 3.3.9.1 RF Output Alignment 3-85 3.3.9.2 Modulation Pulse Alignment 3-87
3.3.10 1kW RF Power Amplifier Alignment .......................................................... 3-88 3.3.10.1 Output Pulse Alignment 3-88 3.3.10.2 Automatic Level Control 3-91
3.3.11 Transmitter Pulse Parameters................................................................... 3-91 3.3.11.1 Test Setup 3-91 3.3.11.2 Output Pulse Power 3-92 3.3.11.3 Output Pulse Shape 3-92 3.3.11.4 Output Pulse Spacing 3-92 3.3.11.5 Output Pulse Peak Power Calibration 3-92 3.3.11.6 Output Pulse Spectrum 3-93
3.3.12 Receiver Performance Tests ..................................................................... 3-93 3.3.12.1 Test Setup 3-93 3.3.12.2 Receiver Sensitivity 3-94 3.3.12.3 Receiver Bandwidth 3-94 3.3.12.4 Receiver Selectivity 3-94 3.3.12.5 Receiver Decoding Window 3-95 3.3.12.6 Receiver CW Protection 3-95 3.3.12.7 Receiver Reply Rate 3-96 3.3.12.8 Dead Time 3-96
3.3.13 Transponder Delay .................................................................................... 3-96 3.3.13.1 Delay Variation with Input Level 3-96 3.3.13.2 Final Receiver Checks 3-97
3.3.14 Echo Suppression ..................................................................................... 3-98 3.3.14.1 Long Distance Echo Suppression 3-98 3.3.14.2 Short Distance Echo Suppression 3-98
3.3.15 Ident........................................................................................................... 3-99 3.3.15.1 Internal Ident 3-99 3.3.15.2 External Ident 3-99 3.3.15.3 Master Ident 3-100 3.3.15.4 Ident Frequency 3-100
3.3.16 Monitor Fault Limits ................................................................................. 3-100
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3.3.16.1 Test Setup 3-100 3.3.16.2 Delay Monitor 3-100 3.3.16.3 Spacing Monitor 3-101 3.3.16.4 Efficiency Monitor 3-102 3.3.16.5 Rate Monitor 3-103 3.3.16.6 Power Monitor 3-103 3.3.16.7 Ident Monitor 3-103 3.3.16.8 Antenna Monitor 3-104 3.3.16.9 Shape Monitor 3-104 3.3.16.10 Monitor Self Test 3-105 3.3.16.11 Monitor Fault Limits 3-105
3.3.17 24V DC Power Supply/Battery Charger .................................................. 3-106 3.3.17.1 Normal Operation 3-106 3.3.17.2 High Voltage Shutdown Adjust 3-107 3.3.17.3 Low Battery Alarm Adjust 3-108 3.3.17.4 Low Voltage Shutdown Adjust 3-108 3.3.17.5 Low Voltage Performance 3-109 3.3.17.6 DC Supply Adjustment 3-110
3.3.18 Control System - Single DME.................................................................. 3-111 3.3.18.1 Normal Operation 3-111 3.3.18.2 Primary Fault 3-112 3.3.18.3 Secondary Fault 3-113 3.3.18.4 Recycle Function 3-114 3.3.18.5 RCMS Remote Control 3-115
3.3.19 Control System - Dual DME .................................................................... 3-116 3.3.19.1 Normal Operation - No. 1 is MAIN 3-116 3.3.19.2 Primary Fault - No. 1 is MAIN 3-117 3.3.19.3 Secondary Fault - No. 1 is MAIN 3-119 3.3.19.4 Normal Operation - No. 2 is MAIN 3-121 3.3.19.5 Primary Fault - No. 2 is MAIN 3-122 3.3.19.6 Secondary Fault - No. 2 is MAIN 3-124 3.3.19.7 Operation in Maintenance Mode - No. 1 is MAIN 3-125 3.3.19.8 Operation in Maintenance Mode - No. 2 is MAIN 3-127 3.3.19.9 Recycle Function - No. 1 is MAIN 3-129 3.3.19.10 Recycle Function - No. 2 is MAIN 3-131 3.3.19.11 Hot/Cold Standby 3-132 3.3.19.12 RCMS Remote Control 3-132
3.3.20 Rack Current Drain.................................................................................. 3-133 3.3.21 Tidy Up .................................................................................................... 3-134 3.3.22 Y-channel Operation................................................................................ 3-134
3.4 LRU PERFORMANCE CHECKS AND ALIGNMENT 3-138 3.4.1 Introduction.............................................................................................. 3-138
3.4.1.1 Definition and Scope 3-138 3.4.1.2 List of Procedures 3-138 3.4.1.3 DME Rack Operation 3-138 3.4.1.4 Test Equipment 3-141 3.4.1.5 Common Procedures 3-141
3.4.2 Attenuator 1A69737................................................................................. 3-143 3.4.2.1 Test Equipment 3-143 3.4.2.2 Return Loss Check 3-144 3.4.2.3 Insertion Loss and Attenuation Check 3-144
3.4.3 Directional Coupler 1A69755................................................................... 3-144 3.4.3.1 Test Equipment 3-144 3.4.3.2 Return Loss Check 3-145 3.4.3.3 Insertion Loss Check 3-145
HA72500 SECTION 3
3-v
3.4.3.4 Coupling Ratio Check 3-145 3.4.4 Directional Coupler 2A69755................................................................... 3-146
3.4.4.1 Test Equipment 3-146 3.4.4.2 Return Loss Check 3-146 3.4.4.3 Insertion Loss Check 3-147 3.4.4.4 Coupling Ratio Check 3-147
3.4.5 250W RF Amplifier 1A69873 ................................................................... 3-148 3.4.5.1 Test Equipment 3-148 3.4.5.2 Setup 3-148 3.4.5.3 Calibration Procedure 3-149 3.4.5.4 Amplifier Test Procedure 3-150
3.4.6 AC Power Supply 3A71130 ..................................................................... 3-153 3.4.6.1 Test Equipment 3-153 3.4.6.2 Setup 3-153 3.4.6.3 Output Voltage Tests 3-156 3.4.6.4 Current Limit Adjustment 3-156 3.4.6.5 Performance Under Load 3-156 3.4.6.6 Transient Response 3-157 3.4.6.7 Output Ripple 3-157 3.4.6.8 Output Fall Alarm - Low Float Voltage 3-157 3.4.6.9 Output Fail Alarm - Charge Fail 3-158 3.4.6.10 High Voltage Alarm - Selective Shutdown Mode 3-158 3.4.6.11 High Voltage Alarm Delay Shutdown Mode 3-158 3.4.6.12 Fuse Alarm 3-159
3.4.7 Monitor Module 1A72510 ........................................................................ 3-159 3.4.7.1 Test Equipment 3-159 3.4.7.2 Alignment 3-159 3.4.7.3 Power Supply Check 3-159 3.4.7.4 Peak Power Monitor Check 3-160 3.4.7.5 RF Power Calibration 3-160 3.4.7.6 Front Panel Indicator Check 3-160
3.4.8 Main PWB Assembly Monitor Module 1A72511...................................... 3-161 3.4.8.1 Test Equipment 3-161 3.4.8.2 Determination of Monitor Switch Settings 3-161 3.4.8.3 Setup 3-162 3.4.8.4 Delay Monitor Check 3-163 3.4.8.5 Spacing Monitor Check 3-164 3.4.8.6 Efficiency Monitor Check 3-165 3.4.8.7 Reply Rate Monitor Check 3-165 3.4.8.8 Effective Radiated Power Monitor Check 3-165 3.4.8.9 Antenna Integrity Monitor Check 3-165 3.4.8.10 Level Monitor Check 3-166 3.4.8.11 Ident Monitor Check 3-166 3.4.8.12 Pulse Shape Monitor Check 3-167 3.4.8.13 Monitor Self Test Check 3-169 3.4.8.14 Front Panel Switch Check 3-169
3.4.9 Peak Power Monitor 1A72512................................................................. 3-169 3.4.9.1 Test Equipment 3-169 3.4.9.2 Performance Check 3-170 3.4.9.3 Completion 3-171
3.4.10 Test Interrogator 1A72514....................................................................... 3-171 3.4.10.1 Test Equipment 3-171 3.4.10.2 Signal Pulse Generation Checks 3-171 3.4.10.3 Pulse Switching 3-172 3.4.10.4 Signal Level Calibration 3-172
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3.4.10.5 Reply Signal Checks 3-173 3.4.11 Main PWB Assembly Test Interrogator 1A72515 .................................... 3-175
3.4.11.1 Test Equipment 3-175 3.4.11.2 Setup 3-175 3.4.11.3 Interrogation Generation Check 3-175 3.4.11.4 Spacing Offset Control 3-176 3.4.11.5 Reply Signal Processing Check 3-176 3.4.11.6 Measurement Facilities Check 3-177 3.4.11.7 Transponder Output Power Calibrate Alignment 3-178 3.4.11.8 Monitor Fault Limit Facilities Check 3-178 3.4.11.9 Final Check 3-178
3.4.12 RF Generator 1A72516 ........................................................................... 3-178 3.4.12.1 Test Equipment 3-178 3.4.12.2 Setup 3-179 3.4.12.3 Alignment 3-179 3.4.12.4 Completion 3-181
3.4.13 RF Filter 1A72517 ................................................................................... 3-182 3.4.13.1 Test Equipment 3-182 3.4.13.2 Requirement 3-182 3.4.13.3 Insertion Loss - Equipment Calibration 3-182 3.4.13.4 Filter Tuning Procedure 3-182 3.4.13.5 Insertion Loss - Measurement 3-183 3.4.13.6 Return Loss - Equipment Calibration 3-183 3.4.13.7 Return Loss - Measurement 3-183 3.4.13.8 Filter Adjustments 3-183 3.4.13.9 Filter Response at 1100 MHz 3-184 3.4.13.10 Filter Response at 960 MHz 3-184 3.4.13.11 Filter Response at 1215 MHz 3-184 3.4.13.12 Test at Station Frequency 3-185
3.4.14 Modulator and Detector 1A72518............................................................ 3-185 3.4.14.1 Test Equipment 3-185 3.4.14.2 Performance Check and Adjustment 3-185
3.4.15 Reply Detector 1A72519 ......................................................................... 3-187 3.4.15.1 Test Equipment 3-187 3.4.15.2 Performance Check 3-187 3.4.15.3 Detector Check 3-187 3.4.15.4 Timing Pulses Check 3-188 3.4.15.5 Detector Coincidence Check 3-188 3.4.15.6 Completion 3-188
3.4.16 Receiver Video 1A72520......................................................................... 3-189 3.4.16.1 Test Equipment 3-189 3.4.16.2 Setup 3-189 3.4.16.3 Performance Tests 3-190
3.4.17 Main PWB Assembly Receiver Video 1A72521 ...................................... 3-192 3.4.17.1 Test Equipment 3-192 3.4.17.2 Initial Setup 3-192 3.4.17.3 Decoder Checks 3-194 3.4.17.4 Over Interrogation Check 3-196 3.4.17.5 Dead Time Check 3-196 3.4.17.6 Long Distance Echo Suppression Check 3-197 3.4.17.7 Short Distance Echo Suppression Check 3-197 3.4.17.8 Squitter Check 3-197 3.4.17.9 Ident Check 3-198 3.4.17.10 Replies Inhibit Check 3-198
3.4.18 RF Source 1A72522 ................................................................................ 3-198
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3.4.18.1 Test Equipment 3-198 3.4.18.2 Setup 3-198 3.4.18.3 Alignment 3-199 3.4.18.4 Completion 3-200
3.4.19 IF Amplifier 1A72523 ............................................................................... 3-200 3.4.19.1 Test Equipment 3-200 3.4.19.2 Setup 3-201 3.4.19.3 No Signal Checks 3-201 3.4.19.4 IF Checks 3-201 3.4.19.5 Narrow Band Checks 3-202 3.4.19.6 AGC Checks 3-205 3.4.19.7 Final Checks 3-205
3.4.20 RF Amplifier 1A72524 ............................................................................. 3-207 3.4.20.1 Test Equipment 3-207 3.4.20.2 Setup 3-207 3.4.20.3 DC Voltages 3-207 3.4.20.4 Power Stage Check 3-207 3.4.20.5 Local Oscillator Leakage Check 3-207 3.4.20.6 Low Noise Amplifier and Mixer Calibration 3-208
3.4.21 Transponder Power Supply 1A72525...................................................... 3-209 3.4.22 Main PWB Assembly Transponder Power Supply 1A72526 ................... 3-209
3.4.22.1 Test Equipment 3-209 3.4.22.2 Setup 3-210 3.4.22.3 HT Supply Tests 3-210 3.4.22.4 Performance Tests 3-211 3.4.22.5 +15V Supply and +18V Supply Tests 3-213 3.4.22.6 Control Signals 3-214
3.4.23 Transmitter Driver 1A72530 .................................................................... 3-214 3.4.23.1 Test Equipment 3-214 3.4.23.2 Setup 3-214 3.4.23.3 Exciter Alignment 3-216 3.4.23.4 Medium Power Driver Alignment 3-216 3.4.23.5 Power Modulation Amplifier Alignment 3-217
3.4.24 Pulse Shaper PWB Assembly 1A72531.................................................. 3-218 3.4.24.1 Test Equipment 3-218 3.4.24.2 Setup 3-218 3.4.24.3 Rectangular Modulation Test 3-219 3.4.24.4 Driver Level Monitor Tests 3-219 3.4.24.5 Function Generator Test 3-220 3.4.24.6 Shaped Pulse Modulation and TD_MOD_LVL Tests 3-221 3.4.24.7 ALC Loop Check 3-221 3.4.24.8 Second Pulse Equalising Test 3-222 3.4.24.9 Medium Power Driver Supply Test 3-222 3.4.24.10 Exciter Supply Test 3-222 3.4.24.11 Power Modulation Amplifier Supply Test 3-222 3.4.24.12 VC1 Supply and BIAS Test 3-223 3.4.24.13 Completion 3-223
3.4.25 Exciter 1A72532 ...................................................................................... 3-224 3.4.25.1 Test Equipment 3-224 3.4.25.2 Test Overview 3-224 3.4.25.3 Preliminary Checks 3-224 3.4.25.4 DC Checks 3-224 3.4.25.5 Alignment 3-225
3.4.26 Medium Power Driver 1A72533............................................................... 3-226 3.4.26.1 Test Equipment 3-226
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3.4.26.2 Preliminary Electrical Tests 3-226 3.4.26.3 Calibration Procedure 3-227 3.4.26.4 Amplifier Test Procedure 3-229
3.4.27 Power Modulation Amplifier 1A72534 ..................................................... 3-230 3.4.27.1 Test Equipment 3-230 3.4.27.2 Preliminary Electrical Tests 3-230 3.4.27.3 Test Overview 3-231 3.4.27.4 Calibration Procedure 3-231 3.4.27.5 Amplifier Test and Tuning Procedure 3-232
3.4.28 1kW RF Power Amplifier 1A72535 .......................................................... 3-233 3.4.28.1 Test Equipment 3-233 3.4.28.2 Setup 3-234 3.4.28.3 Amplifier Performance Tests 3-236 3.4.28.4 Level Monitors 3-238 3.4.28.5 Completion 3-238
3.4.29 Power Divider 1A72536........................................................................... 3-239 3.4.29.1 Test Equipment 3-239 3.4.29.2 Return Loss Measurement 3-239 3.4.29.3 Insertion Loss Measurement 3-239 3.4.29.4 10 dB Attenuator and Detector 3-239
3.4.30 Power Combiner 1A72537 ...................................................................... 3-240 3.4.30.1 Test Equipment 3-240 3.4.30.2 Test Arrangements 3-241 3.4.30.3 Two-way Splitter 3-241 3.4.30.4 Eight-Way Combiner 3-241 3.4.30.5 Attenuator and Detector 3-241
3.4.31 1kW PA Power Supply 1A72540 ............................................................. 3-242 3.4.31.1 Test Equipment 3-242 3.4.31.2 Alignment 3-242 3.4.31.3 Control Circuit Checks 3-242 3.4.31.4 Relay and Voltage Checks 3-243 3.4.31.5 Load Tests 3-243 3.4.31.6 Completion 3-243
3.4.32 Control and Status PWB Assembly 1A72541.......................................... 3-243 3.4.32.1 Test Equipment 3-243 3.4.32.2 Setup 3-243 3.4.32.3 Control Circuitry Tests 3-244 3.4.32.4 HT OUT Monitoring 3-244 3.4.32.5 RF Amplifier Monitoring Tests 3-245 3.4.32.6 Completion 3-246
3.4.33 DC-DC Converter PWB Assembly 1A72542 ........................................... 3-247 3.4.33.1 Test Equipment 3-247 3.4.33.2 Setup 3-247 3.4.33.3 Regulator 3-247 3.4.33.4 Output Voltage Adjustment Range 3-248 3.4.33.5 Primary Current Limit Preset 3-249 3.4.33.6 Input Regulation 3-249 3.4.33.7 Output Regulation 3-249 3.4.33.8 Input Current Monitor 3-250 3.4.33.9 Completion 3-250
3.4.34 Preselector Filter 1A72546 ...................................................................... 3-250 3.4.34.1 Test Equipment 3-250 3.4.34.2 Filter Tuning Procedure - 1020 MHz 3-250 3.4.34.3 Filter Tuning Procedure - 1160 MHz 3-251 3.4.34.4 Filter Tuning Procedure - Station Frequency 3-251
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3.4.35 RF Panel PWB Assembly Single DME 1A72547 .................................... 3-251 3.4.36 RF Panel PWB Assembly Dual DME 2A72547 ....................................... 3-251 3.4.37 Power Distribution Panel Single DME 1A72549...................................... 3-252
3.4.37.1 Test Equipment 3-252 3.4.37.2 Continuity Checks 3-252
3.4.38 Power Distribution Panel Dual DME 2A72549 ........................................ 3-252 3.4.38.1 Test Equipment 3-252 3.4.38.2 Continuity Checks 3-253
3.4.39 Control and Test Unit 1A72550 ............................................................... 3-254 3.4.39.1 Introduction 3-254 3.4.39.2 Test Equipment 3-254 3.4.39.3 Setup 3-254 3.4.39.4 DC-DC Converter Output 3-255 3.4.39.5 LCD Display and Softkeys 3-255 3.4.39.6 Front Panel Controls and Indicators Check 3-255 3.4.39.7 CTU Bus Interface to Test Interrogator and Monitor Modules 3-255 3.4.39.8 CTU Direct Interface to the Transponder Modules 3-256 3.4.39.9 Control System Check 3-256 3.4.39.10 Restore Operation 3-256
3.4.40 CTU Processor PWB Assembly 1A72552............................................... 3-256 3.4.40.1 Test Equipment 3-256 3.4.40.2 Setup 3-256 3.4.40.3 Power Supplies 3-257 3.4.40.4 Self Test LED Indicators 3-257 3.4.40.5 Watchdog 3-257 3.4.40.6 External Oscillator Signal 3-257 3.4.40.7 Ident Buzzer 3-257 3.4.40.8 Completion 3-258
3.4.41 CTU Front Panel PWB Assembly 1A72553 ............................................ 3-258 3.4.41.1 Test Equipment 3-258 3.4.41.2 Setup 3-258 3.4.41.3 Power Supplies 3-258 3.4.41.4 Heartbeat LED 3-258 3.4.41.5 Pushbuttons 3-259 3.4.41.6 ALARM DELAY Switch 3-259 3.4.41.7 View Angle Adjust 3-259 3.4.41.8 Completion 3-260
3.4.42 RCMS Interface PWB Assembly 1A72555.............................................. 3-260 3.4.42.1 Test Equipment 3-260 3.4.42.2 Setup 3-260 3.4.42.3 Power Supplies 3-260 3.4.42.4 Heartbeat LED 3-260 3.4.42.5 Relays 3-260 3.4.42.6 Transponder 2 Interface 3-262 3.4.42.7 Completion 3-262
3.4.43 External I/O PWB Assembly 1A72557 .................................................... 3-263 3.4.43.1 Test Equipment 3-263 3.4.43.2 Setup 3-263 3.4.43.3 Modem 12 Volts Supply Check 3-263 3.4.43.4 Protected 24 Volts Supply Check 3-263 3.4.43.5 Status Outputs 3-263 3.4.43.6 Completion 3-265
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LIST of FIGURES
Figure 3-1 Power Supply Control Module Links.....................................................3-75 Figure 3-2 Standard Return Loss Test Setup ......................................................3-142 Figure 3-3 Typical Display for Return Loss Test..................................................3-142 Figure 3-4 Standard Insertion Loss Test Setup ...................................................3-143 Figure 3-5 Typical Display for Insertion Loss Test...............................................3-143 Figure 3-6 Switched Attenuator Test Configuration .............................................3-144 Figure 3-7 250W Amplifier Test Setup.................................................................3-152 Figure 3-8 Connections to Alarm Connector TB/3 ...............................................3-154 Figure 3-9 Test Setup for Receiver Video Module...............................................3-190 Figure 3-10 Test Setup for IF Amplifier Checks.....................................................3-206 Figure 3-11 Power and Output Cable for IF Amplifier Checks...............................3-206 Figure 3-12 Test Setup for RF Amplifier Checks ...................................................3-209 Figure 3-13 Exciter Test Setup ..............................................................................3-225 Figure 3-14 Medium Power Driver Test Setup.......................................................3-228 Figure 3-15 Power Modulation Amplifier Test Setup .............................................3-231 Figure 3-16 1kW RF Power Amplifier Test Setup ..................................................3-235 Figure 3-17 Attenuator and Detector Test Setup ...................................................3-240 Figure 3-18 Detector Test Cable............................................................................3-241 Figure 3-19 10 dB Attenuator and Detector Test Setup.........................................3-242
LIST of TABLES Table 3-1 Numerical List of Line Replaceable Units...............................................3-139 Table 3-2 Hierarchical List of Line Replaceable Units ............................................3-140
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3. ALIGNMENT AND ADJUSTMENT 3.1 INTRODUCTION This section contains the procedures required for alignment, adjustment and testing of an LDB-102 DME beacon and its constituent subassemblies.
Procedures are included for the testing and alignment of a complete DME, either on-site or in a maintenance depot, and for testing the line-replaceable units as individual items.
The individual sections contained within this part of the handbook are:
• Section 3.2 - FIELD PERFORMANCE CHECKS AND ALIGNMENT, which contains the procedures for doing basic testing and adjustments on-site, using a minimum of test equipment.
• Section 3.3 - DEPOT PERFORMANCE CHECKS AND ALIGNMENT, which contains the procedures for doing a detailed alignment and performance test using a full range of test equipment as would be held in a maintenance depot.
• Section 3.4 - LRU PERFORMANCE CHECKS AND ALIGNMENT, which contains the procedures for aligning modules and subassemblies in a maintenance depot test rack, following repair or re-tuning of the units.
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3.2 FIELD PERFORMANCE CHECKS AND ALIGNMENT
3.2.1 Introduction This section contains the alignment and testing procedures to be performed on an LDB-102 DME beacon when installed at a field site. These procedures are applicable to the alignment and checking of a DME immediately following installation, or for the periodic testing of a DME subsequent to its commissioning. The procedures assume that the DME is fully installed, with an antenna connected and with AC mains power applied to the equipment.
The DME rack should be in full working order before commencing final alignment (that is, free from any faults). If any faults are found in modules during these tests, then the defective unit should be replaced with a serviceable unit before the tests are continued.
The procedures described here mostly refer to a single DME transponder. For a dual beacon, the same series of procedures are performed on the second transponder, with some additional checks relating to the monitor and control system.
This section contains procedures applicable to two requirements:
1. Testing procedures, to be carried out during regular performance inspections of the DME. The abbreviated procedures forming the sub-set of checks that are applicable to equipment that previously has been aligned to the current operating channel.
These procedures are shown in normal (Helvetica) type.
2. Alignment and testing procedures, to be performed upon installation of the DME, for re-tuning the DME to a different operating channel, or after repair and replacement of a line-replaceable unit. For this application, the full procedures should be performed, including, as necessary, the detailed alignment procedures in Sections 3.2.5 through 3.2.9.
The additional procedures required for full alignment are shown in italics.
For a comprehensive test of all aspects of the DME performance, refer to Section 3.3 DEPOT PERFORMANCE CHECKS AND ALIGNMENT.
3.2.2 Test Equipment The test equipment required to perform the procedures specified in this section is detailed in Section E.1.
3.2.3 General Requirements Extensive use is made of the built-in test facility, located in the CTU module at the top of the rack. The operator should become familiar with its use and functions before commencing these procedures. Operation of the test facility is described in Section A.3.
Preset controls within the modules should not be touched unless the procedure contains instructions to do so. Some modules have internal switches which must be set for a particular station configuration. If not already set to the correct positions, they may be initially set as stated in Section 3.2.4.2 Module Presets.
CAUTION THE FOLLOWING PRECAUTIONARY REQUIREMENTS SHOULD BE NOTICES OBSERVED AT ALL TIMES THROUGHOUT EQUIPMENT TESTING FAILURE TO OBSERVE THESE REQUIREMENTS MAY RESULT IN DAMAGE BEING CAUSED TO THE EQUIPMENT.
Although the beacon includes protection to guard against excessive load mismatch, the transmitter must not be operated unless a suitable load is
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present at the ANTENNA output. The protection circuit is intended for accidental mismatching only.
The peak power from the transmitter is in excess of 1200 watts, which is too high for direct application to most test instruments. Therefore, care should be taken when connecting instruments to the transmitter output to ensure that a suitably rated attenuator or directional coupler is used to isolate the instruments from the high power.
Modules must not be removed or inserted with power applied. For most units, it is sufficient to switch off the rack at the CTU. For the CTU it is necessary to switch off the 24 volts at the circuit breakers on the power distribution module.
Equipment repairs and tests should be performed only by personnel suitably qualified to the level of proficiency required by an equipment of this type and complexity.
3.2.4 Test Procedures
3.2.4.1 Preliminaries
3.2.4.1.1 Initial Testing If the DME is being tested for the first time following installation, it is necessary to set a number of preset switches inside the modules. Section 3.2.4.2 below gives the details for the standard settings for these presets, and the test procedures throughout this section assume that standard settings are used. For some sites, different settings of these presets may be preferred, depending on the station requirements. For these cases, the appropriate corrections must be made to the expected results in some of these procedures. Details of the function of the internal preset switches are given in Section A.5.
At the start of these test procedures, some front panel preset controls are set to nominal values at installation. During subsequent testing it may be found necessary to make changes to these settings.
If the DME is undergoing a regular performance inspection, the procedures in Section 3.2.4.2 should be omitted and the tests commenced at Section 3.2.4.3.
3.2.4.1.2 RF Crystal Selection Refer to Appendix N for crystal specification.
1. Receiver video crystals
Check that the correct crystal is installed as G1 in the RF source of the receiver video. The crystal frequency is one-twelfth of the station reply frequency.
Example: Channel 84X reply frequency= 1171 MHz hence crystal frequency = 1171/12 = 97.5833 MHz
2. Test interrogator crystals
Check that the crystals are installed in the RF generator of the test interrogator. The crystal frequency is one-twelfth of the station interrogation frequency.
Example: Channel 84X interrogation frequency = 1108 MHz = Fo hence crystal frequency = 1108/12 = 92.3333 MHz = Fx
The five interrogation frequencies and the corresponding crystal frequencies are shown in the table below.
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SWITCH FUNCTION SETTING G1 Fo Fx G2 Fo + 160 kHz Fx + 13.3 kHz G3 Fo - 160 kHz Fx - 13.3 kHz G4 Fo + 900 kHz Fx + 75 kHz G5 Fo - 900 kHz Fx - 75 kHz
3.2.4.2 Module Presets CAUTION Powering the Rack
DO NOT apply power to the equipment under test before the following settings are made.
3.2.4.2.1 Power Distribution Panel Presets 1. On the power distribution panel, set all circuit breakers off.
3.2.4.2.2 1kW RF Power Amplifier Presets 1. On the 1kW RF power amplifiers, switch AMPLIFIER DC POWER to OFF.
3.2.4.2.3 Control and Test Unit Presets 1. On the CTU front panel, set the switch ALARM DELAY to 10 seconds.
2. On the CTU, set the switches on the CTU processor board as follows:
S1, 8-way DIP switch
SWITCH FUNCTION SETTING
1 NORMAL/PRODUCTION TESTS ON = NORMAL
2 INDICATES IF NAVAID MAINTENANCE PROCESSOR (NMP) IS FITTED OFF = NO NMP
3 SUBTRACT 0.1 µs FROM No. 2 DELAY MONITOR FAULT LIMIT READINGS ON = INACTIVE
4 ADD 0.1 µs TO No. 2 DELAY MONITOR FAULT LIMIT READING ON = INACTIVE
5 STATISTICS ON DELAY MEASUREMENTS ON = INACTIVE
6 SUBTRACT 0.1 µs FROM No. 1 DELAY MONITOR FAULT LIMIT READINGS ON = INACTIVE
7 ADD 0.1 µs TO No. 1 DELAY MONITOR FAULT LIMIT READINGS ON = INACTIVE
8 SINGLE/DUAL ON if SINGLE DME OFF if DUAL DME
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S2, 8-way DIP switch
SWITCH FUNCTION SETTING
1 MAIN AND/OR VOTING (FOR DUAL) ON = AND 2 STANDBY AND/OR VOTING (FOR DUAL) ON = AND 3 RMM/RCMS CONTROL OFF = RCMS 4 COLD/WARM STANDBY ON = COLD 5 1 ELEMENT ANT. FLT: NOT/IS FITTED OFF = IS FITTED 6 1 ELEMENT ANT. FLT: NO ACTION/ACTION ON = NO ACTION 7 2 ELEMENT ANT. FLT: NOT/IS FITTED ON = NOT FITTED 8 2 ELEMENT ANT. FLT: NO ACTION/ACTION ON = NO ACTION
NOTE If the DME is to be used with a Remote Maintenance Monitoring (RMM) system, perform all checks and adjustments in this Section 3.2 before configuring the CTU for operation with the RMM. Refer to the RMM Handbook for details.
3. Set the ALARM POWER ON INHIBIT switch (S11 on the CTU front panel board) for a delay of 6 seconds (refer to Section A.5.1.6).
4. On the CTU processor board, ensure that no links are installed on the 2-pin headers XN5 (MA IDENT OUTPUT referenced to GROUND), XN6 (WATCHDOG DISABLE), XN7 (SIGNATURE ANALYSIS), XN8 (IDENT TEST) and XN9 (WATCHDOGTEST). Check that a link is fitted to the 2-pin header XN10 (ASSOC IDENT INPUT pulled up to +24 volts).
3.2.4.2.4 Receiver Video Presets 1. On the receiver video, set the switches on the receiver video main board as
follows:
If the DME is to be used on a 'Y' channel, then set SELECT ENCODER MODE (S4) and SELECT DECODER MODE (S5) accordingly. (Refer to Section 3.2.10)
SWITCH FUNCTION SETTING
S4 SELECT ENCODER MODE X S5 SELECT DECODER MODE X S6 SET LDES PERIOD 6 S7 SET DEAD TIMES 6 S8 SDES OFF S9 LDES OFF
2. On the receiver video, set the ident code switches S13, S14, S15 and S16 on the receiver video main board to generate the desired station ident code, as follows:
b. Convert the required ident letters into International Morse Code, using the following table:
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LETTER MORSE SYMBOL LETTER MORSE SYMBOL
A dot dash N dash dot B dash dot dot dot 0 dash dash dash C dash dot dash dot P dot dash dash dot D dash dot dot Q dash dash dot dash E dot R dot dash dot F dot dot dash dot S dot dot dot G dash dash dot T dash H dot dot dot dot U dot dot dash 1 dot dot V dot dot dot-dash J dot dash dash W dot dash dash K dash dot dash X dash dot dot dash L dot dash dot dot Y dash dot dash dash M dash dash Z dash dash dot dot
c. Set the switches using the following code (shading indicates switch position):
Example: for ident code AWA, switch settings are:
3. On the receiver video, set the front panel switches to the following nominal
positions:
SWITCH FUNCTION SETTING
S1 BEACON DELAY, COARSE 9 S2 BEACON DELAY, FINE 4 S3 REPLY PULSE SPACING (REPLY
PULSE SEPARATION on early modules) 8
S11 IDENT NORMAL
3.2.4.2.5 Transmitter Driver Presets 1. On the pulse shaper board in the transmitter driver, set the switches as follows:
SWITCH FUNCTION SETTING
S2 ALC LOOP OPEN S3 ALC VIDEO S4 MED COLL DC
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2. On the pulse shaper board, place POWER link X1 in the 1kW position.
3. On the transmitter driver front panel, set switch DRIVER DC POWER to OFF.
3.2.4.2.6 Transponder Power Supply Presets 1. On the transponder power supply front panel, set switch TRANSPONDER DC
POWER to OFF.
3.2.4.2.7 Test Interrogator Presets 1. On the test interrogator main board, set the switch S4 (MODE) to X (or to Y if the
DME is to be used on a ‘Y’ channel. Refer to Section 3.2.10
2. On the test interrogator front panel, set the switches as follows:
SWITCH FUNCTION SETTING
S5 REPLY GATE DELAY COARSE 2 S6 REPLY GATE DELAY, FINE F S7 MONITOR & INTERROGATOR DC
POWER NORMAL
3. On the test interrogator, set the switch NORMAL/TEST (S1) on the modulator and detector to NORMAL.
4. On the test interrogator, set switch S1 (6-way DIP switch) on the RF generators as follows:
SWITCH FUNCTION SETTING 1 INTERROGATION FREQ = Fo ON 2 INTERROGATION FREQ = Fo + 160 kHz OFF 3 INTERROGATION FREQ = Fo - 160 kHz OFF 4 INTERROGATION FREQ = Fo + 900 kHz OFF 5 INTERROGATION FREQ = Fo - 900 kHz OFF 6 CW/PULSE OFF = PULSE
3.2.4.2.8 Monitor Module Presets 1. On the monitor, set the switches on the monitor main board as follows (shading
indicates switch position):
PULSE WIDTH LOWER LMT SET (8-way DIP switch S1): 2.9 microseconds
1 2 3 4 5 6 7 8 ON OFF
FALL TIME UPPER LMT (8-way DIP switch S2): 3.6 microseconds
1 2 3 4 5 6 7 8 ON OFF
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RISE TIME UPPER LMT (8-way DIP switch S3): 3.1 microseconds
1 2 3 4 5 6 7 8 ON OFF
PULSE WIDTH WINDOW SET (8-way DIP switch S4): 1.2 microseconds
1 2 3 4 5 6 7 8 ON OFF
PWR LVL FLT SET (8-way DIP switch S7): -3.0 dB
1 2 3 4 5 6 7 8 ON OFF
IDENT GAP FLT SET (8- way DIP switch S8): 62 seconds
1 2 3 4 5 6 7 8 ON OFF
DELAY WINDOW SET (8-way DIP switch S9): 1.0 microseconds
1 2 3 4 5 6 7 8 ON OFF
SPACING WINDOW SET (8-way DIP switch S10): 1.0 microseconds
1 2 3 4 5 6 7 8 ON OFF
DELAY LOWER LMT SET (10-way DIP switch S12): 49.5 microseconds
(For ‘Y’ channel settings refer to Section 3.2.10)
1 2 3 4 5 6 7 8 9 10 ON OFF
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SPACING LOWER LMT SET (10-way DIP switch S13): 11.5 microseconds
(For ‘Y’ channel settings refer to Section 3.2.10)
1 2 3 4 5 6 7 8 9 10 ON OFF
2. On both monitor front panels, set switch MONITOR OUTPUTS to NORMAL.
NOTE Referencing the Two Systems in a Dual DME
Where reference is required to distinguish between the transponders and monitoring systems, the modules higher in the DME rack will be referenced as “No.1” while those lower will be referenced as “No.2”.
3.2.4.2.9 RF Panel Presets a. SINGLE
1. On the RF Panel (at the rear of the rack at the top), check that the following components and connecting cables are installed.
a. 10 dB attenuator to connector TI-1 REPLY DET.
b. Coaxial cable (RG-188 with SMA connectors) from 10 dB attenuator to connector FWD-B on the directional coupler.
c. 10 dB attenuator to connector FWD-A on the directional coupler.
d. 50 ohms termination to connector REV-A on the directional coupler.
e. Coaxial cable (RG-188 with SMA connectors) from connector FWD-C on the directional coupler to TI-1 TEST INTRGS.
2. Check that antenna DC continuity monitor is connected to XN2 on the RF panel board.
b. DUAL
1. On the RF panel (at the rear of the rack at the top), check that the following components and connecting cables are installed.
a. 10 dB attenuator each to connectors TI-1 REPLY DET and TI-2 REPLY DET.
b. Coaxial cable (RG-188 with SMA connectors) from 10 dB attenuator on TI-1 REPLY DET to connector FWD-D on No.2 directional coupler.
c. Coaxial cable (RG-188 with SMA connectors) from 10 dB attenuator on TI-2 REPLY DET to connector FWD-B on No.2 directional coupler.
d. 50 ohms termination to connector REV-A on No.2 directional coupler.
e. 10 dB attenuator to connector FWD-A on No.2 directional coupler.
f. Coaxial cable (RG-188 with SMA connectors) from connector FWD-E on No.2 directional coupler to TI-1 TEST INTRGS.
g. Coaxial cable (RG-188 with SMA connectors) from connector FWD-C on No.2 directional coupler to TI-2 TEST INTRGS.
2. Check that the antenna DC continuity monitor is connected to XN2 on the RF panel board.
3. On the RF panel, set the ANTENNA RELA Y switch to NORMAL.
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3.2.4.3 Procedural Requirements
3.2.4.3.1 Testing Notes a. Oscilloscope Triggering
Unless otherwise stated in a particular test, the oscilloscope should be triggered from test jacks TRIGGER and EARTH on the test interrogator.
b. Measurements during Ident Avoid making performance measurements during the ident message.
c. Procedure for Extending Transponder Modules
If any of receiver video, transmitter driver or transponder power supply are to be put on a transponder extender frame in order to gain access to internal controls etc, the following procedure is to be followed:
1. At the transponder power supply in the same transponder subrack, mentally record the position of the front panel switch TRANSPONDER DC POWER, then switch it to OFF.
2. Extend the required module using the transponder extender frame.
3. On the transponder power supply front panel, restore the TRANSPONDER DC POWER switch to its original position.
Follow the same sequence of steps to restore the module to its transponder subrack.
d. Procedure for Extending Test Interrogator/Monitor Modules
If either of test interrogator or monitor are to be put on the transponder extender frame in order to gain access to internal controls, the following procedure is to be followed:
1. At the test interrogator in the same transponder subrack, mentally record the position of the front panel switch MONITOR AND INTERROGATOR DC POWER, then switch it to OFF.
2. Extend the required module using the transponder extender frame.
3. On the test interrogator front panel, restore the MONITOR AND INTERROGATOR DC POWER switch to its original position.
Follow the same sequence of steps to restore the module to its transponder subrack.
e. Duplication of Tests for Dual System
The tests of Sections 3.2.4.4 to 3.2.4.15 (inclusive) should be performed on both transponders and both monitor systems. The tests for the two systems may be performed in parallel, or the tests of one system may be completed before the tests on the second system are commenced.
f. Monitoring of Transponders in Maintenance Mode
In Maintenance mode, monitor system 1 is selected to perform the monitoring tests by selecting key Ch.1 at the top level menu on the CTU Test Facility; monitor system 2 is selected to perform the monitoring tests by selecting key Ch.2 at the top level menu on the CTU Test Facility. In a dual system under normal conditions, both monitor systems monitor the operating transponder.
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3.2.4.3.2 Powering the Rack 1. In a dual DME, check that the DC output of the two AC power supplies is
connected to the BATTERY 1 and BATTERY 2 terminals at the rear of the DME rack.
2. In a dual DME, check that the power supply signalling cable, from TB-3 in the power supply cabinet is connected to XN2 in the DME.
3. On the AC power supply, switch POWER to ON.
4. Check the reading on the power supply voltmeter. This should be 27.0 ±0.5 volts. (if outside this range, adjust FLOAT 2 VOLTAGE on the control module of the AC power supply).
5. On the power distribution panel, switch on the CTU and transponder circuit breakers.
6. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
7. Check that on the CTU, some indicators are on, on the monitor front panel, no indicators are on, and on the test interrogator front panel, no indicators are on.
8. On the transponder power supply front panel the TEST indicator should be the only indicator on.
9. On the transmitter driver front panel the TEST indicator should be the only indicator on.
10. On the 1kW PA power supply front panel the TEST indicator should be the only indicator on.
3.2.4.4 Test Interrogator Alignment
3.2.4.4.1 RF Generator Alignment 1. Extend the test interrogator using the transponder extender frame. On the test
interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
2. If the RF generator has not yet been aligned for its operating interrogation frequencies, perform the alignment using the procedures of Section 3.2.5.
3. On the test interrogator, undo the cable connector at the output of the RF generator, and connect the calibrated detector (with 4.7 kilohm load attached). Connect the oscilloscope to the output of the loaded detector.
3.2.4.4.2 RF Generator at Nominal Interrogation Frequency 1. On the oscilloscope, measure the peak amplitude of the pulse from the calibrated
detector. Compare this amplitude with the calibration chart for the detector (with load) to determine the true output from the RF generator. The output should be +11.5 ±0.5 dBm.
(If the reading is outside this range, remove the cover of the modulator and detector and adjust R13 (PULSE AMPLITUDE) on this module to set the peak power meter reading to a value in the specified range).
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NOTE Ensure that the oscilloscope probes are correctly compensated, otherwise pulse amplitude errors may result. Refer to the oscilloscope manual for probe compensation procedure.
2. Connect the oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH on the front panel of the test interrogator. Measure the following parameters of the displayed pulses, as below.
If the pulse amplitude and/or shape are outside the above limits, they can be corrected by removing the lid of the modulator and detector on the test interrogator and adjusting R13 (PULSE AMPLITUDE) and R20 (PULSE SHAPE) as required. Ensure that the output from the RF generator remains within the limit stated above (that is, +11.5 ±0.5 dBm). (After completing step 5, replace the lid on the modulator and detector).
3. From the table below, use the measured value of the peak amplitude from step 2 to determine the limit for the recorded results in step 5. Make a note of this value as the limit for step 5.
PEAK AMPLITUDE LIMITS FOR RESULTS OF STEP 5 2.7 to 3.0 0.9 (±0.1) 3.1 to 3.3 1.0 (±0.1)
4. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
5. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on the oscilloscope should remain the same except that the baseline should move up the pulse. Measure the DC level shift of the baseline level from the reference level set in the previous step. Set S1:6 to OFF when completed.
If the DC level shift is outside the above limits, it can be corrected by removing the lid of the modulator and detector on the test interrogator (if not already removed) and adjusting R37 (PULSE PEDESTAL) as required. Replace the lid on the modulator and detector when finished.
3.2.4.4.3 RF Generator at Test Frequencies Confirm correct operation of the RF generator test frequencies by repeating tests in 3.2.4.4.2 steps 1 and 2 with each of the test crystals selected. The crystals are selected by switch S1 in the RF generator as shown in the table below:
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FREQUENCY SWITCH fo S1-1 fo +160 kHz S1-2 fo - 160 kHz S1-3 fo +900 kHz S1-4 fo - 900 kHz S1-5
When a test frequency is selected, each of the other switches in S1 must be set to off.
Select the normal interrogate frequency, by setting S1:1 to on, when finished.
3.2.4.4.4 Spacing Offset Control 1. Connect channel 1 of the oscilloscope to test jacks DETECTED
INTERROGATIONS and EARTH, and channel 2 of the oscilloscope to test jacks 1 µs MARKERS and EARTH on the front panel of the test interrogator. Using the displayed markers (or an accurately calibrated oscilloscope), measure the spacing between the detected pulses (channel 1 on the oscilloscope). It should be 12.0 ±0.1 microseconds measured at the half amplitude points on the leading edges. (For ‘Y’ channel values refer to Section 3.2.10)
2. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, REJECT to +2 microseconds. Measure the increase in spacing between the detected pulses. It should be 2.0 ±0.1 microseconds.
3. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, REJECT to -2 microseconds. Measure the decrease in spacing between the detected pulses. It should be 2.0 ±0.1 microseconds.
4. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, ACCEPT to +1 microseconds. Measure the increase in spacing between the detected pulses. It should be 1.0 ±0.1 microseconds.
5. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, ACCEPT to -1 microseconds. Measure the decrease in spacing between the detected pulses. It should be 1.0 ±0.1 microseconds.
3.2.4.4.5 RF Generator Output Frequencies 1. To check the RF frequency of the RF generator it is necessary to remove its
cover and couple some signal from the crystal oscillator to a frequency counter. For this purpose, it is necessary to have a piece of coaxial cable, approximately 1 metre long, with a 1 cm diameter loop at one end connected between the centre conductor and the earth braid. The other end connects to the counter. To make a measurement, the coupling loop should be placed near coil L1, to couple enough signal to activate the counter. The frequency displayed will be the same as that marked on the crystal, which is 1/12 the final output frequency.
Read the frequency counter frequency. It should be within ±1.67 kHz of the crystal frequency derived at Section 3.2.4.1.2, for Fo.
2. On the RF generator, and set switch S1:1 to OFF and switch S1:2 to ON (to change the interrogation frequency to Fo + 160 kHz). Read the frequency counter frequency. It should be within +1.67 kHz of the crystal frequency derived at Section 3.2.4.1.2, for Fo + 160 kHz.
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3. On the RF generator, and set switch S1:2 to OFF and switch S1:3 to ON (to change the interrogation frequency to Fo - 160 kHz). Read the frequency counter frequency. It should be within ±1.67 kHz of the crystal frequency derived at Section 3.2.4.1.2, for Fo - 160 kHz.
4. On the RF generator, and set switch S1:3 to OFF and switch S1:4 to ON (to change the interrogation frequency to Fo + 900 kHz). Read the frequency counter frequency. It should be within ±1.67 kHz of the crystal frequency derived at Section 3.2.4.1.2, for Fo + 900 kHz.
5. On the RF generator, and set switch S1:4 to OFF and switch S1:5 to ON (to change the interrogation frequency to Fo - 900 kHz). Read the frequency counter frequency. It should be within ±1.67 kHz of the crystal frequency derived at Section 3.2.4.1.2, for Fo - 900 kHz.
6. On the RF generator, set switch S1:5 to OFF and switch S1:1 to ON (to change the interrogation frequency back to the nominal frequency).
3.2.4.4.6 Test Interrogator Signal Timing Parameters On the CTU front panel, select Hi Eff (High Efficiency) test in the Maintenance mode, and a TI RATE of 1 kHz (refer Section A.1 for CTU operating instructions).
1. Connect the frequency counter to test jacks 1 µs MARKERS and EARTH on the front panel of the test interrogator. Measure the frequency; it should be 1000.0 ±0.10 kHz.
2. Connect channel 1 of the oscilloscope to test jacks REPLY ACCEPT GATES and EARTH on the test interrogator. Measure the following characteristics of the displayed pulses:
PULSE WIDTH 6.0 ±1.0 microseconds PULSE SPACING 12.0 ±0.2 microseconds PULSE REPETITION PERIOD 1.0 ±0.1 milliseconds
(For ‘Y’ channel values refer to Section 3.2.10)
3. Connect channel 1 of the oscilloscope to test jacks INTERROGATIONS TIMING and EARTH and channel 2 of the oscilloscope to test jacks REPLY TIMING and EARTH on the test interrogator. On the front panel of the test interrogator press and hold operated CHECK DETECTOR COINCIDENCE and measure the time interval, on the oscilloscope, between the leading edges of the pulses on the two channels. The time interval should be ±0.1 microseconds.
3.2.4.5 RF Source and RF Amplifier Alignment and Tests 1. Extend the receiver video using the transponder extender frame.
2. If the RF source and RF filter have not yet been aligned for their operating reply frequency, perform the alignment using the procedures of Section 3.2.6.
3. To check the RF frequency of the RF source, it is necessary to remove its cover and couple some signal from the crystal oscillator to a frequency counter. For this purpose, it is necessary to have a piece of coaxial cable, approximately 1 metre long, with a 1 cm diameter loop at one end, connected between the centre conductor and the earth braid. The other end connects to the counter.
To make a measurement, the coupling loop should be placed near coil L1, to couple enough signal to activate the counter. The frequency displayed will be the same as that marked on the crystal, which is 1/12 the final output frequency.
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Measure the frequency of the oscillator, which should be within ±1.67 kHz of the crystal frequency derived in Section 3.2.4.1.2.
4. Measure the DC voltage at the LOCAL OSC LEVEL test jack on the receiver video front panel. This should be 2.0 ±1.0 volts.
5. Measure the DC voltage at the RF LEVEL test jack on the receiver video front panel. This should be 3.0 ±1.5 volts.
6. Replace the receiver video module in the transponder subrack.
3.2.4.6 RF Panel Preselector Filter Alignment and Tests 1. On the test interrogator front panel, switch MONITOR AND INTERROGATOR
DC POWER to OFF. Withdraw the test interrogator, remove the 30 dB attenuator from above the switched attenuator and reconnect the output coaxial cable directly to the switched attenuator output. Install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
2. On the CTU front panel, select Hi Eff test in Maintenance mode, and a TI RATE of 1 kHz.
3. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator front panel) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video front panel. With an oscilloscope timebase of 5 microseconds/division, a pulse pair should be displayed above the noise.
If the signal is not visible, more signal can be achieved (temporarily until initial alignment is achieved and significant signal is available) by disconnecting the coaxial cable from Ti-1 TEST INTRGS at port FWD-E - for monitor system 1 (the coaxial cable from TI-2 TEST INTRGS at port FWD-C - for monitor system 2) on No.2 directional coupler and reconnecting it to the preselector filter IN connector (after removing the semirigid cable link to the circulator).
4. Loosen the locknuts on the preselector filter and tune adjusters A and C together, keeping them equal distances out from the body; if the frequency is to be increased, tune the adjusters out (counter-clockwise); if the frequency is to be decreased, tune the adjusters in (clockwise).
5. Tune both adjusters A and C for a peak, then detune adjuster B until the signal is only just clearly visible.
6. Retune adjusters A and C successively for peaks. While monitoring the oscilloscope display, to ensure that the signal level does not change, lock adjusters A and C with their locknuts. Then retune adjuster B for absolute peak, locking it in the same way.
CAUTION Extreme care must be exercised during this tuning as even a slight detuning of one cavity will cause a skewed response.
7. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to OFF. Withdraw the test interrogator and replace the 30 dB attenuator. Install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
8. (If changed, as above, on the RF panel, disconnect the cable from connector TI-1 TEST INTRGS - for monitor system 1 (TI-2 TEST INTRGS - for monitor system 2) at the preselector IN connector and reconnect it to port FWD-E - for monitor
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system 1 (port FWD-C - for monitor system 2) on No.2 directional coupler. Replace the semirigid cable between the preselector filter IN connector and the circulator.)
3.2.4.7 Receiver Video Alignment 1. Extend the receiver video using the transponder extender frame.
2. On the CTU front panel, select Hi Eff test in Maintenance mode, and a TI RATE of 1 kHz.
3. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator front panel) to test points XT13 and XT21 (GND) on the receiver video main board. Measure and record the peak pulse amplitude above the 0 volts reference.
4. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to OFF.
5. Withdraw the test interrogator, remove the 30 dB attenuator from above the switched attenuator and reconnect the output coaxial cable directly to the switched attenuator output.
6. Install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
7. With this increase of 30 dB in the signal level into the receiver video, on the oscilloscope, again measure and record the peak pulse amplitude above the 0 volts reference.
8. Calculate the difference between the recorded results of steps 3 and 7, and divide it by 5. Record this voltage; it should be 220 ±40 mV. This voltage is the average voltage increment per 6 dB of signal level.
9. Connect the digital multimeter (on 2 volts range) to test points XT13 and XT6 on the receiver video main board and check that it is within ±1 0 mV of the voltage calculated in step 8.
If the voltage is outside this range, set ADJUST 6 dB OFFSET (R45), so that the multimeter reading equals (to within ±5 mV) the offset voltage calculated in step 8.
10. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to OFF. Withdraw the test interrogator and replace the 30 dB attenuator. Install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
11. On the oscilloscope, measure the peak pulse amplitude above the 0 volts reference. It should be within ±5 mV of the value recorded in step 3.
12. Replace the receiver video in the transponder subrack.
3.2.4.8 Transmitter Driver RF Output Alignment The object of the alignment procedure in this section and in Section 3.2.4.9 is to obtain a correctly shaped DME output pulse at the specified output power, with each of the stages in the amplifier chain operating at the proper power level. Section 3.2.4.8 describes the procedure for adjusting the RF drive and modulation to the 1kW RF power amplifier. Section 3.2.4.9 describes the final adjustments to the modulation to achieve the specified pulse shape and power. At the conclusion of the procedure, the collector
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currents of some of the amplifier stages may be different from the values initially set in Section 3.2.4.8.
1. If the transmitter driver has not been aligned for operation at the station reply frequency, then perform the procedure detailed in Section 3.2.7. The alignment of the function generator (on the pulse shaper board) is detailed in Section 3.2.8.
2. Extend the transmitter driver using the transponder extender frame.
3. Set the switches as follows:
DRIVER DC POWER (on front panel) to OFF ALC LOOP (S2 on the pulse shaper board) to OPEN, ALC (S3 on the pulse shaper board) to VIDEO. MED COLL (S4 on the pulse shaper board) to DC. POWER link (X1 on pulse shaper board) to 1kW.
4. On the CTU front panel, press the SELECT MAIN NO 1 or SELECT MAIN NO 2 key as appropriate for the transponder being tested. On the transponder power supply, switch the TRANSPONDER DC POWER to ON.
5. On the pulse shaper board, set MOD PULSE AMPLITUDE (R58) fully counter-clockwise to remove any pulse modulation.
6. On the receiver video, set the IDENT switch to CONTINUOUS.
7. Connect the multimeter (on 200 volts range) to test jacks HT and EARTH on the transponder power supply front panel. The measured voltage should be 42.0 ±0.2 volts. (If out of range, set the voltage within the specified range by adjusting HT VOLTAGE (R26) on the transponder power supply main board.
8. Set the transmitter driver DRIVER DC POWER to OFF and set the 1kW power amplifier AMPLIFIER DC POWER to OFF.
Remove the cover from the 1kW power amplifier then remove the cover from the power modulation amplifier diecast box.
9. Switch the transmitter driver DRIVER DC POWER and the 1kW power amplifier AMPLIFIER DC POWER to ON.
10. On the pulse shaper board, adjust PEDESTAL VOLTAGE (R53) for a voltage of 15 ±1 volts, as measured on the oscilloscope at the SHAPED MODULATION test jack (this is just a starting value).
11. Connect the current probe to the oscilloscope and set the sensitivity to give a display of 2 amperes per division. Clip the current probe sensor to the supply lead (red lead) in the power modulation amplifier of the 1kW power amplifier.
12. Monitor the collector current and adjust the POWER MOD AMP control (R69) on the pulse shaper board for a peak current of 9 amperes. Do not exceed this value.
13. Move the current probe to the supply lead of the left hand amplifier of the driver pair in the 1kW power amplifier (the amplifier A1). Adjust PEDESTAL VOLTAGE (R53) for a collector pulse current of 2 amperes. Following this adjustment, adjust MOD PULSE AMPLITUDE (R58) on the pulse shaper board to give a peak collector current of 7 amperes.
14. Vary MOD PULSE AMPLITUDE (R58) from the 7 ampere setting to zero, and check that the displayed current pulse varies smoothly in amplitude. If there is evidence of instability (indicated by discontinuities or breaking up of the pulse) then slightly reduce the trimmer capacitor C4, in the power modulation amplifier,
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by turning it counter-clockwise, to a maximum of one turn. Set the peak collector current to 7 amperes when this check is completed.
15. Move the current probe back to the collector lead in the power modulator amplifier and, if necessary, adjust the POWER MOD AMP control (R69) for a peak current of 9 amperes.
3.2.4.9 1kW RF Power Amplifier Alignment The 1kW RF power amplifier is a broadband unit and requires no internal alignment.
3.2.4.9.1 Output Pulse Alignment 1. On the RF panel of a dual DME, set the ANTENNA RELAY switch to No 1 TO
ANT or No2 TO ANT as appropriate for the transponder being tested.
2. On the CTU, press the SELECT MAIN NO 1 or SELECT MAIN NO 2 as required, then select the Pwr.Out measurement for the transmitter being tested (if necessary, refer to the CTU operating instructions in Section A.1).
3. Connect the oscilloscope to the DETECTED REPLIES test jack on the test interrogator. Trigger the oscilloscope from the TRIGS TO MODULATOR test jack or the receiver video.
4. On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to ON.
5. Connect the multimeter (on 200 volts range) to test jacks HT and EARTH on the 1kW PA power supply front panel. The measured voltage should be 50.0 ±0.2 volts. If out of range, set the voltage within the specified range by adjusting R112 on the regulator of the 1kW PA power supply.
6. On the transmitter driver front panel, switch DRIVER DC POWER to NORMAL.
7. While monitoring the displayed output power on the CTU, slowly increase MOD PULSE AMPLITUDE (R58) on the pulse shaper board of the transmitter driver to produce a Pwr.Out reading of 1200 ±50 watts. This will give a detected pulse amplitude of typically 6 to 7 volts peak.
8. Perform a small number of successive adjustments to PEDESTAL VOLTAGE (R53) and MOD PULSE AMPLITUDE (R58) to obtain an output pulse shape generally similar to that shown in the figure below with a peak power of 1.2 kW, a pulse width in the range 3.2 to 3.8 microseconds, and rise and fall times in the range 1.9 to 2.5 microseconds. For final shape adjustment, see steps 9 to 14.
CAUTION During the adjustments, do NOT let the peak power exceed a power of 1.6 kW.
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9. On the oscilloscope, check the displayed signal from DETECTED REPLIES. On
the pulse shaper board of the transmitter driver, adjust PEDESTAL VOLTAGE (R53) so that the pedestal is about 5% of the total pulse amplitude, and clearly visible, as shown in the figure below.
10. On the pulse shaper board, adjust INTEGRATOR BALANCE (R 17) so that there
is an equal pedestal step at each side of the pulse, that is, RISE PEDESTAL equals FALL PEDESTAL.
11. On the pulse shaper board, adjust PEDESTAL VOLTAGE (R53) to reduce the pedestal until there is a smooth transition between the pulse and the baseline. Then adjust MOD PULSE AMPLITUDE (R58) to give 1.2 kW peak power output.
12. If the pulse shape at the completion of step 11 does not meet the limits of step 8, it may be necessary to readjust the function generator controls, R3 to R13 on the pulse shaper board to achieve the required pulse shape parameters. The object is to obtain the rated power output whilst meeting the pulse shape requirements of step 8.
13. On the oscilloscope display of DETECTED REPLIES, check the relative amplitudes of the two pulses of the pulse pair. If the second pulse is higher than the first, reduce its amplitude with 2ND PULSE EQUALISING (R54) on the pulse
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shaper board. (Otherwise leave this control fully clockwise.) If the second pulse is lower than the first, increase the amplitude by a SMALL adjustment only of INTEGRATOR BALANCE (R17) on the pulse shaper board.
14. If necessary, adjust MOD PULSE AMPLITUDE (R58) on the pulse shaper board to give 1.2 kW peak power output as in step 7.
15. Using the oscilloscope, measure the following parameters (with respect to an EARTH test jack or earth test point on the same module - as appropriate). Record these in the station log book for future reference.
MODULE MONITOR POINT PARAMETER Test Point XT9 DC Voltage Pulse Shaper Test Point XT5 DC Voltage
Pedestal Voltage Test Jack SHAPED MODULATION Pulse Peak Voltage Test Jack POWER AMP DRIVER Pulse Peak Voltage
1kW PA Power Supply
Test Jack POWER AMP MODULATOR
Pulse Peak Voltage
3.2.4.9.2 Automatic Level Control CAUTION In the next 2 steps, the output pulse peak power as measured by the CTU
Pwr.Out display should fall when specified switches are operated. If the peak power rises instead, there is a fault in the equipment. Reverse the operation of the switch and rectify the fault before continuing the test. The pulse peak power should NOT be allowed to exceed 1.8 kW for more than a few seconds.
1. On the pulse shaper board, switch ALC LOOP (S3) to OPEN. Adjust RF OUTPUT (R62) on the transmitter driver front panel fully counter-clockwise. Set switch ALC (S3) to DETECTED RF. Switch ALC LOOP to CLOSED. Observe that the output pulse peak power has been reduced. Adjust RF OUTPUT to give 1.2 kW peak power output (see Section 3.2.4.9.1step 7). Leave ALC (S3) in the DETECTED RF position.
2. On the transponder power supply front panel, switch TRANSPONDER DC POWER to OFF. Replace the transmitter driver in the transponder subrack. On the transponder power supply front panel, switch TRANSPONDER DC POWER to ON.
3. On the CTU Pwr.Out display, read the output pulse peak power, it should be 1200 ±50 watts.
3.2.4.10 Transmitter Pulse Parameters Ensure that the oscilloscope probes are correctly compensated and the vertical amplifiers are calibrated just prior to the commencement of this section. The parameters measured and recorded at the time of commissioning should be retained for later reference.
3.2.4.10.1 Test Setup 1. On the receiver video front panel, switch IDENT to CONTINUOUS.
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2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to test jacks DETECTED REPLIES and EARTH on the test interrogator front panel.
3. On the CTU front panel, press the SELECT MAIN, OFF/RESET key.
4. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to NORMAL.
5. On the transponder power supply front panel, switch TRANSPONDER DC POWER to NORMAL.
6. On the transmitter driver front panel, switch DRIVER DC POWER to NORMAL.
7. On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to NORMAL.
8. On the CTU front panel, press the SELECT MAIN NO 1 or SELECT MAIN NO 2 key as appropriate for the transponder being tested. Ensure MONITOR ALARM is set to INHIBIT.
3.2.4.10.2 Output Pulse Power 1. On the CTU softkeys, select Pwr.Out measurement in the Param menu. Read
the displayed power, which should be 1200 ±60 watts.
3.2.4.10.3 Output Pulse Shape 1. From the display on the oscilloscope, measure the following parameters, which
should be within the limits shown:
PARAMETER LIMITS 1st pulse: pulse width at half-amplitude 3.5 ±0.3 microseconds 2nd pulse: pulse width at half-amplitude 3.5 ±0.3 microseconds 1st pulse: rise time, 10% to 90% 2.2 ±0.3 microseconds 2nd pulse: rise time, 10% to 90% 2.2 ±0.3 microseconds 1st pulse: fall time, 10% to 90% 2.2 ±0.3 microseconds 2nd pulse: fall time, 10% to 90% 2.2 ±0.3 microseconds Amplitude difference between pulses 2%
2. On the CTU front panel, display the following parameters:
PARAMETER LIMITS Pulse width 3.5 ±0.3 microseconds Rise time 2.2 ±0.3 microseconds Fall time 2.2 ±0.3 microseconds
NOTE The CTU pulse shape measurement facility measures the parameters of the second pulse of a transmitted pulse pair.
3.2.4.10.4 Output Pulse Spacing 1. Connect channel 2 of the oscilloscope to test jacks 1 µs MARKERS and EARTH
on the test interrogator front panel. Use the displayed markers to correct the oscilloscope time base calibration and then measure and record the pulse
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spacing between the half-amplitude points on the leading edge of each pulse. It should be 12.0 ±0.1 microseconds. (If the pulse spacing is outside this limit, adjust REPLY PULSE SPACING (REPLY PULSE SEPARATION on early modules) on the receiver video front panel to set this parameter to a value in the specified range. (For ‘Y’ channel values refer to Section 3.2.10)
2. On the receiver video, switch IDENT to OFF.
3. On the CTU front panel, display the Spacing reading. The reading should be within the limits of step 1 above. (For ‘Y’ channel values refer to Section 3.2.10)
4. On the receiver video, switch IDENT to NORMAL.
3.2.4.10.5 Output Pulse Peak Power Calibration NOTE This procedure need only be performed following replacement or repair of the
following units:
Test Interrogator 1A72514 Test Interrogator Main PWB Assembly 1A72515 Reply Detector 1A72519
This procedure calibrates the power output measurement displayed on the CTU, and for this purpose it is necessary to take the peak power meter and attenuators (detailed in Section E.1) to the DME site.
As an alternative to the peak power meter, a calibrated detector may be used as detailed in Table E-1 of Section E.1.
1. With the DME switched off, disconnect the antenna feed cable from the ANTENNA connector on the RF panel at the rear of the rack. To the ANTENNA connector, connect firstly, a 30 dB 50 watts attenuator then a 20 dB 1 watt attenuator. Connect the peak power meter (or calibrated detector) to the output of the 20 dB attenuator.
2. Extend the test Interrogator, using the transponder extender frame.
3. On the CTU, press the SELECT MAIN NO 1 or NO 2 key as required for the transponder under test.
On the CTU front panel, display the Pwr.Out reading, Ch 1 or Ch2, as required for the test interrogator being adjusted.
4. While monitoring the CTU display, adjust TPDR OP LVL CAL (R7) on the test interrogator main board to display a Pwr.Out reading equal (within ±15 watts) to the reading on the peak power meter. Be sure to include any correction necessary from the calibration data of the attenuator and peak power meter (or detector).
5. Replace the test interrogator in the rack. Re-check the CTU Pwr.Out display which should be within ±30 watts of the corrected peak power meter reading. (If the reading is outside the limits, extend the test interrogator on the extender frame, adjust TPDR OP LVL CAL to produce the required correction, then replace the test interrogator in the rack).
6. Switch off the DME, disconnect the meter and attenuators and replace the antenna feed cable.
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3.2.4.11 Receiver Performance Tests
3.2.4.11.1 Receiver On-channel Threshold NOTE If this procedure is to be performed on an installed DME beacon, the DME
antenna must first be disconnected at the RF Panel and a suitable dummy load connected to the ANTENNA connector. This is to prevent incoming aircraft interrogations giving a false count.
1. Connect a frequency counter to the ON CHANNEL VIDEO and EARTH test jacks on the receiver video. Set the counter time base to 1 second. Make the following switch settings on the transponder.
• Test interrogator, MONITOR AND INTERROGATOR DC POWER to OFF (both modules, on a dual DME)
• Transmitter driver, DRIVER DC POWER to OFF
• Transponder power supply, TRANSPONDER DC POWER to ON
2. Measure the ON CHANNEL VIDEO pulse count on the frequency counter. This should be between 20 and 200 pulses per second.
3. If the pulse count is outside this range, then switch the TRANSPONDER DC POWER to OFF. Remove the receiver video module from the rack and remove the cover from the IF amplifier enclosure. Plug the module into the rack using a transponder extender frame.
4. Switch on the TRANSPONDER DC POWER; leave the test interrogator and transmitter driver switched off.
5. With a multimeter, measure the DC voltage at test pin XT13 on the IF amplifier board (referenced to ground); it should be 6.0 ±0.1 volts. If necessary, adjust the AGC preset (R15) to set the voltage within this range.
6. Measure the voltage at test pin XT10 (referenced to ground); it should be 5.0 ±0.1 volts. If necessary, adjust the ON CHANNEL preset (R50) to set the voltage within this range.
7. Measure the DC voltage at test point XT6 and adjust the GAIN preset (R29) to give a voltage of 4.0 ±0.4 volts.
8. Check that the ON CHANNEL pulse count is now within the required range. If it is not, then make a further gain adjustment to R29 to achieve the specified pulse count, ensuring that the voltage at XT6 stays within the limits of 4.0 ±0.4 volts. If any adjustment is made, re-check the voltage now at XT6.
9. If any adjustment has been made, measure the voltage at test pin XT1; it should be within the range 5.0 to 7.0 volts.
10. Switch off the transponder. Replace the cover on the IF amplifier and replace the receiver video module in the rack. Set all transponder front panel switches to NORMAL.
CAUTION On DME equipment manufactured before 1993, ensure that the cut-out in the IF amplifier cover is aligned with the ribbon cable entering the box.
3.2.4.11.2 Test Setup NOTE The receiver performance tests require the use of two SMA attenuators: a 6 dB
attenuator and a 3 dB attenuator. These are supplied with the DME. When required, the attenuator is inserted in series with the cable that connects to the TEST INTRGS connector on the RF panel at the rear of the rack. When an
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attenuator is called for in the following text, the cable at TEST INTRGS should be removed, the attenuator fitted to the TEST INTRGS connector, and the cable attached to the attenuator.
NOTE For some receiver tests, it is necessary to apply a high level signal, at –10 dBm, to the receiver input. When this is required, proceed as follows:
a. In the test interrogator, remove the 30 dB attenuator at the output of the switched attenuator, and connect the output cable directly to the switched attenuator.
b. On the RF panel, remove the short cable between the circulator and the input to the preselector filter.
c. On the RF panel, make a direct connection from the TEST INTRGS connector to the input of the preselector filter (a cable is supplied for this purpose).
d. On the CTU, select Hi Eff measurement in Maintenance mode. A -10 dBm signal is now being applied to the receiver input.
1. Extend the test interrogator, using the transponder extender frame. Switch on the DME in the maintenance mode, by first selecting MAINTENANCE, MONITOR INHIBIT then SELECT MAIN NO 1 or NO 2 as required.
2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks REPLY TIMING and EARTH, also on the test interrogator.
3. Connect channel 2 on the oscilloscope to test jacks REPLY ACCEPT GATES and EARTH on the test interrogator.
4. On the oscilloscope, check that the centre of the REPLY ACCEPT GATES align, within ±0.5 microseconds, with leading edges of the REPLY TIMING pulses. If it is outside this range, adjust the REPLY GATE DELAY controls on the test interrogator.
5. On the CTU front panel, select Lo Eff parameter measurement in Maintenance mode, and a TI RATE of 1 kHz. Check that a reply efficiency greater than 90% is being displayed.
3.2.4.11.3 Receiver Sensitivity 1. Insert the 6 dB attenuator in series with the TEST INTRGS cable (of the RF
panel), to apply an input of -91 dBm to the receiver. Select TI RATE, 1 kHz. On the CTU, measure the reply efficiency (using Lo Eff) averaged over a 10 second period. The average reply efficiency should be greater than 70%.
If the reply efficiency in step 1 is not achieved, then check the following:
• tuning of the preselector filter;
• alignment of the IF amplifier;
• receiver video alignment
(Refer to Section 3.2.9 for an abbreviated alignment procedure, or to Section 3.4 for detailed alignment)
3.2.4.11.4 Receiver Bandwidth 1. Remove the 6 dB attenuator on TEST INTRGS and replace it with the 3 dB
attenuator, to apply an input of -88 dBm to the receiver. On the CTU, measure
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the reply efficiency (using Lo Eff) averaged over a 10 second period. The average reply efficiency should be greater than 90%.
2. On the RF generator, set switch S1:1 to OFF and switch S1:2 to ON (to change the interrogation frequency to 160 kHz above the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
3. On the RF generator, set switch S1:2 to OFF and switch S1:3 to ON (to change the interrogation frequency to 160 kHz below the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
If the reply efficiencies in step 1 to 3 are not achieved, then check the narrow band alignment of the IF amplifier. (Refer to Section 3.2.9 for an abbreviated alignment procedure, or to Section 3.4 for detailed alignment.)
4. On the RF generator, set switch S1:3 to OFF and switch S1:1 to ON (to change the interrogation frequency back to the nominal frequency).
3.2.4.11.5 Receiver Selectivity 1. Apply an input of -10 dBm to the receiver, as described in Section 3.2.4.11.2. On
the CTU, measure the reply efficiency (using Hi Eff) averaged over a 10 second period. The average reply efficiency should be greater than 90%.
2. On the RF generator, set switch S1:1 to OFF and switch S1:4 to ON (to change the interrogation frequency to 900 kHz above the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 2%.
3. On the RF generator, set switch S1:4 to OFF and switch S1:5 to ON (to change the interrogation frequency to 900 kHz below the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 2%.
4. On the RF generator, set switch S1:5 to OFF and switch S1:1 to ON (to change the interrogation frequency back to the nominal frequency).
3.2.4.11.6 Receiver Decoding Window 1. Apply an input of -10 dBm to the receiver, as described in Section 3.2.4.11.2.
Switch and hold TEST TRANSPONDER DECODING REJECT on the test interrogator to +2 microseconds. On the CTU, measure the reply efficiency (using Hi Eff) averaged over a 10 second period. The average reply efficiency should be less than 5%.
2. On the test interrogator, switch and hold TEST TRANSPONDER DECODING REJECT to -2 microseconds. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 5%.
3. Restore normal connections on the RF panel and replace the 30 dB attenuator in the test interrogator. Insert the 3 dB attenuator at TEST INTRGS to give an input of -88 dBm to the receiver. On the CTU, retain a TI RATE of 1 kHz and select Lo Eff measurement.
4. On the test interrogator, switch and hold TEST TRANSPONDER DECODING ACCEPT to +1 microsecond. On the CTU, measure the reply efficiency (using Lo Eff) averaged over a 10 second period. The average reply efficiency should be greater than 70%.
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5. On the test interrogator, switch and hold TEST TRANSPONDER DECODING ACCEPT to -1 microsecond. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
6. On the test interrogator, switch and hold TEST TRANSPONDER DECODING REJECT to +2 microseconds. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 10%.
7. On the test interrogator, switch and hold TEST TRANSPONDER DECODING REJECT to -2 microseconds. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 10%.
8. Remove the 3 dB attenuator from the RF panel when finished.
3.2.4.11.7 Receiver CW Protection 1. In the test interrogator, remove the 30 dB attenuator at the switched attenuator
output and re-connect the output cable. This applies a receiver input level of -40 dBm. On the CTU, select a TI RATE of 1 kHz, and select H1 Eff measurement.
2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video. Measure the pulse peak amplitude (with respect to mean noise baseline); it should be at least 2.2 volts.
3. On the RF generator, set switch S1:6 to ON to add a CW signal to the interrogation pulse. On the oscilloscope, measure the pulse peak amplitude (with respect to mean noise baseline); it should be not more than 0.7 volts. (This reduction in pulse peak amplitude proves correct operation of the automatic gain control.)
4. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 90%.
5. On the RF generator, set switch S1:6 to OFF to remove the CW signal from the interrogation pulse. Replace the 30 dB attenuator in the test interrogator and restore all connections to normal.
3.2.4.11.8 Receiver Reply Rate 1. With all connections on the RF panel and in the test interrogator restored to
normal, select a TI RATE of 1 kHz on the CTU.
2. On the CTU, select Tx.Rate parameter measurement.
3. On the receiver video, switch and hold TEST switch to INHIBIT INTERROGATIONS. On the CTU, read the average of five displayed Tx.Rate readings. This squitter reply rate should be 945 ±10 Hz.
4. On the receiver video, switch and hold TEST switch to REPLY RATE MONITOR TEST. On the CTU, read the average of five displayed Tx.Rate readings. This reply rate should be 810 ±10 Hz.
5. While holding TI RATE 10 kHz on the CTU pressed, read the average of five displayed Tx.Rate readings. This maximum reply rate should be 2800 ±100 Hz.
6. On the CTU, select D.Rate parameter measurement at a TI RATE of 1 kHz. On a dual DME, temporarily switch off the second test interrogator module to prevent
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additional interrogation. Read the average of five displayed D.Rate readings. This decoded pulse rate should be 1000 ±10 Hz.
7. On the CTU select Hi Eff measurement to give an input of -70 dBm. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video. Measure the pulse peak amplitude (with respect to mean noise baseline); it should be at least 1.1 volts.
8. While observing the oscilloscope display, press TI RATE, 10 kHz on the CTU. Measure the pulse peak amplitude (with respect to mean noise baseline); it should be not more than 0.7 volts. (This reduction in pulse peak amplitude proves correct operation of the automatic gain control.)
3.2.4.11.9 Dead Time The performance tests include the setting of the DEAD TIME to position 6 of the switch. This gives a nominal dead time of 60 microseconds, which is usually used if no better value is known. Particular sites may do better if a different value is chosen. The performance testing should be done at the site value.
1. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DEAD TIME and EARTH on the receiver video. The duration of the displayed pulse will have random variations. Check that the pulse duration remains in the range 58 to 73 microseconds for a DEAD TIME switch setting of 6. The dead time will jitter between these limits because the system clock is not synchronous with the incoming interrogations.
3.2.4.12 Echo Suppression
3.2.4.12.1 Long Distance Echo Suppression (LDES) Long distance echo suppression stops the DME replying to echoes of the interrogation pulse pair which arrive after the dead time has elapsed. This can occur at some sites where aircraft interrogations suffer multi-path reflections from terrain that is 5 to 25 nautical miles distant from the beacon. If the reflections are of a comparable amplitude to the direct signal, the transponder gives an additional synchronous reply, which may cause a false lock-on at the interrogator. The effect in the aircraft is a stable DME indication, which sometimes jumps to a larger erroneous value. The presence of echoes is difficult to detect at the transponder, but it is helpful to connect the oscilloscope to test point XT13 on the receiver video main board and observe the received aircraft interrogation pulses. Trigger the oscilloscope internally, and look for synchronous interrogations of reduced amplitude that appear after the dead time period. The LDES THRESHOLD is set so that it is triggered by the direct signal, and the LDES PERIOD is set so that the LDES suppression pulse extends beyond the observed echoes. The final setting may need to be determined by experiment, to suit the amplitude and delay of the echoes at the particular site.
The procedure below uses nominal settings to test the LDES. At sites where the LDES is in use, the previously determined settings should be used.
1. On the CTU, select Hi Eff parameter measurement at a TI RATE of 1 kHz.
2. While extending the receiver video using the transponder extender frame, switch LDES (S9) on the receiver video main board to ON.
3. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test points XT13 and XT21 on
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the receiver video main board. On the oscilloscope, measure the peak interrogation pulse voltage. This voltage should be 2.70 ±0.50 volts.
4. Connect channel 2 of the oscilloscope to test points XT9 and XT21 (GND) on the receiver video main board. While observing the oscilloscope display, adjust LDES LEVEL (R46) to set the long distance echo suppression level to 0.10 to 0.15 volts less than the voltage recorded in the previous step.
5. Move channel 2 of the oscilloscope to test jacks DEAD TIME and EARTH on the receiver video. The duration of the displayed pulse will have random variations. Check that the pulse duration remains in the range 115 to 140 microseconds.
6. On the CTU, select Lo Eff parameter measurement. On the oscilloscope, check that the pulse duration remains in the range 58 to 73 microseconds.
7. On the receiver video main board, switch LDES (S9) to OFF (unless it is to be used at this site).
3.2.4.12.2 Short Distance Echo Suppression (SDES) Short distance echo suppression permits the decoding of an interrogation pulse pair when echoes of the first pulse occur between the two pulses. It may be found necessary at sites where reflections from nearby structures or terrain corrupt the second pulse of the interrogation pulse pair. The effect in the aircraft is the absence of replies, and the loss of DME indication at certain locations. The need for SDES may be determined on-site by connecting the oscilloscope (internally triggered) to test point XT13 on the receiver video main board, and observing the interrogation pulse pairs from nearby aircraft. If extraneous pulses appear between the two pulses, or if the second pulse leading edge is distorted, then switch SDES to ON, and check it this improves the DME reception in the aircraft.
The procedure below checks the operation of the SDES circuit. If SDES is used, it should be left switched ON at the end of this check procedure.
1. On the CTU, select Hi Eff parameter measurement.
2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test points XT13 and XT21 (GND) on the receiver video main board. Connect channel 2 of the oscilloscope to test jacks SDES PULSE and EARTH on the receiver video. On the oscilloscope, check that the displayed XT13 waveform is similar to that shown in the figure below for SDES OFF.
3. On the receiver video main board, switch SDES to ON. On the oscilloscope,
check that an SDES pulse is now present and that the displayed XT13 waveform has the leading edge of the second pulse masked out in line with the SDES pulse
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as shown in the figure above for SDES ON. (The SDES pulse has a nominal width of 2.5 microseconds and is delayed a nominal 14 microseconds from the TRIGGER pulse.)
4. On the receiver video main board, switch SDES to OFF (unless it is to be used at this site). Install the receiver video back in the transponder subrack.
3.2.4.13 Transponder Delay
3.2.4.13.1 Reply Delay Adjustment 1. On the CTU, select Delay parameter measurement at a TI RATE of 1 kHz. The
displayed reading will probably fluctuate ±0.1 microseconds about the average value. If necessary, adjust the BEACON DELAY, COARSE and FINE controls on the receiver video to achieve an average as near as possible to 50.0 microseconds. Due to the limited resolution of the FINE control, it will sometimes be necessary to accept 49.9 or 50.1 microseconds. A reading on the low side is preferred since the antenna feeder will increase the transponder delay as measured by an aircraft. Record this Reference Delay value in the log book. (For ‘Y’ channel values refer to Section 3.2.10)
3.2.4.13.2 Final Receiver Checks 1. On the CTU, select Delay parameter measurement at a TI RATE of 1 kHz.
2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks INTERROGATIONS TIMING and EARTH and channel 2 of the oscilloscope to test jacks REPLY TIMING and EARTH on the test interrogator. Measure the time interval between the first interrogation pulse and the first synchronised reply pulse (at half-amplitude points on the pulse leading edges) and measure by reference to the 1 microsecond markers at 1 µs MARKERS test jack on the test interrogator. The time interval should be within ±0.1 microseconds of the value displayed on the CTU. (For ‘Y’ channel values refer to Section 3.2.10)
3. On the CTU, select Lo Eff parameter measurement at a TI RATE of 1 kHz.
4. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video. Measure the amplitude of the displayed synchronous video pulses with respect to the 0 volts reference (taking the mean of the noise on the peak of the pulses). The amplitude should be 1.2 ±0.5 volts.
5. On the CTU, select Hi Eff parameter measurement. On the oscilloscope measure the amplitude of the displayed synchronous video pulses with respect to the 0 volts reference. The amplitude should be 1.8 ±0.5 volts.
6. Calculate the difference in amplitudes of steps 4 and 5. This difference should be in the range 0.4 to 0.7 volts.
7. On the CTU, select Effncy parameter measurement. On the oscilloscope, check (see figure below) that the displayed synchronous video pulses alternate between the two levels recorded above. Measure the time interval from the rising edge of the first pulse of a low level synchronous video pulse pair to the rising edge of the first pulse of a high level synchronous video pulse pair. This time interval should be 1.00 ±0.05 milliseconds. (Synchronous reply pulses, probably at a higher level, will also be present on the displayed waveform.)
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3.2.4.14 Ident The ident code used for testing should be the one assigned to the DME station.
3.2.4.14.1 Internal ldent 1. On the CTU, switch MAINTENANCE to OFF. Under the Misc menu select Mon 1
- for No.1 transponder (Mon 2 - for No.2 transponder) as the ident (speaker) source. Switch MAINTENANCE back to ON. Listen to the ident from the CTU mounted speaker and check that it is correct for the assigned ident (as set in Section 3.2.4.2.4). If necessary, set the internal speaker volume preset (R33) to provide a suitable ident level (refer Section A.5.1.3). If external ident tone is required, it may be appropriate to set the level here; refer to Section A.5.1.7.
2. Using a stopwatch, measure the ident repetition period. It should be 40 ±4 seconds.
If it is outside this range, it may be adjusted by the preset IDENT REPTN RATE (R39) in the receiver video. (IDENT CODE SPEED (R37) sets the rate at which the dots and dashes are transmitted).
3.2.4.14.2 External Ident 1. On the external I/O board at the rear of the rack, locate terminals XB1:4 (ASSOC
IDENT IN) and XB11:5 (GND).
2. Apply a pulsed short circuit between these terminals to simulate Morse code from an external source. Listen to the CTU mounted speaker and confirm that ident is transmitted whenever the short circuit is applied.
3. Listen for the internally generated ident and start a stopwatch at the commencement of the internal ident.
4. Immediately, on the external I/O board terminals, apply the short circuit for 1 to 2 seconds.
5. Using a stopwatch, measure the elapsed time until the commencement of the next internal ident. This elapsed time should be less than 58 seconds.
3.2.4.14.3 Master Ident 1. On the external I/O board, connects a continuity test between terminals XB1:1
and XB1:2 (ASSOC IDENT OUT). Using a stopwatch, measure the time period between the commencement of the internally generated ident messages. Check that this time period is 10 ±1 seconds for three out of four ident messages.
2. Check that every fourth ident message is suppressed.
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3. Check that the suppressed ident message coincides with the ident message transmitted by the DME.
3.2.4.14.4 Ident Frequency 1. On the CTU, select Tx.Rate parameter measurement.
2. On the receiver video, switch IDENT to CONTINUOUS. On the CTU, read the average of five displayed transmitted pulse rate readings. This ident frequency should be 1350±20 Hz.
3. On the receiver video, switch IDENT to NORMAL.
3.2.4.15 Monitor Fault Limits For the tests described in this section, it is assumed that the monitor fault limits have been set, using the internal preset switches, to the values specified in Section 3.2.4.2.8. If these limits have been set to values other than those specified, then the appropriate corrections must be made to the limit values given in the following tests.
For most of the fault limit tests below, two procedures are given, marked 'a' and b'. The use of these is as follows:
a. This procedure uses the internal fault limit test facility to measure the monitor fault limit. DME operation is not interrupted and no preset controls are disturbed. This procedure should be used for periodic inspections.
b. This procedure may interrupt the operation of the DME and requires disturbance of some controls.
This procedure should be used only after repair or replacement of the monitor.
3.2.4.15.1 Test Setup 1. On the monitor main board, ensure that each of the fault limit switches has been
set as specified in Section 3.2.4.2.8, step 1 (or to the fault limits required for the station).
2. At the rear of the rack, ensure that the cables providing signals into the ERP IN connectors of the transponders have been connected.
3. On the RF panel, ensure that the antenna integrity monitor cable (from the antenna DC continuity monitor) is connected to XN2 on the RF panel board.
If the antenna does not have a DC continuity monitor, then switches S2:5 and S2:7, on the CTU processor board, must be set to ON (refer Section 3.2.4.2.3).
4. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to NORMAL.
5. On the transponder power supply front panel, switch TRANSPONDER DC POWER to NORMAL.
6. On the transmitter driver front panel, switch DRIVER DC POWER to NORMAL.
7. On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to NORMAL.
8. On the RF panel, ensure ANTENNA RELAY switch is set to NORMAL in a dual DME.
9. On the CTU front panel select MAINTENANCE, then press the SELECT MAIN NO 1 or NO 2 key as appropriate for the transponder being tested.
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10. On the monitor, ensure that the eight green parameter indicators are on and the red PRIMARY and yellow SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
3.2.4.15.2 Delay Monitor a. Procedure a:
1. On the CTU, select the FltLimit menu and the Delay parameter for measurement.
2. Check that the displayed values are within the following limits:
Delay, Lower: 49.5 +0.1. -0.0 microseconds Delay, Upper: 50.5 +0.1, -0.0 microseconds
(For ‘Y’ channel values refer to Section 3.2.10)
If a consistent error exists in the Upper and Lower Delay limits, a correction of +0.1 microseconds or -0.1 microseconds can be added, for each monitor system, by using the 8-bit DIP switch S1 on the CTU processor board as follows. Record the final settings of these four switches for future reference.
SWITCHES FOR MONITOR SYSTEM 1
SWITCHES FOR MONITOR SYSTEM 2 CORRECTION
µs 6 7 3 4
0 ON ON ON ON +0.1 ON OFF ON OFF -0.1 OFF ON OFF ON (0) OFF OFF OFF OFF
b. Procedure b:
1. On the CTU, select Delay parameter measurement at a TI RATE of 1 kHz.
2. On the receiver video, read and record the position of the BEACON DELAY, COARSE and FINE switches (to enable these switches to be restored to their original positions at the completion of these tests).
3. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed Delay of 49.5 microseconds on the CTU. Check that the DELAY indicator on the monitor is off and the PRIMARY indicator is on.
4. While observing the monitor DELAY indicator, slowly continue to adjust the BEACON DELAY, COARSE switch towards position 0 to reduce the beacon delay. Check that the DELAY indicator remains off.
For delays outside the range 48 to 52 microseconds, the CTU will display "OVERFLOW".
For delays around 38 microseconds, the second pulse of the pulse pair will fall within the accept window around 50 microseconds and the DELAY indicator will again turn on. This is acceptable.
5. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed Delay of 50.5 microseconds on the CTU. Check that the DELAY indicator on the monitor is off and the PRIMARY indicator is on.
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6. While observing the monitor DELAY indicator, slowly continue to adjust the BEACON DELAY, COARSE switch towards position F to increase the beacon delay. Check that the DELAY indicator remains off.
7. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed Delay of 50.3 microseconds on the CTU. Check that the DELAY indicator on the monitor is on.
8. While observing the monitor DELAY indicator, slowly continue to adjust the BEACON DELAY, COARSE and FINE switches to decrease the beacon delay (but not below 49.7 microseconds). Check that the DELAY indicator remains on.
9. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed Delay of 49.7 microseconds on the CTU. Check that the DELAY indicator on the monitor is on.
10. On the receiver video, restore the BEACON DELAY, COARSE and FINE switches to their original settings.
(For ‘Y’ channel values refer to Section 3.2.10)
3.2.4.15.3 Spacing Monitor a. Procedure a:
1. On the CTU, select the FltLimit menu and the Spacing parameter for measurement.
2. Check that the displayed values are within the following limits:
Spacing, lower: 11.5 +0.0, -0.1 microseconds Spacing, upper: 12.5 +0.0, -0.1microseconds
(For ‘Y’ channel values refer to Section 3.2.10)
b. Procedure b:
1. On the CTU, select Spacing parameter measurement at a TI RATE of 1 kHz.
2. On the receiver video, read and record the position of the REPLY PULSE SPACING (REPLY PULSE SEPARATION on earlier modules) switch (to enable this switch to be restored to its original position at the completion of these tests).
3. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed Spacing of 11.4 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 11.4 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to 11.4 microseconds, but never greater than 11.4 microseconds.) Check that the SPACING indicator on the monitor is off and the PRIMARY indicator is on.
4. While observing the monitor SPACING indicator, slowly continue to adjust the REPLY PULSE SPACING switch towards position 0 to reduce the pulse spacing. Check that the SPACING indicator remains off.
5. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed spacing of 12.6 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 12.6 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to
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12.6 microseconds, but never less than 12.6 microseconds.) Check that the SPACING indicator on the monitor is off and the PRIMARY indicator is on.
6. While observing the monitor SPACING indicator, slowly continue to adjust the REPLY PULSE SPACING switch towards position F to increase the pulse spacing. Check that the SPACING indicator remains off.
7. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed Spacing of 12.3 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 12.3 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to 12.3 microseconds, but never greater than 12.3 microseconds.) Check that the SPACING indicator on the monitor is on.
8. While observing the monitor SPACING indicator, slowly continue to adjust the REPLY PULSE SPACING switch to decrease the pulse spacing (but not below 11.7 microseconds). Check that the SPACING indicator remains on.
9. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed spacing of 11.7 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 11.7 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to 11.7 microseconds, but never less than 11.7 microseconds.) Check that the monitor SPACING indicator is on.
10. On the receiver video, restore the REPLY PULSE SPACING switch to its original setting.
(For ‘Y’ channel values refer to Section 3.2.10)
3.2.4.15.4 Efficiency Monitor a. Procedure a:
1. On the CTU, select the FltLimit menu and the Effncy parameter for measurement.
2. Check that the displayed value is within the following limit:
Effncy, lower: 60 ±2%
b. Procedure b:
There is no alternative procedure for this test.
3.2.4.15.5 Rate Monitor a. Procedure a:
1. On the CTU, select the FltLimit menu and the Tx.Rate parameter for measurement.
2. Check that the displayed values are within the following limits:
Tx.Rate, lower: 833 ±10 Hz Tx.Rate, upper: 3000 ±30 Hz
b. Procedure b:
1. On the CTU, select Tx.Rate parameter measurement at a TI RATE of 50 Hz (100 Hz for a dual DME).
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2. On the monitor, check that the RATE indicator is on while the CTU displays a transmit pulse rate reading of 945 ±10 Hz.
3. On the receiver video, switch and hold TEST switch to REPLY RATE MONITOR TEST. On the monitor, check that the RATE indicator is off and the SECONDARY indicator is on while the CTU displays a transmitted pulse rate reading of 810 ±10 Hz.
3.2.4.15.6 Power Monitor
3.2.4.15.6.1 Adjustment This procedure is intended for use at installation or after module repair.
1. Extend the monitor on the transponder extender frame. Switch on the DME and confirm that it is giving normal transmitter power.
2. Select the required fault limit point on switch PWR LVL FLT SET (S7) on the monitor main board. This fault limit is normally set to -3 dB, and the following check procedure assumes a fault limit of -3 dB.
3. With a multimeter, (on the 20V range) measure the voltage between test points XT1 and XT13 (GND) on the monitor main board. This should be 5.000 ±0.002 volts.
4. Connect the multimeter to test point XT2 and XT13 (GND). Adjust R87 (PEAK POWER MONITOR CALIBRATION) preset to give a voltage of 2.50 ±0.05 volts. Check that the monitor RF POWER indicator is on.
5. Replace the module in the rack.
3.2.4.15.6.2 Measurement a. Procedure a:
1. On the CTU, select the FltLimit menu and the Ant.Pwr parameter for measurement.
2. Check that the displayed value is within the following limit:
Ant.Power, lower: -3 ±0 dB
b. Procedure b:
1. Extend the monitor module on the transponder extender frame. Switch on the DME and confirm normal operation. Check that the monitor RF POWER indicator is on.
2. Connect a multimeter (20V DC range) to test points XT2 and XT13 (GND) on the monitor main board. Measure and record the voltage at XT2.
3. Adjust R87 (PEAK POWER MONITOR CALIBRATION) preset to reduce the voltage at XT2. Measure the voltage at which the RF POWER indicator just turns off. This should be 1.77 ±0.1 volts.
4. Restore R87 for the XT2 voltage measured in step 2 above.
5. Replace the monitor module in the rack.
3.2.4.15.7 Ident Monitor a. Procedure a:
There is no fault limit test for this parameter.
b. Procedure b:
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1. On the CTU, set MONITOR ALARM to NORMAL to allow ident to be transmitted.
2. On the receiver video, switch IDENT to NORMAL. Check that ident code is being transmitted and is audible from the CTU mounted speaker.
3. Immediately after the transmission of an ident code group, switch IDENT on the receiver video to OFF. Measure (with a stopwatch) the time taken for the monitor IDENT indicator to turn off and the SECONDARY indicator to turn on. This should be 60 ±3 seconds.
4. On the CTU, set MONITOR ALARM to INHIBIT (to prevent the beacon from shutting down).
5. On the receiver video, switch IDENT to CONTINUOUS. Measure (with a stopwatch) the time taken for the monitor DELAY and SPACING indicators to both turn off. This should be ±3 seconds.
6. On the receiver video, switch IDENT to NORMAL.
7. On the CTU, set MONITOR ALARM to NORMAL.
NOTE The ident fault delay time may be set as low as 45 seconds, if required, provided that the internal ident generator (in the receiver video) is set for a repetition period of 40 seconds. However, if an external ident source is used (for example, from an associated DVOR), then the ident fault delay time must be set to a value not less than 60 seconds. This is to ensure adequate time for the internal ident to start should the external ident fail.
Details for setting the ident fault delay time (switch IDENT GAP FLT SET (S8) on the monitor main board) are given in Section A.5.
3.2.4.15.8 Antenna Monitor a. Procedure a:
There is no fault limit test for this parameter.
b. Procedure b:
1. On the monitor, check that the ANTENNA indicator is on.
2. On the RF panel at the rear of the rack, disconnect the antenna DC continuity cable from XN2 on the RF panel board. Check that the monitor ANTENNA, indicator is off.
3. Re-connect the antenna DC continuity cable to XN2. Replace monitor in the rack.
3.2.4.15.9 Shape Monitor a. Procedure a:
There is no fault limit test for this parameter.
b. Procedure b:
1. Extend the monitor using the transponder extender frame.
2. On the monitor, check that the SHAPE indicator is on. (If it is not, then check that the transmitter pulse shape is correct and that switches S1, S2, S3 and S4 on the monitor main board are correctly set - see Section 3.2.4.2.8, step 1.).
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3. On the monitor, switch S1.5 to ON to change the Pulse Width Lower Reject Limit from 2.9 microseconds to 1.3 microseconds (and thus the Upper Limit from 4.1 microseconds to 2.5 microseconds). Check that the SHAPE indicator is off and the SECONDARY indicator is on. Switch S1:5 back to OFF (and ensure that the SHAPE indicator is on again).
4. On the monitor, switch S1:6 to OFF to change the Pulse Width Lower Reject Limit from 2.9 microseconds to 6.1 microseconds. Check that the SHAPE indicator is off. Switch S1:6 back to ON (and ensure that the SHAPE indicator is on again).
5. On the monitor, switch S2:6 to ON to change the pulse Fall Time Upper Reject Limit from 3.6 microseconds to 0.4 microseconds. Check that the SHAPE indicator is off and the SECONDARY indicator is on. Switch S2:6 back to OFF (and ensure that the SHAPE indicator is on again).
6. On the monitor, switch S3:5 to ON to change the pulse Rise Time Upper Reject Limit from 3.1 microseconds to 1.5 microseconds. Check that the SHAPE indicator is off and the SECONDARY indicator is on. Switch S3:5 back to OFF (and ensure that the SHAPE indicator is on again).
7. Restore the monitor back in the transponder subrack.
NOTE The monitor pulse shape monitor checks the parameters of the first pulse of a transmitted pulse pair. The CTU pulse shape measurement facility however, measures the second pulse of the pair.
3.2.4.15.10 Monitor Self Test 1. With the DME operating in Maintenance mode, ensure that all eight monitor
parameter indicators are on.
2. On the monitor, check that the SELF TEST indicator flashes on at regular intervals. Using a stopwatch, measure the time period of these indicator flashes. The time period should be 16 ±2 seconds.
3. Check that simultaneously with this indicator flashing on, the DELAY and SPACING indicators are off and the PRIMARY indicator is on.
3.2.4.15.11 Monitor Fault Limits - Final Check 1. With the DME operating in Maintenance mode, ensure that all 8 monitor
parameter indicators are on.
2. On the CTU, select the FltLimit parameters listed in the table below. For each parameter, the displayed fault limits should be within the ranges listed in the table. (For ‘Y’ channel values refer to Section 3.2.10)
PARAMETER SPECIFIED VALUE
LIMITS UNITS
+0.1 Delay; Lower 49.5 --0.0
µs
+0.1 Delay; Upper 50.5 --0.0 µs
+0.0 Spacing; Lower 11.5 -0.1 µs
+0.0 Spacing; Upper 12.5 -0.1 µs
Effncy; (Lower) 60 ±2 % Tx Rate; Lower 833 ±10 Hz Tx Rate; Upper 3000 ±30 Hz Ant Power; (Lower) -3 0 dB
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If a consistent error exists in the Upper and Lower Delay limits, a correction of +0.1 microseconds or -0.1 microseconds can be added, for each monitor system, by using the 8-bit DIP switch S1 on the CTU processor board as follows.
SWITCHES FOR MONITOR SYSTEM 1
SWITCHES FOR MONITOR SYSTEM 2 CORRECTION
µs 6 7 3 4 0 ON ON ON ON
+0.1 ON OFF ON OFF -0.1 OFF ON OFF ON (0) OFF OFF OFF OFF
3.2.4.16 Control System - PART 1 - SINGLE DME
3.2.4.16.1 Normal Operation 1. On the monitor, ensure switch MONITOR OUTPUTS is set to NORMAL.
2. On the test interrogator, ensure switch MONITOR AND INTERROGATOR DC POWER is set to NORMAL.
3. On the transponder power supply, ensure switch TRANSPONDER DC POWER is set to NORMAL.
4. On the transmitter drivers, ensure switch DRIVER DC POWER is set to NORMAL.
5. On the receiver video, ensure switch IDENT is set to NORMAL.
6. On the 1kW PA power supply, ensure switch AMPLIFIER DC POWER is set to NORMAL.
7. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not off), RECYCLE (if RECYCLE indicator is not off).
8. On the CTU, set the ALARM DELAY switch to 10 seconds.
9. On the CTU, press the SELECT MAIN NO 1 key. Check that the state of each of the CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON ON NO 2 ON OFF NORMAL ON
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE OFF ALARM REGISTER ALL OFF
MODULES OFF TEST ANT RELAY OFF AC POWER NORM ON
BATT CHG 1 ON BATT CHG 2 OFF POWER
BATT LOW OFF
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10. On the monitor, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
When setting up the DME for normal operation, it may be necessary to wait up to 10 seconds (90 seconds for ident) for normal operation to commence from the last action which initiated the normal operation.
3.2.4.16.2 Primary Fault This test involves generating a primary fault, and then monitoring the sequence of events following this action.
1. Ensure that the DME is operating in the normal state of Section 3.2.4.16.1.
2. Using a stopwatch, measure the time period from the PRIMARY alarm register indicator on the CTU turning on to the NO 1 ON STATUS indicator on the CTU turning off - in response to switching and holding TEST, on the receiver video to INHIBIT INTERROGATIONS. This alarm delay time should be 10 ±1 seconds.
3. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NORMAL OFF STATUS
SHUTDOWN ON DELAY ON
SPACING ON ALARM REGISTER PRIMARY ON
4. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
5. Confirm that the DME is operating in the normal state of Section 3.2.4.16.1.
3.2.4.16.3 Secondary Fault This test involves generating a secondary fault, and then monitoring the status following this action.
1. Ensure that the DME is operating in the normal state of Section 3.2.4.16.1.
2. Disconnect the input to the ERP IN connector at the rear of the transponder subrack.
3. On the monitor, check that the RF POWER indicator is off.
4. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE STATUS NORMAL OFF
ALARM REGISTER SECONDARY ON
5. Restore normal operation by reconnecting the coaxial cable to connector ERP IN on the rear of the transponder subrack.
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6. Confirm that the DME is operating in the normal state of Section 3.2.4.16.1.
3.2.4.16.4 Recycle Function This test involves causing a shutdown by generating a primary fault, and then monitoring the sequence of restart events following this action.
1. Ensure that the DME is operating in the normal state of Section 3.2.4.16.1.
2. On the CTU, reset the restart count to 0 using the Misc menu. Press RECYCLE key to turn the RECYCLE indicator on.
3. Cause the DME to shutdown by switching MONITOR OUTPUTS on the monitor to FAILED and check that the rack shuts down after the selected 10 ±1 seconds.
4. Measure the time period from this shutdown to the following restart. This should be 30 ±3 seconds.
5. Leaving the MONITOR OUTPUTS switch in the FAILED position, count the total number of restart attempts (including the first one in the step above). This number should be 3.
6. Check that the rack then remains shutdown.
7. On the CTU, select the Misc menu and check that the displayed number of restart attempts is 3.
8. On the CTU, check that the state of the listed CTU indicators is as shown in the table below:
INDICATOR REQUIRED STATE NO 1 ON OFF NORMAL OFF STATUS
SHUTDOWN ON DELAY ON
SPACING ON EFFICIENCY ON
TX RATE ON RF POWER ON
IDENT OFF PULSE SHAPE ON
ANTENNA ON PRIMARY ON
SECONDARY ON MONITOR OFF
ALARM REGISTER
CTU OFF
9. On the monitor, switch MONITOR OUTPUTS to NORMAL.
10. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
11. Confirm that the DME is operating in the normal state of Section 3.2.4.16.1.
12. If the recycle function is not required, press RECYCLE key on the CTU to turn the RECYCLE indicator off.
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3.2.4.16.5 High Voltage Shutdown Adjust 1. On the control module of the AC power supply, set the controls listed in the table
below as indicated:
SHUT DOWN DELAY fully counter-clockwise, H/V SHUTDOWN fully clockwise.
2. With the multimeter connected to the rack BATTERY terminals, switch and hold the TEST/FLOAT switch to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 28.5 ±0.1 volts.
3. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust H/V SHUT DOWN control counter-clockwise until the DME shuts down. Check that the H/V SHUT DOWN indicator on the control module is on.
4. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control counter-clockwise to produce a multimeter reading of 27.5 ±0.2 volts. The DME should return to normal operation.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control clockwise again until the DME again shuts down. Read the multimeter reading. It should be 28.5 ±0.2 volts.
6. On the AC power supply, release the TEST/FLOAT switch. Confirm that the DME is powered up and operating in the normal state of Section 3.2.4.16.1.
7. On the control module of the AC power supply, adjust the SHUT DOWN DELAY control to mid-position.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control counter-clockwise to produce a multimeter reading of 29.0 ±0.2 volts. Release the TEST/FLOAT switch to enable the DME to return to normal operation.
9. Using a stopwatch, measure the time period from pressing the TEST/FLOAT switch to the DME shutting down. This time delay should be 3 ±1 seconds. (If necessary readjust SHUT DOWN DELAY control to achieve this delay.)
3.2.4.16.6 Low Voltage Alarm Adjust 1. On the control module of the AC power supply, set LOW VOLTALARM control
fully counter-clockwise.
2. With the multimeter connected to the rack BATTERY terminals, switch and hold the TEST/FLOAT switch to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 23.5 ±0.1 volts.
3. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust LOW VOLTALARM control clockwise until the O/P FAIL indicator on the control module turns on. The DME should remain in operation.
4. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 24.5 ±0.2 volts.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control counter-clockwise again until the O/P FAIL indicator again turns on. Read the multimeter reading. It should be 23.5 ±0.2 volts.
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6. On the AC power supply, release the TEST/FLOAT switch. Confirm that the DME is powered up and operating in the normal state of Section 3.2.4.16.1.
7. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 23.0 ±0.1 volts.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, check that the BATT CHG 1 indicator on the CTU is off.
3.2.4.16.7 Low Voltage Shutdown Adjust 1. On the power distribution panel, switch circuit breaker CTU & TRANSPONDER
to OFF. Extend the CTU using two Eurocard extenders. Switch circuit breaker CTU & TRANSPONDER to ON. If batteries are used, temporarily disconnect them from the BATTERY terminals.
2. On the CTU processor board of the CTU, adjust the low volts preset R32 fully counter-clockwise.
3. With the multimeter connected to the rack BATTERY terminals, switch and hold the TEST/FLOAT switch to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 22.0 ±0.1 volts.
4. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, on the CTU processor board, adjust R32 clockwise until the DME shuts down and the BATT LOW indicator on the CTU turns on. Then slowly adjust R32 counter-clockwise until the BATT LOW indicator on the CTU turns off. Slowly adjust R32 clockwise again until the BATT LOW indicator on the CTU again turns on.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 24.5 ±0.2 volts. The DME should return to normal operation.
6. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control counter-clockwise again while observing the multimeter. Measure the voltage immediately prior to DME shutdown. It should be 22.0 ±0.2 volts.
7. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, check that the CTU BATT LOW indicator is on.
8. On the AC power supply, release the TEST/FLOAT switch. Confirm that the DME is powered up and operating in the normal state of Section 3.2.4.16.1.
9. On the power distribution panel, switch circuit breaker CTU & TRANSPONDER to OFF. Restore the CTU to the CTU subrack. Switch circuit breaker CTU & TRANSPONDER to ON.
3.2.4.16.8 DC Supply Adjustment 1. Connect the multimeter (on 200 volts range) to the 24 volts BATTERY terminals
at the rear of the rack.
2. With the DME operating in the normal state of Section 3.2.4.16.1, measure the primary DC supply voltage. It should be 27 ±0.2 volts.
If it is outside this limit, it may be adjusted by the FLOAT2 VOLTAGE control on the control module of the AC power supply.
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3.2.4.16 Control System - PART 2 - DUAL DME From this point on, the tests are only to be performed once on the equipment under test.
When an action is taken on the DME to initiate a shutdown or a transfer, and the time delay from the action to the response is to be measured, it is recommended that the action take place within a period 2 to 7 seconds after the completion of monitor self test. This will ensure that the measured time period is not affected by the presence of a monitor self test.
3.2.4.16.1 Normal Operation - No. 1 is MAIN 1. On both monitors, ensure switch MONITOR OUTPUTS is set to NORMAL.
2. On both test interrogators, ensure switch MONITOR AND INTERROGATOR DC POWER is set to NORMAL.
3. On both transponder power supplies, ensure switch TRANSPONDER DC POWER is set to NORMAL.
4. On both transmitter drivers, ensure switch DRIVER DC POWER is set to NORMAL.
5. On both receiver videos, ensure switch IDENT is set to NORMAL.
6. On both 1kW PA power supplies, ensure switch AMPLIFIER DC POWER is set to NORMAL.
7. On the RF panel, ensure switch ANTENNA RELAY is set to NORMAL.
8. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not off), RECYCLE (if RECYCLE indicator is not off).
9. On the CTU, set the ALARM DELAY switch to 10 seconds.
10. On the CTU, press the SELECT MAIN NO 1 key. Check that the state of each of the CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON ON NO 2 ON OFF NORMAL ON
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE OFF ALARM REGISTER ALL OFF
MODULES OFF TEST ANT RELAY OFF AC POWER NORM ON
BATT CHG 1 ON BATT CHG 2 ON POWER
BATT LOW OFF
11. On both monitors, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
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When setting up the DME for normal operation, it may be necessary to wait up to 10 seconds (90 seconds for ident) for normal operation to commence from the last action which initiated the normal operation.
3.2.4.16.2 Primary Fault - No.1 is MAIN This test involves generating primary faults, and then monitoring the sequence of events following this action.
1. Ensure that the DME is operating in the No.1 normal state of Section 3.2.4.16.1.
2. On both receiver video modules, read and record the position of the REPLY PULSE SPACING (REPLY PULSE SEPARATION on earlier modules) switch (to enable these switches to be restored to their original positions at the completion of these tests).
3. On the No.1 receiver video, turn REPLY PULSE SPACING through 5 positions. Using a stopwatch, measure the time period from the PRIMARY ALARM REGISTER indicator on the CTU turning on to the NO 1 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No.1 receiver video through 5 positions. This alarm delay time should be 10 ±1 seconds.
4. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON ON NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF SPACING ON ALARM REGISTER PRIMARY ON
5. On the No.2 receiver video, turn REPLY PULSE SPACING through FIVE positions. Using a stopwatch, measure the time period from the PRIMARY alarm indicator on either monitor turning on to the NO 2 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No.2 receiver video through 5 positions. This alarm delay time should be 10 ±1 seconds.
6. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER OFF STATUS
SHUTDOWN ON SPACING ON ALARM REGISTER PRIMARY ON
7. On both receiver video modules, restore switches REPLY PULSE SPACING to their original positions recorded at Section 3.2.4.16.2 step 2.
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8. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
9. Confirm that the DME is operating in the No. 1 normal state of Section 3.2.4.16.1.
3.2.4.16.3 Secondary Fault - No. 1 is MAIN This test involves generating secondary faults, and then monitoring the status following this action. (Ensure that the cable connectors to ERP IN at the rear of the two transponders are able to be distinguished so that they are returned to their correct connections at the completion of this test.)
1. Ensure that the DME is operating in the No. 1 normal state of Section 3.2.4.16.1.
2. Disconnect the input to the ERP IN connector at the rear of No.1 transponder subrack. On No.1 monitor, check that the RF POWER indicator is off.
3. Wait at least 20 seconds. On the CTU, check that the state of the listed CTU indicators is as shown in the table below. No transfer to standby will occur until this fault is registered on both monitors.
INDICATOR REQUIRED STATE NO 1 ON ON NO 2 ON OFF NORMAL ON
TRANSFER OFF STATUS
SHUTDOWN OFF RF POWER OFF
SECONDARY OFF ALARM REGISTER PRIMARY OFF
4. Disconnect the input to the ERP IN connector at the rear of the No.2 transponder subrack. Using a stopwatch, measure the time period from the SECONDARY alarm indicator on the No.2 monitor turning on to the NO 1 ON STATUS indicator on the CTU turning off - in response to disconnecting the input to the ERP IN connector at the rear of No.2 transponder subrack. This alarm delay time should be 10 ±1 seconds.
5. On No.2 monitor, check that the RF POWER indicator is off.
6. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON ON NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF RF POWER ON ALARM REGISTER SECONDARY ON
7. Restore normal operation by reconnecting the coaxial cables to connectors ERP IN on the rear of the transponder subracks (ensuring the original connections are restored) and on the CTU, pressing the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
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8. Confirm that the DME is operating in the No.1 normal state of Section 3.2.4.16.1.
3.2.4.16.4 Normal Operation - No.2 is MAIN 1. On both monitors, ensure switch MONITOR OUTPUTS is set to NORMAL.
2. On both test interrogators, ensure switch MONITOR AND INTERROGATOR DC POWER is set to NORMAL.
3. On both transponder power supplies, ensure switch TRANSPONDER DC POWER is set to NORMAL.
4. On both transmitter drivers, ensure switch DRIVER DC POWER is set to NORMAL.
5. On both receiver video modules, ensure switch IDENT is set to NORMAL.
6. On both 1kW PA power supplies, ensure switch AMPLIFIER DC POWER is set to NORMAL.
7. On the RF panel, ensure switch ANTENNA RELAY is set to NORMAL.
8. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not off), RECYCLE (if RECYCLE indicator is not off).
9. On the CTU, ensure switch ALARM DELAY is set to 10 seconds.
10. On the CTU, press the SELECT MAIN NO 2 key. Check that the state of each of the CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON ON NORMAL ON
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE OFF ALARM REGISTER RF ALL OFF
MODULES OFF TEST ANT RELAY OFF
AC POWER NORM ON BATT CHG 1 ON BATT CHG 2 ON POWER
BATT LOW OFF
11. On both monitors, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
3.2.4.16.5 Primary Fault - No. 2 is MAIN This test involves generating primary faults, and then monitoring the sequence of events following this action.
1. Ensure that the DME is operating in the No.2 normal state of Section 3.2.4.16.4.
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2. On the No.2 receiver video, turn REPLY PULSE SPACING through five positions. Using a stopwatch, measure the time period from the PRIMARY ALARM REGISTER indicator on the CTU turning on to the NO 2 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No 2 receiver video through five positions. This alarm delay time should be 10 ±1 seconds.
3. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON ON NO 2 ON OFF NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF SPACING ON ALARM REGISTER PRIMARY ON
4. On the No.1 receiver video, turn REPLY PULSE SPACING through five positions. Using a stopwatch, measure the time period from the PRIMARY alarm indicator on either monitor turning on to the NO 1 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No.1 receiver video through five positions. This alarm delay time should be 10 ±1 seconds.
5. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER OFF STATUS
SHUTDOWN ON SPACING ON ALARM REGISTER PRIMARY ON
6. On both receiver video modules, restore switches REPLY PULSE SPACING to their original positions recorded at Section 3.2.4.16.2 step 2.
7. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 2.
8. Confirm that the DME is operating in the No.2 normal state of Section 3.2.4.16.4.
3.2.4.16.6 Secondary Fault - No. 2 is MAIN This test involves generating secondary faults, and then monitoring the status following this action.
1. Ensure that the DME is operating in the No.2 normal state of Section 3.2.4.16.4.
2. Disconnect the input to the ERP IN connector at the rear of No.2 transponder subrack. On No.2 monitor, check that the RF POWER indicator is off.
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3. Wait at least 20 seconds. On the CTU, check that the state of the listed CTU indicators is as shown in the table below. No transfer to standby will occur until this fault is registered on both monitors.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON ON NORMAL ON
TRANSFER OFF STATUS
SHUTDOWN OFF RF POWER OFF
SECONDARY OFF ALARM REGISTER PRIMARY OFF
4. Disconnect the input to the ERP IN connector at the rear of the No.1 transponder subrack. Using a stopwatch, measure the time period from the SECONDARY alarm indicator on the No.1 monitor turning on to the NO 2 ON STATUS indicator on the CTU turning off - in response to disconnecting the input to the ERP IN connector at the rear of No. 1 transponder subrack. This alarm delay time should be 10 ±1 seconds.
5. On No. 1 monitor, check that the RF POWER indicator is off.
6. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON ON NO 2 ON OFF NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF RF POWER ON ALARM REGISTER SECONDARY ON
7. Restore normal operation by reconnecting the coaxial cables to connectors ERP IN on the rear of the transponder subracks (ensuring the original connections are restored) and on the CTU, pressing the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 2.
8. Confirm that the DME is operating in the No.2 normal state of Section 3.2.4.16.4.
3.2.4.16.7 Recycle Function - No. 1 is MAIN This test involves causing a transfer and a shutdown by generating a primary fault, and then monitoring the sequence of restart events following this action.
1. Ensure that the DME is operating in the No.1 normal state of Section 3.2.4.16.1.
2. On the CTU, reset the restart count to 0 using the misc menu. Press RECYCLE key to turn the RECYCLE indicator on.
3. On No.2 receiver video, turn rotary switch REPLY PULSE SPACING through five positions (so that when a transfer occurs to No.2 transponder, a primary fault will be immediately present).
4. On No.1 receiver video, turn rotary switch REPLY PULSE SPACING through five positions and check that a transfer to No.2 transponder occurs after the selected
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10 ±1 seconds and that the rack then shuts down after an additional 11 ±2 seconds.
5. Measure the time period from this shutdown to the following restart. This should be 30 ±3 seconds.
6. Leaving the REPLY PULSE SPACING switches set as above, count the total number of restart attempts (including the first one in the step above). This number should be 3.
7. Check that the rack then remains shutdown.
8. On the CTU, select the misc menu and check that the displayed number of restart attempts is 3.
9. On the CTU, check that the state of the listed. CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER OFF STATUS
SHUTDOWN ON SPACING ON ALARM REGISTER PRIMARY ON
10. On both receiver video modules, restore switches REPLY PULSE SPACING to their original positions recorded at Section 3.2.4.16.2 step 2.
11. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 2.
12. Confirm that the DME is operating in the No.2 normal state of Section 3.2.4.16.4.
3.2.4.16.8 Recycle Function - No. 2 is MAIN 1. Ensure that the DME is operating in the No.2 normal state of Section 3.2.4.16.4.
2. On the CTU, reset the restart count to 0 using the Misc menu. Press RECYCLE key to turn the RECYCLE indicator on.
3. On No.1 receiver video, turn rotary switch REPLY PULSE SPACING through five positions (so that when a transfer occurs to No. 1 transponder, a primary fault will be immediately present).
4. On No.2 receiver video, turn rotary switch REPLY PULSE SPACING through five positions and check that a transfer to No. 1 transponder occurs after the selected 10 ±1 seconds and that the rack then shuts down after an additional 11 ±2 seconds.
5. Measure the time period from this shutdown to the following restart. This should be 30 ±3 seconds.
6. Leaving the REPLY PULSE SPACING switches set as above, count the total number of restart attempts (including the first one in the step above). This number should be 3.
7. Check that the rack then remains shutdown.
8. On the CTU, select the Misc menu and check that the displayed number of restart attempts is 3.
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9. On the CTU, check that the state of the listed CTU indicators is as shown in the table below.
INDICATOR REQUIRED STATE NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER OFF STATUS
SHUTDOWN ON SPACING ON ALARM REGISTER PRIMARY ON
10. On both receiver video modules, restore switches REPLY PULSE SPACING to their original positions recorded at Section 3.2.4.16.2 step 2.
11. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
12. Confirm that the DME is operating in the No.1 normal state of Section 3.2.4.16.1.
13. If the recycle function is not required, press RECYCLE key on the CTU to turn the RECYCLE indicator off.
3.2.4.16.9 Warm/Cold Standby This procedure is performed only if 'warm' standby operation is required at the site. For a definition of 'warm’ standby operation, refer to Appendix A.
1. On the power distribution panel, switch circuit breaker CTU & TRANSPONDER off. Withdraw the CTU module from the rack.
2. On the CTU processor board, set switch 4 of S2 to OFF to change from COLD standby to WARM standby operation. Replace the CTU in the rack.
3. On the power distribution panel, switch circuit breaker CTU & TRANSPONDER on.
4. Operate the DME in the No. 1 normal state of Section 3.2.4.16.1.
5. For No.2 transponder, on the front panel of each of transponder power supply, transmitter driver, receiver video and 1kW PA power supply, check that the DC POWER ON indicator is on.
6. Remove the CTU from the rack and set switch 4 of S2 to ON if "warm" standby operation is not required.
3.2.4.16.10 High Voltage Shutdown Adjust 1. On the control module of the AC power supply, set the controls listed in the table
below as indicated:
SHUT DOWN DELAY Fully counter-clockwise, H/V SHUT DOWN Fully clockwise.
2. With the multimeter connected to the rack BATTERY terminals, switch and hold the TEST/FLOAT switch to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 28.5 ±0.1 volts.
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3. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust H/V SHUT DOWN control counter-clockwise until the DME shuts down. Check that the H/V SHUT DOWN indicator on the control module is on.
4. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control counter-clockwise to produce a multimeter reading of 27.5 ±0.2 volts. The DME should return to normal operation.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control clockwise again until the DME again shuts down. Read the multimeter reading. It should be 28.5 ±0.2 volts.
6. On the AC power supply, release the TEST/FLOAT switch. Confirm that the DME is powered up and operating in the normal state of Section 3.2.4.16.1.
7. On the control module of the AC power supply, adjust the SHUT DOWN DELA Y control to mid-position.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control counter-clockwise to produce a multimeter reading of29.0 ±0.2 volts. Release the TEST/FLOAT switch to enable the DME to return to normal operation.
9. Using a stopwatch, measure the time period from pressing the TEST/FLOAT switch to the DME shutting down. This time delay should be 3 ±1 seconds. (If necessary readjust SHUT DOWN DELAY control to achieve this delay.)
3.2.4.16.11 Low Voltage Alarm Adjust 1. On the control module of the AC power supply connected to BATTERY 1
terminals, set LOW VOLT ALARM control fully counter-clockwise.
2. With the multimeter connected to the rack BATTERY 1 terminals, switch and hold the TEST/FLOAT switch to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 23.5 ±0.2 volts.
3. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust LOW VOLT ALARM control clockwise until the O/P FAIL indicator on the control module turns on. The DME should remain in operation.
4. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 24.5 ±0.2 volts.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control counter-clockwise again until the O/P FAIL indicator again turns on. Read the multimeter reading. It should be 23.5 ±0.2 volts.
6. On the AC power supply, release the TEST/FLOAT switch. Confirm that the DME is powered up and operating in the normal state of Section 3.2.4.16.1.
7. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 23.0 ±0.1 volts.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, check that the BATT CHG 1 indicator on the CTU is off.
9. Repeat the procedure for the No.2 AC power supply on the BATTERY 2 terminals.
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3.2.4.16.12 Low Voltage Shutdown Adjust 1. Extend the CTU module using the two special extender cards.
2. On the AC power supply connected to BATTERY 2 terminals, switch off the MAINS power. If batteries are used, temporarily disconnect them from the BATTERY 1 and BATTERY 2 terminals.
3. On the CTU processor board of the CTU, adjust the low volts preset R32 fully counter-clockwise.
4. With the multimeter connected to the rack BATTERY 1 terminals, switch and hold the TEST/FLOAT switch to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 22.0 ±0.1 volts.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, on the CTU processor board, adjust R32 clockwise until the DME shuts down and BATT LOW indicator on the CTU turns on. Then slowly adjust R32 counter-clockwise until the BATT LOW indicator on the CTU turns off Slowly adjust R32 clockwise again until the BATT LOW indicator on the CTU again turns on.
6. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 24.5 ±0.2 volts. The DME should power up and return to normal operation.
7. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control counter-clockwise again while observing the multimeter. Measure the voltage immediately prior to DME shutdown. It should be 22.0 ±0.2 volts.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, check that the CTU BATT LOW indicator is on.
9. On the AC power supply, release the TEST/FLOAT switch. Confirm that the DME is powered up and operating in the No.1 normal state of Section 3.2.4.16.1.
10. On the power distribution panel, switch circuit breaker CTU off. Restore the CTU to the CTU subrack. Switch circuit breaker CTU on.
3.2.4.16.13 DC Supply Adjustment 1. Connect the multimeter (on 200 volts range) to the 24 volts BATTERY terminals
at the rear of the rack.
2. With the DME operating in the normal state of Section 3.2.4.16.1, measure the primary DC supply voltage. It should be 27 ±0.2 volts.
If it is outside this limit, it may be adjusted by the FLOAT2 VOLTAGE control on the control module of the AC power supply.
3.2.4.17 Rack Current Drain 1. Operate the DME in the No.1 normal state of Section 3.2.4.16.1.
2. Measure the rack current drain from the AC power supply. It should be not more than 6 amperes for a single DME, and not more than 7 amperes for a dual DME.
3. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, MAINTENANCE key (to turn its associated indicator on), SELECT MAIN NO 1 MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
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4. On the CTU, select Ch.1 monitoring. While holding TI RATE, 10 kHz pressed (to produce maximum reply rate). Measure the rack current drain from the AC power supply. It should be not more than 12 amperes for a single DME and not more than 13 amperes for a dual DME.
3.2.4.18 Final Check The performance checks and alignment of the DME has now been completed. In the case of a newly installed DME, the equipment is now ready for flight testing and commissioning. In the case of a DME undergoing a regular performance inspection, the beacon is now ready to be returned to service.
To return the DME beacon to normal operation, proceed as follows:
1. On the AC power supply, select POWER ON.
2. On the power distribution panel, switch all circuit breakers on.
3. On the CTU, select OFF/RESET (if the DME is not already off).
4. On the following modules, set all front panel switches to NORMAL:
a. Monitor.
b. Test interrogator.
c. Transponder power supply.
d. Transmitter driver.
e. Receiver video.
f. 1kW power amplifier.
5. On a dual DME, set the ANTENNA RELAY switch on the RF panel to NORMAL.
6. On the CTU:
a. Select LOCAL control.
b. Set MAINTENANCE off (MAINTENANCE indicator is off).
c. Reset the restart count to 0 using the Misc menu.
d. Select RECYCLE ON (if the Recycle facility is required).
e. Select MONITOR INHIBIT off.
7. On the CTU, select the No.1 transponder by pressing SELECT MAIN NO 1.
8. On all modules, check that no red TEST indicators are on.
9. On the CTU, check that the state of each of the CTU indicators is as shown in the table below:
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INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF NORMAL OFF
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE OFF ALARM REGISTER All OFF
MODULES OFF TEST ANT RELAY OFF AC PWR NORM ON
BATT CHG 1 ON
BATT CHG 2 OFF for Single ON for Dual
POWER
BATT LOW OFF
10. On each monitor, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
11. Using the CTU parameter measurement facility, measure the following parameters for the transponder (these values apply to an X channel DME). (For ‘Y’ channel values refer to Section 3.2.10)
PARAMETER NOMINAL VALUE
LIMITS UNITS
DELAY 50.0 ±0.2 µs SPACING 12.0 ±0.1 µs EFFNCY 90 > 85 % TX RATE 945 ±10 Hz RF POWER 1200 ±100 W RESTART COUNT 0 0 -
12. On a dual DME, select OFF/RESET at the CTU, then SELECT MAIN NO 2.
13. Repeat the measurements of step 11 for the No.2 transponder in dual DME.
14. When checks are completed, select the desired transponder (in a dual DME), then select REMOTE if the DME is to be operated remotely.
3.2.5 Test Interrogator Alignment 1. Extend the test interrogator using the transponder extender frame. On the test
interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
2. Remove the lids and shims from the RF generator box and the modulator and detector box.
3. On the modulator and detector board, switch S1 to the test position.
4. On the CTU front panel, select Hi Eff (High Efficiency) test in the Maintenance mode, and a TI RATE of 1 kHz (refer Section A.1 for operating instructions for the CTU).
5. On the RF generator, switch 1 to 4 of S1 to OFF, S1:5 to ON and S1:6 to OFF.
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6. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to the test point XT1 on the RF generator (connect the oscilloscope EARTH lead to the diecast box) and tune the core in L1 for peak positive DC voltage on the oscilloscope display (1.9 volts minimum).
7. Check that the oscillator is operating at the crystal frequency by using a one-turn coupling loop connected to the frequency counter and loosely coupled to L1, as described in Section 3.2.4.4.5.
8. On the RF generator, switch S1:1 to ON, and 2 to 6 of S1 to OFF.
9. Move channel 1 of the oscilloscope to test point XT2 on the RF generator board and tune C10 for peak positive voltage during the pulse. If necessary, restrict the bandwidth of the oscilloscope to eliminate crystal frequency appearing on the trace.
10. Move channel 1 of the oscilloscope to test point XT3 and tune C14 for a peak
pulse indication (0.6 volts minimum).
11. Move channel 1 of the oscilloscope to test point XT4 and tune C18 for a peak
pulse indication (0.2 volts minimum).
12. Move channel 1 of the oscilloscope to test jack DETECTED INTERROGATIONS
on the front panel of the test interrogator (to display the detected output of the RF generator) and tune C22 for maximum detector output.
13. On the modulator and detector board, switch S1 to the normal position.
14. The shape of the detected output pulses (channel 1 of the oscilloscope) should be as shown below.
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PEAK AMPLITUDE (from BASE LINE): 3.0 ±0.3 V HALF AMPLITUDE PULSE WIDTH: 3.4 ±0.3 µs FLAT TOP DURATION: 1.0 ±0.2 µs BASE LINE DC LEVEL: 3.6 ±0.3 V
If the pulse amplitude and/or shape are outside the above limits, they can be corrected by adjusting R13 (PULSE AMPLITUDE), and R20 (PULSE SHAPE) as required.
15. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
16. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on channel 2 of the oscilloscope should remain the same except that the baseline should move up the pulse. The DC level shift of the baseline level from the reference level set in the previous step should be 0.95 ±0.05 volts. (If the DC level shift is outside the above limits, it can be corrected by and adjusting R37, (PULSE PEDESTAL) on the modulator and detector.)
17. Restore the connections to the RF generator.
18. Replace the shims and lids of the diecast boxes (the lids are deliberately warped to ensure good RF sealing). Tighten the screws firmly.
3.2.6 Receiver Video Alignment 1. Extend the receiver video using the transponder extender frame.
2. Remove the lids from the RF source and the RF amplifier boxes.
3. On the RF source, set capacitors C8, C12 and C18 to mid-range, as shown below, so that clockwise movement will increase frequency.
4. Connect channel 1 of the oscilloscope (internally triggered to channel 1) to the
test point XT1 on the RF source (connect the oscilloscope EARTH lead to the diecast box) and tune the core in L1 for peak indication on the oscilloscope, checking that a smooth peak is obtained [approximately 2 volts].
5. Check that the oscillator is operating at the crystal frequency by using a one-turn coupling loop connected to the frequency counter and loosely coupled to L1, as described in Section 3.2.4.5, step3. (If the frequency is out of range, then retune L1 for correct mode and then re-peak, after first removing the loop.)
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6. Move channel 1 of the oscilloscope to test point XT2 on the RF source. Tune C8 to give peak indication [approximately 0.6 volts].
7. Move channel 1 of the oscilloscope to test point XT3 on the RF source. Tune C12 to give peak indication [approximately 2.5 volts].
8. Move channel 1 of the oscilloscope to test point XT4 on the RF source. Tune C18 to give peak indication [approximately 1.8 volts].
9. Disconnect the RF filter from the output of the RF source and connect the calibrated detector (with 4.7 kilohm load attached). Connect the oscilloscope probe to the output of the loaded detector. Carefully adjust trimmer capacitor C26 (through the end hole in the box of the RF source) to give a peak indication on the oscilloscope.
10. Measure the DC output voltage from the calibrated detector. Compare this voltage with the calibration chart for the detector (with load) to determine the true output from the RF source. The output level should be between +5 and +7 dBm. If the output exceeds +7 dBm, then adjust C26 inwards (that is, clockwise) to reduce the output to +7 dBm.
11. Disconnect the detector from the output of the RF source and reconnect the RF filter. Connect the detector to the RF filter output. Adjust trimmer capacitors C1 and C2 on the filter to obtain maximum output from the filter, as indicated by the detector output on the oscilloscope. Measure this output (making reference to the detector calibration), which should be not less than +3 dBm.
12. Disconnect the detector from the filter output and re-connect the cable to the RF amplifier. Remove the cable from connector XC4 of the RF amplifier and connect the calibrated detector in its place.
13. Measure the DC voltage from the detector and refer to the calibration chart to determine the RF output level. This should be +12.5 dBm ±l.5 dB. If the power exceeds the upper limit, then reduce it by slightly detuning capacitor C1 in the RF filter.
14. Connect a multimeter to feed-through capacitor, C23, on the outside of the RF amplifier box. - The DC voltage should be 1.3 ±0. 5 volts.
15. With the multimeter, measure the DC voltage between the test jacks RF LEVEL and EARTH on the receiver video front panel. This should be 3.0 ± 1.0 volts.
16. Replace the covers on the boxes for the RF source and RF amplifier.
3.2.7 Transmitter Driver Alignment
3.2.7.1 Preparation 1. Remove the transmitter driver and remove the covers from the three diecast
boxes. Extend the transmitter driver using the transponder extender frame, but leave transponder power supply switch TRANSPONDER DC POWER set to OFF.
2. On the transmitter driver, switch DRIVER DC POWER to ON.
3. On the pulse shaper board, set the switches as follows:
ALC LOOP (S2) to OPEN, ALC (S3) to VIDEO, MED COLL (S4) to DC.
4. On the pulse shaper board, adjust the following controls all fully counter-clockwise:
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MOD PULSE AMPLITUDE (R58), RF OUTPUT (POWER MOD AMP DC (R69) on the printed wiring board), 1W PULSE (R85), EXCITER DC (R97), and MED POWER DRIVER DC (R115).
5. Remove the cover from the 1kW power amplifier and remove the cover from the power modulation amplifier box.
6. On the transponder power supply, switch TRANSPONDER DC POWER to ON. Switch the receiver video IDENT switch to CONTINUOUS. Trigger the oscilloscope from the TRIGS TO MODULATOR jack on the receiver video (negative trigger).
7. On the transmitter driver, display the rectangular modulation pulses at the SQUARE PULSE MODULATION test jack (XA1) and the shaped modulation pulses at the SHAPED MODULATION test jack (XA3) simultaneously. Ensure that the shaped pulses are centred on the rectangular modulation pulses. Check that the space between the two rectangular pulses is 1.3 ±0.1 microseconds. If it is outside this range, adjust BACK PORCH (R36) on the pulse shaper board to give the required spacing.
Set 2ND PULSE EQUALISING (R54) fully clockwise.
8. Using the oscilloscope, monitor the collector supply voltage of V3, V4 in the exciter; check that positive pulses are present.
9. The control 1W PULSE (R85) on the main board (pulse shaper) adjusts the amplitude of the rectangular modulation pulses. The required pulse amplitude is dependent on the frequency of operation of the transmitter. Adjust 1W PULSE (R85) accordingly to obtain:
1. Frequencies 960-1170 MHz: 11 volts peak.
2. Frequencies 1171-1220 MHz: 15 volts peak.
10. Other collector supply voltages in the module are DC, and should beset as shown below, again using the oscilloscope:
ADJUSTMENT RESISTOR ON PULSE
SHAPER BOARD ADJUST TO GIVE VOLTAGE
RF UNIT TEST POINT
(collector supply) REF LEGEND FREQUENCY
RANGE (MHz) REQUIRED VOLTAGE
(VDC) 960-1050 20
1050-1170 26 Exciter V5 and V6 R97 Exciter
1170-1220 30 960-1050 25
1050-1170 27 Medium Power Driver V1 R115 Medium Power
Driver 1170-1220 28 960-1050 28
1050-1170 25 Power Modulation Amplifier
V1 R69 Pwr Mod Amp
1170-1220 30
11. On the power distribution panel, switch the 1kW POWER AMP circuit breaker on. On the 1kW power amplifier, switch AMPLIFIER DC POWER to ON; check that one red and two green indicators are on. Measure the voltage at the HT test jack; this should be 50.0 ±0.2 volts.
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12. Set the DC level at the SHAPED MODULATION test jack on the front panel to + 12 volts, by adjusting the PEDESTAL VOLTAGE (R53).
13. Transfer the oscilloscope to the FUNCTION GENERATOR test jack on the front panel and display the waveform, using oscilloscope gain and shift controls to expand a single pulse; compare the displayed pulse with the shape shown below, observing the discontinuities. Pulse amplitude should be +7.5 ±0.5 volts, relative to earth, at the peak.
The shape shown above is typical only, and may need to be modified to achieve the final RF envelope shape. If the pulse shape has not been previously adjusted, perform the procedure described in Section 3.2.8. The pulse shape should only be adjusted if it differs greatly from that shown in the figure above.
14. Transfer the oscilloscope back to the SHAPED PULSE MODULATION test jack, and increase the pulse amplitude using the MOD PULSE AMPLITUDE (R58) preset on the main board; increase the level slowly, until the pulse is about 7 volts above the base line.
15. Again compare the pulse with the figure shown above, and check that the discontinuities are considerably smoothed.
16. Remove the pulses by rotating MOD PULSE AMPLITUDE (R58) fully counter-clockwise.
17. Switch the 1kW power amplifier AMPLIFIER DC POWER to OFF.
18. On the transponder power supply, switch TRANSPONDER DC POWER to OFF.
3.2.7.2 RF Alignment This alignment is started with the voltages listed in Section 3.2.7.1 step10. These voltages are only a starting point, and will be modified to provide optimum drive to each stage as the tuning proceeds. As a general guide, the collector current of a stage is determined by the input drive, which is adjusted by the collector voltage of the previous stage. There may be a wide variation in collector current depending upon the frequency at which the unit is aligned. At the end of the alignment, the collector current of a particular stage may be different from the initial value.
1. Connect the current probe output to the oscilloscope, and adjust the sensitivity of the oscilloscope for 200 mA/division.
2. Switch the transmitter driver DRIVER DC POWER to NORMAL.
3. Clip the current probe pickup to the test loop in the exciter V3, V4 supply, with the arrow on the probe pointing towards the transistors. Check that the V3, V4 supply current pulses are in the range 200-500 mA.
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4. Move the current probe to the V5, V6 collector supply loop. Check that the V5, V6 supply current is in the range 400-700 mA. If necessary adjust 1W PULSE (R85) to bring the current within this range.
NOTE If the peak collector currents for the exciter stages are not within the ranges specified above, then the exciter may require a full alignment. This is described in Section 3.4.25.
5. Move the current probe to the medium power driver V1 collector supply loop. Check that the V1 supply current is in the range 2.0-2.7 amperes. If necessary, adjust the preset EXCITER DC (R97) to bring the current within this range.
6. Switch the 1kW RF amplifier AMPLIFIER DC POWER to ON.
7. Move the current probe to the collector supply lead (red lead) in the power modulation amplifier (in the transmitter driver). Check that the current is in the range 6 to 8 amperes and, if necessary, adjust the preset MED POWER DRIVER (R115) on the main board to achieve this current.
8. Observe the displayed current pulses and check that the tilt on the pulse tops does not exceed 5%, as shown in the diagram below. If the tilt exceeds this amount, then make further small adjustments to EXCITER DC (R97) and MED POWER DRIVER DC (R115) to reduce the tile by changing the drive to the Power Modulation Amplifier. Note the following points during this adjustment:
a. 1W PULSE (R85) controls the drive to the exciter 8 watt stage. EXCITER DC (R97) controls the drive to the medium power driver. MED POWER DRIVER DC (R115) controls the drive to the power modulation amplifier.
b. In adjusting for pulse flatness, up to 5% negative or positive tilt is acceptable, as shown below.
c. If the output pulses have a positive tilt, this indicates that the power
modulation amplifier is under-driven; if the tilt is negative, the amplifier is over-driven.
3.2.8 Function Generator Alignment The displayed pseudo-Gaussian waveform is generated from a series of sloping lines – six parts with upward slopes to the peak of the pulse, and six downward slopes from the peak to the baseline. Each upward (and corresponding downward) slope is determined by the time constant of the R-C network presets, R3, R5, R7, R9, R11 and R13, with R13 controlling the apex.
a. Adjust the shape presets in sequence until the displayed pulse at the FUNCTION GENERATOR test jack fits the waveform drawn on the graticule, keeping the peak of the pulse at an amplitude of 7.5 ±0.5 volts peak. Several re-adjustments may be required to ensure that there is no abrupt transition from one slope to another - the transition must be as smooth as possible, as shown below.
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The waveform shown above represents a generalised pulse shape. Individual equipment may require variations to this basic general shape.
b. Turn INTEGRATOR BALANCE (R17) in both directions and check the change in the level of the trailing edge of the pulse (see figure above). This edge will increase or decrease relative to the leading edge of the pulse. Finally, set the trailing edge to be level with the leading edge. Re-adjust the shape of the pulse, as necessary.
3.2.9 IF Amplifier Alignment
3.2.9.1 Preliminary Adjustments 1. Remove the receiver video from the rack and remove the cover from the IF
amplifier.
2. Extend the receiver video on the transponder extender frame and switch on the DME.
3. Measure the voltage at IF amplifier test point XT7; this should be 3.0 ±0.1 volts. A voltage outside this range indicates a fault in the IF amplifier.
4. Measure the voltage attest point XT13; this should be 6.0 ±0.1 volts. If it is outside this range, adjust preset SET AGC (R15) to achieve the required voltage.
5. Check that preset SET GAIN (R29) is set fully clockwise.
3.2.9.2 Preamplifier Tuning 1. Monitor the signal at the front panel DETECTED LOG VIDEO test jack with the
oscilloscope. Set the oscilloscope to a time base of 5 seconds/division, triggered from the TRIGGER test jack on the test interrogator. Set the sensitivity to 0.5 volts/division.
2. On the CTU, select Lo Eff measurement, in the Maintenance mode, and TI RATE, 1 kHz.
3. On the IF amplifier, carefully tune inductors L7 and L5 for peak signal amplitude.
3.2.9.3 Local Oscillator Tuning 1. Connect oscilloscope to test point XT8 (LO) on the IF amplifier and display a DC
level.
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2. Adjust L4 tuning core into the coil so that it is 2 to 3 turns below being flush with the top of the former. With the digital multimeter, measure the DC voltage on XT8; it should be between 0.7 and 0.76 volts.
3. Adjust L4 tuning core counter-clockwise until the voltage is seen to jump to between 0.9 and 1.2 volts. Note the core position. Continue adjusting the core counter-clockwise until either a voltage peak or 2.0 volts is reached; leave the core in this position. Check that the core has been rotated more than one-half turn beyond the position of the voltage jump observed above.
NOTE Tuning must be done with the core initially being in the position stated above. Do not exceed the XT8 voltage stated, otherwise a spurious mode of oscillation may be induced.
4. Check that the final voltage at XT8 is between 1.2 and 2.1 volts.
5. Switch the power supply off and on at least three times, and check that the XT8 voltage returns to the same value each time.
3.2.9.4 Narrowband Detector Tuning 1. Observe the signal at IF amplifier test point XT6 with the oscilloscope set to 1
volt/division.
2. Carefully tune L3 and L6 for maximum pulse amplitude above the noise baseline. Repeat the tuning until no further increase can be achieved. Record the pulse peak amplitude as a reference.
3. Remove the test interrogator from the rack, set switch S1:1 to OFF (the “Fo” frequency) and set S1:2 to ON to select the +160 kHz frequency.
4. Replace the test interrogator in the rack and measure the new pulse amplitude at IF amplifier XT6. Record this pulse amplitude.
5. Again remove the test interrogator, set switch S1:2 to OFF, and set S1:3 to ON, to select the -160 kHz frequency. Replace the test interrogator in the rack.
6. Measure the new pulse amplitude at IF amplifier XT6. Record this pulse amplitude.
7. Compare the pulse amplitude recorded at steps 2, 4 and 6. The amplitude difference should not exceed 0.2 volts. If the variation exceeds this amount, it is necessary to repeat the tuning of L3 and L5 so that the response is symmetrical with equal amplitude pulse outputs at ±160 kHz.
8. When completed, remove the test interrogator, set switch S1:1 to ON (to select the “Fo” crystal) and set all remaining switches of S1 to OFF.
9. When finished, replace the IF amplifier cover, then replace the receiver video in the rack.
3.2.10 Y-channel Operation The following changes are applicable when a DME is to be used on a Y-channel. Compared with the more common X-channel settings, a Y-channel has a different reply delay setting, and a different pulse spacing for interrogate and reply pulse pairs.
The numbers below refer to the relevant paragraphs in this section of the handbook:
3.2.4.2 Module Presets
3.2.4.2.4 Receiver Video Presets
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Set switches S4, ENCODER MODE, and S5, DECODER MODE, to the ‘Y’ position. Set the front panel rotary switches as follows:
SWITCH FUNCTION SETTING S1 Beacon Delay, Coarse 3 S2 Beacon Delay, Fine 0 S3 Reply Pulse Spacing 8
3.2.4.2.7 Test Interrogator Presets Set switch S4, MODE, to the ‘Y’ position. Set the front panel rotary switches as follows:
SWITCH FUNCTION SETTING S5 Reply Gate Delay, Coarse 3 S6 Reply Gate Delay, Fine 5
3.2.4.2.8 Monitor Module Presets Set preset switch S12, DELAY LOWER LIMIT SET, for 55.5 microseconds, and switch S13, SPACING LOWER LIMIT SET, for 29.5 microseconds, as shown in the following figure:
DELAY LOWER LIMIT SET, S12 55.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
SPACING LOWER LIMIT SET, S13 29.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
Y-CHANNEL SETTINGS
3.2.4.4.4 Spacing Offset Control 1 For ‘Y’ channel, the spacing between the detected pulses shall be
36.0+/-0.1 usec.
3.2.4.4.6 Test Interrogator Signal Timing Parameters 2 For ‘Y’ channel, the displayed pulse spacing shall be 30.0+/-0.2 usec.
3.2.4.10.4 Output Pulse Spacing 1 For ‘Y’ channel, the spacing between the half-amplitude points on the leading
edge of the pulses shall be 30.0+/-0.1 usec. 3 For ‘Y’ channel, the CTU displayed pulse spacing shall be 30.0+/-0.1 usec.
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3.2.4.13.1 Reply Delay Adjustment 1 For ‘Y’ channel, set the receiver video BEACON DELAY, COARSE and FINE,
controls to give a displayed delay as near as possible to 56.0, but always within the range 56.0+/-0.1 usec.
3.2.4.13.2 Final Receiver Checks 2 For ‘Y’ channel, the Reply Delay displayed on the CTU, and the Reply Delay
measured on the oscilloscope, shall be 56.0+/-0.2 usec. These two values shall be within 0.1 usec of each other.
3.2.4.15 Monitor Fault Limits
3.2.4.15.2 Delay Monitor Procedure a: For ‘Y’ channel, the following values and limits apply for Delay:
PARAMETER VALUE RANGE UNIT Delay; Lower 55.5 to 55.6 usec Delay; Upper 56.5 to 56.6 usec
Procedure b: For ‘Y’ channel, set the BEACON DELAY, COARSE and FINE, controls to give the following values, for each of the steps indicated: 3. 55.5 usec 4. Less than 55.5 usec 5. 56.5 usec 6. Greater than 56.5 usec 7. 56.3 usec 8. 55.7 to 56.3 usec 9. 55.7 usec
3.2.4.15.3 Spacing Monitor Procedure a: For ‘Y’ channel, the following values and limits apply for Spacing:
PARAMETER VALUE RANGE UNIT Spacing; Lower 29.4 to 29.5 usec Spacing; Upper 30.4 to 30.5 usec
Procedure b: For ‘Y’ channel, set the REPLY PULSE SPACING control to give the following values, for each of the steps indicated: 3. 29.4 usec (as close as possible to 29.4, but not greater than 29.4 usec) 4. Less than 29.4 usec 5. 30.6 usec (as close as possible to 30.6, but not less than 30.6 usec) 6. Greater than 30.6 usec 7. 30.3 usec (as close as possible to 30.3, but not greater than 30.3 usec) 8. 29.7 to 12.3 usec 9. 29.7 usec (as close as possible to 29.7, but not less than 29.7 usec)
3.2.4.15.11 Monitor Fault Limits - Final Check For ‘Y’ channel, the following values and limits apply for Delay and Spacing:
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PARAMETER VALUE RANGE UNIT Delay; Lower 55.5 to 55.6 usec Delay; Upper 56.5 to 56.6 usec Spacing; Lower 29.4 to 29.5 usec Spacing; Upper 30.4 to 30.5 usec
3.2.4.18 Final Check 11. For ‘Y’ channel, the following values and limits apply for Delay and Spacing:
PARAMETER VALUE RANGE UNIT Delay 55.8 to 56.2 usec Spacing 29.9 to 30.1 usec
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3.3 DEPOT PERFORMANCE CHECKS AND ALIGNMENT
3.3.1 Introduction This section contains the full alignment and performance verification procedures to be performed on an LDB-102 DME at a maintenance depot or, in some circumstances, at a beacon site. These procedures describe in detail the tasks necessary to fully verify the correct operation of the DME. For this reason an extensive range of test equipment is required.
The procedures in this section are to be performed on a DME that is operating into dummy loads. The procedures are especially applicable to a rack that is used as a module repair facility in a maintenance depot. In this case it may be necessary to perform only those procedures relevant to the module being repaired. For example, if a transmitter driver module has been repaired, then it is necessary to only perform the tests associated with the transmitter sub-section.
For periodic testing of an operational DME beacon, refer to the procedures in Section 3.2.
Since a dual DME is essentially two single DMEs in a single rack (except for the RF panel, the operation of the control section and the location of the battery charger/power supplies) the test and alignment procedures are applicable to either a single or a dual DME (unless specifically indicated otherwise). The procedures, however, have been written for a dual rack to cover the more complex situation.
CAUTION THE FOLLOWING PRECAUTIONARY REQUIREMENTS SHOULD BE NOTICES OBSERVED AT ALL TIMES THROUGHOUT EQUIPMENT TESTING. FAILURE TO OBSERVE THESE REQUIREMENTS MAY RESULT IN DAMAGE BEING CAUSED TO THE EQUIPMENT.
Although the beacon includes protection to guard against excessive load mismatch, the transmitter must not be operated unless a suitable load is present at the ANTENNA output. The protection circuit is intended for accidental mismatching only.
The peak power from the transmitter is in excess of 1200 watts, which is too high for direct application to most test instruments. Therefore, care should be taken when connecting instruments to the transmitter output to ensure that a suitably rated attenuator or directional coupler is used to isolate the instruments from the high power.
Modules must not be removed or inserted with power applied. For most units, it is sufficient to switch off the rack at the CTU. For the CTU, it is necessary to switch off the 24 volts at the circuit breakers on the power distribution panel.
Equipment repairs and tests should be performed only by personnel suitably qualified to the level of proficiency required by an equipment of this type and complexity.
3.3.2 Test Equipment Required See Section E.2 for the list of test equipment required to perform the alignment of the DME.
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3.3.3 Module Presets NOTE Alternative Module Preset Values
The module preset values listed below are typical of the values that would be set for operational equipment. For alternative values and/or an explanation of the settings, see Appendix A. If alternative values are set, the results of some of the tests may be different from the specified results.
CAUTION DO NOT apply power to the equipment under test before the following settings are made.
3.3.3.1 Power Distribution Panel Presets On the power distribution panel, set all circuit breakers off.
3.3.3.2 1kW RF Power Amplifier Presets On the 1kW RF power amplifiers, switch AMPLIFIER DC POWER to OFF.
3.3.3.3 Control and Test Unit Presets 1. On the CTU front panel, set the switch ALARM DELAY to 10.
2. On the CTU, set the switches on the CTU processor board as follows:
S1, 8-way DIP switch
SWITCH FUNCTION SETTING
1 NORMAL/PRODUCTION TESTS ON = NORMAL
2 INDICATES IF NAVAID MAINTENANCE PROCESSOR (NMP) IS FITTED OFF = NO NMP
3 SUBTRACT 0.1 µs FROM No. 2 DELAY MONITOR FAULT LIMIT READINGS ON = INACTIVE
4 ADD 0.1 µs TO No. 2 DELAY MONITOR FAULT LIMIT READING ON = INACTIVE
5 STATISTICS ON DELAY MEASUREMENTS ON = INACTIVE
6 SUBTRACT 0.1 µs FROM No. 1 DELAY MONITOR FAULT LIMIT READINGS ON = INACTIVE
7 ADD 0. 1 µs TO No. 1 DELAY MONITOR FAULT LIMIT READINGS ON = INACTIVE
8 SINGLE/DUAL ON if SINGLE DME OFF if DUAL DME
NOTE If the DME is to be used with a Remote Maintenance Monitoring (RMM) system, perform all checks and adjustments in this Section 3.3 before configuring the CTU for operation with the RMM. Refer to the RMM Handbook for details.
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S2, 8-way DIP switch
SWITCH FUNCTION SETTING
1 MAIN AND/OR VOTING (FOR DUAL) ON = AND 2 STANDBY AND/OR VOTING (FOR DUAL) ON = AND 3 RMM/RCMS CONTROL OFF = RCMS 4 COLD/WARM STANDBY ON = COLD 5 1 ELEMENT ANT. FLT: NOT/IS FITTED OFF = IS FITTED 6 1 ELEMENT ANT. FLT: NO ACTION/ACTION ON = NO ACTION 7 2 ELEMENT ANT. FLT: NOT/IS FITTED OFF = IS FITTED 8 2 ELEMENT ANT. FLT: NO ACTION/ACTION ON = NO ACTION
3. Set the ALARM POWER ON INHIBIT switch (S11 on the CTU front panel board) for a delay of 6 seconds (refer to Section A.5.1.6).
4. On the CTU processor board, ensure that no links are installed on the 2-pin headers XN5 (MA IDENT OUTPUT referenced to GROUND), XN6 (WATCHDOG DISABLE), XN7 (SIGNATURE ANALYSIS), XN8 (IDENT TEST) and XN9 (WATCHDOG TEST). Fit a link to the 2-pin header XN10 (ASSOC IDENT INPUT pulled up to +24 volts).
3.3.3.4 Receiver Video Presets 1. On the receiver video modules, set the switches on the receiver video main
board as follows:
SWITCH FUNCTION SETTING
S4 SELECT ENCODER MODE X S5 SELECT DECODER MODE X S6 SET LDES PERIOD 6 S7 SET DEAD TIMES 6 S8 SDES OFF S9 LDES OFF
(For ‘Y’ channel settings refer to Section 3.3.22)
2. On the receiver video modules, set the ident CODE ELEMENT switches (S13, S14, S15 and S16 on the receiver video main board) as follows:
a. Convert the required ident letters into International Morse Code, using the following table.
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LETTER MORSE SYMBOL LETTER MORSE SYMBOL
A dot dash N dash dot B dash dot dot dot 0 dash dash dash C dash dot dash dot P dot dash dash dot D dash dot dot Q dash dash dot dash E dot R dot dash dot F dot dot dash dot S dot dot dot G dash dash dot T dash H dot dot dot dot U dot dot dash 1 dot dot V dot dot dot-dash J dot dash dash W dot dash dash K dash dot dash X dash dot dot dash L dot dash dot dot Y dash dot dash dash M dash dash Z dash dash dot dot
b. Set the switches using the following code (shading indicates switch position):
Example: for ident code AWA, switch settings are:
3. On the receiver video modules, set the front panel switches as follows:
SWITCH FUNCTION SETTING
S1 BEACON DELAY, COARSE 9 S2 BEACON DELAY, FINE 4
S3 REPLY PULSE SPACING (REPLY PULSESEPARATION on early modules) 8
S11 IDENT NORMAL
4. On the IF amplifiers of the receiver video modules, ensure that no link is installed on the 2-pin headers MAN of XN2. Fit a link to the 2-pin headers AGC of XN2.
5. Install the correct oscillator crystals as G1 in the RF sources of the receiver video modules. The crystal frequency is one-twelfth of the station reply frequency.
Example: Channel 84X reply frequency = 1171 MHz hence crystal frequency = 1171/12 = 97.5833 MHz
The crystal specification is given in Appendix N.
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NOTE In the depot test facility (unless an RF source is to be aligned) the frequency is set by an RF signal generator. See Appendix K for details.
3.3.3.5 Transmitter Driver Presets 1. On the pulse shaper boards of the transmitter drivers, set the switches as
follows:
SWITCH FUNCTION SETTING
S2 ALC LOOP OPEN S3 ALC VIDEO S4 MED COLL DC
2. On the transmitter driver front panels, set switch DRIVER DC POWER to OFF.
3.3.3.6 Transponder Power Supply Presets 1. On the transponder power supply front panels, set switch TRANSPONDER DC
POWER to OFF.
3.3.3.7 Test Interrogator Presets 1. On the test interrogators, set the mode switch S4 on the test interrogator main
board to X. (For ‘Y’ channel settings refer to Section 3.3.22)
2. On the test interrogator front panels, set the switches as follows:
SWITCH FUNCTION SETTING
S5 REPLY GATE DELAY, COARSE 2 S6 REPLY GATE DELAY, FINE F S7 MONITOR & INTERROGATORDC POWER NORMAL
3. On the test interrogators, set the switch S1, NORMAL/TEST on the modulator and detector to NORMAL.
4. Install the five correct oscillator crystals in each of the RF generators of the two test interrogators. The crystal frequencies are one-twelfth of the station interrogation frequency and the offsets from it.
Example: Channel 84X interrogation frequency = 1108 MHz = Fo hence crystal frequency = 1108/12 = 92.3333 MHz = Fx
The crystal specification is given in Appendix N.
The five interrogation frequencies and the corresponding crystal frequencies are shown in the table below:
SWITCH FUNCTION SETTING
G1 Fo Fx G2 Fo + 160 kHz Fx + 13.3 kHz G3 Fo - 160 kHz Fx - 13.3 kHz G4 Fo + 900 kHz Fx + 75 kHz G5 Fo - 900 kHz Fx - 75 kHz
NOTE In the depot test facility (unless an RF generator is to be aligned) the frequency is set by an RF signal generator. See Appendix K for details
5. On the test interrogators, set the switches on the RF generators as follows:
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S1, 6-way DIP switch
SWITCH FUNCTION SETTING
1 INTERROGATION FREQ = Fo ON 2 INTERROGATION FREQ = Fo + 160 kHz OFF 3 INTERROGATION FREQ = Fo -- 160 kHz OFF 4 INTERROGATION FREQ = Fo + 900 kHz OFF 5 INTERROGATION FREQ = Fo -900 kHz OFF 6 CW/PULSE OFF = PULSE
3.3.3.8 Monitor Module Presets 1. On the monitors, set the switches on the monitor main board as follows (shading
indicates switch position):
PULSE WIDTH LOWER LMT SET (8-way DIP switch S1): 2.9 microseconds
1 2 3 4 5 6 7 8 ON OFF
FALL TIME UPPER LMT (8-way DIP switch S2): 3.6 microseconds
1 2 3 4 5 6 7 8 ON OFF
RISE TIME UPPER LMT (8-way DIP switch S3): 3.1 microseconds
1 2 3 4 5 6 7 8 ON OFF
PULSE WIDTH WINDOW SET (8-way DIP switch S4): 1.2 microseconds
1 2 3 4 5 6 7 8 ON OFF
PWR LVL FLT SET (8-way DIP switch S7): -3.0 dB
1 2 3 4 5 6 7 8 ON OFF
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IDENT GAP FLT SET (8- way DIP switch S8): 62 seconds
1 2 3 4 5 6 7 8 ON OFF
DELAY WINDOW SET (8-way DIP switch S9): 1.0 microseconds
1 2 3 4 5 6 7 8 ON OFF
SPACING WINDOW SET (8-way DIP switch S10): 1.0 microseconds
1 2 3 4 5 6 7 8 ON OFF
DELAY LOWER LMT SET (10-way DIP switch S12): 49.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
(For ‘Y’ channel settings refer to Section 3.3.22)
SPACING LOWER LMT SET (10-way DIP switch S13): 11.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
(For ‘Y’ channel settings refer to Section 3.3.22)
2. On the monitor front panels, set switch MONITOR OUTPUTS to NORMAL.
NOTE Referencing the Two Systems in a Dual DME
Where reference is required to distinguish between the transponders and monitoring systems in a dual DME rack, the modules higher in the DME rack will be referenced as "No.1" while those lower will be referenced as "No.2”.
3.3.3.9 RF Panel Presets - Single DME 1. On the RF panel (at the rear of the rack at the top), install the following
components and connecting cables:
a. 10 dB attenuator to connector TI-1 REPLY DET.
b. Coaxial cable (RG-188 with SMA connectors) from 10 dB attenuator on TI-1 REPLY DET to connector FWD-B on the directional coupler.
c. 50 ohms termination to connector REV-A on the directional coupler.
d. 10 dB attenuator to connector FWD-A on the directional coupler.
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e. Coaxial cable (RG-188 with SMA connectors) from connector FWD-C on the directional coupler to TI-1 TEST INTRGS.
2. Connect a coaxial cable from the output of the 10 dB attenuator on connector FWD-A of the directional coupler to connector ERP IN on the rear of the transponder subrack.
3. Using a multimeter on 2k resistance range, set the resistance of the antenna integrity monitor test fixture (shown below) to 1000 ±10 ohms. Connect the antenna integrity monitor test fixture to connector XN2 on the RF panel board.
3.3.3.10 RF Panel Presets - Dual DME 1. On the RF panel (at the rear of the rack at the top), install the following
components and connecting cables:
a. 10 dB attenuator each to connectors TI-1 REPLY DET and TI-2 REPLY DET.
b. Coaxial cable (RG-188 with SMA connectors) from 10 dB attenuator on TI-1 REPLY DET to connector FWD-D on No.2 directional coupler.
c. Coaxial cable (RG-188 with SMA connectors) from 10 dB attenuator on TI-2 REPLY DET to connector FWD-B on No.2 directional coupler.
d. 50 ohms termination to connector REV-A on No.2 directional coupler.
e. 10 dB attenuator to connector FWD-A on No.2 directional coupler.
f. Coaxial cable (RG-188 with SMA connectors) from connector FWD-E on No.2 directional coupler to TI-1 TEST INTRGS.
g. Coaxial cable (RG-188 with SMA connectors) from connector FWD-C on No.2 directional coupler to TI-2 TEST INTRGS.
2. Connect the input of the power splitter to the 10 dB attenuator on connector FWD-A of No.2 directional coupler (using a suitable cable - if required).
3. Connect two coaxial cables from the outputs of the power splitter to connectors ERP IN on the rear of the two transponder subrack.
4. Set the resistance of the antenna integrity monitor test fixture as in Section 3.3.3.9 step 2, then connect it to connector XN2 on the RF panel board.
5. On the RF panel, set the ANTENNA RELAY switch to NORMAL.
3.3.3.11 AC Power Supply Presets 1. On the AC power supplies, set the switches on or behind the front panel as
follows:
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SWITCH SETTING
MAINS OFF DC ISOLATOR ON TEST/FLOAT FLOAT BATTERY ON/NO BATTERY NO BATTERY (Used without Batteries)
2. On the AC power supplies, wire to appropriate local voltage at the mains voltage selector block inside the top of the unit.
3. Remove the control module from the AC power supplies and ensure that the links are installed in the positions shown in the table following (see Figure 3-1 for the identification of the links on the control module).
U-LINK POSITION OPTION SELECTED
356 402-403 Outputs low volts alarm 357 404-405 Delayed overvoltage shutdown 358 408-409 24 volts operation 359 411-412 24 volts operation 360 414-415 24 volts operation 361 417-418 24 volts operation 362 420-421 24 volts operation 363 423-424 24 volts operation 364 426-427 24 volts operation 365 429-430 24 volts operation 366 432-433 24 volts operation 367 435-436 Function control 368 438-439 Capacitor 8 local alarm 369 441-442 Capacitor 10 local alarm 370 444-445 Normal voltage range 371 446-447 Latching overvoltage alarm 372 449-450 Output contactor isolation for overvoltage protection 373 453-454 Contactor control local (normal)
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Figure 3-1 Power Supply Control Module Links
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3.3.4 Preliminary Check and Setup
3.3.4.1 Inspection 1. Visually inspect power distribution cables into each bay for polarity and secure
connection. Check wiring generally, especially inspect semirigid coaxial cables and soldering to connectors.
2. Check that all modules are correctly inserted.
3.3.4.2 Switching On 1. Connect mains supply to the AC power supplies and switch POWER on these
units to ON.
2. Check the reading on the power supply voltmeters. They should be 27.0±0.2 volts. (If outside this range, adjust FLOAT 2 VOLTAGE on the control module of the AC power supplies.)
3. On the power distribution panel, switch the circuit breakers CTU, TPNDR 1 and TPNDR 2 on.
4. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
5. On the AC power supply check that the current meter indicates an idling current of 0.5 ±0.2 amperes. (For a dual, switch POWER on one of the AC power supplies to OFF and read the current on the meter of the other AC power supply. Then switch POWER back to ON.)
6. On the CTU, some indicators will be on.
7. On the monitor front panels, no indicators should be on.
8. On the test interrogator front panels, no indicators should be on.
9. On the transponder power supply front panels, TEST indicator should be the only indicator on.
10. On the transmitter driver front panels, TEST indicator should be the only indicator on.
11. On the 1kW PA power supply front panels, TEST indicator should be the only indicator on.
3.3.4.3 Procedural Requirements The following general procedural requirements that apply generally throughout the following procedures should be noted.
1. Oscilloscope Triggering.
Unless otherwise stated in a particular test, the oscilloscope should be triggered from test jacks TRIGGER and EARTH on the test interrogator.
2. Measurements During Ident. Avoid making performance measurements during the ident message. (With MONITOR ALARM set to INHIBIT, ident is inhibited.)
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3. Procedure for Extending Transponder Plug-in Modules.
If any of receiver video, transmitter driver or transponder power supply are to be put on a transponder extender frame in order to gain access to internal controls etc, the following procedure is to be followed:
a. At the transponder power supply in the same transponder subrack, mentally record the position of the front panel switch TRANSPONDER DC POWER, then switch it to OFF.
b. Extend the required module using the transponder extender frame.
c. On the transponder power supply front panel, restore the TRANSPONDER DC POWER switch to its original position.
Follow the same sequence of steps to restore the module to its transponder subrack.
4. Procedure for Extending Test Interrogator/Monitor Plug-in Modules.
If either of test interrogator or monitor is to be put on the transponder extender frame in order to gain access to internal controls, etc, the following procedure is to be followed:
a. At the test interrogator in the same transponder subrack, mentally record the position of the front panel switch MONITOR AND INTERROGATOR DC POWER, then switch it to OFF.
b. Extend the required module using the transponder extender frame.
c. On the test interrogator front panel, restore the MONITOR AND INTERROGATOR DC POWER switch to its original position.
Follow the same sequence of steps to restore the module to its transponder subrack.
5. Monitoring of Transponders in Maintenance Mode - Dual DME.
For a dual DME in Maintenance mode, monitor system 1 is selected to perform the monitoring tests by selecting key Ch.1 at the top level menu on the CTU test facility; monitor system 2 is selected to perform the monitoring tests by selecting key Ch.2 at the top level menu on the CTU test facility. With the rack wiring of Section 3.3.3.9, both monitor systems monitor the operating transponder.
6. Duplication of Tests for Dual System.
The tests of Sections 3.3.5 to 3.3.16 (inclusive) should be performed on both transponders and both monitor systems of a dual DME. The tests for the two systems may be performed in parallel, or the tests of one system may be completed before the tests on the second system are commenced.
3.3.5 Test Interrogator Alignment
3.3.5.1 RF Generator Alignment 1. Extend the test interrogator using the transponder extender frame. On the test
interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
2. If the RF generator has not yet been aligned for its operating interrogation frequencies, perform the alignment using the procedures of Section 3.4.12.
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3. On the test interrogator, undo the cable connector at the output of the RF generator, and connect the output of the RF generator to RF IN on the sensor of the peak power meter using a short cable.
3.3.5.2 RF Generator at Nominal Interrogation Frequency 1. On the peak power meter, read the pulse peak amplitude. It should be +11.5 ±0.2
dBm (14.1 ±0.7 mW). (If the reading is outside this range, remove the cover of the modulator and detector and adjust R13 (PULSE AMPLITUDE) on this board to set the peak power meter reading to a value in the specified range.
NOTE Improved Accuracy in Use of Peak Power Meter
The HP 8900D peak power meter provides improved accuracy in COMPARE mode. Connect channel 1 of the oscilloscope to VIDEO OUT of the peak power meter. On the peak power meter, adjust COMPARE LEVEL control to align the reference level with the peak of the pulse as displayed on the oscilloscope. Read the reference level from the peak power meter. If the peak power meter has been characterised to improve its accuracy, the correction factor should be applied to the meter reading to determine the actual peak power.
2. Disconnect channel 1 of the oscilloscope from the peak power meter (if connected as in the note above) and reconnect it to test jacks DETECTED INTERROGATIONS and EARTH on the front panel of the test interrogator. Measure the following parameters of the displayed pulses (see figure below).
NOTE If the pulse amplitude and/or shape are outside the above limits, they can be corrected by removing the lid of the modulator and detector on the test interrogator and adjusting R13 (PULSE AMPLITUDE) and R20 (PULSE SHAPE) as required, and then repeating step 1. After completing step 5, replace the lid on the modulator and detector.
3. From the table below, use the measured value of the peak amplitude from step 2 to determine the limit for the results in step 5.
PEAK AMPLITUDE LIMITS FOR RESULTS OF STEP 5 2.7 to 3.0 0.9 (±0.1) 3.1 to 3.3 1.0 (±0.1)
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4. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
5. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on channel 2 of the oscilloscope should remain the same except that the baseline should move up the pulse. Measure the DC level shift of the baseline level from the reference level set in the previous step. The DC level shift should be within the limits determined at step 3. If the DC level shift is outside the above limits, it can be corrected by removing the lid of the modulator and detector on the test interrogator (if not already removed) and adjusting R37 (PULSE PEDESTAL) as required. Replace the lid on the modulator and detector.
3.3.5.3 RF Generator at 160 kHz Above Nominal Frequency 1. On the RF generator, set switch S1:6 to OFF (to change operation back to
pulsed), and set switch S1:1 to OFF and switch S1:2 to ON (to change the interrogation frequency to 160 kHz above the nominal frequency). On the oscilloscope, measure the parameters of the displayed pulses listed at Section 3.3.5.2, step 2.
2. From the table of Section 3.3.5.2, step 3 use the measured value of the peak amplitude from step 1 to determine the limit for the measured results in step 4.
3. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
4. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on channel 2 of the oscilloscope should remain the same except that the baseline should move up the pulse. Measure the DC level shift of the baseline level from the reference level set in the previous step.
3.3.5.4 RF Generator at 160 kHz Below Nominal Frequency 1. On the RF generator, set switch S1:6 to OFF (to change operation back to
pulsed), and set switch S1:2 to OFF and switch S1:3 to ON (to change the interrogation frequency to 160 kHz below the nominal frequency). On the oscilloscope, measure the parameters of the displayed pulses listed at Section 3.3.5.2, step 2.
2. From the table of Section 3.3.5.2, step 3 use the measured value of the peak amplitude from step 1 to determine the limit for the measured results in step 4.
3. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
4. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on channel 2 of the oscilloscope should remain the same except that the baseline should move up the pulse. Measure the DC level shift of the baseline level from the reference level set in the previous step.
3.3.5.5 RF Generator at 900 kHz Above Nominal Frequency 1. On the RF generator, set switch S1:6 to OFF (to change operation back to
pulsed), and set switch S1:3 to OFF and switch S1:4 to ON (to change the interrogation frequency to 900 kHz above the nominal frequency). On the oscilloscope, measure the parameters of the displayed pulses listed at Section 3.3.5.2, step 2.
2. From the table of Section 3.3.5.2, step 3 use the measured value of the peak amplitude from step 1 to determine the limit for the measured results in step 4.
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3. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
4. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on channel 2 of the oscilloscope should remain the same except that the baseline should move up the pulse. Measure the DC level shift of the baseline level from the reference level set in the previous step.
3.3.5.6 RF Generator at 900 kHz Below Nominal Frequency 1. On the RF generator, set switch S1:6 to OFF (to change operation back to
pulsed), and set switch S1:4 to OFF and switch S1:5 to ON (to change the interrogation frequency to 900 kHz below the nominal frequency). On the oscilloscope, measure the parameters of the displayed pulses listed at Section 3.3.5.2, step 2.
2. From the table of Section 3.3.5.2, step 3 use the measured value of the peak amplitude from step 1 to determine the limit for the measured results in step 4.
3. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
4. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on channel 2 of the oscilloscope should remain the same except that the baseline should move up the pulse. Measure the DC level shift of the baseline level from the reference level set in the previous step.
5. On the RF generator, set switch S1:6 to OFF (to change operation back to pulsed operation), and set switch S1:5 to OFF and switch S1:1 to ON (to change the interrogation frequency back to the nominal frequency).
3.3.5.7 Spacing Offset Control 1. Connect channel 2 of the oscilloscope to test jacks 1 µs MARKERS and EARTH
on the front panel of the test interrogator. Using the displayed markers (or an accurately calibrated oscilloscope), measure the spacing between the detected pulses (channel 1 on the oscilloscope). It should be 12.0 ±0.1 microseconds measured at the half amplitude points on the leading edges. (For ‘Y’ channel values refer to Section 3.3.22)
2. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, REJECT to +2 microseconds. Measure the increase in spacing between the detected pulses. It should be 2.0 ±0.1 microseconds.
3. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, REJECT to -2 microseconds. Measure the decrease in spacing between the detected pulses. It should be 2.0 ±0.1 microseconds.
4. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, ACCEPT to +1 microsecond. Measure the increase in spacing between the detected pulses. It should be 1.0 ±0.1 microsecond.
5. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, ACCEPT to -1 microsecond. Measure the decrease in spacing between the detected pulses. It should be 1.0 ±0.1 microsecond.
3.3.5.8 RF Generator Output Frequencies 1. Disconnect the peak power meter from the output of the RF generator and
replace it with the frequency counter (through a suitable test cable). Terminate the frequency counter input with 50 ohms. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. Read the frequency counter frequency. It
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should be within ±20 kHz of the interrogation frequency of Section 3.3.3.7, step 4 for Fo.
2. On the RF generator, set switch S1:1 to OFF and switch S1:2 to ON (to change the interrogation frequency to Fo + 160 kHz). Read the frequency counter frequency. It should be within ±20 kHz of the interrogation frequency of Section 3.3.3.7, step 4 for Fo + 160 kHz.
3. On the RF generator, set switch S1:2 to OFF and switch S1:3 to ON (to change the interrogation frequency to Fo - 160 kHz). Read the frequency counter frequency. It should be within ±20 kHz of the interrogation frequency of Section 3.3.3.7, step 4 for Fo - 160 kHz.
4. On the RF generator, set switch S1:3 to OFF and switch S1:4 to ON (to change the interrogation frequency to Fo + 900 kHz). Read the frequency counter frequency. It should be within ±20 kHz of the interrogation frequency of Section 3.3.3.7, step 4 for Fo + 900 kHz.
5. On the RF generator, set switch S1:4 to OFF and switch S1:5 to ON (to change the interrogation frequency to Fo - 900 kHz). Read the frequency counter frequency. It should be within ±20 kHz of the interrogation frequency of Section 3.3.3.7, step 4 for Fo - 900 kHz.
6. On the RF generator, set switch S1:6 to OFF (to change operation back to pulsed operation), and set switch S1:5 to OFF and switch S1:1 to ON (to change the interrogation frequency back to the nominal frequency).
3.3.5.9 Test Interrogator Levels 1. On the CTU front panel, select Hi Eff (High Efficiency) test in Maintenance mode,
and a TI RATE of 1 kHz (refer to Section A.3 for operating instructions for the CTU).
2. Disconnect the frequency counter from the output of the RF generator and replace it with the calibrated 10 dB and 1 dB step attenuators connected to the RF generator through a calibrated 0.5 dB semirigid cables. Connect the output of the step attenuators to the spectrum analyser input with a second calibrated 0.5 dB semirigid cable. Select 60 dB in the 10 dB step attenuator and 10 dB in the 1 dB step attenuator.
3. Set the spectrum analyser controls as follows:
Centre frequency Station interrogation frequency Bandwidth 1 MHz Scan width 1 MHz per division Input attenuation to suit. Scan time 0.1 seconds per division Video filter 1 MHz bandwidth Log scan sensitivity to suit.
4. On the spectrum analyser, adjust the display so that the peak of the displayed spectrum is aligned with a reference graticule. This establishes a reference level of –59 dBm at the input to the spectrum analyser (corrected for the losses in the two 0.5 dB cables - refer Section 3.3.5.2, step 1). In the following steps, do not adjust any of the spectrum analyser controls.
5. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to OFF. Disconnect the step attenuators from the output of the RF generator and reconnect the cable from the input to the switched attenuator to the output of the RF generator.
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6. Remove the transponder extender frame and install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
7. On the RF panel, disconnect the connection to connector TI-1 TEST INTRGS -. for monitor system 1 (TI-2 TEST INTRGS - for monitor system 2). Using the same semirigid cables as used in step 2, connect the input of the step attenuators to connector TI-1 TEST INTRGS - for monitor system 1 (T1-2 TEST INTRGS - for monitor system 2). Reduce the attenuation of the step attenuators until the peak of the displayed spectrum on the spectrum analyser is again aligned with the reference graticule of step 4.
8. The high level interrogation level, the sum of the attenuator settings (+ve number) and the reference -59 dBm level, should be -40 ±1 dBm.
9. On the CTU front panel, select Lo Eff (Low Efficiency) test in Maintenance mode, and TI RATE, 1 kHz. Again reduce the attenuation of the step attenuators until the peak of the displayed spectrum on the spectrum analyser is aligned with the reference graticule of step 4.
10. The low level interrogation level, the sum of the attenuator settings (+ve number) and the reference -59 dBm level, should be -55 ±1 dBm.
11. Disconnect the spectrum analyser and the semirigid cable from the RF panel. On the RF panel, restore the connections:
a. for a single DME: from connector FWD-C on the directional coupler to TI-1 TEST INTRGS
b. for a dual DME: from connector FWD-E on No.2 directional coupler to TI-1 TEST INTRGS - for monitor system 1
from connector FWD-C on No.2 directional coupler to TI-2 TEST INTRGS - for monitor system 2
3.3.5.10 Test Interrogator System Timing Parameters 1. Connect the frequency counter to test jacks 1 µs MARKERS and EARTH on the
front panel of the test interrogator. Measure the frequency; it should be 1000.00 ±0.10 kHz.
2. Connect channel 1 of the oscilloscope to test jacks REPLY ACCEPT GATES and EARTH on the test interrogator. Measure the following characteristics of the displayed pulses:
Pulse width 6.0 ±1.0 microseconds Pulse spacing 12.0 ±0.2 microseconds Pulse repetition period 1.0 ±0.1 milliseconds.
(For ‘Y’ channel values refer to Section 3.3.22)
3. Connect channel 1 of the oscilloscope to test jacks INTERROGATIONS TIMING and EARTH and channel 2 of the oscilloscope to test jacks REPLY TIMING and EARTH on the test interrogator. On the front panel of the test interrogator press and hold operated CHECK DETECTOR COINCIDENCE and measure the time interval, on the oscilloscope, between the leading edges of the pulses on the two channels. The time interval should be not more than 0.1 microseconds.
3.3.6 RF Source and RF Filter Alignment and Tests 1. Extend the receiver video using the transponder extender frame.
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2. If the RF source and RF filter connected to the output of the RF source have not yet been aligned for their operating reply frequency, perform the alignment using the station frequency alignment procedures of Section 3.4.18 and for the receiver video module in Section 3.4.17.
3. On the receiver video undo the cable connector at the output of the RF filter, and connect the output of the RF filter to the frequency counter terminated in 50 ohms. Read the frequency counter frequency; it should be within 20 kHz of the reply frequency of Section 3.3.3.4, step 5.
4. Disconnect the frequency counter and reconnect the coaxial cable from the RF amplifier back to the output of the RF filter.
5. Measure the DC level at the LOCAL OSC LEVEL test jack on the receiver video front panel; this should be 2.0 ±0.1 volts.
6. Measure the DC level at the RF LEVEL test jack; this should be 3.0 ±1.5 volts.
7. Remove the transponder extender frame and replace the receiver video module in the rack.
3.3.7 RF Panel Preselector Filter Alignment and Tests 1. On the test interrogator front panel, switch MONITOR AND INTERROGATOR
DC POWER to OFF. Withdraw the test interrogator, remove the 30 dB attenuator from above the switched attenuator and reconnect the output coaxial cable directly to the switched attenuator output. Install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
2. On the CTU front panel, select Hi Eff test in Maintenance mode, and a TI RATE of 1 kHz.
3. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator front panel) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video front panel. With an oscilloscope timebase of 5 microseconds/division, a pulse pair should be displayed above the noise.
NOTE Increasing Signal Level - if Required
If the signal is not visible, more signal can be achieved (temporarily until initial alignment is achieved and significant signal is available) by providing a direct connection from the appropriate TEST INTRGS connector to the corresponding preselector IN connector on the RF panel (after first disconnecting the existing cables to these connectors).
4. Loosen the locknuts on the preselector filter and tune adjusters A and C together, keeping them equal distances out from the body; if the frequency is to be increased, tune the adjusters out (counter-clockwise); if the frequency is to be decreased, tune the adjusters in (clockwise).
5. Tune both adjusters A and C for a peak, then detune adjuster B until the signal is only just clearly visible.
6. Retune adjusters A and C successively for peaks. While monitoring the oscilloscope display, to ensure that the signal level does not change, lock adjusters A and C with their locknuts. Then retune adjuster B for absolute peak, locking it in the same way.
NOTE Extreme care must be exercised during this tuning as even a slight detuning of one cavity will cause a skewed response.
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7. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to OFF. Withdraw the test interrogator and replace the 30 dB attenuator. Install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
8. If changed, as in the note above, on the RF panel, disconnect the cable from TEST INTRGS to the preselector, and restore the connections:
a. for a single DME: from connector FWD-C on the directional coupler to TI-1 TEST INTRGS
b. for a dual DME: from connector FWD-E on No.2 directional coupler to TI-1 TEST INTRGS - for monitor system 1
from connector FWD-C on No.2 directional coupler to TI-2 TEST INTRGS - for monitor system 2
c. for both single and dual DMEs:
from circulator to connector IN (on the preselector filter.)
3.3.8 Receiver Video Alignment
3.3.8.1 6 dB Offset 1. Extend the receiver video using the transponder extender frame.
2. On the CTU front panel, select Hi Eff test in Maintenance mode, and a TI RATE of 1 kHz.
3. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator front panel) to test points XT13 and XT21 (GND) on the receiver video main board. Measure and record the peak pulse amplitude above the 0 volts reference.
4. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to OFF.
5. Withdraw the test interrogator, remove the 30 dB attenuator from above the switched attenuator and reconnect the output coaxial cable directly to the switched attenuator output.
6. Install the test interrogator back into the transponder subrack. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
7. With this increase of 30 dB in the signal level into the receiver video, on the oscilloscope, again measure and record the peak pulse amplitude above the 0 volts reference.
8. Calculate the difference between the recorded results of steps 3 and 7, and divide it by 5. Record this voltage. It should be 220 ±40 mV. This voltage is the average voltage increment per 6 dB of signal level.
9. Connect the digital multimeter (on 2 volts range) to test points XT13 and XT6 on the receiver video main board. Set ADJUST 6 dB OFFSET (R45) so that the multimeter reading equals (to within ±5 mV) the offset voltage calculated in step 8.
10. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to OFF. Withdraw the test interrogator and replace the 30 dB attenuator. Install the test interrogator back into the transponder subrack. On the
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test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
11. On the oscilloscope, measure the peak pulse amplitude above the 0 volts reference. It should be within 5 mV of the value recorded in step 3.
3.3.8.2 Receiver On-channel Threshold 1. Connect a frequency counter to the ON CHANNEL VIDEO and EARTH test
jacks on the receiver video. Set the counter time base to 1 second. Make the following switch settings on the transponder (after first noting their initial positions):
• Test interrogator, MONITOR AND INTERROGATOR DC POWER to OFF (both modules, on a dual DME).
• Transmitter driver, DRIVER DC POWER to OFF.
• Transponder power supply, TRANSPONDER DC POWER to ON.
2. Measure the ON CHANNEL VIDEO pulse count on the frequency counter. This should be between 20 and 200 pulses per second.
3. If the pulse count is outside this range, the switch the TRANSPONDER DC POWER to OFF. Remove the receiver video module from the rack and remove the cover from the IF amplifier enclosure. Plug the module into the rack, using the transponder extender frame.
4. Switch on the TRANSPONDER DC POWER but leave the test interrogator and transmitter driver OFF.
5. With a multimeter, measure the DC voltage at test pin XT13 on the IF amplifier board (referenced to ground). Check that it is 6.0 ±0.1 volts; if necessary, adjust the AGC preset (R15) to set the voltage within this range.
6. Measure the DC voltage at test pin XT10 (referenced to ground) and check that it is 5.0 ±0.1 volts. If necessary, adjust the ON CHANNEL preset (R50) to set the voltage within this range.
7. Measure the DC voltage at test pin XT6 and adjust the GAIN preset (R29) to give a voltage of 4.0 ±0.1 volts.
8. Check that the ON CHANNEL pulse count is now within the required range. If it is not, then make a further gain adjustment to R29 to achieve the specified pulse count, ensuring that the voltage at XT6 stays within the limits of 4.0 ±0.4 volts.
9. If any gain adjustment has been made, measure the voltage at the gain test pin XT1; it should be within the range 5.0 to 7.0 volts.
10. Switch off the transponder. Replace the cover on the IF amplifier and replace the receiver video module in the rack. Set all transponder switched to NORMAL.
3.3.9 Transmitter Driver Alignment
3.3.9.1 RF Output Alignment 1. If the transmitter driver has not been aligned for operation at the station reply
frequency, then perform the procedure detailed in Section 3.4.23.
2. Extend the transmitter driver using the transponder extender frame.
3. Set the switches and controls as follows:
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DRIVER DC POWER (on the front panel) to OFF, ALC LOOP (S2 on the pulse shaper board) to OPEN, ALC (S3 on the pulse shaper board) to VIDEO, MED COLL (S4 on the pulse shaper board) to DC, MOD PULSE AMPLITUDE (R58 on the pulse shaper board) fully counter-clockwise.
4. On the CTU front panel, press the SELECT MAIN NO 1 or NO 2 key as appropriate for the transponder being tested.
5. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to VIDEO OUT on the peak power meter to check the pulse shape (in step 8 onwards).
6. On the receiver video, set the IDENT switch to CONTINUOUS.
7. Connect the multimeter (on 200 volts range) to test jacks HT and EARTH on the transponder power supply front panel. The measured voltage should be 42.0 ±0.2 volts. If out of range, set the voltage within the specified range by adjusting HT VOLTAGE (R26) on the transponder power supply main board.
8. On the 1kW RF power amplifier, disconnect the coaxial cable from the INPUT connector, and connect the cable (with suitable adaptors, through the 30 dB attenuator) to the peak power meter. Record the calibrated loss of the 30 dB attenuator.
CAUTION The sensor on the peak power meter is sensitive to overload, and is easily damaged. To prevent expensive delays and repairs from being incurred, ensure that the correct specified attenuator is connected to the peak power meter sensor before connecting to the RF source to be measured.
9. If the capability is available on the peak power meter, enter an offset to the displayed peak power reading equal to the calibrated loss of the 30 dB attenuator (so that the peak power meter displays the actual power at the input to the 30 dB attenuator). If this capability is not available, use the table below to determine the required reading on the peak power meter corresponding to 40.0 watts into the input of the 30 dB attenuator. Ensure that the characterisation correction factor is also applied to the meter readings.
CALIBRATED ATTENUATOR LOSS METER READING (for 40W) 29.5 44.9 mW 29.6 43.9 mW 29.7 42.9 mW 29.8 41.9 mW 29.9 40.9 mW 30.0 40.0 mW 30.1 39.1 mW 30.2 38.2 mW 30.3 37.3 mW 30.4 36.5 mW 30.5 35.7 mW
10. On the transmitter driver front panel, set switch DRIVER DC POWER to NORMAL. While monitoring the peak power meter, adjust the RF OUTPUT control on the transmitter driver front panel to produce a peak power meter reading of that shown in the table above ±0.5 mW - corrected by the
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characterisation factor - (or 40.0 ±0.5 watts if the reading is corrected for the calibrated loss of the 30 dB attenuator).
11. Check that any tilt on the top of the waveform has a total peak-to-peak value over the two pulses of not more than 10% of the mean pulse height (see figure below).
12. Check that the space between the two pulses is 1.5 ±0.1 microseconds. If it is
not, then set it within this limit using the preset BACK PORCH (R36) on the pulse shaper board. (For ‘Y’ channel values refer to Section 3.3.22)
3.3.9.2 Modulation Pulse Alignment 1. On the power distribution panel, switch the appropriate 1kW PWR AMP circuit
breaker on.
2. On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to ON. Confirm the state of the following indicators:
HT ON on TEST on DC POWER ON on
3. Connect channel 2 of the oscilloscope to test jacks FUNCTION GENERATOR and EARTH on the transmitter driver. Measure the peak height of the displayed waveform with respect to the 0 volts reference. It should be 10.8 ±0.5 volts. (The shape may need to be modified to achieve the final RF envelope shape - see Section 3.3.10. Section 3.4.24 includes procedures for the initial alignment of the pulse shape.)
4. Move channel 2 of the oscilloscope to test jacks SHAPED MODULATION and EARTH on the 1kW PA power supply front panel. A constant voltage display should be observed. Adjust PEDESTAL VOLTAGE (R53) on the pulse shaper board to produce a multimeter reading of 17.0 ±0.5 volts.
5. While observing the oscilloscope, slowly adjust MOD PULSE AMPLITUDE (R58) to produce a pulse rising 15.0 ±0.5 volts above the base line. Ensure that this pulse voltage can be achieved.
6. Remove the pulses by adjusting MOD PULSE AMPLITUDE (R58) fully counter-clockwise.
7. On the transmitter driver front panel, set switch DRIVER DC POWER to OFF.
8. On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to OFF.
9. On the 1kW RF power amplifier, disconnect the coaxial cable from the input of the 30 dB attenuator and reconnect it to the INPUT connector of the 1kW RF power amplifier.
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3.3.10 1kW RF Power Amplifier Alignment
3.3.10.1 Output Pulse Alignment 1. For a dual DME, on the RF panel, set the ANTENNA RELAY switch to No1 TO
ANT or No2 TO ANT as appropriate for the transponder being tested.
2. Connect the peak power meter through the calibrated 30 dB and 20 dB attenuators to the ANTENNA connector on the RF panel at the rear of the rack. (Make a direct connection, without using any cables.) Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to VIDEO OUT on the peak power meter to check the pulse shape. The transmitter driver should be on the transponder extender frame as in the previous section. Ensure that the cover is securely fitted to the 1kW RF power amplifier.
3. Record the calibrated loss of the 20 dB attenuator. Add and record the sum of the calibrated losses of the 20 dB and 30 dB attenuators.
4. If the capability is available on the peak power meter, enter an offset to the displayed peak power reading equal to the sum of the calibrated losses of the 20 dB and 30 dB attenuators (so that the peak power meter displays the actual power at the input to the 30 dB attenuator). If this capability is not available, use the table below to determine the required reading on the peak power meter corresponding to 1200 watts into the input of the 30 dB attenuator. Ensure that the characterisation correction factor is also applied to the meter readings.
CALIBRATED ATTENUATO
R LOSS
METER READING
(FOR 1.2 KW)
CALIBRATED ATTENUATOR
LOSS
METER READING
(FOR 1.2 KW)
49.0 15.1 mW 50.0 12.0 mW 49.1 14.8 mW 50.1 11.7 mW 49.2 14.4 mW 50.2 11.5 mW 49.3 14.1 mW 50.3 11.2 mW 49.4 13.8 mW 50.4 10.9 mW 49.5 13.5 mW 50.5 10.7 mW 49.6 13.2 mW 50.6 10.5 mW 49.7 12.9 mW 50.7 10.2 mW 49.8 12.6 mW 50.8 10.0 mW 49.9 12.3 mW 50.9 9.8 mW 50.0 12.0 mW 51.0 9.5 mW
5. On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to ON.
6. Connect the multimeter (on 200 volts range) to test jacks HT and EARTH on the 1kW PA power supply front panel. The measured voltage should be 50.0 ±0.2 volts. If out of range, set the voltage within the specified range by adjusting R112 on the regulator of the 1kW PA power supply.
7. On the transmitter driver front panel, switch DRIVER DC POWER to NORMAL.
8. Connect channel 2 of the oscilloscope to test jacks DETECTED REPLIES and EARTH on the test interrogator front panel.
9. While monitoring the peak power meter, slowly increase the MOD PULSE AMPLITUDE (R58) preset on the pulse shaper board of the transmitter driver to
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produce a peak power meter reading of 1800 watts (or the maximum power available). Check that no instability or break-up of the shape of the pulse occurs at any power setting up to the specified maximum.
10. While monitoring the peak power meter, decrease the MOD PULSE AMPLITUDE (R58) on the pulse shaper board of the transmitter driver to produce a peak power meter reading of that shown in the table above 0.5 mW (or 1200 ±50 watts if the reading is corrected for the calibrated loss of the 50 dB attenuator).
11. Perform a small number of successive adjustments to the PEDESTAL VOLTAGE (R53) and MOD PULSE AMPLITUDE (R58) presets to obtain an output pulse shape generally similar to that shown in the figure below with a peak power of 1.2 kW, a pulse width in the range 3.2 to 3.8 microseconds, and rise and fall times in the range 1.9 to 2.5 microseconds. For final shape adjustment, see step 15. (During the adjustments, do NOT let the peak power exceed a power 50% above the 1.2 kW limit.)
12. On the oscilloscope, adjust the gain and position controls of channel 2 to set the
detected pulses from the peak power meter and DETECTED REPLIES to the same amplitude. Check that the waveforms coincide within 5%.
13. On the oscilloscope, check the displayed signal from DETECTED REPLIES. On the pulse shaper board of the transmitter driver, adjust PEDESTAL VOLTAGE (R53) so that the pedestal is about 5% of the total pulse amplitude, and clearly visible, as shown in the figure below.
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14. On the pulse shaper board, adjust INTEGRATOR BALANCE (R17) so that there
is an equal pedestal step at each side of the pulse, that is, RISE PEDESTAL equals FALL PEDESTAL.
15. On the pulse shaper board, adjust PEDESTAL VOLTAGE (R53) to reduce the pedestal until there is a smooth transition between the pulse and the baseline. Then adjust MOD PULSE AMPLITUDE (R58) to give 1.2 kW peak power output (see step 10).
16. If the pulse shape at the completion of step 15 does not meet the limits of step 11, it may be necessary to readjust the function generator controls, R3 to R13 on the pulse shaper board to achieve the required pulse shape parameters. The object is to obtain the rated power output whilst meeting the pulse shape requirements of step 11.
17. On the oscilloscope display of DETECTED REPLIES, check the relative amplitudes of the two pulses of the pulse pair. If the second pulse is higher than the first, reduce its amplitude with 2ND PULSE EQUALISING (R54) on the pulse shaper board (otherwise leave this control fully clockwise). If the second pulse is lower than the first, increase the amplitude by a SMALL adjustment only of the INTEGRATOR BALANCE (R17) on the pulse shaper board.
18. If necessary, adjust MOD PULSE AMPLITUDE (R58) on the pulse shaper board to give 1.2 kW peak power output (see step 10).
19. Using the oscilloscope, measure the following parameters (with respect to an EARTH test jack or test point on the same module - as appropriate) and record them for later reference:
MODULE MONITOR POINT PARAMETER
Test Point XT9 DC Voltage Pulse Shaper
Test Point XT5 DC Voltage Pedestal Voltage
Test Jack SHAPED MODULATION Pulse Peak Voltage
Test Jack POWER AMP DRIVER Pulse Peak Voltage 1kW PA Power Supply
Test Jack POWER AMP MODULATOR Pulse Peak Voltage
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3.3.10.2 Automatic Level Control CAUTION In the next two steps, the output pulse peak power as measured by the
peak power meter should fall when specified switches are operated. If the peak power rises instead, there is a fault in the equipment. Reverse the operation of the switch and rectify the fault before continuing the test. The pulse peak power should NOT be allowed to exceed 1.8 kW for more than a few seconds.
1. On the pulse shaper board, ensure ALC switch (S3) is set to VIDEO. Adjust the front panel RF OUTPUT control fully counter-clockwise. Switch ALC LOOP (S2) to CLOSED. Observe that the output pulse peak power has been reduced. Adjust RF OUTPUT to give 1.2 kW peak power output (see Section 3.3.10.1 step 10).
2. On the pulse shaper board, switch ALC LOOP to OPEN. Adjust the front panel RF OUTPUT control fully counter-clockwise. Set the ALC switch to DETECTED RF. Switch ALC LOOP to CLOSED. Observe that the output pulse peak power has been reduced. Adjust RF OUTPUT to give 1.2 kW peak power output (see Section 3.3.10.1 step 10). Leave the ALC switch in the DETECTED RF position.
3. On the transponder power supply front panel, switch TRANSPONDER DC POWER to OFF. Replace the transmitter driver in the transponder subrack. On the transponder power supply front panel, switch TRANSPONDER DC POWER to ON.
4. On the peak power meter, read the output pulse peak power. Correct this reading for the calibrated loss of the 50 dB attenuator and the characterisation correction of the peak power meter. The corrected peak power should be 1200 ±50 watts.
3.3.11 Transmitter Pulse Parameters Ensure that the oscilloscope probes are correctly compensated and the vertical amplifiers are calibrated just prior to the commencement of this section.
3.3.11.1 Test Setup 1. On the receiver video front panel, switch IDENT to CONTINUOUS.
2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to test jacks DETECTED REPLIES and EARTH on the test interrogator front panel.
3. On the CTU front panel, press the SELECT MAIN, OFF/RESET key.
4. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to NORMAL.
5. On the transponder power supply front panel, switch TRANSPONDER DC POWER to NORMAL.
6. On the transmitter driver front panel, switch DRIVER DC POWER to NORMAL.
7. On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to NORMAL.
8. On the CTU front panel, press the SELECT MAIN NO 1 or NO 2 key as appropriate for the transponder being tested. Ensure MONITOR ALARM is set to INHIBIT.
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3.3.11.2 Output Pulse Power 1. On the peak power meter, read the meter reading. Applying the corrections for
the calibration errors of the attenuators and meter, calculate the corrected output pulse peak power. This should be 1200 ±60 watts.
3.3.11.3 Output Pulse Shape 1. From the display on the oscilloscope, measure the following parameters:
PARAMETER LIMITS 1st pulse: pulse width at half-amplitude 3.5 ±0.3 microseconds 2nd pulse: pulse width at half-amplitude 3.5 ±0.3 microseconds 1st pulse: rise time, 10% to 90% 2.2 ±0.3 microseconds 2nd pulse: rise time, 10% to 90% 2.2 ±0.3 microseconds 1st pulse: fall time, 10% to 90% 2.2 ±0.3 microseconds 2nd pulse: fall time, 10% to 90% 2.2 ±0.3 microseconds Amplitude difference between pulses 2%
2. On the CTU front panel display the following parameters:
PARAMETER LIMITS Pulse width 3.5 ±0.3 microseconds Rise time 2.2 ±0.3 microseconds Fall time 2.2 ±0.3 microseconds
NOTE The CTU pulse shape measurement facility measures the parameters of the second pulse of a transmitted pulse pair.
3.3.11.4 Output Pulse Spacing 1. Connect channel 2 of the oscilloscope to test jacks 1 µs MARKERS and EARTH
on the test interrogator front panel. Use the displayed markers to correct the oscilloscope time base calibration and then measure the pulse spacing between the amplitude points on the leading edge of each pulse. It should be 12.0 ±0.1 microseconds. If the pulse spacing is outside this limit, adjust REPLY PULSE SPACING (REPLY PULSE SEPARATION on early modules) on the receiver video front panel to set this parameter to a value in the specified range. (For ‘Y’ channel values refer to Section 3.3.22)
2. On the receiver video, switch IDENT to OFF.
3. On the CTU front panel display the Spacing reading; it should be within the limits of step 1 above. (For ‘Y’ channel values refer to Section 3.3.22)
4. On the receiver video, switch IDENT to CONTINUOUS.
3.3.11.5 Output Pulse Peak Power Calibration 1. On the CTU front panel display the Pwr Out reading.
2. Extend the test interrogator using the transponder extender frame.
3. While monitoring the CTU display, adjust TPDR OP LVL CAL (R7) on the test interrogator main board to display a power output reading equal (within 10 watts) to the corrected peak output power reading of Section 3.3.11.2.
4. Reinstall the test interrogator into the transponder subrack. The CTU power output reading should be within ±30 watts of the corrected peak output power reading of Section 3.3.11.2. If the reading is outside the limits, extend the test
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interrogator on the transponder extender frame, adjust TPDR OP LVL CAL (R7) to produce the required correction and then reinstall the test interrogator.
3.3.11.6 Output Pulse Spectrum 1. At the RF panel, disconnect the sensor of the peak power meter (but leave 30 dB
and 20 dB attenuators terminating the ANTENNA connector). Connect a cable from the output of the 20 dB attenuator to RF IN on the spectrum analyser.
2. Initially set the spectrum analyser controls as follows:
Centre frequency Station reply frequency Bandwidth 100 kHz Scan width 1 MHz per division Input attenuation 20 dB Scan time 0.1 seconds per division Video filter 1 MHz bandwidth Log scan sensitivity to suit
3. On the spectrum analyser, tune in the pulse spectrum. Change the SCAN WIDTH to 200 kHz per division. Set the 0 dB reference to the peak of the displayed spectrum. At 800 kHz either side of the frequency of the peak response, read the spectral response in dB below the 0 dB reference. The magnitude of this difference should not be less than 50 dB.
4. Change the SCAN WIDTH to 5 MHz per division, reset the 0 dB reference to the peak of the displayed spectrum. Confirm that there are no responses between 2 MHz and 50 MHz which are above a level which is 65 dB below the 0 dB reference level. (Responses above the specified level which can be shown to not be generated in the equipment under test are not to be considered.)
5. Change the SCAN WIDTH to 10 MHz per division, reset the 0 dB reference to the peak of the displayed spectrum. Measure the responses at 11/12 and 13/12 of the station reply frequency. These should be below a level which is 60 dB below the 0 dB reference level.
6. On the receiver video front panel, switch IDENT to NORMAL.
3.3.12 Receiver Performance Tests
3.3.12.1 Test Setup 1. Connect channel 1 of the oscilloscope (externally triggered from test jacks
TRIGGER and EARTH on the test interrogator) to test jacks REPLY TIMING and EARTH also on the test interrogator.
2. Connect channel 2 of the oscilloscope to test jacks REPLY ACCEPT GATES and EARTH on the test interrogator.
3. On the oscilloscope, check that the centre of the REPLY ACCEPT GATES align, within ±0.5 microseconds, with leading edges of the REPLY TIMING pulses. If this alignment is outside the specified limits, adjust REPLY GATE DELAY, COARSE and FINE controls on the test interrogator front panel to achieve the required alignment.
4. On the CTU front panel, select Lo Eff parameter measurement in Maintenance mode, and a TI RATE of 1 kHz. Check that a reply efficiency greater than 70% is being displayed.
5. Extend the test interrogator using the transponder extender frame.
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6. On the test interrogator, undo the cable connector at the output of the RF generator, and connect the output of the RF generator to the calibrated 10 dB and 1 dB step attenuators connected through one of the 0.5 dB semirigid cables. Connect the output of the step attenuators to the input of the corresponding preselector filter with the second 0.5 dB semirigid cable - after removing the semirigid cable link to the circulator (see figure below). Select 90 dB in the 10 dB step attenuator and 0 dB in the 1 dB step attenuator. Check that a reply efficiency greater than 70% is being displayed on the CTU.
3.3.12.2 Receiver Sensitivity 1. Select 100 dB on the 10 dB step attenuator and 3 dB on the 1 dB step attenuator
to give an input level of –93 dBm to the preselector filter. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
2. If the reply efficiency in step 1 is not achieved, then check the following:
• tuning of preselector filter (refer to Section 3.4.34.2);
• alignment of IF amplifier (refer to Section 3.4.19);
• gain adjustment of receiver video (refer to Section 3.4.17).
3.3.12.3 Receiver Bandwidth 1. Select 100 dB on the 10 dB step attenuator and 0 dB on the 1 dB step attenuator
to give an input level of -90 dBm to the preselector filter. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
2. On the RF generator, set switch S1:1 to OFF and switch S1:2 to ON (to change the interrogation frequency to 160 kHz above the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
3. On the RF generator, set switch S1:2 to OFF and switch S1:3 to ON (to change the interrogation frequency to 160 kHz below the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
If the reply efficiencies in step 1 to 3 are not achieved, then check the narrowband alignment of the IF amplifier. (Refer to Section 3.4.19)
4. On the RF generator, set switch S1:3 to OFF and switch S1:1 to ON (to change the interrogation frequency back to the nominal frequency).
3.3.12.4 Receiver Selectivity 1. Select 20 dB on the 10 dB step attenuator and 0 dB on the 1 dB step attenuator
to give an input level of –10 dBm to the preselector filter. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
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2. On the RF generator, set switch S1:1 to OFF and switch S1:4 to ON (to change the interrogation frequency to 900 kHz above the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 2%.
3. On the RF generator, set switch S1:4 to OFF and switch S1:5 to ON (to change the interrogation frequency to 900 kHz below the nominal frequency). On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 2%.
4. On the RF generator, set switch S1:5 to OFF and switch S1:1 to ON (to change the interrogation frequency back to the nominal frequency).
3.3.12.5 Receiver Decoding Window 1. With an input level of -10 dBm at the preselector filter (as in Section 3.3.12.4
above), switch and hold TEST TRANSPONDER DECODING REJECT on the test interrogator to +2 microseconds. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 5%.
2. On the test interrogator, switch and hold TEST TRANSPONDER DECODING REJECT to -2 microseconds. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 5%.
3. Select 100 dB on the 10 dB step attenuator and 2 dB on the 1 dB step attenuator to give an input level of -92 dBm to the preselector filter. On the CTU, change the TI RATE to 50 Hz (100 Hz on a single DME).
4. On the test interrogator, switch and hold TEST TRANSPONDER DECODING ACCEPT to +1 microsecond. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
5. On the test interrogator, switch and hold TEST TRANSPONDER DECODING ACCEPT to -1 microsecond. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 70%.
6. On the test interrogator, switch and hold TEST TRANSPONDER DECODING REJECT to +2 microseconds. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 10%.
7. On the test interrogator, switch and hold TEST TRANSPONDER DECODING REJECT to -2 microseconds. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be less than 10%.
3.3.12.6 Receiver CW Protection 1. Select 40 dB on the 10 dB step attenuator and 0 dB on the 1 dB step attenuator
to give an input level of -30 dBm to the preselector filter. On the CTU, change the TI RATE to 1 kHz.
2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video. Measure the pulse peak amplitude (with respect to mean noise baseline). The pulse peak amplitude should be not less than 2.2 volts.
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3. On the RF generator, set switch S1:6 to ON to add a CW signal to the interrogation pulse. On the oscilloscope, measure the pulse peak amplitude (with respect to mean noise baseline). The pulse peak amplitude should be less than 0.7 volts. (This reduction in pulse peak amplitude proves correct operation of the automatic gain control).
4. On the CTU, measure the reply efficiency averaged over a 10 second period. The average reply efficiency should be greater than 90%.
5. On the RF generator, set switch S1:6 to OFF to remove the CW signal from the interrogation pulse.
3.3.12.7 Receiver Reply Rate 1. Select 80 dB on the 10 dB step attenuator and 0 dB on the 1 dB step attenuator
to give an input level of -70 dBm to the preselector filter.
2. On the CTU, select Tx.Rate parameter measurement.
3. On the receiver video, switch and hold TEST switch to INHIBIT INTERROGATIONS. On the CTU, read the average of five displayed transmitted pulse rate readings. This squitter reply rate should be 945 ±10 Hz.
4. On the receiver video, switch and hold TEST switch to REPLY RATE MONITOR TEST. On the CTU, read the average of five displayed transmitted pulse rate readings. This reply rate should be 810 ±10 Hz.
5. While holding TI RATE 10 kHz on the CTU pressed, read the average of five displayed transmitted pulse rate readings. This maximum reply rate should be 2800 ±100 Hz.
6. On the CTU, select D.Rate parameter measurement at a TI RATE of 1 kHz. Read the average of five displayed readings; this decoded pulse rate should be 1000 ±10 Hz.
7. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video. Measure the pulse peak amplitude (with respect to mean noise baseline); it should b at least 1.1 volts.
8. While observing the oscilloscope display, press TI RATE 10 kHz on the CTU. Measure the pulse peak amplitude (with respect to mean noise baseline); it should be not more than 0.7 volts. (This reduction in pulse peak amplitude proves correct operation of the AGC.)
3.3.12.8 Dead Time 1. Connect channel 1 of the oscilloscope (externally triggered from test jacks
TRIGGER and EARTH on the test interrogator) to test jacks DEAD TIME and EARTH on the receiver video. The duration of the displayed pulse will have random variations. Observe that the pulse duration remains in the range 58 to 73 microseconds.
3.3.13 Transponder Delay
3.3.13.1 Delay Variation with Input Level 1. Select 80 dB on the 10 dB step attenuator and 0 dB on the 1 dB step attenuator
to give an input level of –70 dBm to the preselector filter.
2. On the CTU, select Delay parameter measurement at a TI RATE of 1 kHz. The displayed reading will probably fluctuate ±0.1 microseconds about the average
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value. If necessary, adjust the BEACON DELAY, COARSE and FINE controls on the receiver video to achieve an average as near as possible to 50.0 microseconds. Due to the limited resolution of the FINE control, it will sometimes be necessary to accept 49.9 or 50.1 microseconds. A reading on the low side is preferred since the antenna feeder will increase the transponder delay as measured by an aircraft. Record this reference Delay value. (For ‘Y’ channel values refer to Section 3.3.22)
3. Set the step attenuators to the values listed in the table below to produce the specified input levels to the preselector filter. For each setting, read the reply delay reading displayed on the CTU. If there is any fluctuation in the reading, take the mean value averaged over a 10 second period. These delay values should be within the tabulated limits of the recorded reference delay.
ATTENTUATOR SETTING (dB)
INPUT LEVEL AT PRESELECTOR (dBm)
LIMITS (microseconds)
80 -70 ±0.2 100 -90 ±0.2 103 -93 ±0.4 60 -50 ±0.2 40 -30 ±0.2 30 -20 ±0.2 20 -10 ±0.4
4. On the test interrogator, disconnect the step attenuators and the semirigid cable from the output of the RF generator. Restore the connection from the output of the RF generator to the switched attenuator. Remove the transponder extender frame and install the test interrogator back in the transponder subrack.
5. On the RF panel, disconnect the step attenuators and the semirigid cable from the input of the preselector filter. Restore the semirigid cable link from the circulator to the input of the preselector filter.
6. On the CTU, read the displayed delay. It should be within ±0.1 microseconds of the reference delay recorded above.
3.3.13.2 Final Receiver Checks 1. On the CTU, select Delay parameter measurement at a TI RATE of 1 kHz.
2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks INTERROGATIONS TIMING and EARTH and channel 2 of the oscilloscope to test jacks REPLY TIMING and EARTH on the test interrogator. Measure the time interval between the first interrogation pulse and the first synchronised reply pulse (at half-amplitude points on the pulse leading edges) and measure by reference to the 1 microsecond markers at 1 µs MARKERS test jack on the test interrogator. The time interval should be within ±0.1 microseconds of the value displayed on the CTU. (For ‘Y’ channel values refer to Section 3.3.22)
3. On the CTU, select Lo Eff parameter measurement at a TI RATE of 1 kHz.
4. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video. Measure the amplitude of the displayed synchronous video pulses with respect to the 0 volts reference (taking
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the mean of the noise on the peak of the pulses). The amplitude should be 1.2 ±0.5 volts.
5. On the CTU, select Hi Eff parameter measurement. On the oscilloscope measure the amplitude of the displayed synchronous video pulses with respect to the 0 volts reference. The amplitude should be 1.8 ±0.5 volts.
6. Calculate the difference in amplitudes of steps 4 and 5. This difference should be in the range 0.4 to 0.7 volts.
7. On the CTU, select Effncy parameter measurement. On the oscilloscope check (see figure below) that the displayed synchronous video pulses alternate between the two levels measured above. Measure the time interval from the rising edge of the first pulse of a low level synchronous video pulse pair to the rising edge of the first pulse of a high level synchronous video pulse pair. This time interval should be 1.00 ±0.05 milliseconds. (Note that synchronous reply pulses, probably at a higher level, will also be present on the displayed waveform).
3.3.14 Echo Suppression
3.3.14.1 Long Distance Echo Suppression 1. On the CTU, select Hi Eff parameter measurement at a TI RATE of 1 kHz.
2. Extend the receiver video using the transponder extender frame and switch LDES (S9) on the receiver video main board to ON.
3. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to XT13 and XT21 (GND) on the receiver video main board. The peak interrogation pulse voltage should be 2.70 ±0.50 volts.
4. Connect channel 2 of the oscilloscope to test points XT9 and XT21 (GND). Adjust LDES LEVEL (R46) to set the long distance echo suppression level to 0.10 to 0.15 volts less than the voltage measured in the previous step.
5. Move channel 2 of the oscilloscope to test jacks DEAD TIME and EARTH on the receiver video. The duration of the displayed pulse will have random variations, but should remain in the range 115 to 140 microseconds.
6. On the CTU, select Lo Eff parameter measurement. On the oscilloscope, check that the pulse duration remains in the range 58 to 73 microseconds.
7. On the receiver video main board, switch LDES to OFF.
3.3.14.2 Short Distance Echo Suppression 1. On the CTU, select Hi Eff parameter measurement.
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2. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to XT13 and XT21 (GND) on the receiver video main board. Connect channel 2 of the oscilloscope to test jacks SDES PULSE and EARTH on the receiver video. Check that the displayed XT13 waveform is similar to that shown in the figure below for SDES OFF.
3. On the receiver video main board, switch SDES (S8) to ON. Check that an SDES
pulse is now present and that the displayed XT13 waveform has the leading edge of the second pulse masked out in line with the SDES pulse as shown in the figure above for SDES ON. (The SDES pulse has a nominal width of 2.5 microseconds and is delayed a nominal 14 microseconds from the TRIGGER pulse.)
4. Switch SDES to OFF. Install the receiver video back in the transponder subrack.
3.3.15 Ident
3.3.15.1 Internal Ident 1. On the CTU, switch MAINTENANCE to OFF and MONITOR ALARM to
NORMAL. Under the Misc menu, select Mon 1 (for No. 1 transponder) or Mon 2 (for No.2 transponder) as the ident (speaker) source. Switch MAINTENANCE back to ON (after switching the transponder off and then switching the transponder back on). Listen to the ident from the CTU mounted speaker and check that it is correct for the assigned ident (set at Section 3.3.3.4, step 2).
2. Using a stopwatch, measure the ident repetition period; it should be 40 ±4 seconds. If the measured period is outside the limits, connect a counter, set for period measurement, to test points XT7 and XT21 on the receiver video main board, and adjust IDENT REPTN RATE (R39) to produce a period reading in the range 600 to 650 milliseconds on the counter.
3.3.15.2 External Ident 1. On the external I/O board at the rear of the rack, connect the NO (normally open)
contacts of a pushbutton switch (through suitable leads) between terminal 4 of terminal block XB1 (ASSOC_IDENT_IN) and terminal 6 of terminal block XB1 1 (GND).
2. Listen to the CTU mounted speaker and confirm that ident is transmitted whenever the pushbutton is pressed.
3. Listen for the internally generated ident. Within 1 second of the commencement of the internal ident, press and hold the pushbutton for 1 to 2 seconds. Start a stopwatch on releasing the pushbutton.
4. From a stopwatch, read the elapsed time until the commencement of the next internal ident. This elapsed time should be less than 55 seconds.
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5. Remove the pushbutton switch from the external I/O board.
3.3.15.3 Master Ident 1. Connect the indicator test fixture (see Section E.2) to the external I/O board,
positive to terminal 2 of terminal block XB1 (ASSOC_IDENT_OUT -), negative to terminal 6 of terminal block XB11 (GND).
2. Using a stopwatch, measure the time period between the commencement of the internally generated ident messages. This time period should be 10 ±1 seconds for three out of four ident messages.
3. Check that every fourth ident message is suppressed, and that the suppressed ident message coincides with the ident message transmitted by the DME.
3.3.15.4 Ident Frequency 1. On the CTU, select Tx.Rate parameter measurement.
2. On the receiver video, switch IDENT to CONTINUOUS. On the CTU, read the average of five displayed transmitted pulse rate readings. This ident frequency should be 1350 ±20 Hz.
3. On the receiver video, switch IDENT to NORMAL.
3.3.16 Monitor Fault Limits
3.3.16.1 Test Setup 1. On the monitor main board, ensure that each of the fault limit switches has been
set as specified in Section 3.3.3.8, step 1.
2. At the rear of the rack, ensure that the cables providing signals into the ERP IN connectors of the transponders have been connected (see Section 3.3.3.9, step 2 for a single DME; Section 3.3.3.10, steps 2 and 3 for a dual DME).
3. On the RF panel, ensure that the antenna integrity monitor test fixture (see Section 3.3.3.9) is connected to XN2 on the RF panel board.
4. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to NORMAL.
5. On the transponder power supply front panel, switch TRANSPONDER DC POWER to NORMAL.
6. On the transmitter driver front panel, switch DRIVER DC POWER to NORMAL.
7. On the 1kW PA power supply, switch AMPLIFIER DC POWER to NORMAL.
8. On the RF panel, ensure ANTENNA RELAY switch is set to NORMAL.
9. On the CTU front panel, press the SELECT MAIN NO 1 or NO 2 key as appropriate for the transponder being tested.
10. On the monitor, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
3.3.16.2 Delay Monitor 1. Extend the monitor on the transponder extender frame.
2. On the CTU, select Delay parameter measurement at a TI RATE of 1 kHz.
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3. On the receiver video, read and record the position of the BEACON DELAY, COARSE and FINE switches (to enable them to be restored to their original positions at the completion of these tests).
4. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed delay of 49.5 microseconds on the CTU. Check that the DELAY indicator on the monitor is off and the PRIMARY indicator is on.
5. Slowly adjust the BEACON DELAY, COARSE switch towards position 0 to reduce the beacon delay. Check that the monitor DELAY indicator remains off.
NOTES Delay Displayed on CTU
For delays outside the range 48 to 52 microseconds, the CTU will display "OVERFLOW".
Second Pulse Within Delay Window For delays around 38 microseconds, the second pulse of the pulse pair will fall within the accept window around 50 microseconds and the DELAY indicator will again turn on. This is acceptable.
6. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed delay of 50.5 microseconds on the CTU. Check that the DELAY indicator on the monitor is off and the PRIMARY indicator is on.
7. While observing the monitor DELAY indicator, slowly continue to adjust the BEACON DELAY, COARSE switch towards position F to increase the beacon delay. Check that the DELAY indicator remains off.
8. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed delay of 50.3 microseconds on the CTU. Check that the DELAY indicator on the monitor is on.
9. While observing the monitor DELAY indicator, slowly continue to adjust the BEACON DELAY, COARSE and FINE switches to decrease the beacon delay (but not below 49.7 microseconds). Check that the DELAY indicator remains on.
10. On the receiver video, adjust the BEACON DELAY, COARSE and FINE switches to produce a displayed delay of 49.7 microseconds on the CTU. Check that the DELAY indicator on the monitor is on.
11. On the receiver video, restore the BEACON DELAY, COARSE and FINE switches to their original settings.
(For ‘Y’ channel values refer to Section 3.3.22)
3.3.16.3 Spacing Monitor 1. On the CTU, select Spacing parameter measurement at a TI RATE of 1 kHz.
2. On the receiver video, read and record the position of the REPLY PULSE SPACING (REPLY PULSE SEPARATION on earlier modules) switch (to enable this switch to be restored to its original position at the completion of these tests).
3. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed spacing of 11.4 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 11.4 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to 11.4 microseconds, but never greater than 11.4 microseconds.) Check that the SPACING indicator on the monitor is off and the PRIMARY indicator is on.
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4. While observing the monitor SPACING indicator, slowly continue to adjust the REPLY PULSE SPACING switch towards position 0 to reduce the pulse spacing. Check that the SPACING indicator remains off.
5. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed Spacing of 12.6 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 12.6 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to 12.6 microseconds, but never less than 12.6 microseconds.) Check that the SPACING indicator on the monitor is off and the PRIMARY indicator is on.
6. While observing the monitor SPACING indicator, slowly continue to adjust the REPLY PULSE SPACING switch towards position F to increase the pulse spacing. Check that the SPACING indicator remains off.
7. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed spacing of 12.3 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 12.3 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to 12.3 microseconds, but never greater than 12.3 microseconds.) Check that the SPACING indicator on the monitor is on.
8. While observing the monitor SPACING indicator, slowly continue to adjust the REPLY PULSE SPACING switch to decrease the pulse spacing (but not below 11.7 microseconds). Check that the SPACING indicator remains on.
9. On the receiver video, adjust the REPLY PULSE SPACING switch to produce a displayed spacing of 11.7 microseconds on the CTU. (Because of the coarse adjustment of the REPLY PULSE SPACING switch it may not be possible to achieve a steady reading of 11.7 microseconds on the CTU. In this case, adjust the switch to produce a CTU reading as close as possible to 11.7 microseconds, but never less than 11.7 microseconds.) Check that the SPACING indicator on the monitor is on.
10. On the receiver video, restore the REPLY PULSE SPACING switch to its original setting.
(For ‘Y’ channel values refer to Section 3.3.22)
3.3.16.4 Efficiency Monitor 1. On the RF panel, remove the coaxial cable between TI-1 TEST INTRGS and
FWD-E on No.2 directional coupler - for monitor system 1 (between TI-2 TEST INTRGS and FWD-C on No.2 directional coupler - for monitor system 2). Connect the 1 dB step attenuator between these two points using the two 0.5 dB semirigid cables. Set the step attenuator to 0 dB.
2. On the CTU, select Lo Eff parameter measurement at a TI RATE of 1 kHz.
3. While observing both the displayed CTU efficiency reading and the EFFICIENCY indicator on the monitor, slowly increase the attenuation of the step attenuator.
4. Observe that while the displayed CTU efficiency reading is greater than 70%, the monitor EFFICIENCY indicator is on.
5. Observe that while the displayed CTU efficiency reading is less than 50%, the monitor EFFICIENCY indicator is off and the SECONDARY indicator is on.
NOTE Extra Attenuation
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It may be necessary to insert the 10 dB step attenuator (set to 10 dB) in series with the specified attenuator to reduce the efficiency below 50%.
6. Remove the step attenuator and semirigid cables. On the RF panel, restore the connections:
a. for a single DME: from connector FWD-C on the directional coupler to TI-1 TEST INTRGS
b. for a dual DME: from connector FWD-E on No.2 directional coupler to T1-1 TEST INTRGS - for monitor system 1
from connector FWD-C on No.2 directional coupler to TI-2 TEST INTRGS - for monitor system 2
3.3.16.5 Rate Monitor 1. On the CTU, select Tx.Rate parameter measurement at a TI RATE of 50 Hz (100
Hz on a single DME).
2. On the monitor, check that the RATE indicator is on while the CTU displays a transmitted pulse rate reading of 945 ±10 Hz.
3. On the receiver video, switch and hold TEST switch to REPLY RATE MONITOR TEST. Check that the monitor RATE indicator is off and the SECONDARY indicator is on and the CTU shows a transmitted pulse rate reading of 810 ±10 Hz.
3.3.16.6 Power Monitor 1. Connect the multimeter (on 20 volts range) to test points XT1 and XT13 (GND)
on the monitor main board. Measure the voltage of the 5 volts reference. It should be 5.00 ±0.02 volts.
2. At the rear of the rack, disconnect the cable to the ERP IN connector on the transponder subrack and connect it to the 1 dB step attenuator (set to 0 dB). Connect the other end of the 1 dB step attenuator to the ERP IN connector using an additional cable not exceeding 100 mm in length.
3. Move the multimeter (on 20 volts range) to test points XT2 and XT13 (GND) on the monitor main board. Adjust R87, PEAK POWER MONITOR CALIBRATION control to produce a multimeter reading of 2.50 ±0.05 volts.
4. At the rear of the rack, insert a 0.5 dB semirigid cable (plus adaptors as required) between the output of the step attenuator and the short cable to ERP IN.
5. For step attenuator settings of 0 dB, 1 dB and 2 dB, check that the monitor RF POWER indicator is on.
6. For step attenuator settings of 3 dB, 4 dB, 5 dB, 6 dB and 7 dB, check that the monitor RF POWER indicator is off and the SECONDARY indicator is on.
7. Remove the step attenuator and cables and restore the connection to connector ERP IN on the rear of the transponder subrack.
3.3.16.7 Ident Monitor 1. On the CTU, set MONITOR INHIBIT to OFF to allow ident to be transmitted.
2. On the receiver video, switch IDENT to NORMAL. Check that ident code is being transmitted and is audible from the CTU mounted speaker.
3. Immediately after the transmission of an ident code group, start a stopwatch and switch IDENT on the receiver video to OFF. Measure the time taken for the
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monitor IDENT indicator to turn off and the SECONDARY indicator to turn on. This should be 62 ±5 seconds.
4. On the CTU, set MONITOR ALARM to INHIBIT (to prevent transfer or shut down).
5. On the receiver video, switch IDENT to CONTINUOUS. With a stopwatch, measure the time taken for the monitor DELAY and SPACING indicators to both turn off. This should be not more than 3 seconds.
6. On the receiver video, switch IDENT to NORMAL.
7. On the CTU, set MONITOR ALARM to NORMAL.
3.3.16.8 Antenna Monitor 1. Remove the antenna integrity monitor test fixture from connector XN2 on the RF
panel board. Using the multimeter, set the resistance of the test fixture to 1000 ±10 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board. On the monitor, check that the ANTENNA indicator is on.
2. Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture to 1110 ±10 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board. On the monitor, check that the ANTENNA indicator is off and the SECONDARY indicator is on.
3. Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture to 1250 ±10 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board. On the monitor, check that the ANTENNA indicator is off and the SECONDARY indicator is on.
4. Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture to 1450 ±10 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board. On the monitor, check that the ANTENNA indicator is off and the SECONDARY indicator is on.
5. Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture to 150 ±10 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board. On the monitor, check that the ANTENNA indicator is off and the SECONDARY indicator is on.
6. Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture to 1000 ±10 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board.
3.3.16.9 Shape Monitor 1. On the monitor, check that the SHAPE indicator is on. (If it is not, then check that
the transmitter pulse shape is correct and that switches S1, S2, S3 and S4 on the monitor main board are correctly set - see Section 3.3.3.8, step 1.)
2. On the monitor, switch S1:5 to ON to change the Pulse Width Lower Reject Limit from 2.9 microseconds to 1.3 microseconds (and thus the Upper Limit from 4.1 microseconds to 2.5 microseconds). Check that the SHAPE indicator is off and the SECONDARY indicator is on. Switch S1:5 back to OFF (and ensure that the SHAPE indicator is on again).
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3. On the monitor, switch S1:6 to OFF to change the Pulse Width Lower Reject Limit from 2.9 microseconds to 6.1 microseconds. Check that the SHAPE indicator is off. Switch S1:6 back to ON (and ensure that the SHAPE indicator is on again).
4. On the monitor, switch S2:6 to ON to change the pulse Fall Time Upper Reject Limit from 3.6 microseconds to 0.4 microseconds. Check that the SHAPE indicator is off and the SECONDARY indicator is on. Switch S2:6 back to OFF (and ensure that the SHAPE indicator is on again).
5. On the monitor, switch S3:5 to ON to change the pulse Rise Time Upper Reject Limit from 3.1 microseconds to 1.5 microseconds. Check that the SHAPE indicator is off and the SECONDARY indicator is on. Switch S3:5 back to OFF (and ensure that the SHAPE indicator is on again).
6. Restore the monitor back in the transponder subrack.
3.3.16.10 Monitor Self Test 1. With the DME operating in Maintenance mode, ensure that all 8 monitor
parameter indicators are on.
2. On the monitor, check that the SELF TEST indicator flashes on at regular intervals. Using a stopwatch, measure the time period of these indicator flashes. The time period should be 16 ±2 seconds.
3. Check that simultaneously with this indicator flashing on, the DELAY and SPACING indicators are off and the PRIMARY indicator is on.
3.3.16.11 Monitor Fault Limits 1. With the DME operating in Maintenance mode, ensure that all 8 monitor
parameter indicators are on.
2. On the CTU, select the FltLimit parameters listed in the table below. For each parameter, the displayed fault limits should be within the ranges listed in the table.
PARAMETER SPECIFIED VALUE LIMITS UNITS
Delay; Lower 49.5 +0.1 -0.0 µs
Delay; Upper 50.5 +0.1 -0.0 µs
Spacing; Lower 11.5 +0.0 -0.1 µs
Spacing; Upper 12.5 +0.0 -0.1 µs
Effncy; (Lower) 60 ±2 % Tx Rate; Lower 833 ±10 Hz Tx Rate; Upper 3000 ±30 Hz Ant Power; (Lower) -3 0 dB
(For ‘Y’ channel values refer to Section 3.3.22)
If a consistent error exists in the Upper and Lower Delay limits, a correction of +0.1 microseconds or -0.1 microseconds can be added, for each monitor system, by using the 8-bit DIP switch S1 on the CTU processor board as follows.
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SWITCHES FOR MONITOR SYSTEM 1
SWITCHES FOR MONITOR SYSTEM 2 CORRECTION
µs 6 7 3 4
0 ON ON ON ON +0.1 ON OFF ON OFF -0.1 OFF ON OFF ON (0) OFF OFF OFF OFF
3.3.17 24V DC Power Supply/Battery Charger
3.3.17.1 Normal Operation 1. On the monitors, ensure switch MONITOR OUTPUTS is set to NORMAL.
2. On the test interrogators, ensure switch MONITOR AND INTERROGATOR DC POWER is set to NORMAL.
3. On the transponder power supplies, ensure switch TRANSPONDER DC POWER is set to NORMAL.
4. On the transmitter drivers, ensure switch DRIVER DC POWER is set to NORMAL.
5. On the receiver video modules, ensure switch IDENT is set to NORMAL.
6. On the 1kW PA power supplies, ensure switch AMPLIFIER DC POWER is set to NORMAL.
7. For a dual DME, on the RF panel, ensure switch ANTENNA RELAY is set to NORMAL.
8. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not off), RECYCLE (if RECYCLE indicator is not off), SELECT MAIN NO 1.
9. On the CTU, check that the state of each of the CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON
NO 2 ON OFF STATUS
NORMAL ON ALARM REGISTER ALL OFF
MODULES OFF TEST
ANT RELAY OFF AC PWR NORM ON POWER
BATT CHG 1 ON
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BATT CHG 2 ON for Dual OFF for Single
BATT LOW OFF
10. On the monitors, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
3.3.17.2 High Voltage Shutdown Adjust NOTE Power Supply Adjustment for a Dual DME
For a dual DME, switch one AC power supply off in turn while the other AC power supply is being tested and adjusted.
1. Ensure that the DME is operating in the normal state of Section 3.3.17.1. Then press MONITOR ALARM on the CTU to set it to INHIBIT. (This inhibits ident and ensures a steady load to the AC power supply and thus a steady output voltage from the AC power supply.)
2. On the control module of the AC power supply, set the controls:
SHUT DOWN DELAY Fully counter-clockwise H/V SHUT DOWN Fully clockwise
3. With the multimeter connected to the appropriate rack BATTERY terminals, switch and hold the TEST/FLOAT switch of the AC power supply to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module to produce a multimeter reading of 28.5 ±0.1 volts.
4. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust H/V SHUT DOWN control counter-clockwise until the DME shuts down. Check that the H/V SHUT DOWN indicator on the control module is on.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control counter-clockwise to produce a multimeter reading of 27.5 ±0.2 volts. The DME should return to normal operation.
6. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control clockwise until the DME again shuts down. The multimeter reading should be 28.5 ±0.2 volts.
7. Release the TEST/FLOAT switch of the AC power supply and adjust the SHUT DOWN DELAY control on the control module of the AC power supply to mid-position.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control counter-clockwise to produce a multimeter reading of 29.0 ±0.2 volts. Release the TEST/FLOAT switch to enable the DME to power up again.
9. Using a stopwatch, measure the time period from pressing the TEST/FLOAT switch to the DME shutting down. This time delay should be 3 ±1 seconds; if necessary, readjust SHUT DOWN DELAY control to achieve this delay.
10. Press MONITOR ALARM on the CTU to set it to NORMAL. (On a dual DME, switch the other AC power supply on.) Confirm that the DME is powered up and operating in the normal state of Section 3.3.17.1.
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3.3.17.3 Low Battery Alarm Adjust NOTE Power Supply Adjustment for a Dual DME
For a dual DME, switch one AC power supply off in turn while the other AC power supply is being tested and adjusted.
1. Ensure that the DME is operating in the normal state of Section 3.3.17.1. Then press MONITOR ALARM on the CTU to set it to INHIBIT. (This inhibits ident and ensures a steady load to the AC power supply and thus a steady output voltage from the AC power supply.)
2. On the control module of the AC power supply, set LOW VOLT ALARM control fully counter-clockwise.
3. With the multimeter connected to the rack BATTERY terminals, switch and hold the TEST/FLOAT switch to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 23.5 ±0.1 volts.
4. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust LOW VOLT ALARM control clockwise until the O/P FAIL indicator on the control module turns on. The DME should remain in operation.
5. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 24.5 ±0.2 volts (to turn the O/P FALL indicator on the control module off).
6. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control counter-clockwise again until the O/P FAIL indicator again turns on. The multimeter reading should be 23.5 ±0.2 volts.
7. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 23.0 ±0.1 volts.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, check that the BATT CHG indicator on the CTU corresponding to the AC power supply being tested is off.
9. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, on the external I/O board, check that the BATT CH NORM output to the RCMS interface board for the AC power supply under test is off. (For BATT CH NORM 1, the normally open contacts (terminals 2 and 4 of terminal block XB4) are open circuit, and the normally closed contacts (terminals 6 and 4 of terminal block XB4) are short circuit. For BATT CH NORM 2, the normally open contacts (terminals 1 and 3 of terminal block XB4) are open circuit, and the normally closed contacts (terminals 5 and 3 of terminal block XB4) are short circuit.)
10. On the AC power supply, release the TEST/FLOAT switch. (On a dual DME, switch the other AC power supply on.) Press MONITOR ALARM on the CTU to set it to NORMAL. Confirm that the DME is powered up and operating in the normal state of Section 3.3.17.1.
3.3.17.4 Low Voltage Shutdown Adjust 1. Ensure that the DME is operating in the normal state of Section 3.3.17.1. Then
press MONITOR ALARM on the CTU to set it to INHIBIT. (This inhibits ident and ensures a steady load to the AC power supply and thus a steady output voltage from the AC power supply.)
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2. On the power distribution panel, switch circuit breaker CTU (CTU & TRANSPONDER on a single DME) to OFF. Extend the CTU using two Eurocard extenders. Switch circuit breaker CTU on.
3. On the CTU processor board, adjust the low volts preset R32 fully counter-clockwise.
4. On a dual DME, switch AC power supply 2 off.
5. With the multimeter connected to the rack BATTERY terminals, switch and hold the TEST/FLOAT switch on AC power supply to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of this AC power supply to produce a multimeter reading of 22.0 ±0.1 volts.
6. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, on the CTU processor board, adjust R32 clockwise until the DME shuts down and the BATT LOW indicator on the CTU turns on. Then slowly adjust R32 counter-clockwise until the BATT LOW indicator on the CTU turns off. Slowly adjust R32 clockwise again until the BATT LOW indicator on the CTU again turns on.
7. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, adjust FLOAT 1 VOLTAGE control clockwise to produce a multimeter reading of 27.0 ±0.2 volts. The DME should power up.
8. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, slowly adjust FLOAT 1 VOLTAGE control counter-clockwise again until the DME again shuts down. The multimeter reading should be 22.0 ±0.2 volts.
9. On the AC power supply, release the TEST/FLOAT switch. Press MONITOR ALARM on the CTU to set it to NORMAL.
10. On a dual DME, switch AC power supply 2 on.
11. On the power distribution panel, switch circuit breaker CTU off. Restore the CTU to the CTU subrack. Switch circuit breaker CTU on. Confirm that the DME is powered up and operating in the normal state of Section 3.3.17.1.
3.3.17.5 Low Voltage Performance 1. With the multimeter connected to the rack BATTERY terminals, switch and hold
the TEST/FLOAT switch of the AC power supply to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 22.5 ±0.1 volts. Check that the BTY CHG 1 indicator on the CTU is off.
2. While keeping the TEST/FLOAT switch of the AC power supply held to TEST, measure the following parameters from the monitor systems using the CTU parameter measurement facility. The measured parameters should be within the following limits:
PARAMETER NOMINAL VALUE LIMITS UNITS
DELAY 50.0 ±0.1 µs SPACING 12.0 ±0.1 µs EFFNCY 95 > 90 % TX RATE 945 ±10 Hz
RF POWER 1200 ±100 W
(For ‘Y’ channel values refer to Section 3.3.22)
3. Release the TEST/FLOAT switch on the AC power supply.
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3.3.17.6 DC Supply Adjustment NOTE For a dual DME, switch one AC power supply off in turn while the other AC
power supply is being tested and adjusted.
1. Connect the multimeter (on 200 volts range) to the 24 volts BATTERY terminals at the rear of the rack.
2. With the DME operating in the normal state of Section 3.3.17.1, measure the primary DC supply voltage. It should be 27 ±0.1 volts; if it is outside this limit, it may be adjusted by the FLOAT 2 VOLTAGE control on the control module of the AC power supply.
NOTEs Duplication of Tests
From this point on, the tests are only to be performed once on the equipment under test.
Affect of Monitor Self Test on Alarm Delay Measurements When an action is taken on the DME to initiate a shutdown or a transfer, and the time delay from the action to the response is to be measured, it is recommended that the action take place within a period 3 to 7 seconds after the completion of monitor self test. This will ensure that the measured time period is not affected by the presence of a monitor self test.
RCMS Interface The test procedures below require checking the state of the RCMS Interface parameters. If the intended application of the DME does not use the RCMS Interface, these references in the test procedures can be ignored. If the RCMS Interface is to be included in the tests to be performed on the DME rack, the RCMS Interface can be checked in a number of ways. The RCMS Interface is located on the external I/O board at the rear of the rack. Connections are via terminal blocks. Each output parameter has three terminals on a terminal block: C (common), NO (normally open) and NC (normally closed).
a. When the parameter is off, the NO contact is open circuit and the NC contact is connected to the C contact.
b. When the parameter is on, the NC contact is open circuit and the NO contact is connected to the C contact.
A protected 24 volts supply is provided on XB1:1, and a ground is provided on XB11:6. If desired, a test fixture could be built, using indicators to monitor the state of the output parameters. If this test fixture cannot be justified, a LED Indicator can be used to check the state of the output parameters as shown below.
A lighted LED when connected to the NO contact indicates the output parameter is on.
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A lighted LED when connected to the NC contact indicates the output parameter is off.
3.3.18 Control System - Single DME NOTE The tests in this section are only to be performed on a single DME. The tests
for a dual DME are in Section 3.3.19.
3.3.18.1 Normal Operation 1. On the monitor, ensure switch MONITOR OUTPUTS is set to NORMAL.
2. On the test interrogator, ensure switch MONITOR AND INTERROGATOR DC POWER is set to NORMAL.
3. On the transponder power supply, ensure switch TRANSPONDER DC POWER is set to NORMAL.
4. On the transmitter driver, ensure switch DRIVER DC POWER is set to NORMAL.
5. On the receiver video, ensure switch IDENT is set to NORMAL.
6. On the 1kW PA power supply, ensure switch AMPLIFIER DC POWER is set to NORMAL.
7. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not off), RECYCLE (if RECYCLE indicator is not off), SELECT MAIN NO 1.
8. On the CTU, check that the state of each of the CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF NORMAL ON
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE OFF ALARM REGISTER ALL OFF
MODULES OFF TEST
ANT RELAY OFF AC POWER NORM ON
BATT CHG1 ON BATT CHG 2 OFF
POWER
BATT LOW OFF
9. On the monitor, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about
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every 16 seconds when some of these indicators will flash during monitor self test).
10. On the RCMS interface board, check that the state of each of the output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
BATT CH NORM 1 ON BATT CH NORM 2 OFF AC PWR NORM ON
MAINS OK ON NO 1 ON ON NO 2 ON OFF
SHUTDOWN OFF NON ALM OFF LOC CTRL ON
MAINT OFF PRI ALM OFF SEC ALM OFF NORMAL ON
TRANSFER OFF
NOTE Checking for Normal Operation
When setting up the DME for normal operation, it may be necessary to wait up to 10 seconds (90 seconds for ident) for normal operation to commence from the last action which initiated the normal operation.
3.3.18.2 Primary Fault This test involves generating a primary fault, and then monitoring the sequence of events following this action.
1. Ensure that the DME is operating in the normal state of Section 3.3.18.1 steps 8 to 10.
2. On the receiver video, read and record the position of the REPLY PULSE SPACING (REPLY PULSE SEPARATION on earlier modules) switch (to enable this switch to be restored to its original position at the completion of this test).
3. Using a stopwatch, measure the time period from the PRIMARY ALARM REGISTER indicator on the CTU turning on to the NO 1 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on the receiver video through 4 to five positions. This alarm delay time should be 10 ±1 seconds.
4. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF STATUS NORMAL ON
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SPACING ON ALARM REGISTER
PRIMARY ON
5. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF SHUTDOWN ON
PRI ALM ON NORMAL OFF
6. On the receiver video, restore switch REPLY PULSE SPACING to its original position recorded at Section 3.3.18.2 step 2.
7. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
8. Confirm that the DME is operating in the normal state of Section 3.3.18.1 steps 8 to 10 (including the status of the output parameters on the RCMS interface board).
3.3.18.3 Secondary Fault This test involves generating a secondary fault, and then monitoring the status following this action.
1. Ensure that the DME is operating in the normal state of Section3.3.18.1 steps 8 to 10.
2. Disconnect the input to the ERP IN connector at the rear of the transponder subrack.
3. On the monitor, check that the RF POWER indicator is off.
4. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
STATUS NORMAL OFF ALARM REGISTER SECONDARY ON
5. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON ON SEC ALM ON NORMAL OFF
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6. Restore normal operation by reconnecting the coaxial cable from the 10 dB attenuator on connector FWD-A of the directional coupler to connector ERP IN on the rear of the transponder subrack.
7. Confirm that the DME is operating in the normal state of Section 3.3.18.1 steps 8 to 10 (including the status of the output parameters on the RCMS interface board).
3.3.18.4 Recycle Function This test involves causing a shutdown by generating a primary fault, and then monitoring the sequence of restart events following this action.
1. Ensure that the DME is operating in the normal state of Section 3.3.18.1 steps 8 to 10.
2. On the CTU, reset the restart count to 0 using the Misc menu. Press RECYCLE key to turn the RECYCLE indicator on.
3. Cause the DME to shutdown by switching MONITOR OUTPUTS on the monitor to FAILED and check that the rack shuts down after the selected 10 ±1 seconds.
4. Measure the time period from this shutdown to the following restart. This should be 30 ±3 seconds.
5. Leaving the MONITOR OUTPUTS switch in the FAILED position, count the total number of restart attempts (including the first one in the step above). This number should be 3.
6. Check that the rack then remains shutdown.
7. On the CTU, select the Misc menu and check that the displayed number of restart attempts is 3.
8. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NORMAL OFF STATUS
SHUTDOWN ON DELAY ON
SPACING ON EFFICIENCY ON
TX RATE ON RF POWER ON
IDENT OFF PULSE SHAPE ON
ANTENNA ON PRIMARY ON
SECONDARY ON MONITOR OFF
ALARM REGISTER
CTU OFF
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9. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF SHUTDOWN ON
MON ALM OFF PRI ALM ON SEC ALM ON NORMAL OFF
10. On the monitor, switch MONITOR OUTPUTS to NORMAL.
11. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
12. Confirm that the DME is operating in the normal state of Section 3.3.18.1 steps 8 to 10 (including the status of the output parameters on the RCMS interface board).
13. On the CTU, press RECYCLE key to turn the RECYCLE indicator off.
3.3.18.5 RCMS Remote Control 1. To provide remote inputs on the RCMS interface board, on the external I/O board
at the rear of the rack, connect the NO (normally open) contacts of 3 pushbutton switches (through suitable leads) respectively between terminal 1 of terminal block XB1 (+24V) and:
Terminal 2 of terminal block XB10 for REMOTE OFF,
Terminal 4 of terminal block XB10 for REMOTE NO 1 ON,
Terminal 6 of terminal block XB10 for REMOTE NO 2 ON.
With suitable leads, connect together terminals 1, 3 and 5 of terminal block XB10 and terminal 6 of terminal block XB11 on the external I/O board for GND common connection.
2. On the CTU, press the SELECT MAIN, OFF/RESET key and the MAINTENANCE key (to turn their associated indicators on).
3. On the RCMS interface board, check that the LOC CTRL and MAINT output parameters are both in the on state.
4. On the CTU, press the MAINTENANCE key (to turn its associated indicator off) and the REMOTE key (to turn its associated indicator on).
5. On the RCMS interface board, check that the LOC CTRL output parameter is in the off state.
6. On the RCMS interface board, momentarily press switch NO 1 ON. Confirm that the DME is powered up and operating in the normal state of Section 3.3.18.1 steps 8 to 10 (including the status of the output parameters on the RCMS interface board - except LOC CTRL, which should be off).
7. On the RCMS interface board, momentarily press switch REMOTE OFF. Confirm that the DME switches off.
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8. On the CTU, press the LOCAL key (to turn its associated indicator on and turn the REMOTE indicator off).
3.3.19 Control System - Dual DME NOTE The tests in this section are only to be performed on a dual DME. The tests for
a single DME are in Section 3.3.18.
3.3.19.1 Normal Operation - No. 1 is MAIN 1. On both monitors, ensure switch MONITOR OUTPUTS is set to NORMAL.
2. On both test interrogators, ensure switch MONITOR AND INTERROGATOR DC POWER is set to NORMAL.
3. On both transponder power supplies, ensure switch TRANSPONDER DC POWER is set to NORMAL.
4. On both transmitter drivers, ensure switch DRIVER DC POWER is set to NORMAL.
5. On both receiver videos, ensure switch IDENT is set to NORMAL.
6. On both 1kW PA power supplies, ensure switch AMPLIFIER DC POWER is set to NORMAL.
7. On the RF panel, ensure the ANTENNA RELAY switch is set to NORMAL.
8. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not off), RECYCLE (if RECYCLE indicator is not off), SELECT MAIN NO 1.
9. On the CTU, check that the state of each of the CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF NORMAL ON
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE OFF ALARM REGISTER ALL OFF
MODULES OFF TEST
ANT RELAY OFF AC POWER NORM ON
BATT CHG 1 ON BATT CHG 2 ON
POWER
BATT LOW OFF
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10. On both monitors, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
11. On the RCMS interface board, check that the state of each of the indicated output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
BATT CH NORM 1 ON BATT CH NORM 2 ON AC PWR NORM ON
MAINS OK ON NO 1 ON ON NO 2 ON OFF
SHUTDOWN OFF MON ALM OFF LOC CTRL ON
MAINT OFF PRI ALM OFF SEC ALM OFF NORMAL ON
TRANSFER OFF
NOTE Checking for Normal Operation
When setting up the DME for normal operation, it may be necessary to wait up to 10 seconds (90 seconds for ident) for normal operation to commence from the last action which initiated the normal operation.
3.3.19.2 Primary Fault - No. 1 is MAIN This test involves generating primary faults, and then monitoring the sequence of events following this action.
1. Ensure that the DME is operating in the No. 1 normal state of Section 3.3.19.1 steps 9 to 11.
2. On both receiver videos, read the position of the REPLY PULSE SPACING (REPLY PULSE SEPARATION on earlier modules) switch (to enable these switches to be restored to their original positions at the completion of these tests).
3. Using a stopwatch, measure the time period from the PRIMARY ALARM REGISTER indicator on the CTU turning on to the NO 1 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No. 1 receiver video through four to five positions. This alarm delay time should be 10 ±1 seconds.
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4. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON ON NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF SPACING ON
ALARM REGISTER PRIMARY ON
5. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON ON
SHUTDOWN OFF PRI ALM ON NORMAL OFF
TRANSFER ON
6. Using a stopwatch, measure the time period from the PRIMARY alarm indicator on either monitor turning on to the NO 2 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No.2 receiver video through four to five positions. This alarm delay time should be 10 ±1 seconds.
7. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF
NO 2 ON OFF
NORMAL OFF TRANSFER OFF
STATUS
SHUTDOWN ON SPACING ON
ALARM REGISTER PRIMARY ON
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8. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF
SHUTDOWN ON PRI ALM ON NORMAL OFF
TRANSFER OFF
9. On both receiver videos, restore the REPLY PULSE SPACING switches to their original positions recorded at Section 3.3.19.2 step 2.
10. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
11. Confirm that the DME is operating in the No. 1 normal state of Section 3.3.19.1 steps 9 to 11 (including the status of the output parameters on the RCMS interface board).
3.3.19.3 Secondary Fault - No. 1 is MAIN This test involves generating secondary faults, and then monitoring the status following this action. (Ensure that the cable connectors to ERP IN at the rear of the two transponders are able to be distinguished so that they are returned to their correct connections at the completion of this test.)
1. Ensure that the DME is operating in the No. 1 normal state of Section 3.3.19.1 steps 9 to 11.
2. Disconnect the input to the ERP IN connector at the rear of No. 1 transponder subrack. On No. 1 monitor, check that the RF POWER indicator is off.
3. Wait at least 20 seconds. On the CTU, check that the state of the listed CTU Indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF NORMAL ON
TRANSFER OFF STATUS
SHUTDOWN OFF RF POWER OFF
SECONDARY OFF ALARM REGISTER PRIMARY OFF
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4. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON ON NO 2 ON OFF
SHUTDOWN OFF SEC ALM OFF NORMAL ON
TRANSFER OFF
5. Using a stopwatch, measure the time period from the SECONDARY alarm indicator on the No. 2 monitor turning on to the NO 1 ON STATUS indicator on the CTU turning off. In response to disconnecting the input to the ERP IN connector at the rear of No. 2 transponder subrack. This alarm delay time should be 10 ±1 seconds.
6. On No. 2 monitor, check that the RF POWER indicator is off.
7. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON ON NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF RF POWER ON
ALARM REGISTER SECONDARY ON
8. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON ON
SHUTDOWN OFF SEC ALM ON NORMAL OFF
TRANSFER ON
9. Restore normal operation by reconnecting the coaxial cables from the power splitter to connectors ERP IN on the rear of the transponder subracks (ensuring the original connections are restored) and on the CTU, pressing the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
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10. Confirm that the DME is operating in the No. 1 normal state of Section 3.3.19.1 steps 9 to 11 (including the status of the output parameters on the RCMS interface board).
3.3.19.4 Normal Operation - No. 2 is MAIN 1. On both monitors, ensure switch MONITOR OUTPUTS is set to NORMAL.
2. On both test interrogators, ensure switch MONITOR AND INTERROGATOR DC POWER is set to NORMAL.
3. On both transponder power supplies, ensure switch TRANSPONDER DC POWER is set to NORMAL.
4. On both transmitter drivers, ensure switch DRIVER DC POWER is set to NORMAL.
5. On both receiver videos, ensure switch IDENT is set to NORMAL.
6. On both 1kW PA power supplies, ensure switch AMPLIFIER DC POWER is set to NORMAL.
7. On the RF panel, ensure switch ANTENNA RELAY is set to NORMAL.
8. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not off), RECYCLE (if RECYCLE indicator is not off), SELECT MAIN NO 2.
9. On the CTU, cheek that the state of each of the CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON ON NORMAL ON
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE OFF ALARM REGISTER ALL OFF
MODULES OFF TEST
ANT RELAY OFF AC POWER NORM ON
BATT CHG 1 ON BATT CHG 2 ON
POWER
BATT LOW OFF
10. On both monitors, ensure that the eight parameter indicators are on and the PRIMARY and SECONDARY indicators are off (except for short periods about every 16 seconds when some of these indicators will flash during monitor self test).
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11. On the RCMS interface board, check that the state of each of the indicated output - parameters is as shown below.
INDICATOR NAME REQUIRED STATE
BATT CH NORM 1 ON BATT CH NORM 2 ON
AC PWR NORM ON MAINS OK ON NO 1 ON OFF NO 2 ON ON
SHUTDOWN OFF MON ALM OFF LOC CTRL ON
MAINT OFF PRI ALM OFF SEC ALM OFF NORMAL ON
TRANSFER OFF
3.3.19.5 Primary Fault - No. 2 is MAIN This test involves generating primary faults, and then monitoring the sequence of events following this action.
1. Ensure that the DME is operating in the No.2 normal state of Section 3.3.19.4 steps 9 to 11.
2. Using a stopwatch, measure the time period from the PRIMARY ALARM REGISTER indicator on the CTU turning on to the NO 2 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No.2 receiver video through four to five positions. This alarm delay time should be 10 ±1 seconds.
3. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF SPACING ON
ALARM REGISTER PRIMARY ON
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4. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON ON NO 2 ON OFF
SHUTDOWN OFF PRI ALM ON NORMAL OFF
TRANSFER ON
5. Using a stopwatch, measure the time period from the PRIMARY alarm indicator on either monitor turning on to the NO 1 ON STATUS indicator on the CTU turning off - in response to turning rotary switch REPLY PULSE SPACING on No.1 receiver video through four to five positions. This alarm delay time should be 10 ±1 seconds.
6. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER OFF STATUS
SHUTDOWN ON SPACING ON
ALARM REGISTER PRIMARY ON
7. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF
SHUTDOWN ON PRI ALM ON NORMAL OFF
TRANSFER OFF
8. On both the receiver videos, restore switches REPLY PULSE SPACING to their original positions recorded at Section 3.3.19.2 step 2.
9. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 2.
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10. Confirm that the DME is operating in the No.2 normal state of Section 3.3.19.4 steps 9 to 11 (including the status of the output parameters on the RCMS interface board).
3.3.19.6 Secondary Fault - No. 2 is MAIN This test involves generating secondary faults, and then monitoring the status following this action.
1. Ensure that the DME is operating in the No.2 normal state of Section 3.3.19.4 steps 9 to 11.
2. Disconnect the input to the ERP IN connector at the rear of No.2 transponder subrack. On No.2 monitor, check that the RF POWER indicator is off.
3. Wait at least 20 seconds. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON ON NORMAL ON
TRANSFER OFF STATUS
SHUTDOWN OFF RF POWER OFF
SECONDARY OFF ALARM REGISTER PRIMARY OFF
4. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON ON
SHUTDOWN OFF SEC ALM OFF NORMAL ON
TRANSFER OFF
5. Using a stopwatch, measure the time period from the SECONDARY alarm indicator on the No.1 monitor turning on to the NO 2 ON STATUS indicator on the CTU turning off - in response to disconnecting the input to the ERP IN connector at the rear of No. 1 transponder subrack. This alarm delay time should be 10 ±1 seconds.
6. On No.1 monitor, check that the RF POWER indicator is off.
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7. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF NORMAL OFF
TRANSFER ON STATUS
SHUTDOWN OFF RF POWER ON
ALARM REGISTER SECONDARY ON
8. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON ON NO 2 ON OFF
SHUTDOWN OFF SEC ALM ON NORMAL OFF
TRANSFER ON
9. Restore normal operation by reconnecting the coaxial cables from the power splitter to connectors ERP IN on the rear of the transponder subracks (ensuring the original connections are restored) and on the CTU, pressing the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 2.
10. Confirm that the DME is operating in the No.2 normal state of Section 3.3.19.4 steps 9 to 11 (including the status of the output parameters on the RCMS interface board).
3.3.19.7 Operation in Maintenance Mode - No. 1 is MAIN 1. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, MAINTENANCE to select Maintenance mode on, SELECT MAIN NO 1.
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2. Check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON ON NO 2 ON OFF NORMAL OFF
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE ON ALARM REGISTER ALL OFF
TEST MODULES OFF
3. On the RCMS interface board, check that the state of the indicated output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON ON NO 2 ON OFF
SHUTDOWN OFF MAINT ON
PRI ALM OFF SEC ALM OFF NORMAL OFF
TRANSFER OFF
4. On No.2 monitor, switch MONITOR OUTPUTS to FAILED. Wait at least 20 seconds and check that the operating state of the DME has not changed from that of steps 2 and 3 except MODULES TEST indicator on the CTU is on.
5. On No.2 monitor, switch MONITOR OUTPUTS to NORMAL. Check that MODULES TEST indicator on the CTU is off.
NOTE Allowing for Ident Power Up Alarm Delay
Ensure that step 6 is not commenced before at least 90 seconds have elapsed from completion of step 1. (This ensures that the 90 second ident alarm delay has timed out and no faults on the monitors are rejected.)
6. On No. 1 monitor, switch MONITOR OUTPUTS to FAILED and check that No. 1 transponder shuts down after the selected 10 ±1 seconds.
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7. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER ON SHUTDOWN ON
STATUS
MAINTENANCE ON DELAY ON
SPACING ON EFFICIENCY ON
TX RATE ON RF POWER ON
IDENT ON PULSE SHAPE ON
ANTENNA ON PRIMARY ON
ALARM REGISTER
SECONDARY ON TEST MODULES ON
8. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF
SHUTDOWN ON MON ALM OFF
MAINT ON PRI ALM ON SEC ALM ON NORMAL ON
9. On No.1 monitor, switch MONITOR OUTPUTS to NORMAL.
3.3.19.8 Operation in Maintenance Mode - No. 2 is MAIN 1. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 2.
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2. Check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON ON NORMAL OFF
TRANSFER OFF SHUTDOWN OFF
STATUS
MAINTENANCE ON ALARM REGISTER ALL OFF
TEST MODULES OFF
3. On the RCMS interface board, check that the state of the indicated output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON ON
SHUTDOWN OFF MAINT ON
PRI ALM OFF SEC ALM OFF NORMAL OFF
TRANSFER OFF
4. On No. 1 monitor, switch MONITOR OUTPUTS to FAILED. Wait at least 20 seconds and check that the operating state of the DME has not changed from that of steps 2 and 3 except MODULES TEST indicator on the CTU is on.
5. On No.1 monitor, switch MONITOR OUTPUTS to NORMAL. Check that MODULES TEST indicator on the CTU is off.
NOTE Allowing for Ident Power Up Alarm Delay
Ensure that step6 is not commenced before at least 90 seconds have elapsed from completion of step 1. (This ensures that the 90 second ident alarm delay has timed out and no faults on the monitors are rejected.)
6. On No.2 monitor, switch MONITOR OUTPUTS to FAILED and check that No.2 transponder shuts down after the selected 10 ±1 seconds.
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7. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER OFF SHUTDOWN ON
STATUS
MAINTENANCE ON ALARM REGISTER DELAY ON
SPACING ON EFFICIENCY ON TX RATE ON RF POWER ON IDENT ON PULSE SHAPE ON ANTENNA ON PRIMARY ON SECONDARY ON
TEST MODULES ON
8. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF
SHUTDOWN ON MON ALM OFF
MAINT ON PRI ALM ON SEC ALM ON NORMAL OFF
9. On No.2 monitor, switch MONITOR OUTPUTS to NORMAL.
10. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, MAINTENANCE to select Maintenance mode off, SELECT MAIN NO 1.
3.3.19.9 Recycle Function - No. 1 is MAIN This test involves causing a transfer and a shutdown by generating a primary fault, and then monitoring the sequence of restart events following this action.
1. On the power distribution panel, switch circuit breaker CTU off.
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2. Extract the CTU and, on the CTU processor board, set switches 1 and 2 of S2 both to OFF to change the main and standby voting both to OR. Reinstall the CTU in the CTU subrack.
3. On the power distribution panel, switch circuit breaker CTU on.
4. Ensure that the DME is operating in the No. 1 normal state of Section 3.3.19.1 steps 9 to 11.
5. On the CTU, reset the restart count to 0 using the Misc menu. Press RECYCLE key to turn the RECYCLE indicator on.
6. On No.2 receiver video, turn rotary switch REPLY PULSE SPACING through five positions (so that when a transfer occurs to No.2 transponder, a primary fault will be immediately present).
7. On No.1 receiver video, turn rotary switch REPLY PULSE SPACING through five positions and check that a transfer to No.2 transponder occurs after the selected 10 ±1 seconds and that the rack then shuts down after an additional 11 ±2 seconds.
8. Measure the time period from this shutdown to the following restart. This should be 30 ±3 seconds.
9. Leaving the REPLY PULSE SPACING switches set as above, count the total number of restart attempts (including the first one in the step above). This number should be 3.
10. Check that the rack then remains shut down.
11. On the CTU, select the Misc menu and check that the displayed number of restart attempts is 3.
12. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO2 ON OFF NORMAL OFF
TRANSFER OFF STATUS
SHUTDOWN ON SPACING ON
ALARM REGISTER PRIMARY ON
13. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF
SHUTDOWN ON MON ALM OFF PRI ALM ON NORMAL OFF
TRANSFER OFF
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14. On both receiver videos, restore switches REPLY PULSE SPACING to their original positions recorded at Section 3.3.19.2 step 2.
15. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 2.
16. Confirm that the DME is operating in the No.2 normal state of Section 3.3.19.4 steps 9 to 11 (including the status of the output parameters on the RCMS interface board).
3.3.19.10 Recycle Function - No. 2 is MAIN 1. Ensure that the DME is operating in the No.2 normal state of Section 3.3.19.4
steps 9 to 11.
2. On the CTU, reset the restart count to 0 using the Misc menu. Press RECYCLE key to turn the RECYCLE indicator on.
3. On No.1 receiver video, turn rotary switch REPLY PULSE SPACING through five positions (so that when a transfer occurs to No.1 transponder, a primary fault will be immediately present).
4. On No.2 receiver video, turn rotary switch REPLY PULSE SPACING through five positions and check that a transfer to No.1 transponder occurs after the selected 10 ±1 seconds and that the rack then shuts down after an additional 11 ±2 seconds.
5. Measure the time period from this shutdown to the following restart. This should be 30 ±3 seconds.
6. Leaving the REPLY PULSE SPACING switches set as above, count the total number of restart attempts (including the first one in the step above). This number should be 3.
7. Check that the rack then remains shut down.
8. On the CTU, select the Misc menu and check that the displayed number of restart attempts is 3.
9. On the CTU, check that the state of the listed CTU indicators is as shown below.
INDICATOR REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF NORMAL OFF
TRANSFER OFF STATUS
SHUTDOWN ON SPACING ON
ALARM REGISTER PRIMARY ON
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10. On the RCMS interface board, check that the state of the listed output parameters is as shown below.
INDICATOR NAME REQUIRED STATE
NO 1 ON OFF NO 2 ON OFF
SHUTDOWN ON MON ALM OFF PRI ALM ON NORMAL OFF
TRANSFER OFF
11. On both receiver videos, restore switches REPLY PULSE SPACING to their original positions recorded at Section 3.3.19.2 step 2.
12. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
13. Confirm that the DME is operating in the No.1 normal state of Section 3.3.19.1 steps 9 to 11 (including the status of the output parameters on the RCMS interface board).
14. On the CTU, press RECYCLE key to turn the RECYCLE indicator off.
3.3.19.11 Hot/Cold Standby 1. On the power distribution panel, switch circuit breaker CTU off. Extend the CTU
using two Eurocard extenders. Switch circuit breaker CTU on.
2. Operate the DME in the No. 1 normal state of Section 3.3.19.1 steps 9 to 11.
3. For No.2 transponder, on the front panel of each of transponder power supply, transmitter driver, receiver video and 1kW PA power supply, check that the DC POWER ON indicator is off.
4. On the power distribution panel, switch circuit breaker CTU off.
5. On the CTU processor board, set switch S2:4 to OFF to change from COLD standby to WARM standby operation.
6. On the power distribution panel, switch circuit breaker CTU on.
7. For No.2 transponder, on the front panel of each of transponder power supply, transmitter driver, receiver video and 1kW PA power supply, check that the DC POWER ON indicator is on.
8. On the power distribution panel, switch circuit breaker CTU off.
9. On the CTU processor board, set switch S2:4 to ON to change from WARM standby back to COLD standby operation
10. On the power distribution panel, switch circuit breaker CTU on.
3.3.19.12 RCMS Remote Control 1. To provide remote inputs on the RCMS interface board, on the external I/O board
at the rear of the rack, connect the NO (normally open) contacts of three
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pushbutton switches (through suitable leads) respectively between terminal 1 of terminal block XB1 (+24V) and:
Terminal 2 of terminal block XB10 for REMOTE OFF,
Terminal 4 of terminal block XB10 for REMOTE NO 1 ON,
Terminal 6 of terminal block XB10 for REMOTE NO 2 ON.
With suitable leads, connect together terminals 1, 3 and 5 of terminal block XB10 and terminal 6 of terminal block XB11 on the external I/O board for GND common connection.
2. On the CTU, press the SELECT MAIN, OFF/RESET key.
3. On the RCMS interface board, check that the LOC CTRL output parameter is in the on state.
4. On the CTU, press the REMOTE key (to turn its associated indicator on).
5. On the RCMS interface board, check that the LOC CTRL output parameter is in the off state.
6. On the RCMS interface board, momentarily press switch NO 1 ON. Confirm that the DME is powered up and operating in the No. 1 normal state of Section 3.3.19.1 steps 9 to 11 (including the status of the output parameters on the RCMS interface board - except that BATT CHG 2 on the CTU and BATT CH NORM 2 and LOC CTRL on the RCMS interface board are off).
7. On the RCMS interface board, momentarily press switch REMOTE OFF. Confirm that the DME switches off.
8. On the RCMS interface board, momentarily press switch NO 2 ON. Confirm that the DME is powered up and operating in the No.2 normal state of Section 3.3.19.4 steps 9 to 11 (including the status of the output parameters on the RCMS interface board - except that BATT CHG 2 on the CTU and BATT CH NORM 2 and LOC CTRL on the RCMS interface board are off).
9. On the RCMS interface board, momentarily press switch REMOTE OFF. Confirm that the DME switches off.
10. On the CTU, press the LOCAL key (to turn its associated indicator on and turn the REMOTE indicator off).
3.3.20 Rack Current Drain 1. Operate the DME in its normal state (see Section 3.3.18.1 for a single DME, or
Section 3.3.19.1 for a dual DME).
2. Measure the rack current drain from the AC power supply. It should be 6 amperes for a single DME and not more than 7 amperes for a dual DME.
3. On the CTU, press the following front panel keys in the specified sequence:
SELECT MAIN, OFF/RESET, MAINTENANCE key (to turn its associated indicator on), SELECT MAIN NO 1 MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
4. On the CTU, select Ch.1 monitoring. While holding TI RATE, 10 kHz pressed (to produce maximum reply rate), measure the rack current drain from the AC power supply. It should be not more than 12 amperes for a single DME and not more than 13 amperes for a dual DME.
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5. On the CTU, press the MAINTENANCE key (to turn its associated indicator off). Confirm that the DME is operating in the normal state of step 1.
3.3.21 Tidy Up 1. Operate the DME in its normal state (see Section 3.3.18.1 for a single DME, or
Section 3.3.19.1 for a dual DME).
2. Using the CTU parameter measurement facility, measure the following parameters and ensure that they are within the specified limits. For a dual DME, ensure measurements from both monitoring systems are within the limits, firstly with the system operating with No. 1 as main (as in Section 3.3.19.1), then with No.2 as main (as in Section 3.3.19.4).
PARAMETER NOMINAL VALUE
LIMITS UNITS
DELAY 50.0 +0.2 µs SPACING 12.0 +0.1 µs EFFNCY 95 >80 % TX RATE 945 +10 Hz
RF POWER 1200 +100 W
(For ‘Y’ channel values refer to Section 3.3.22)
3. On the CTU press SELECT MAIN, OFF/RESET to turn the DME off.
4. Remove all test connections and fixtures except:
a. 10 dB attenuators connected to connectors TI-1 REPLY DET (and TI-2 REPLY DET for a dual DME) on the RF panel.
b. On a single DME, coaxial cable connected from 10 dB attenuator on TI-1 REPLY DET to connector FWD-B on the directional coupler.
c. On a dual DME, coaxial cables connected from 10 dB attenuators on TI-1 REPLY DET and TI-2 REPLY DET to connectors FWD-D and FWD-B respectively on No.2 directional coupler.
d. 50 ohms termination(s) connected to connectors REV-A on the directional coupler(s).
e. 10 dB attenuator connected to connector FWD-A on the directional coupler (No.2 directional coupler on the dual DME).
f. On a single DME, coaxial cable from connector FWD-C on the directional coupler to TI-1 TEST INTRGS.
g. On a dual DME, coaxial cable from connectors FWD-C and FWD-E on No.2 directional coupler to TI-2 TEST INTRGS and TI-1 TEST INTRGS respectively.
5. On the power distribution panel, switch all circuit breakers off.
3.3.22 Y-channel Operation The following changes are applicable when a DME is to be used on a Y-channel. Compared with the more common X-channel settings, a Y-channel has a different reply delay setting, and a different pulse spacing for interrogate and reply pulse pairs. The numbers below refer to the relevant paragraphs in this section of the handbook:
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3.3.3 Module Presets 3.3.3.4 Receiver Video Presets
Set switches S4, ENCODER MODE, and S5, DECODER MODE, to the ‘Y’ position. Set the front panel rotary switches as follows:
SWITCH FUNCTION SETTING S1 Beacon Delay, Coarse 3 S2 Beacon Delay, Fine 0 S3 Reply Pulse Spacing 8
3.3.3.7 Test Interrogator Presets Set switch S4, MODE, to the ‘Y’ position. Set the front panel rotary switches as follows:
SWITCH FUNCTION SETTING S5 Reply Gate Delay, Coarse 3 S6 Reply Gate Delay, Fine 5
3.3.3.8 Monitor Module Presets Set preset switch S12, DELAY LOWER LIMIT SET, for 55.5 microseconds, and switch S13, SPACING LOWER LIMIT SET, for 29.5 microseconds, as shown in the following figure:
DELAY LOWER LIMIT SET, S12 55.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
SPACING LOWER LIMIT SET, S13 29.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
Y-CHANNEL SETTINGS
3.3.5.7 Spacing Offset Control 1 For ‘Y’ channel, the spacing between the detected pulses shall be
36.0+/-0.1 usec.
3.3.5.10 Test Interrogator System Timing Parameters 2 For ‘Y’ channel, the displayed pulse spacing shall be 30.0+/-0.2 usec.
3.3.9.1 RF Output Alignment
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12 For ‘Y’ channel, the space between the two pulses shall be 20+/-1 usec.
3.3.11.4 Output Pulse Spacing 1 For ‘Y’ channel, the spacing between the half-amplitude points on the leading
edge of the pulses shall be 30.0+/-0.1 usec. 3 For ‘Y’ channel, the CTU displayed pulse spacing shall be 30.0+/-0.1 usec.
3.3.13.1 Delay Variation with Input Level 2 For ‘Y’ channel, set the receiver video BEACON DELAY, COARSE and FINE,
controls to give a displayed delay as near as possible to 56.0+/-0.1 usec. The set value becomes the Reference Delay for the remainder of this test.
3.3.13.2 Final Receiver Checks 2 For ‘Y’ channel, the Reply Delay displayed on the CTU, and the Reply Delay
measured on the oscilloscope, shall be 56.0+/-0.2 usec. These two values shall be within 0.1 usec of each other.
3.3.16.2 Delay Monitor For ‘Y’ channel, set the BEACON DELAY, COARSE and FINE, controls to give the following values, for each of the steps indicated: 4. 55.5 usec 5. Less than 55.5 usec 6. 56.5 usec 7. Greater than 56.5 usec 8. 56.3 usec 9. 55.7 to 56.3 usec 10. 55.7 usec
3.3.16.3 Spacing Monitor For ‘Y’ channel, set the REPLY PULSE SPACING control to give the following values, for each of the steps indicated: 3. 29.4 usec (as close as possible to 29.4, but not greater than 29.4 usec) 4. Less than 29.4 usec 5. 30.6 usec (as close as possible to 30.6, but not less than 30.6 usec) 6. Greater than 30.6 usec 7. 30.3 usec (as close as possible to 30.3, but not greater than 30.3 usec) 8. 29.7 to 12.3 usec 9. 29.7 usec (as close as possible to 29.7, but not less than 29.7 usec)
3.3.16.11 Monitor Fault Limits For ‘Y’ channel, the following values and limits apply for Delay and Spacing:
PARAMETER VALUE RANGE UNIT Delay; Lower 55.5 to 55.6 usec Delay; Upper 56.5 to 56.6 usec Spacing; Lower 29.4 to 29.5 usec Spacing; Upper 30.4 to 30.5 usec
3.3.17.5 Low Voltage Performance
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2 For ‘Y’ channel, the following values and limits apply for Delay and Spacing:
PARAMETER VALUE RANGE UNIT Delay 55.9 to 56.1 usec Spacing 29.9 to 30.1 usec
3.3.21 Tidy Up 2 For ‘Y’ channel, the following values and limits apply for Delay and Spacing:
PARAMETER VALUE RANGE UNIT Delay 55.8 to 56.2 usec Spacing 29.9 to 30.1 usec
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3.4 LRU PERFORMANCE CHECKS AND ALIGNMENT
3.4.1 Introduction
3.4.1.1 Definition and Scope A line replaceable unit is defined as the lowest-order subassembly that should be replaced during field maintenance to restore an equipment to service.
This section describes, for each line replaceable unit within the LDB-102 DME, the procedure to be followed to check the operational performance and characteristics of the unit. Such tests may typically be performed either to determine the degree of serviceability of a suspected faulty unit or to check the performance characteristics of a unit following repair.
All the tests and procedures within this section are designed to apply only with the two following prerequisite conditions:
a. That the unit to be tested is mounted in place of the existing equivalent unit in an operational equipment rack used as a test bed. The Depot Test Facility type 3A72500, is specially designed for this purpose.
b. The supporting test equipment nominated for each procedure (and detailed in a consolidated list in Section E.3) or items having equivalent performance characteristics is available.
3.4.1.2 List of Procedures The major assemblies and subassemblies of the LDB-102 DME are shown in two lists below. The first list (Table 3-1) is arranged in numerical type number sequence; the second list (Table 3-2) shows the equipment assembly/subassembly configuration for those assemblies which have subordinate subassemblies and is arranged in numerical order of module. Both lists show the procedures which apply to each assembly/ subassembly. Some higher-order assemblies may consist of two or more subassemblies which are themselves line replaceable units; in the second list, the section/s in which applicable test procedures appear are shown against each item.
3.4.1.3 DME Rack Operation The LRU test procedures in this section require the availability of a fully functional DME rack, operating into a dummy load. For the operation and configuration of the rack, refer to the following sections:
a. General operating instructions: Section 3.1.
b. Module internal presets: Section 3.3.
c. Preliminary check and setup: Sections 3.4.
When these procedures are performed on a Depot Test Facility, type 3A72500, refer to Appendix K for a description of the depot test facility and operating instructions specific to it.
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Table 3-1 Numerical List of Line Replaceable Units
ASSEMBLY/SUBASSEMBLY VERSION USED ON
Type No. Name SECTION
1A 2A 3A 1A69737 Attenuator 3.4.2 ● ● ● 1A69755 Directional Coupler 3.4.3 ● ● ● 2A69755 Directional Coupler 3.4.4 ● 1A69873 250W RF Amplifier 3.4.5 ● ● ● 3A71130 AC Power Supply 3.4.6 ● 1A72510 Monitor Module 3.4.7 ● ● ● 1A72511 Main PWB Assembly. Monitor Module 3.4.8 ● ● ● 1A72512 Peak Power Monitor 3.4.9 ● ● ● 1A72514 Test Interrogator 3.4.10 ● ● 2A72514 Test Interrogator (Modified) 3.4.10 ● 1A72515 Main PWB Assembly, Test Interrogator 3.4.11 ● ● ● 1A72516 RF Generator 3.4.12 ● ● 2A72516 RF Generator (Modified) 3.4.12 ● 1A72517 RF Filter 3.4.13 ● ● ● 1A72518 Modulator and Detector 3.4.14 ● ● ● 1A72519 Reply Detector 3.4.15 ● ● ● 1A72520 Receiver Video 3.4.16 ● ● 2A72520 Receiver Video (Modified) 3.4.16 ● 1A72521 Main PWB Assembly, Receiver Video 3.4.17 ● ● ● 1A72522 RF Source 3.4.18 ● ● ● 1A72523 IF Amplifier 3.4.19 ● ● ● 1A72524 RF Amplifier 3.4.20 ● ● ● 1A72525 Transponder Power Supply 3.4.21 ● ● ● 1A72526 Main PWB Assembly, Transponder Power Supply 3.4.22 ● ● ● 1A72530 Transmitter Driver 3.4.23 ● ● ● 1A72531 Pulse Shaper PWB Assembly 3.4.24 ● ● ● 1A72532 Exciter 3.4.25 ● ● ● 1A72533 Medium Power Driver 3.4.26 ● ● ● 1A72534 Power Modulation Amplifier 3.4.27 ● ● ● 1A72535 1kW RF Power Amplifier 3.4.28 ● ● ● 1A72536 Power Divider 3.4.29 ● ● ● 1A72537 Power Combiner 3.4.30 ● ● ● 1A72540 1kW PA Power Supply 3.4.31 ● ● ● 1A72541 Control and Status PWB Assembly 3.4.32 ● ● ● 1A72542 DC-DC Converter PWB Assembly 3.4.33 ● ● ● 1A72546 Preselector Filter 3.4.34 ● ● ● 1A72547 RF Panel PWB Assembly - Single DME 3.4.35 ● ● 2A72547 RF Panel PWB Assembly - Dual DME 3.4.36 ● 1A72549 Power Distribution Panel - Single DME 3.4.37 ● ● 2A72549 Power Distribution Panel - Dual DME 3.4.38 ● 1A72550 Control and Test Unit 3.4.39 ● ● ● 1A72552 CTU Processor PWB Assembly 3.4.40 ● ● ● 1A72553 CTU Front Panel PWB Assembly 3.4.41 ● ● ● 1A72555 RCMS Interface PWB Assembly 3.4.42 ● ● ● 1A72557 External I/O PWB Assembly 3.4.43 ● ● ●
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Table 3-2 Hierarchical List of Line Replaceable Units
ASSEMBLY/SUBASSEMBLY VERSION USED ON
Type No. Name SECTION
1A 2A 3A 1A72510 Monitor Module 3.4.7 ● ● ● 1A72511 Main PWB Assembly, Monitor Module 3.4.8 ● ● ● 1A72512 Peak Power Monitor 3.4.9 ● ● ● 1A72514 Test Interrogator 3.4.10 ● ● 1A72515 Main PWB Assembly, Test Interrogator 3.4.11 ● ● ● 1A72516 RF Generator 3.4.12 ● ● 1A69737 Attenuator 3.4.2 ● ● ● 1A72518 Modulator and Detector 3.4.14 ● ● ● 1A72519 Reply Detector 3.4.15 ● ● ● 2A72514 Test Interrogator (Modified) 3.4.10 ● 1A72515 Main PWB Assembly, Test Interrogator 3.4.11 ● ● ● 2A72516 RF Generator (Modified) 3.4.12 ● 1A69737 Attenuator 3.4.2 ● ● ● 1A72518 Modulator and Detector 3.4.14 ● ● ● 1A72519 Reply Detector 3.4.15 ● ● ● 1A72520 Receiver Video 3.4.16 ● ● 1A72521 Main PWB Assembly, Receiver Video 3.4.17 ● ● ● 1A72522 RF Source 3.4.18 ● ● ● 1A72523 IF Amplifier 3.4.19 ● ● ● 1A72524 RF Amplifier 3.4.20 ● ● ● 1A72517 RF Filter 3.4.13 ● ● ● 2A72520 Receiver Video (Modified) 3.4.16 ● 1A72521 Main PWB Assembly, Receiver Video 3.4.17 ● ● ● 1A72522 RF Source 3.4.18 ● ● ● 1A72523 IF Amplifier 3.4.19 ● ● ● 1A72524 RF Amplifier 3.4.20 ● ● ● 1A72517 RF Filter 3.4.13 ● ● ● 1A72525 Transponder Power Supply 3.4.21 ● ● ● 1A72526 Main PWB Assembly, Transponder Power Supply 3.4.22 ● ● ● 1A72530 Transmitter Driver 3.4.23 ● ● ● 1A72531 Pulse Shaper PWB Assembly 3.4.24 ● ● ● 1A72532 Exciter 3.4.25 ● ● ● 1A72533 Medium Power Driver 3.4.26 ● ● ● 1A72534 Power Modulation Amplifier 3.4.27 ● ● ● 1A72535 1kW RF Power Amplifier 3.4.28 ● ● ● 1A72536 Power Divider 3.4.29 ● ● ● 1A72537 Power Combiner 3.4.30 ● ● ● 1A69873 250W RF Amplifier 3.4.5 ● ● ● 1A72534 Power Modulation Amplifier 3.4.27 ● ● ● 1A72540 1kW PA Power Supply 3.4.31 ● ● ● 1A72541 Control and Status PWB Assembly 3.4.32 ● ● ● 1A72542 DC-DC Converter PWB Assembly 3.4.33 ● ● ● 1A72545 RF Panel - Single DME Not LRU ● ● 1A72546 Preselector Filter 3.4.34 ● ● ● 1A72547 RF Panel PWB Assembly - Single DME 3.4.35 ● ● 1A69755 Directional Coupler 3.4.3 ● ● ● 2A72545 RF Panel - Dual DME Not LRU ● 1A72546 Preselector Filter 3.4.34 ● ● 2A72547 RF Panel PWI3 Assembly - Dual DME 3.4.36 ● 1A69755 Directional Coupler 3.4.3 ● ● ● 2A69755 Directional Coupler 3.4.4 ● ●
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ASSEMBLY/SUBASSEMBLY VERSION USED ON
Type No. Name SECTION
1A 2A 3A 3A71130 AC Power Supply 3.4.6 ● ● 1A72549 Power Distribution Panel - Single DME 3.4.37 ● 2A72549 Power Distribution Panel - Dual DME 3.4.38 ● ● 1A72550 Control and Test Unit 3.4.39 ● ● ● 1A72552 CTU Processor PWB Assembly 3.4.40 ● ● ● 1A72553 CTU Front Panel PWB Assembly 3.4.41 ● ● ● 1A72555 RCMS Interface PWB Assembly 3.4.42 ● ● ● 1A72557 External I/O PWB Assembly 3.4.43 ● ● The following items do not require tuning and are not repairable:
a. Coaxial Changeover Relay (in RF Panel).
b. Circulators (in RF Panel and 1kW Power Amplifier).
3.4.1.4 Test Equipment A complete list of the test equipment and accessories required to conduct the range of test and alignment procedures for LRUs as specified in this section is contained in Section E.3. That list gives the required performance characteristics for each item of test equipment, and nominates a notional type (or types) which would be suitable for the range of procedures specified. The procedure for each LRU gives a summary list of test equipment items required.
It is assumed that the extenders, cables and other accessories contained in the DME Test and Accessory Kits types 1A72561-1A72564 (refer Appendix F) are available for all procedures; items contained in these kits are not repeated in the summary lists of items for each procedure.
3.4.1.5 Common Procedures The equipment setup requirements detailed in this section for return loss testing and insertion loss testing are common to the testing procedures for a number of LRUs. To avoid unnecessary repetition of detail, these are located in this common section, and referred to as necessary from within individual procedures. The test equipment required for these tests is listed in the sections detailing the individual procedures.
3.4.1.5.1 Return Loss Testing Setup The return loss test method uses a signal generator, spectrum analyser and directional coupler to measure the power reflected back from the unit under test. Set up the equipment as shown in Figure 3-2 and set the signal generator output to a CW level of +10 dBm.
Set the spectrum analyser controls to:
Centre frequency: 1100 MHz Sweep time: 10 milliseconds/division Span: 40 MHz/division (50) Amplitude: 10 dB/division Resolution bandwidth: 1 MHz Video bandwidth: 10 kHz
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Figure 3-2 Standard Return Loss Test Setup
Connect the short circuit to the return loss port. Calibrate the test equipment for a reference return loss of 0 dB over the range 950-1250 MHz by tuning the signal generator over the band and noting the envelope of the response peaks on the spectrum analyser.
Remove the short circuit and connect a 50 ohms termination to the return loss port. Measure the return loss over the range 950-1250 MHz. The worst measured value (that is, the value of the return loss which is the least number of dB below the 0 dB reference - see the typical display shown in Figure 3-3) must be greater than 27 dB.
Figure 3-3 Typical Display for Return Loss Test
3.4.1.5.2 Insertion Loss Testing Setup Set up the equipment as shown in Figure 3-4, but with the SMA back-to-back adaptor in place of the unit under test. The 10 dB attenuators should be placed as close to the unit under test as possible (they ensure a well-defined impedance at the connection points to the unit under test). Set the signal generator output to a level of +10 dBm and the spectrum analyser to the 2 dB/division amplitude range.
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Figure 3-4 Standard Insertion Loss Test Setup
Calibrate the test equipment for a reference insertion loss of 0 dB over the frequency range 950-1250 MHz by tuning the signal generator over the band and noting the envelope of the response peaks on the spectrum analyser display. (If the variation of the level meter reading over the frequency band is less than or equal to 0.2 dB peak-to-peak, calibrate the test equipment to give a reference response within ±0.1 over the frequency band. It the variation of the level meter reading over the frequency band is greater than 0.2 dB peak-to-peak, correction factors will have to be applied for all frequencies of interest).
When the expected insertion loss is of the order of 30 dB, greater precision may be obtained by calibrating the test equipment with a 30 dB attenuator of known accuracy.
For this procedure, set the spectrum analyser to 10 dB/division amplitude range and insert the 30 dB attenuator in place of the unit under test. Calibrate the test equipment for a reference insertion loss of 30 dB over the frequency range, as described above.
Figure 3-5 Typical Display for Insertion Loss Test
3.4.2 Attenuator 1A69737
3.4.2.1 Test Equipment Power supply, 15 volts. Spectrum analyser. Signal generator. Directional coupler. Attenuator, miniature, 30 dB. Attenuator, miniature, 10 dB: Qty 2. Resistor, 4.75 kilohm. Resistor, 475 ohms. Coaxial cables and adaptors.
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3.4.2.2 Return Loss Check Set up the attenuator under test as described in Section 3.4.1.5.1.
Connect the RF input connector XMA on the switched attenuator, in place of the 50 ohms termination, to the return loss port.
Connect the power supply to the switched attenuator through the resistor divider as shown in Figure 3-6. Do not switch on.
Connect the matched load (50 ohms) to the RF output connector XFA on the switched attenuator. Measure the return loss over the frequency range 1000 to 1200 MHz; this should not be less than 15 dB.
Figure 3-6 Switched Attenuator Test Configuration
3.4.2.3 Insertion Loss and Attenuation Check Set up the attenuator under test as described in Section 3.4.1.5.2
Connect the attenuator under test between the 10 dB attenuators. Measure the insertion loss of the switched attenuator over the frequency range 1000 to 1200 MHz. This should not be greater than 1 dB.
Set the power supply to 15.0 ±0.1 volts and switch on. The insertion loss of the attenuator should remain unchanged unless resistors R1 and R2 are already fitted. Switch off the power supply.
If required, the two resistors R1 and R2 must now be chosen so that a 15 dB drop in the RF output level occurs when the power supply is switched on with the respect to the level when the supply is off. The total value of the R1 and R2 required is about 700 ohms and two standard value resistors are to be fitted to give 15 ±0.5 dB attenuation difference.
Measure the attenuation difference, from off state to on state, over the frequency range 1000 to 1200 MHz; it should be 15.0 ±0.5 dB.
3.4.3 Directional Coupler 1A69755
3.4.3.1 Test Equipment Spectrum analyser. Signal generator. Directional coupler. Attenuator miniature, 30 dB. Attenuator, miniature, 10 dB: Qty 2. Coaxial cables and adaptors.
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3.4.3.2 Return Loss Check NOTE It is possible, during repair, that internal resistor pills may become misaligned; if
the results for the FWD-B and FWD-C measurements are outside the specified limits, it will be necessary to dis-assemble the coupler and re-assemble it with tabs accurately aligned with tracks.
Set up the coupler under test as described in Section 3.4.1.5.1.
Connect the connectors of the coupler under test one at a time, as shown in the table below, in place of the 50 ohms termination, to the return loss port of the test setup. Connect 50 ohms terminations to the unused ports listed in this table. Measure the return loss for each port over the frequency range 950-1220 MHz; this should be greater than 22 dB.
MEASURE RETURN LOSS AT PORT
TERMINATE THESE PORTS WITH 50 OHMS
IN OUT FWD-A REV-A OUT FWD-A FWD-B OUT FWD-A FWD-C OUT FWD-A
OUT IN REV-A FWD-A IN REV-A
3.4.3.3 Insertion Loss Check Set up the coupler under test as described in Section 3.4.1.5.2 but with the SMA back-to-back female adaptor in place of the coupler under test. The 10 dB attenuators should be placed as close to the unit under test as possible (they ensure a well defined impedance at the connection points to the coupler under test).
Set the oscillator output to a level of +10 dBm and the spectrum analyser to 2 dB/division amplitude range.
Calibrate the test equipment for a reference insertion loss of 0 dB over the frequency range 950-1220 MHz.
Remove the SMA back-to-back female adaptor from the test setup and connect the coupler under test in its place as shown in the table below. Connect 50 ohms terminations to the unused ports listed in this table. Measure the worst insertion loss over the frequency range 950-1220 MHz (that is, the largest number of dB below the reference level). The measured value should be less than 0.4 dB.
PORT TO SIGNAL
GENERATOR
PORT TO SPECTRUM ANALYSER
TERMINATE THESE PORTS WITH 50 OHMS
IN OUT FWD-A FWD-B FWD-C OUT IN REV-A
3.4.3.4 Coupling Ratio Check The test method is the same as that used for Section 3.4.3.3 except that the test equipment is calibrated at an insertion loss of 30 dB. Since the nominal value of the forward coupling ratios of the coupler under test is 30 dB, this gives improved accuracy of measurement compared with calibration at an insertion loss of 0 dB.
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Set up the equipment as described in Section 3.4.1.5.2, but with the 30 dB attenuator and the SMA back-to-back female adaptor in place of the coupler under test. The 10 dB attenuators should be placed as close to the unit under test as possible (they ensure a well defined impedance at the connection points to the coupler under test). Set the oscillator output to a level of +10 dBm and the spectrum analyser to 10 dB/division amplitude range.
Calibrate the test equipment for a 0 dB reference over the frequency range 950-1220 MHz, and record the calibrated value of the 30 dB attenuator.
Remove the 30 dB attenuator and the SMA back-to-back female adaptor from the test setup and connect the coupler under test in its place as shown in the table below. Connect 50 ohms terminations to the unused ports listed in this table. Measure the smallest (most negative) and largest (most positive) values of the relative response over the frequency range 950-1220 MHz. (Responses below the 0 dB reference line are to be treated as positive; those above the 0 dB reference line to be treated as negative.)
Add the measured response values to the recorded calibrated value of the 30 dB attenuator. The added values should be in the ranges listed in the table.
PORT TO SIGNAL
GENERATOR
PORT TO SPECTRUM ANALYSER
TERMINATE PORTS WITH 50 OHMS LIMITS (dB)
IN FWD-A (1) OUT REV-A 30.0 ±0.8 IN FWD-B OUT REV-A 30.0 ±0.5 IN FWD-C OUT REV-A 30.0 ±0.5 IN REV-A OUT FWD-A ≥15 dB below
FWD-A (1) OUT REV-A (2) IN FWD-A 30.0 ±0.8 OUT FWD-A IN REV-A ≥15 dB below
REV-A (2) OUT FWD-B IN REV-A ≥ 45.0 OUT FWD-C IN REV-A ≥ 45.0
3.4.4 Directional Coupler 2A69755
3.4.4.1 Test Equipment Spectrum analyser. Signal generator. Directional coupler. Attenuator, miniature, 30 dB. Attenuator, miniature, 10 dB: Qty 2. Coaxial cables and adaptors.
3.4.4.2 Return Loss Check NOTE It is possible, during repair, that internal resistor pills may become misaligned; if
the results for the FWD-B through FWD-E measurements are outside the specified limits, it will be necessary to dis-assemble the coupler and re-assemble it with tabs accurately aligned with tracks.
Set up the coupler under test as described in Section 3.4.1.5.1.
Connect the connectors of the coupler under test one at a time, as shown in the table below, in place of the 50 ohms termination, to the return loss port of the test setup. Connect 50 ohms terminations to the unused ports listed in this table. Measure the return loss over the frequency range 950-1220 MHz; this should be greater than 22 dB.
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MEASURE RETURN LOSS AT PORT
TERMINATE THESE PORTS WITH 50 OHMS
IN OUT FWD-A REV-A OUT FWD-A FWD-B OUT FWD--A FWD-C OUT FWD-A FWD-D OUT FWD-A FWD-E OUT FWD-A
OUT IN REV-A FWD-A IN REV-A
3.4.4.3 Insertion Loss Check Set up the coupler under test as described in Section 3.4.1.5.2 but with the SMA back-to-back female adaptor in place of the coupler under test. The 10 dB attenuators should be placed as close to the unit under test as possible (they ensure a well defined impedance at the connection points to the coupler under test).
Set the oscillator output to a level of +10 dBm and the spectrum analyser to 2 dB/division amplitude range.
Calibrate the test equipment for a reference insertion loss of 0 dB over the frequency range 950-1220 MHz.
Remove the SMA back-to-back female adaptor from the test setup and connect the coupler under test in its place as shown in the table below. Connect 50 ohms terminations to the unused ports listed in this table. Measure the worst insertion loss over the frequency range 950-1220 MHz (i.e., the largest number of dB below the reference level). The measured value should be less than 0.4 dB.
PORT TO SIGNAL
GENERATOR
PORT TO SPECTRUM ANALYSER
TERMINATE THESE PORTS WITH 50 OHMS
IN OUT FWD-A FWD-B FWD-C FWD-D FWD-E OUT IN REV-A
3.4.4.4 Coupling Ratio Check The test method is the same as that used for Section 3.4.3.3 except that the test equipment is calibrated at an insertion loss of 30 dB. Since the nominal value of the forward coupling ratios of the coupler under test is 30 dB, this gives improved accuracy of measurement compared with calibration at an insertion loss of 0 dB.
Set up the equipment as described in Section 3.4.1.5.2, but with the 30 dB attenuator and the SMA back-to-back female adaptor in place of the coupler under test. The 10 dB attenuators should be placed as close to the unit under test as possible (they ensure a well defined impedance at the connection points to the coupler under test). Set the oscillator output to a level of +10 dBm and the spectrum analyser to 10 dB/division amplitude range.
Calibrate the test equipment for a 0 dB reference over the frequency range 950-1250 MHz and record the calibrated value of the 30 dB attenuator.
Remove the 30 dB attenuator and the SMA back-to-back female adaptor from the test setup and connect the coupler under test in its place as shown in the table below.
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Connect 50 ohms terminations to the unused ports listed in this table. Measure the smallest (most negative) and largest (most positive) values of the relative response over the frequency range 950-1220 MHz. (Responses below the 0 dB reference line are to be treated as positive; those above the 0 dB reference line to be treated as negative.)
Add the measured response values to the recorded calibrated value of the 30 dB attenuator. The added values should be in the ranges listed in the table following.
PORT TO SIGNAL
GENERATOR
PORT TO SPECTRUM ANALYSER
TERMINATE PORTS WITH 50 OHMS LIMITS (dB)
IN FWD-A (1) OUT REV-A 30.0 ±0.8 IN FWD-B OUT REV-A 30.0 ±0.5 IN FWD-C OUT REV-A 30.0 ±0.5 IN FWD-D OUT REV-A 30.0 ±0.5 IN FWD-E OUT REV-A 30.0 ±0.5 IN REV-A OUT FWD-A ≥ 15 dB below
FWD-A (1) OUT REV-A (2) IN FWD-A 30.0 ±0.8 OUT FWD-A IN REV-A ≥ 15 dB below
REV-A (2) OUT FWD-B IN REV-A ≥ 45.0 OUT FWD-C IN REV-A ≥ 45.0 OUT FWD-D IN REV-A ≥ 45.0 OUT FWD-E IN REV-A ≥ 45.0
3.4.5 250W RF Amplifier 1A69873
3.4.5.1 Test Equipment Oscilloscope. Directional coupler. Attenuator, medium, 10 dB; Qty 2. Attenuator, power, 30 dB. Attenuator, medium, 3 dB. Attenuator, medium, 6 dB. Peak power meter and sensor. Detector; Qty 2. Resistor, 4.75 kilohm. Coaxial cables and adaptors. Calibration link (semi-flexible cable, 100 mm long, SMA(F) to SMA(F)).
3.4.5.2 Setup Remove the cover from the 1kW power amplifier in the depot test facility and arrange an insulator (such as a sheet of cardboard) to cover the power combiner board. The RF test equipment and the amplifier under test can lay on top of the heat sink or cardboard, as convenient.
Remove the transmitter driver module and connect it to the rack on the module extender frame.
The amplifier under test is to be powered from the capacitor bank on the underside of the power combiner. The red lead attached to the amplifier is the positive supply connection, and the quick-connect terminal should be inserted in place of one of the leads supplying a 250W amplifier in the 1kW power amplifier in the depot test facility.
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The earth return must be a very short, low impedance link from the body of the amplifier under test to the heatsink of the power amplifier.
For the RF connection, loosen and remove the N-type coaxial plug on the semirigid cable from the INPUT connector on the power amplifier heatsink and reconnect it, via a N-type elbow, to the directional coupler (or 6 dB attenuator for calibration).
3.4.5.3 Calibration Procedure Arrange the test setup as shown in Figure 3-7 with the calibration link connected in circuit instead of the amplifier which is to be tested. Remove the 10 dB attenuator at the peak power sensor, and connect the sensor directly to the 30 dB attenuator. Connect the 6 dB attenuator before the directional coupler.
Set the depot test facility transmit frequency to 1213 MHz.
Set the switches in the transmitter driver as follows:
ALC LOOP (S2) to OPEN ALC (S3) to VIDEO MED COLL (S4) to DC.
Switch on the mains to all the test equipment, with the depot test facility transmitter driver DRIVER DC POWER switch set to OFF.
Set the oscilloscope sweep time to 1 microsecond per division and trigger the oscilloscope from the receiver video TRIGS TO MODULATOR front panel test jack.
On the peak power meter, set the correction to that stated on the correction table for frequencies up to 2 GHz. Set the reading offset to 30 dB and the range switch to 100 mW. Set the peak power meter to measure in DIRECT mode.
Reverse the directional coupler, end for end, using two coaxial adaptors (male-male and female-female), keep the two detectors attached to the same connectors.
Rotate the transmitter driver POWER MOD AMP DC (R69) preset fully counter-clockwise (this is located on the printed wiring board).
Connect the reverse detector, using the 4.75 kilohm resistor in parallel, to the oscilloscope channel 2.
Set the transmitter driver DRIVER DC POWER switch to NORMAL and check the 'reflected' pulse of channel 2 and the 'output' pulse via the peak power meter.
Adjust the POWER MOD AMP DC preset to give 10 watts on the power meter, and then note the 'reflected' pulse amplitude This becomes a reference level which represents 10 watts reflected power.
Switch DRIVER DC POWER to OFF.
Rotate the directional coupler to its original direction.
Set the peak power meter to the COMPARE mode.
Adjust the COMPARE LEVEL controls on the peak power meter to give a meter reading which corresponds to 50.0 watts into the 30 dB attenuator. The actual meter reading will depend on the exact attenuation of the 30 dB attenuator, and it is important that its calibration be taken into account when deriving the meter reading. As an example, the figures below show the correct meter reading for various values of attenuation:
P input (watts) ATTENUATION (dB) P meter (watts) 50.0 29.7 53.6 50.0 29.8 52.4
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50.0 29.9 51.2 50.0 30.0 50.0 50.0 30.1 48.9 50.0 30.2 47.8 50.0 30.3 46.7
With the meter set to the appropriate value, there will be a horizontal trace on oscilloscope channel 1, which represents a true 50.0 watts into the 30 dB attenuator.
Remove the 6 dB attenuator from the input to the directional coupler.
CAUTION The power sensor diode of the peak power meter is easily destroyed, so check that the 30 dB of attenuation is connected in front of the power sensor.
Set the transmitter driver POWER MOD AMP DC preset fully counter-clockwise and set the DRIVER DC POWER switch to NORMAL.
Observe the following:
a. a forward power pulse on channel 1 of the oscilloscope, and
b. a reflected power pulse on channel 2 of the oscilloscope.
Increase the output power using the POWER MOD AMP DC preset on the transmitter driver printed wiring board until the main body of the pulse lies on the 50.0 watts horizontal trace on the oscilloscope (that is, ignore any initial spike in the pulse). If the top of the main body of the pulse slopes, then take an average level.
Check that the voltage on channel 2 of the oscilloscope represents a reflected power of 1 watt or less (this confirms that the system is properly matched). This voltage should be below 0.316 of the 10 watts reference established above.
Once 50 watts of power is available with less than 1 watt reflected and the pulse width and repetition rate are correct, measure the output from the FWD detector on the oscilloscope and record the peak pulse voltage to the nearest 20 mV. This value then becomes the '50W available' calibration at this frequency. (The detector output may be a negative-going pulse.)
Switch DRIVER DC POWER to OFF. Replace the 10 dB attenuator between the peak power sensor and the 30 dB attenuator.
3.4.5.4 Amplifier Test Procedure Arrange the test setup as shown in Figure 3-7, with the amplifier under test in circuit in place of the SMA calibration link. Recheck that there is a total of 40 dB attenuation between the amplifier and peak power sensor.
Set the RANGE switch on the peak power meter to 100 mW and the MODE switch to DIRECT. The reading offset should be switched to 40 dB and the correction set for 2 GHz from the correction table on the sensor.
Connect the oscilloscope to display input (50 watts) power on channel 1 and reflected power on channel 2 with the graticule line representing 10 watts of reflected power (from previous calibration). This line is a limit which must not be exceeded by the reflected power pulse from the amplifier under test.
Set the POWER MOD AMP DC preset on the transmitter driver to minimum (counter-clockwise) setting, switch the DRIVER DC POWER to ON, then switch the AMPLIFIER DC POWER switch on the 1kW PA power supply to ON.
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Check that the supply voltage to the amplifier under test is 50.0 ±0.5 volts.
Slowly raise the input power from the transmitter driver by adjusting the POWER MOD AMP DC preset in the clockwise direction, whilst monitoring:
a. output power from the amplifier on the peak power meter, and
b. reflected power from the input of the amplifier on channel 2 of the oscilloscope.
Observe the output from the detector on channel 1 of the oscilloscope and continue to increase the input signal level whilst continually checking that the reflected power does not rise above the 10 watts calibration level.
CAUTION For a normal 250W RF amplifier the power reflected back from its input is around 1 to 5 watts, so that the power to the reverse detector is around 5 to 25 mW. The object of continually checking on the reflected power is to avoid destroying the detector diode should a large mismatch be present for any reason at the input of the 250W RF amplifier.
When the '50W available' calibration point has been reached at the input, measure the output power on the peak power meter. This must be at least 250 watts peak. Observe the pulse shape, from the video output of the meter, on channel 1 of the oscilloscope. On channel 2 of the oscilloscope, measure the input reflected power pulse amplitude. This must not exceed the 10 watts peak level.
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Figure 3-7 250W Amplifier Test Setup
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3.4.6 AC Power Supply 3A71130
3.4.6.1 Test Equipment Oscilloscope. Digital multimeter. Output cables (power connectors, or pair of heavy duty cables). Variable load resistor network, 0.7 to 30 ohms, to dissipate 900 watts maximum.
3.4.6.2 Setup Remove the printed circuit board and, referring to the Control Board layout drawing below, check that the U-links are inserted as follows:
U-LINK POSITION OPTION SELECTED
356 402-403 Output low volts alarm 357 404-405 Delayed overvoltage shutdown 358 408-409 24 volts operation 359 411-412 24 volts operation 360 414-415 24 volts operation 361 417-418 24 volts operation 362 420-421 24 volts operation 363 423-424 24 volts operation 364 426-427 24 volts operation 365 429-430 24 volts operation 366 432-433 24 volts operation 367 435-436 Function control 368 438-439 Capacitor 8 local alarm 369 441-442 Capacitor 10 local alarm 370 444-445 Normal voltage range 371 446-447 Latching overvoltage alarm 372 449-450 Output contactor isolation for overvoltage protection 373 453-454 Contactor control local (normal)
Set the trimpots as follows:
TRIMPOT SETTING
FLOAT 1 Mid-range FLOAT 2 Mid-range BOOST Mid-range CURRENT LIMIT Fully clockwise H/V SHUTDOWN Fully clockwise SHUTDOWN DELAY Fully anticlockwise LOW VOLTS ALARM Fully anticlockwise
Extend the printed circuit board in the power supply under test.
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Figure 3-8 Connections to Alarm Connector TB/3
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Control Board Layout
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3.4.6.3 Output Voltage Tests Set the function switch to the TEST position. Set the battery switch to the NO BATTERY position. Set the output isolate switch to OFF.
Check that the tapping for the mains transformer has been correctly selected and, using a suitable power cord, connect the unit to a mains outlet.
Turn the POWER ON switch to its ON position, and switch on the power outlet.
Check that there is a click from the relay RL2 (the mains fail relay), that contacts 4 and 5 on the alarm connector TB/3 are short circuit, and that contacts 18 and 19 are open circuit.
Temporarily set the POWER ON switch to its OFF position, and check that RL2 de-energises, and that now contacts 18 and 19 on TB/3 are short circuit and 19 and 20 open circuit. Restore the power.
Measure the AC voltage between the 0 volts and 240 volts contacts on the TB/1 primary tap selecting block.
If this voltage is close to 240 volts, use the 0 volts terminal as a reference and check that the marked voltages are present on the other terminals.
Check that the green POWER ON indicator is lit.
Switch the DC ISOLATOR switch to its ON position, and check that the output contactor can be clearly heard to operate.
Connect the digital multimeter to the test points below the voltmeter.
The TEST/FLOAT switch must be manually held in the TEST position for this check. Vary the FLOAT 1 trimpot and check that the TEST voltage may be varied over the range 18 volts to 32 volts. Set the output to 25 volts on the digital multimeter.
Check that the voltage indicated on the built-in meter is 25.0 ±0.5 volts.
Set the function switch to FLOAT. Vary the FLOAT 2 trimpot and check that the FLOAT voltage may be varied over the range 25.0 to 29.0 volts. Set the output to 26.4 volts on the digital multimeter.
3.4.6.4 Current Limit Adjustment Set the function switch to the FLOAT position and check that the output is 26.4 volts.
Connect the output test cable to the output, and connect load resistors until a current of about 35 amperes is flowing.
Adjust the CURRENT LIMIT trimpot until the output current is limited to 31 amperes.
Short-circuit the load, and check that the current does not exceed 31.5 amperes.
Reduce the load to 30 amperes, and check that the output voltage is not less than 26.0 volts measured on the digital multimeter. (It may be necessary to marginally increase the current limit to meet this requirement, but it must NOT be advanced beyond 31.5 amperes.)
3.4.6.5 Performance Under Load Reduce the output load to 20 amperes, and check that the output is 26.4 volts.
Remove the load, and check that the rise in output is less than 0.1 volts.
Select the TEST function, and check that the change in output is less than 0.1 volts when the load is applied.
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3.4.6.6 Transient Response Set the function switch to FLOAT, and check that the output is 20 amperes at 26.4 volts.
Disconnect the load, and check that the battery switch is set to NO BATTERY.
Connect an oscilloscope across the output, and check the dip in output voltage when the load is re-applied. Repeat several times, and check that the undershoot is less than 6 volts for a 0-20 amperes current step. Recovery to within 2 volts of the final value must occur within 200 milliseconds. The typical transient performance is shown as waveform 1 below.
Remove the load, and check the output overshoot transient. Repeat several times, and check that the overshoot is less than 3 volts for a 20-0 amperes current step. Recovery to within 1 volt of the final value must occur within 200 milliseconds. The typical transient performance is shown as waveform 2 above.
Disconnect the output load.
3.4.6.7 Output Ripple Connect the AC power supply under test in place of the depot test facility AC power supply.
Set the power supply under test to FLOAT, and check that its output is 26.4 volts.
Switch the depot test facility on with all systems operating.
Connect an oscilloscope across the battery terminals to display the AC ripple components on the 24 volts supply line.
Measure the 100 Hz ripple component; it should be not more than 0.5 volts peak-to-peak.
Disconnect the depot test facility as load on the AC power supply under test. Following tests use resistor loads.
3.4.6.8 Output Fall Alarm - Low Float Voltage Set the function switch to the TEST position.
Check that U-link 356 links 402-403 (low volts alarm mode).
Adjust the load to give an output current of about 10 amperes.
Adjust the FLOAT 1 trimpot until the output is 23.0 volts, measured with the digital multimeter.
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Slowly rotate the LOW VOLT ALARM trimpot in a clockwise direction until the O/P FAIL indicator lights and relay 123 releases. Check the operation of relay 123 by measuring the continuity between contacts on the alarm connector TB/3. Contact 12 (common) should be a short circuit to 13 when the O/P FAIL indicator is extinguished, and short circuit to 11 when it is lit. Check also that contacts 14 and 15 are short circuit when the indicator is extinguished, and open circuit when it is lit.
Increase the output voltage with the FLOAT 1 trimpot, and check that the indicator is extinguished and the relay 123 operated for an output not greater than 24.0 volts.
Check the setting of the alarm limit by again decreasing and then increasing the output. As the voltage is decreased, the alarm indicator should light for voltages less than 23 volts; as the voltage is increased, the indicator should be extinguished for voltages greater than 24 volts. Adjust, if necessary, the LOW VOLT ALARM trimpot until this condition is obtained.
Re-set the TEST (FLOAT 1) output to 25.0 volts.
3.4.6.9 Output Fail Alarm - Charge Fail Set the function switch to FLOAT, and the battery switch to BATTERY ON.
Adjust the load to give an output current of about 10 amperes.
Change U-link 356 from 402-403 (low volts alarm mode) to 401-402 (charge fail alarm mode).
Pull out the output fuse (F4) and check that the O/P FAIL indicator lights. Relay 125 should release, and the O/P FUSE indicator should light.
Re-insert the output fuse (F4) and check that both indicators are extinguished.
Restore U-link 356 to the 402-403 position (low volts alarm mode).
Re-set the battery switch to the NO BATTERY position.
3.4.6.10 High Voltage Alarm - Selective Shutdown Mode Check that U-link 357 links 405-406 (selective overvolts shutdown).
Set the function switch to TEST, and adjust the load until the output current is 10 amperes.
Increase the output to 29.0 volts by adjustment of the FLOAT 1 trimpot.
Slowly rotate the H/V SHUTDOWN trimpot in a counter-clockwise direction until the H/V SHUTDOWN indicator lights and the output contactor releases. Alarm relay 124 should also release; operation of this relay may be verified by monitoring the continuity between contact 9 and 10 on the alarm connector TB/3. These contacts should be open circuit when the indicator is extinguished, and short circuit when it is lit.
Reduce the output voltage slightly with the FLOAT 1 trimpot, and check that the output contactor operates, the H/V SHUTDOWN indicator is extinguished, and alarm relay 124 operates. Also check for continuity between contacts 10 and 16 on TB/3.
If the FLOAT 1 voltage is set very close to the alarm limit, the contactor may pull in and drop out sporadically. This should not happen for outputs below 28.5 volts.
Set the output voltage to 26.4 volts with the FLOAT 1 trimpot.
3.4.6.11 High Voltage Alarm Delay Shutdown Mode Change U-link 357 to link 404-405 (delay shutdown mode).
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Rapidly increase the output, using the FLOAT 1 trimpot, to greater than 29.0 volts. The high voltage shutdown should operate after a 1 to 2 seconds time delay.
Reduce the output to below 28.5 volts, and check that the output contactor pulls in and the H/V ALARM indicator is extinguished.
Set the SHUTDOWN DELAY trimpot fully clockwise, and repeat the above two steps. The shutdown delay should now be in excess of 10 seconds.
Set the SHUTDOWN DELAY trimpot fully counter-clockwise.
Re-adjust the TEST output to 25.0 volts with the FLOAT 1 trimpot.
3.4.6.12 Fuse Alarm With the function switch in the FLOAT position set up a load to draw about 10 amperes.
Remove the output fuse F4 and check that the O/P FUSE indicator lights, and that alarm relay 125 operates. The operation of this relay may be verified by monitoring the continuity between contacts 7 and 8 on the alarm connector TB/3. These contacts should be open circuit when the indicator is extinguished, and short circuit when it is lit.
Replace the output fuse (F4) and check that the O/P FUSE indicator is extinguished.
Switch the POWER switch to OFF, and change U-link 368 to link 437-438 (capacitor 8 fuse remote alarm). Remove fuse F2, and switch POWER to ON.
Check that the C1 FUSE indicator lights, and that relay 125 operates, as above,
Switch the POWER to OFF, and after checking that C8 is discharged, re-insert fuse.
Change U-link 368 to link 438-439 (capacitor 8 fuse local alarm).
Change U-link 369 to link 440-441 (capacitor 10 fuse remote alarm).
Remove fuse F9, and switch the POWER to ON.
Check that the C1 FUSE indicator is extinguished, and that the C2 FUSE indicator is lit.
Check that relay 125 has operated.
Switch the POWER to OFF, check that C10 is discharged, and re-insert fuse F9.
Change U-link 369 to 441-442 (capacitor 10 local alarm).
Switch the POWER switch to ON, and check that ail alarm indicators are extinguished, and that relay 125 is not operated.
3.4.7 Monitor Module 1A72510
3.4.7.1 Test Equipment Oscilloscope. Digital multimeter.
3.4.7.2 Alignment If the LRU alignment procedure has been carried out on the Main PWB Assembly Monitor 1A72511 and the Peak Power Monitor 1A72512, then no alignment apart from RF power calibration (see Section 3.4.7.5) is necessary on the Monitor 1A72510.
3.4.7.3 Power Supply Check The following voltages should be present at the front panel test jacks of the monitor module:
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+5V +4.75 volts to +5.25 volts +15V +14.2 volts to + 15.3 volts.
3.4.7.4 Peak Power Monitor Check Place the monitor module in the transponder extender frame.
On the CTU press switches in the following order:
SOURCE LOCAL MAINTENANCE OFF MONITOR ALARM INHIBIT SELECT MAIN NO 1.
On the RF panel (at the rear of the rack at the top), ensure that the following components and connecting cables have been installed:
a. 50 ohms termination to connector REV-A on the directional coupler.
b. 10 dB attenuator to connector FWD-A on the directional coupler.
c. Coaxial cable from connector FWD-A of the directional coupler to connectors ERP IN on the rear of the transponder subrack.
On the CTU front panel, press ESC, Ch.1, Param and PwrOut. Check that the measured output power is in the range 1.1 to 1.3 kW.
Trigger the oscilloscope from the front panel jack TRIGGER on the test interrogator module. Connect the oscilloscope channel 1 to the front panel test jack ERP PULSE on the monitor module, using AC coupling. Check that the waveform is a pair of Gaussian-shaped pulses of amplitude in the range 6.0 to 8.5 volts (see figure below).
Connect the digital voltmeter to XN2:14 on the monitor main board. Check that the DC voltage is in the range 7.4 to 10.4 volts.
3.4.7.5 RF Power Calibration Check that the voltage on XT2 of the monitor main board is 2.50 ±0.01 volts. If it is not, adjust R87 on the monitor main board until this voltage is achieved.
3.4.7.6 Front Panel Indicator Check Check that all front panel indicators are lit except PRIMARY, SECONDARY, and SELF TEST. If any indicators are not lit, refer to LRU alignment and test procedure for the Main PWB Assembly Monitor Module 1A72511 (see Section 3.4.8).
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3.4.8 Main PWB Assembly Monitor Module 1A72511
3.4.8.1 Test Equipment Oscilloscope. Digital multimeter. Antenna integrity monitor test fixture (see below).
3.4.8.2 Determination of Monitor Switch Settings Use the following procedure to determine switch settings for the DELAY, SPACING and WIDTH monitors according to the table below.
MONITOR PARAMETER SWITCH
Lower Limit Count S12 DELAY
Window Count S9 Lower Limit Count S13
SPACING Window Count S10 Lower Limit Count S1
WIDTH Window Count S4
1. Determine upper and lower FAULT limits in units of microseconds.
2. Multiply each FAULT limit by 10 to determine upper and lower FAULT counts as a decimal number.
3. Subtract 1 from lower FAULT count.
4. Convert the decimal number in step 3 to a binary number.
5. Set the Lower Limit Count switch with the binary value from step 4, noting that the lowest significant bit in the binary number is set on switch position 1 and that a switch in the ON position signifies a binary 0.
6. Subtract the lower fault count from the upper fault count.
7. Subtract 1 from the decimal number gained in step 6.
8. Convert the decimal number in step 7 to a binary number.
9. Set the Window Count switch with the binary value from step 8, noting that the lowest significant bit in the binary number is set on switch position 1 and that a switch in the ON position signifies a binary 0.
Use the following procedure to determine switch settings for the RISE and FALL monitors and the Ident Gap Set switch according to the table below.
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MONITOR PARAMETER SWITCH
RISE Upper Limit Count S3 FALL Upper Limit Count S2 IDENT Gap Set S8
1. Determine upper FAULT limits in units of microseconds for RISE and FALL.
NOTE For Ident Gap Set the ident upper fault limit (in seconds) is equal to the upper fault count. Go to step 3.
2. Multiply each FAULT limit by 10 to determine upper FAULT counts as a decimal number.
3. Subtract 2 from upper FAULT count.
4. Convert the decimal number in step 3 to a binary number.
5. Set the appropriate switch with the binary value from step 4, noting that the lowest significant bit in the binary number is set on switch position 1 and that a switch in the ON position signifies a binary 0.
Use the following procedure to determine switch settings for the POWER monitor:
1. With the transponder operating normally, adjust R87 on the monitor main board so that the voltage on test point XT2 is 2.50 ±0.01 volts.
2. Set switch POWER LVL FLT SET (S7) according to the following table.
SWITCH POSITION 1 2 3 4 5 6 7 8
0 dBm off off off off off off off off -1 dBm on off off off off off off off -2 dBm on on off off off off off off -3 dBm on on on off off off off off -4 dBm on on on on off off off off -5 dBm on on on on on off off off -6 dBm on on on on on on off off -7 dBm on on on on on on on off
Refer to Section 3.3.3.8 for nominal settings of the monitor fault limit preset switches.
3.4.8.3 Setup The tests following assume that the depot test facility has been aligned to specification.
If this is a new board, ensure that all programmable devices are inserted correctly. Place the monitor module in the depot test facility on the transponder extender frame.
On the CTU press the switches in the following order
SOURCE LOCAL MAINTENANCE ON MONITOR ALARM INHIBIT SELECT MAIN NO 1
The following voltages should be present at the front panel test jacks of the monitor:
+5V +4.75 volts to +5.25 volts +15V +14.2 volts to +15.3 volts.
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Connect the oscilloscope channel 1 to XT4. Check that the waveform is a 10 MHz clock.
3.4.8.4 Delay Monitor Check Connect the oscilloscope to the monitor main board, with channel 1 to test point XT6 (DELAY PULSE) and channel 2 to test point XT5 (DELAY COUNT); trigger the oscilloscope from channel 2.
Set fault limits as described in Section 3.4.8.2 for a Delay Fault limit of 50.0 ±0.5 microseconds (see below - shading indicates switch position).
DELAY LOWER LMT SET (10-way DIP switch S12): 49.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
DELAY WINDOW SET (8-way DIP switch S9): 1.0 microsecond
1 2 3 4 5 6 7 8 ON OFF
Perform fault limit test on this parameter as follows:
a. On the CTU softkeys, select Ch.1, then FltLmt, then Delay.
b. The indication on the CTU front panel display should read:
lower limit 49.5 ±0.1 microseconds upper limit 50.5 ±0.1 microseconds.
On the CTU front panel press ESC, then select Ch.1 then TI RATE 1 kHz. Display the measured Delay parameter reading on the CTU; it should be 50.0 ±0.3 microseconds.
Examine the pulses on channel 1 and channel 2 of the oscilloscope. Check that the failing edge of the pulse on XT6 is within ±0.3 microseconds of half way between the failing edges of the two pulses on XT5.
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Check that the DELAY front panel indicator on the monitor is lit.
3.4.8.5 Spacing Monitor Check Connect the oscilloscope to the monitor main board, with channel 1 to test point XT8 (SPACING PULSE) and channel 2 to test point XT14 (SPACING COUNT); trigger the oscilloscope off channel 2.
Set fault limits as described in Section 3.4.8.2 for a Spacing Fault limit of 12.0 ±0.5 microseconds (see below).
SPACING LOWER LMT SET (10-way DIP switch S3): 11.5 microseconds
1 2 3 4 5 6 7 8 9 10 ON OFF
SPACING WINDOW SET (8-way DIP switch S10): 1.0 microsecond
1 2 3 4 5 6 7 8 ON OFF
Perform fault limit test on this parameter as follows:
a. On the CTU softkeys, select Ch.1 then FltLmt, then Spacing.
b. The indication on the front panel display should read:
lower limit= 11.5 ±0.1 microseconds upper limit = 12.5 ±0.1 microseconds.
On the CTU front panel press ESC, then select Ch.1 then TI RATE 1 kHz. Display the measured Spacing parameter on the CTU; it should be 12.0 ±0.1 microseconds.
Examine the pulses on channel 1 and channel 2 of the oscilloscope. Check that the falling edge of the pulse on XT8 is within ±0.1 microseconds of half way between the falling edges of the two pulses on XT14.
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Check that the SPACING front panel indicator on the monitor is lit.
3.4.8.6 Efficiency Monitor Check On the CTU softkeys, select Ch.1, then FltLmt, then Effncy.
The CTU front panel display should show a lower limit of 60%.
On the CTU front panel press ESC.
Check that the EFFICIENCY front panel indicator on the monitor is lit.
3.4.8.7 Reply Rate Monitor Check On the CTU softkeys, select Ch.1, then FltLmt, then Tx.Rate.
The indication on the front panel display should read:
lower limit in the range 828 to 838 Hz upper limit in the range 2985 to 3015 Hz.
Press ESC on the CTU front panel.
Check that the RATE front panel indicator on the monitor is lit.
3.4.8.8 Effective Radiated Power Monitor Check Set fault limits as described in Section 3.4.8.2 for a Power Fault limit of -3 dBm (see below - shading indicates switch position).
POWER LVL FLT SET (8-way DIP switch S7): -3. 0 dB
1 2 3 4 5 6 7 8 ON OFF
On the CTU softkeys select Ch.l. then FltLmt, then Ant.Pwr; ensure that the CTU displays -3 d B as the fault limit.
Check that the POWER front panel indicator on the monitor is lit.
3.4.8.9 Antenna Integrity Monitor Check Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture to 1000 ±1 0 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board. On the monitor, check that the ANTENNA indicator is on. Using the digital multimeter, check that the voltages on D6:2 and D6:3 are both less than 0.2 volts.
Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture in turn to each of the
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values listed in the table below. Restore the antenna integrity test fixture to XN2 on the RF panel board. For each resistance setting, check that the ANTENNA and SECONDARY indicators are in the state shown in the table. Check also that the voltages at D6:2 and D6:3 correspond with the values shown in the table.
TEST FIXTURE
RESISTANCE (ohms)
±10 ohms
ANTENNA Indicator
SECONDARY Indicator
D6:2 VOLTAGE
(volts)
D6:3 VOLTAGE (volts)
1000 ON OFF < 0.2 < 0.2 1110 OFF ON < 0.2 > 4.5 1250 OFF ON > 4.5 > 4.5 1450 OFF ON > 4.5 > 4.5 150 OFF ON > 4.5 < 0.2
Remove the antenna integrity monitor test fixture from connector XN2 on the RF panel board. Using the multimeter, set the resistance of the test fixture to 1000 ±10 ohms. Restore the antenna integrity monitor test fixture to XN2 on the RF panel board.
3.4.8.10 Level Monitor Check On the CTU softkeys, select Ch.1, then select each of the internal signal levels and power supply voltages listed in the PARAMETER column of the table below. Check that the displayed reading for each one is within the limits shown in the table.
NOTE The DME rack must be fully functional for this test.
PARAMETER LOWER LIMIT UPPER LIMIT NOTES
RV Local Oscillator 1.0 volts 3.0 volts RV RF Drive 1.5 volts 4.5 volts TD Drive 1.5 volts 2.5 volts TD Modulation 1.5 volts 3.5 volts PA Modulation 1.0 volts 3.5 volts PA Drive 2.0 volts 4.8 volts PA Output 2.0 volts 4.8 volts TI Interrogation Level 2.7 volts 3.3 volts Auxiliary 24 V 21 volts DC 28 volts DC Varies with battery voltage. Power Amplifier HT 49.5 volts DC 50.5 volts DC Transponder 15 V 14.6 volts DC 15.6 volts DC Transponder 18 V 17.2 volts DC 18.6 volts DC Driver HT 41.8 volts DC 44.0 volts DC
Press ESC on the CTU front panel.
On the CTU softkeys, select Ch.1, then Status, then MON PS; the CTU front panel display should read NORMAL.
Press ESC on the CTU front panel.
3.4.8.11 Ident Monitor Check Set fault limits as described in Section 3.4.8.2 for an Ident Gap Fault limit of 62 seconds (see below - shading indicates switch position).
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IDENT GAP FLT SET (8-way DIP switch S8): 62 seconds
1 2 3 4 5 6 7 8 ON OFF
Operate the DME rack under normal conditions and check that the IDENT indicator on the monitor is lit. Immediately following the sound of an ident code group, select MONITOR ALARM INHIBIT to ON on the CTU (to stop ident transmission). Check that the IDENT indicator goes out within 62 ±3 seconds.
Switch the front panel IDENT switch on the receiver video from NORMAL to CONTINUOUS. Check that a continuous ident tone is heard from the CTU and that the IDENT indicator on the monitor is initially lit. Check that after approximately 2 seconds the DELAY indicator goes out, and that after 15 seconds the IDENT indicator goes out. Return the receiver video IDENT switch to NORMAL.
On the CTU, switch the MONITOR ALARM INHIBIT to OFF.
Switch the front panel IDENT switch on the receiver video from NORMAL to CONTINUOUS and then back again. Check that an ident tone is heard while the switch is in the CONTINUOUS position and the IDENT indicator on the monitor is lit.
Switch the front panel IDENT switch on the receiver video from NORMAL to CONTINUOUS and then to OFF. Check that the IDENT indicator goes out within 62 ±3 seconds of the ident being switched off.
3.4.8.12 Pulse Shape Monitor Check Connect the oscilloscope to the monitor main board to check the pulse width monitor by connecting channel 1 to test point XT11 (WIDTH PULSE) and channel 2 to test point XT7 (WIDTH COUNT); trigger the oscilloscope from channel 1.
Set fault limits as described in Section 3.4.8.2 for a Width Fault limit of 3.5 ±0.6 microseconds (see below - shading indicates switch position).
PULSE WIDTH WINDOW SET (8-way DIP switch S4):1.2 microseconds
1 2 3 4 5 6 7 8 ON OFF
PULSE WDTH LOWER LIMIT SET (8-way DIP switch S1): 2.9 microseconds
1 2 3 4 5 6 7 8 ON OFF
On the CTU front panel press ESC, then press Ch.1 then 1 kHz.
Examine the pulses on channel 1 and channel 2 of the oscilloscope. Check that the first falling edge of the pulse on XT7 occurs 2.9 ±0.1 microseconds after the trigger and that the second falling edge occurs 4.1 ±0.1 microseconds after the trigger. Check that the falling edge of the pulse on XT11 falls within the window between the two falling edges of the pulse on XT7.
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Connect the oscilloscope to the monitor main board to check the pulse rise time monitor by connecting channel 1 to test point XT3 (RISE PULSE) and channel 2 to test point XT1 5 (RISE COUNT); trigger the oscilloscope from channel 1.
Set fault limits as described in Section 3.4.8.2 for a Rise Fault upper limit of 3.1 microseconds.
RISE TIME UPPER LMT (8-way DIP switch S3): 3.1 microseconds
1 2 3 4 5 6 7 8 ON OFF
On the CTU front panel press ESC then Ch.1 then 1 kHz.
Examine the pulses on channel 1 and channel 2 of the oscilloscope. Check that the falling edge of the pulse on XT15 occurs 3.1 ±0.1 microseconds after the trigger. Check that the falling edge of the pulse on XT3 falls before the falling edge of the pulse on XT15.
Connect the oscilloscope to the monitor main board to check the pulse fall time monitor by connecting channel 1 to test point XT10 (FALL PULSE) and channel 2 to test point XT16 (FALL COUNT); trigger the oscilloscope from channel 1.
Set fault limits as described in Section 3.4.8.2 for a Fall Fault upper limit of 3.6 microseconds.
FALL TIME UPPER LMT (8-way DIP switch S2): 3.6 microseconds
1 2 3 4 5 6 7 8 ON OFF
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On the CTU front panel press ESC then Ch.1 then 1 kHz.
Examine the pulses on channel 1 and channel 2 of the oscilloscope. Check that the falling edge of the pulse on XT16 occurs 3.6 ±0.1 microseconds after the trigger. Check that the falling edge of the pulse on XT10 falls before the falling edge of the pulse on XT16.
Check that the SHAPE front panel indicator on the monitor is lit.
3.4.8.13 Monitor Self Test Check Select Ch.1 on the CTU softkeys.
Check that approximately every 15 seconds a monitor self check is initiated and that on the monitor the DELAY and SPACING indicators go out and that the PRIMARY indicator is lit immediately following the SELF TEST indicator being lit.
3.4.8.14 Front Panel Switch Check On the CTU press the switches in the following order:
SELECT MAIN, OFF/RESET SOURCE LOCAL MAINTENANCE OFF MONITOR ALARM NORMAL SELECT MAIN NO 1.
After the first ident code, check that all front panel indicators except PRIMARY, SECONDARY and SELF TEST are lit.
Toggle the monitor front panel switch MONITOR OUTPUTS to the FAILED position. Check that all green indicators are now extinguished and that the PRIMARY and SECONDARY indicators are lit. Return the switch to the NORMAL position, and check that all green indicators are on.
3.4.9 Peak Power Monitor 1A72512
3.4.9.1 Test Equipment Oscilloscope. Digital multimeter. Peak power meter. Stepped attenuator, 11 dB.
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3.4.9.2 Performance Check Place the monitor module in the transponder extender frame and replace the peak power monitor with the unit to be tested. Ensure that the cable connections from the monitor main board to the peak power monitor board are correct.
On the RF panel (at the rear of the rack at the top), connect the following components and connecting cables:
a. 50 ohms termination to connector REV-A on the directional coupler.
b. 10 dB attenuator to connector FWD-A on the directional coupler.
c. 11 dB stepped attenuator connected via a short coaxial cable to the 10 dB attenuator above.
d. Coaxial cable from the 11 dB stepped attenuator to the ERP IN connector on the rear of the transponder subrack.
On the CTU front panel, press ESC, Ch.1, Param and PwrOut. Check that the measured output power is in the range 1.1 to 1.3 kW.
On the CTU front panel press the switches in the following order:
SOURCE LOCAL MAINTENANCE OFF MONITOR ALARM INHIBIT SELECT MAIN NO 1.
Disconnect the coaxial cable from the input of the unit under test and reconnect it to the peak power meter. Set the peak power meter to 0 dB and 100 mW ranges, and to the DIRECT measurement mode. Measure the peak power and set the level to 10.0 ±0.5 mW by adjusting the stepped attenuator and then using the RF OUTPUT control on the transmitter driver front panel as a fine adjustment.
Reconnect the cable to the input connector of the unit under test.
Trigger the oscilloscope from the test interrogator front panel jack TRIGGER and connect channel 1 to the monitor module front panel ERP PULSE test jack using AC coupling. Check that the waveform at this point is a pair of Gaussian-shaped pulses of amplitude in the range 2.0 to 2.4 volts.
Connect the digital multimeter to XN2:14 on the monitor main board. Check that the DC voltage is in the range 2.45 to 2.95 volts.
Reconnect the input cable to the peak power meter again, then repeat the above procedure to set the peak power level to 100 ±5 mW.
Again reconnect the input cable to the unit under test, and at the ERP PULSE test jack check the amplitude of the pulses present; they should be between 6.6 and 7.4 volts.
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Measure the DC voltage at XN2:14; it should be between 8.2 and 9.2 volts.
3.4.9.3 Completion On the CTU, press the SELECT/OFF RESET switch.
Remove the stepped attenuator and extra cables from the RF panel and restore the original connections.
Remove the tested unit from the monitor module, and replace the original peak power monitor.
3.4.10 Test Interrogator 1A72514
3.4.10.1 Test Equipment Oscilloscope. Peak power meter. Spectrum analyser. Digital multimeter. Test cable, RG-213, 800 mm, N(M) to N(M). Cable, coaxial, 0.5 dB.
3.4.10.2 Signal Pulse Generation Checks Ensure that the RF Generator 1A72516 of the unit under test has been aligned as described in Section 3.4.12.
Extend the test interrogator using the transponder extender frame. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
On the test interrogator, undo the cable connector at the output of the RF generator, and connect the output of the RF generator to RF IN on the sensor of the peak power meter using a short semirigid coaxial cable.
On the peak power meter, read the pulse peak amplitude. It should be +11.5 ±0.2 dBm (14.1 ±0.7 mW). If the reading is outside this range, remove the cover of the modulator and detector and adjust PULSE AMPLITUDE on this board to set the peak power meter reading to a value in the specified range.
Connect channel 1 of the oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH on the front panel of the test interrogator. Measure the following parameters of the displayed pulses (see figure below).
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NOTE If the pulse amplitude and/or shape are outside the above limits, they can be corrected by removing the lid of the modulator and detector on the test interrogator and adjusting R13 (PULSE AMPLITUDE), R20 (PULSE SHAPE) and R37 (PULSE PEDESTAL) providing that the pulse amplitude on the peak power meter remains at 14.1 ±0.7 mW. The DC level shift is measured by observing the baseline lifting from its normal position when switch S 1:6 on the RF generator is set to ON, temporarily.
Disconnect the peak power meter and restore the connection from the output of the RF generator to the attenuator.
3.4.10.3 Pulse Switching On the CTU, select Lo Eff parameter measurement at a TI RATE of 1 kHz.
Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the receiver video. Measure the amplitude of the displayed synchronous video pulses with respect to the 0 volts reference (taking the mean of the noise on the peak of the pulses). The amplitude should be 1.2 ±0.5 volts.
On the CTU, select Hi Eff parameter measurement. On the oscilloscope measure the amplitude of the displayed synchronous video pulses with respect to the 0 volts reference. The amplitude should be 1.8 ±0.5 volts.
Calculate the difference between these two amplitudes; this difference should be in the range 0.4 to 0.7 volts.
On the CTU, select Effncy parameter measurement. On the oscilloscope check (see figure below) that the displayed synchronous video pulses alternate between the two levels measured above. Measure the time interval from the rising edge of the first pulse of a low level synchronous video pulse pair to the rising edge of the first pulse of a high level synchronous video pulse pair. This time interval should be 1.00 ±0.05 milliseconds. (Note that synchronous reply pulses, probably at a higher level, will also be present on the displayed waveform.)
3.4.10.4 Signal Level Calibration Using the 0.5 dB semi flexible coaxial cable, connect the pair of 1 dB and 10 dB stepped attenuators to the output of the RF generator. Set the attenuators to a total of 66 dB, to establish a reference level of -55 dBm.
Connect the spectrum analyser to the stepped attenuator output using the 800 mm test cable. Set the spectrum analyser controls to:
Centre frequency: Test interrogator frequency Bandwidth: 1 MHz Video filter: 1 MHz
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Scan width: 1 MHz per division Scan time: 5 to 10 seconds Input attenuator: to suit Log sensitivity: to suit.
Measure and record the peak signal level equivalent to -55 dBm, averaging the reading over 5 scans to reduce any error due to noise jitter. This reference level is defined as "Pcal 55”.
Set the attenuators to a total of 51 dB, to establish a reference level of -40 dBm. Measure and record the spectrum analyser peak signal level equivalent to this reference, again averaging over 5 scans. This reference level is defined as “Pcal 40”.
NOTE Once the reference levels have been established, DO NOT adjust any spectrum analyser controls in the following steps.
Disconnect the spectrum analyser cable from the stepped attenuators, disconnect the 0.5 dB cable from XC1 of the RF generator and reconnect the test interrogator's fixed and switched attenuators between the RF generator and the module output.
Connect the spectrum analyser cable to the module output using a suitable coaxial adaptor. Use the same test cable on the spectrum analyser as was used in establishing the reference levels.
Set the Attenuator 1A69737 to the ON state by removing the connection from its connector XFB. Observe the high level interrogation signal on the spectrum analyser. Measure and record the averaged (over 5 scans) displayed level and, by comparing it with the Pcal 40 reference, calculate the corrected output signal level, which should be -40.0 ±1.0 dBm.
Set the attenuator to the OFF state by replacing the connection to connector XFB and then using a shorting lead to ground the upper end of R2 on the test interrogator main board (a ground point is available at the nearby XA2 test jack). Observe the low level interrogation on the spectrum analyser. Measure and record the averaged (over 5 scans) displayed level and, by comparing it to the Pcal 55 reference, calculate the corrected output signal level, which should be -55.0 ±1.0 dBm.
Remove the shorting lead and recheck the calibration described above, to ensure that the reference levels are still valid. If the reference levels have changed, the measurements must be repeated.
Restore all connections within the module.
3.4.10.5 Reply Signal Checks Connect channel 1 of the oscilloscope (externally triggered from the test jacks TRIGGER and EARTH on the test interrogator) to DETECTED REPLIES and EARTH on the test interrogator.
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Measure the half-height pulse width of the second pulse of the synchronous replies. On the CTU, select Width parameter measurement. The displayed width should be within ±0.1 microseconds of the width measured on the oscilloscope.
On the oscilloscope, measure the rise time (10% to 90%) of the second pulse of the synchronous replies. On the CTU, select Rise parameter measurement. The displayed rise time measurement should be within ±0.1 microseconds of the rise time measured on the oscilloscope.
On the oscilloscope, measure the fall time (90% to 10%) of the second pulse of the synchronous replies. On the CTU, select Fall parameter measurement. The displayed fall time measurement should be within ±0.1 microseconds of the fall time measured on the oscilloscope.
On the oscilloscope, measure the spacing between the two pulses of the synchronous replies (use the 1 µs MARKERS on the test interrogator front panel for greater accuracy if required). On the CTU, select Spacing parameter measurement. The displayed spacing measurement should be within ±0.1 microseconds of the spacing measured on the oscilloscope.
Connect channel 2 of the oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH on the test interrogator. Measure the delay from the half-height point of the first pulse of the interrogations to the half-height point on the first pulse of the synchronous replies (use the 1 µs MARKERS on the test interrogator front panel for greater accuracy if required). On the CTU, select Delay parameter measurement. The displayed delay measurement should be within ±0.1 microseconds of the delay measured in on the oscilloscope.
Connect the digital voltmeter to XN2:1 8 on the main board (COMMON to chassis). The voltmeter reading should be in the range 5.4 to 6.8 volts.
On the CTU, select PwrOut parameter measurement and on the test interrogator main board adjust TPNDR OP LVL CAL (R7) to produce a CTU reading of 1.2 kW.
On the CTU, select Hi Eff parameter measurement (in Maintenance mode). The displayed efficiency reading should be greater than 99.8%.
On the CTU, select Lo Eff parameter measurement. The displayed efficiency reading should be greater than 80%.
Connect channel 1 of the oscilloscope to test jacks INTERROGATIONS TIMING and EARTH and channel 2 of the oscilloscope to test jacks REPLY TIMING and EARTH on the test interrogator. On the front panel of the test interrogator, press and hold operated CHECK DETECTOR COINCIDENCE and measure on the oscilloscope the time interval between the leading edges of the pulses on the two channels; this time interval should be not greater than 0.1 microseconds.
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3.4.11 Main PWB Assembly Test Interrogator 1A72515
3.4.11.1 Test Equipment Oscilloscope. Digital multimeter. Peak power meter.
3.4.11.2 Setup On the front panel of the test interrogator, switch MONITOR AND INTERROGATOR DC POWER to OFF.
Remove the test interrogator from the depot test facility, remove the test interrogator main board from the module and assemble the board to be tested in its place. Ensure that both of the programmable devices are inserted correctly and that the ribbon cable connector is plugged into XN2 on the rear of the board.
Install the test interrogator into the transponder extender frame, and the extender frame into the transponder subrack.
Set the mode switch S4 on the test interrogator main board to X.
On the CTU front panel, press the switches in the following order:
SOURCE LOCAL MAINTENANCE ON MONITOR ALARM INHIBIT SELECT MAIN NO 1.
On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
Check the front panel test jacks on the test interrogator module and ensure that:
+5V is in the range 4.75 to 5.25 volts; +1 5V is in the range 14.7 to 15.3 volts.
3.4.11.3 Interrogation Generation Check 1. On the CTU, ensure that the interrogation rate is set to 100 Hz (by toggling the TI
RATE, 1 kHz switch, if necessary).
2. Connect channel 1 of the oscilloscope (triggered to channel 1) to the test jacks TRIGGER and EARTH on the front panel of the test interrogator. The period of the displayed waveform should be 10 ±1 milliseconds.
3. Connect channel 2 of the oscilloscope to XN2:20 on the test interrogator main board. Check that a square wave signal is present, with an amplitude of 1.1 ±0.2 volts and a period of 20.0 ±0.4 milliseconds.
4. On the CTU, press TI RATE, 1 kHz. The period of the display on channel 1 of the oscilloscope should change to 1.0 ±0.1 milliseconds.
5. On the CTU, select Effncy parameter measurement.
6. Connect channel 2 of the oscilloscope to the test jacks DETECTED LOG VIDEO and EARTH on the front panel of the receiver video. The display should be as shown below, with the level of interrogations alternating between high and low levels (the synchronous reply pulses also will be present on the displayed waveform).
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7. On the CTU select Lo Eff parameter measurement. The channel 2 display should
show all interrogations to be at the lower level of step 6.
8. On the CTU select Hi Eff parameter measurement. The channel 2 display should show all interrogations to be at the higher level of step 6.
9. On the CTU, press and hold TI RATE, 10 kHz. The period of the display on channel 1 of the oscilloscope should change to 100 ±10 microseconds.
10. On the CTU, select Effncy parameter measurement. The channel 2 display on the oscilloscope should be similar to that of step 6, except that:
a. the interrogations should be spaced at 100 microseconds;
b. only about one-third of the replies will be indicated; and
c. all the interrogations should be at the high level established above.
If necessary, the display of step 6 can be recalled by temporarily releasing the TI RATE, 10 kHz key.
On completion of the measurements, release the TI RATE, 10 kHz key.
3.4.11.4 Spacing Offset Control Connect channel 1 of the oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH.
Connect channel 2 of the oscilloscope to test jacks 1 µs MARKERS and EARTH on the front panel of the test interrogator. Using the displayed markers (or an accurately calibrated oscilloscope), measure the spacing between the detected pulses (channel 1 on the oscilloscope). It should be 12.0 ±0.1 microseconds measured at the half amplitude points on the leading edges. While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, REJECT to +2 microseconds. Measure the increase in spacing between the detected pulses. It should be 2.0 ±0.1 microseconds.
While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, REJECT to -2 microseconds. Measure the decrease in spacing between the detected pulses. It should be 2.0 ±0.1 microseconds.
While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, ACCEPT to +1 microsecond. Measure the increase in spacing between the detected pulses. It should be 1.0 ±0.1 microsecond.
While observing the oscilloscope display, switch TEST TRANSPONDER DECODING, ACCEPT to -1 microsecond. Measure the decrease in spacing between the detected pulses. It should be 1.0 ±0. 1 microsecond.
3.4.11.5 Reply Signal Processing Check On the CTU, select Hi Eff parameter measurement and TI RATE, 1 kHz.
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Move channel 2 of the oscilloscope to test jacks DETECTED REPLIES and EARTH on the front panel of the test interrogator. Gaussian-shaped pulses should be displayed, delayed about 50 microseconds from the interrogation triggers displayed on channel 1.
Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks REPLY TIMING and EARTH on the test interrogator.
Connect channel 2 of the oscilloscope to test jacks REPLY ACCEPT GATES and EARTH on the test interrogator.
While observing the oscilloscope, adjust REPLY GATE DELAY, COARSE and FINE control on the test interrogator front panel to align the centre of the REPLY ACCEPT GATES within ±0.5 microseconds of the leading edges of the REPLY TIMING pulses.
3.4.11.6 Measurement Facilities Check On the CTU, select each of the following check parameters in turn; confirm that each is within the stated limits:
Vcal : 5.00 ±0.02 volts Rcal : 5000±2Hz Tcal : 100.0 ±0.2 microseconds.
On the CTU, select Delay parameter measurement; the displayed reading should be 50.0 ±0.2 microseconds.
On the CTU, select Spacing parameter measurement; the displayed reading should be 12.0 ±0.1 microseconds.
On the CTU, select Effncy parameter measurement; the displayed reading should be greater than 90%.
On the CTU, select D.Rate parameter measurement; the displayed reading should be between 990 and 1000 Hz.
On the CTU, select Tx.Rate parameter measurement; the displayed reading should be 1000 ±10 Hz.
On the receiver video, hold the TEST switch operated to the REPLY RATE MONITOR TEST position. The displayed CTU reading should be 810 ±10 Hz.
On the CTU, select Width measurement; the displayed reading should be 3.5 ±0.3 microseconds.
On the CTU, select Rise measurement; the displayed reading should be between 1.9 and 2.5 microseconds.
On the CTU, select Fall measurement; the displayed reading should be between 1.9 and 2.5 microseconds.
On the CTU, select PwrOut parameter measurement and make a note of the power reading. Adjust the preset TPDR OP LVL CAL (R7) to give a CTU reading of 1.3 kW to prove that this value can be achieved. Readjust R7 to give a CTU reading of 0.7 kW to prove that this value can be achieved. Readjust R7 again to give the original CTU reading.
On the CTU, select TI PS status display; the displayed status should be NORMAL.
On the receiver video, ensure that IDENT is switched to NORMAL.
On the monitor, ensure that all green indicators are on and that all other indicators are off (except for approximately every 16 seconds when monitor SELF TEST flashes).
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3.4.11.7 Transponder Output Power Calibrate Alignment With the DME switched off, disconnect the load from the antenna connector on the RF panel at the rear of the rack. To the antenna connector, connect firstly a 30 dB, 50 watts attenuator then a 20 dB, 1 watt attenuator. Connect the peak power meter (or calibrated detector) to the output of the 20 dB attenuator.
Extend the test interrogator module, using the transponder extender frame.
On the CTU, press either the SELECT MAIN NO 1 or NO 2 key as required for the transponder under test. Set the CTU softkeys to display the PwrOut parameter, reading Ch.1 or Ch.2 as required for the test interrogator being adjusted.
While monitoring the CTU display, adjust the preset TPDR OP LVL CAL (R7) on the test interrogator main board to display a power output reading to within ±1 5 watts of the reading on the peak power meter. Be sure to include any correction factor necessary from the calibration data of the attenuators and peak power meter (or detector).
Remove the extender and replace the test interrogator into the depot test facility and re-check the power output reading on the CTU display which should be within ±30 watts of the corrected peak power meter reading. If the CTU reading is outside these limits, again extend the test interrogator and adjust TPDR OP LVL CAL (R7) to give the required adjustment, then replace the test interrogator in the depot test facility.
Switch off the DME, disconnect the peak power meter and attenuators, and replace the load at the antenna connector.
3.4.11.8 Monitor Fault Limit Facilities Check NOTE For this test, the monitor fault limit switches must be set as detailed in Section
3.3.
With the DME operating in Maintenance mode, ensure that all eight monitor parameter indicators are on.
On the CTU, select the FltLimit parameters listed in the table below. For each parameter, the displayed fault limits should be within the ranges listed in the table.
PARAMETER SPECIFIED VALUE LIMITS UNITS
Delay; Lower 49.5 ±0.1 µs
Delay; Upper 50.5 ±0.1 µs
Spacing; Lower 11.5 ±0.1 µs
Spacing; Upper 12.5 ±0.1 µs
Effncy; (Lower) 60 ±2 %
Tx Rate; Lower 833 ±10 Hz
Tx Rate; Upper 3000 ±30 Hz
Ant Power, (Lower) -3 0 dB
3.4.11.9 Final Check Check that the DELAY, SPACING, EFFICIENCY, POWER, SHAPE and RATE parameter indicators on the monitor module are on.
3.4.12 RF Generator 1A72516
3.4.12.1 Test Equipment Oscilloscope. Spectrum analyser. Frequency counter.
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Peak power meter. Test crystals (see Section 3.4.12.3 step 1).
3.4.12.2 Setup 1. Switch the depot test facility off. Remove the coaxial cable connected to the
INTERROGATION SIGNAL GENERATOR connector on the front panel of the test interrogator. Remove the test interrogator from the transponder subrack. Remove the lids and shims from the RF generator (modified) and the modulator and detector diecast boxes.
2. Replace the RF generator (modified) from the depot test facility with the RF generator to be tested (after first removing the coaxial connected to the output connector, XC1, the test interrogator main board, the four screws securing the RF generator (modified) to the chassis and the six leads from the modulator and detector).
3. Reconnect the six leads from the modulator and detector. Restore the test interrogator main board to its chassis. Extend the test interrogator in the transponder subrack using the transponder extender frame.
4. Connect the peak power meter to the output connector, XC1, of the RF generator, using a short, semi-rigid coaxial cable.
5. Switch the test facility on. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
6. On the modulator and detector board, set switch S1 to the test position.
7. On the CTU front panel, select Hi Eff test in Maintenance mode, and TI RATE, 1 kHz.
8. Using channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator front panel) check the following voltages and waveforms on the RF generator (connect the oscilloscope earth lead to the RF generator diecast box).
3.4.12.3 Alignment To fully test and prove an RF generator, the tests of this section should be performed at both the minimum and maximum DME interrogation frequencies, 1025 MHz and 1150 MHz respectively. However, if the RF generator is only to be realigned for its operational DME interrogation frequency, the tests of this section need only be performed at this operational frequency.
1. Install the five oscillator crystals in the RF generator. The crystal frequencies are one-twelfth of the station interrogation frequency and the offsets from it.
Example: Channel 84X interrogation frequency = 1108 MHz Fo hence crystal frequency = 1108/12 = 92.3333 MHz Fx
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The five interrogation frequencies and the corresponding crystal frequencies are shown in the table below:
CRYSTALFREQUENCY CCT REF
INTERROGATION FREQUENCY For 1025 MHz For 1150 MHz For Operational Freq
G1 F0 85.4167 MHz 95.8333 MHz Fx = F0 /12
G2 F0 +160 kHz 85.4300 MHz 95.8467 MHz Fx +13.3 kHz
G3 F0 -160 kHz 85.4033 MHz 95.8200 MHz Fx -13.3 kHz
G4 F0+ 900 kHz 85.4197 MHz 95.9083 MHz Fx +75 kHz
G5 F0 -900 kHz 85.3417 MHz 95.7583 MHz Fx -75 kHz
2. On the RF generator, switch 1 to 4 of S1 to OFF, S1:5 to ON and S1:6 to OFF.
3. Move channel 1 of the oscilloscope to test point XT1 on the RF generator and tune the core in L1 for peak positive DC voltage on the oscilloscope display (1.9 volts minimum).
4. Check that the oscillator is operating at the crystal frequency by using a one-turn coupling loop connected to the frequency counter and loosely coupled to L1.
5. On the RF generator, set switch S1:1 to ON, and switches 2 to 6 of S1 to OFF.
6. Move channel 1 of the oscilloscope to test point XT2 on the RF generator board and tune C10 for peak positive voltage during the pulse. If necessary, restrict the bandwidth of the oscilloscope to eliminate crystal frequency appearing on the trace.
7. Move channel 1 of the oscilloscope to test point XT3 and tune C14 for a peak
pulse indication (0.6 volts minimum).
8. Move channel 1, of the oscilloscope to test point XT4 and tune C18 for a peak
pulse indication (0.2 volts minimum).
9. Move channel 1 of the oscilloscope to VIDEO OUT on the peak power meter and
tune C22 for maximum output. The peak pulse output should be not less than 60 mW.
10. On the modulator and detector, set switch S1 to the normal position.
11. On the peak power meter, read the pulse peak amplitude. It should be 14.0 ±0.2 mW. (If the reading is outside this range, adjust R13 (PULSE AMPLITUDE) on the modulator and detector to set the peak power meter reading to a value in the specified range).
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12. Move channel 1 of the oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH on the front panel of the test interrogator. Measure the following parameters of the displayed pulses:
PEAK AMPLITUDE (FROM BASELINE): 3.0 ±0.3V HALF AMPLITUDE PULSE WIDTH: 3.4 ±.02µs FLAT TOP DURATION: 1.0 ±.02µs BASE LINE DC LEVEL: 3.6 ±0.3V
If the pulse amplitude and/or shape are outside the above limits, they can be corrected by adjusting R13 (PULSE AMPLITUDE) and R20 (PULSE SHAPE) on the modulator and detector as required and then repeating step 11.
13. On the oscilloscope, use the vertical shift control to align the baseline of the display onto a graticule line.
14. On the RF generator, set switch S1:6 to ON to add a CW signal to the pulse. The display on channel 2 of the oscilloscope should remain the same except that the baseline should move up the pulse. The DC level shift of the baseline level from the reference level set in the previous step should be 0.95 ±0.05 volts. If the DC level shift is outside the above limits, it can be corrected by and adjusting R37 (PULSE PEDESTAL) on the modulator and detector.
15. Remove the peak power meter from XC1 and replace it with the frequency counter (through a suitable cable). Terminate the frequency counter with 50 ohms. Set switch S1:6 to ON to add a CW signal to the pulse. Measure the output frequency selecting each crystal in turn (switches 1 to 5 of S1 set to ON one at a time in turn). The frequencies should be within ±10 kHz of those of the table of step 1.
16. Disconnect the frequency counter from the output of the RF generator and connect the spectrum analyser. On the RF generator switch S1:1 to ON and 2 to 6 of S1 to OFF. On the spectrum analyser, check that all undesired harmonics and spurious are at least 30 dB below the desired signal.
3.4.12.4 Completion After having performed the above tests at the required frequencies, switch the depot test facility off, remove the RF generator under test from the test interrogator in the depot test facility, and replace it with the RF generator (modified), ensuring that all screws and electrical connections are correctly replaced and securely tightened.
Replace the shims and lids of the diecast boxes. Note that the lids are deliberately warped to ensure good RF sealing. Tighten the screws firmly.
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Remove the transponder extender frame and install the test interrogator back in the depot test facility.
3.4.13 RF Filter 1A72517
3.4.13.1 Test Equipment Signal generator. Spectrum analyser. Directional coupler. Adaptor SMA (female). 50 ohms termination SMA (male). Coaxial cables: Qty 4 (two with SMA male on cable).
3.4.13.2 Requirement This procedure is suitable for a thorough test of a refurbished unit. If it is required to test a unit without re-tuning, use only the test procedure in Section 3.4.13.12.
The procedure uses a separate oscillator, spectrum analyser and directional coupler to measure the power reflected back from the unit under test.
3.4.13.3 Insertion Loss - Equipment Calibration Set the spectrum analyser for:
Centre frequency 1100 MHz Span 40 MHz/division (50) Sweep time 10 millisecond/division Amplitude scale 10 dB/division Resolution bandwidth 1 MHz Reference level 0 dBm
Set up the equipment as shown in Figure 3-4, but with a direct connection in place of the unit under test. The 10 dB attenuators should be placed as close to the unit under test as possible (they ensure a well defined impedance at the connection points to the unit under test). Set the oscillator output to a level of +10 dBm and the spectrum analyser to 2 dB/division amplitude range.
Calibrate the test equipment for a reference insertion loss of 0 dB over the frequency range 950-1250 MHz as described in Section 3.4.1.5.2.
3.4.13.4 Filter Tuning Procedure Set the spectrum analyser back to 10 dB/division and the signal generator to 1100 MHz.
Connect the filter as the unit under test.
Adjust filter capacitors C1 and C2 for the best response (minimum insertion loss) at 1100 MHz and compare the response with that shown below (marker 2) by sweeping the signal generator frequency, manually or automatically.
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3.4.13.5 Insertion Loss - Measurement Reset the spectrum analyser to 2 dB/division scale and measure the insertion loss at 1100 MHz. When correctly aligned, the insertion loss should not exceed 2.8 dB.
3.4.13.6 Return Loss - Equipment Calibration Set up the equipment as shown in Figure 3-2 and set the oscillator output to a CW level of +10 dBm.
Set the spectrum analyser controls as before.
Calibrate the test equipment for return loss measurement as described in Section 3.4.1.5.1.
3.4.13.7 Return Loss - Measurement Connect the input connector XC1 in place of 50 ohms termination with termination now connected to XC2.
Display the return loss for the filter, by sweeping the signal generator frequency, and compare with the results shown in the figure below (marker 2). When correctly aligned, the return loss at the centre of the passband (1100 MHz) should be not less than 25 dB, the shape being as below.
3.4.13.8 Filter Adjustments If the required response and return loss characteristics cannot be achieved, it may be necessary to adjust the coupling between the filter sections. This is achieved by varying
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the spacing of the wire loops in relation to the slot in the centre partition. The loops must be moved only in small amounts, as this spacing is critical. There are two conditions which indicate incorrect coupling:
a. Under-coupled, indicated by excessive insertion loss and low return loss with a single shoulder notch. Increase the coupling by gently squeezing the loops closer together, on each side of the slot. Keep the loops equally spaced from the partition.
b. Over-coupled, indicated by a “double hump" transmission response and low return loss with a double peak characteristic. Decrease the coupling, by gently bending the wire loops away from the slot, but keeping them equally spaced from the partition.
If satisfactory return loss cannot be achieved after adjustment of coupling, it is possible that the connectors are not soldered to equal tapping points on the wire loops. Carefully examine each connection point, and ensure that the length of wire from each connector centre pin to ground is identical.
When the filter is correctly aligned, the transmission and return loss responses should be very similar to those shown in the above figures.
3.4.13.9 Filter Response at 1100 MHz With the filter tuned for 1100 MHz, measure the following performance characteristics, which should be within the limits stated:
1. Return loss not less than 25 dB.
2. Insertion loss not exceeding 2.8 dB.
3. Response at 1000 MHz not less than 33 dB below peak response.
4. Response at 1200 MHz not less than 33 dB below peak response.
3.4.13.10 Filter Response at 960 MHz Tune the filter for minimum insertion loss and maximum return loss at 960 MHz, by adjustment of C1 and C2 only. It should not be necessary to make any changes to the coupling if the alignment at 1100 MHz was done correctly. If the coupling is changed, for any reason, then the measurements at 1100 MHz must be repeated.
Check that the transmission and return loss characteristics are very similar to those shown in the figures for filter tuning and return loss measurement (marker 1) respectively.
Measure the following performance characteristics, which should be within the limits stated:
1. Return loss not less than 17 dB.
2. Insertion loss not exceeding 3.0 dB.
3. Response at 1060 MHz not less than 37 dB below peak response.
3.4.13.11 Filter Response at 1215 MHz Tune the filter for minimum insertion loss and maximum return loss at 1215 MHz, by adjustment of C1 and C2 only. If the coupling is changed, for any reason, then the measurements at 1100 MHz and 960 MHz must be repeated.
Check that the transmission and return loss characteristics are very similar to those shown in the figures for filter tuning and return loss measurement (marker 3) respectively.
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Measure the following performance characteristics, which should be within the limits stated:
1. Return loss not less than 17 dB.
2. Insertion loss not exceeding 2.8 dB.
3. Response at 1115 MHz not less than 33 dB below peak response.
3.4.13.12 Test at Station Frequency Repeat the procedures for insertion loss and filter tuning at the station frequency.
Tune the filter for minimum insertion loss and maximum return loss at the required frequency, by adjustment of C1 and C2 only.
Measure the three parameters:
1. Return loss.
2. Insertion loss.
3. Response at ±100 MHz.
and check that the results are between the limits stated for 1100 MHz and the end-of-band frequency (beyond the station frequency).
3.4.14 Modulator and Detector 1A72518
3.4.14.1 Test Equipment Oscilloscope. Peak power meter. Detector.
3.4.14.2 Performance Check and Adjustment Switch the depot test facility off. Extend the test interrogator on the transponder extender frame.
Remove lids from the RF generator and the modulator and detector subassemblies in the module.
Remove the modulator and detector board from the module and install the board to be tested.
Set switch S1 on the modulator and detector board to the test position and connect the peak power meter, via a short semirigid coaxial cable, to XC1 of the RF generator.
Switch the depot test facility on. On the CTU front panel, set the following switches:
SOURCE LOCAL MAINTENANCE ON MONITOR ALARM INHIBIT SELECT MAIN NO 1 PARAM 1 kHz. Set the MONITOR AND INTERROGATOR DC POWER switch on the test interrogator front panel to ON. Check with the oscilloscope that pulses at XS7 are 3 microseconds duration, +15 volts amplitude and 1 millisecond period.
Check for the following voltages and waveforms on the modulator and detector board.
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Set all three preset resistors to mid-position and set switch S1 to the normal position.
On the peak power meter, read the pulse peak amplitude. It should be +11.5 ±0.2 dBm (14.1 ±0.7 mW). If the reading is outside this range, adjust PULSE AMPLITUDE (R13) to set the peak power meter reading to a value in the specified range.
Connect channel 1 of the oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH on the front panel of the test interrogator. Measure the following parameters of the displayed pulses (see figure below).
Switch CW TEST switch S1:6 on the RF generator board to ON, and adjust R37 (PULSE PEDESTAL) on the modulator and detector board for 0.2 volts shift from the baseline. Switch S1:6 to OFF. On the modulator and detector board, adjust the R20 (PULSE SHAPE) and (R13) PULSE AMPLITUDE until the correct shape is achieved.
Connect the oscilloscope probe on channel 1 to XS6 on the modulator and detector board and check that the pulse shape on channel 1 closely matches that on channel 2 and the amplitude of the pulse on channel 1 is 1.5 ±0.2 volts.
Connect the oscilloscope probe on channel 1 to XS5 on the modulator and detector board and check that the pulse shape closely matches that on channel 2 and the amplitude of the pulse is 3.0±0.4 volts.
Connect the oscilloscope probe on channel 2 to XS3 and measure the DC voltage. It should be 3.0 ±0.4 volts.
Vary the pulse amplitude with R13 (PULSE AMPLITUDE) and ensure that the DC voltage at XS3 closely tracks the amplitude of the pulse at XS5.
Move the oscilloscope probe on channel 2 to XS4 on the modulator and detector board and check that a positive pulse of amplitude not less than 14 volts is present. Measure
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the duration between half-amplitude points of the pulse at XS5 and measure the width of the pulse at XS4. The two timings should be within ±0.1 microseconds.
NOTE When using a Depot Test Facility equipment the 2A72516 RF Generator (Modified) requires different settings of the preset controls compared with the 1A72516, so R20 (PULSE SHAPE) may be close to one end of its travel.
3.4.15 Reply Detector 1A72519
3.4.15.1 Test Equipment Oscilloscope. Digital multimeter. Peak power meter. Stepped attenuator, 11 dB.
3.4.15.2 Performance Check Place the test interrogator module in the transponder extender frame and replace the reply detector with the unit to be tested. Ensure that the cable connections from the test interrogator main board to the reply detector board are correct.
On the RF panel (at the rear of the rack at the top), connect the following components and connecting cables:
a. 50 ohms termination to connector REV-A on the directional coupler.
b. 10 dB attenuator to connector FWD-A on the directional coupler.
c. 11 dB stepped attenuator connected via a short coaxial cable to the 10 dB attenuator above.
d. Coaxial cable from the 11 dB stepped attenuator to the input connector on the reply detector under test.
On the CTU front panel, press ESC, Ch.1, Param and PwrOut. Check that the measured output power is in the range 1.1 to 1.3 kW.
On the CTU front panel press the switches in the following order:
SOURCE LOCAL MAINTENANCE OFF MONITOR ALARM INHIBIT SELECT MAIN NO 1.
3.4.15.3 Detector Check Disconnect the coaxial cable from the input of the unit under test and reconnect it to the peak power meter. Set the peak power meter to 0 dB and 100 mW ranges, and to the DIRECT measurement mode. Measure the peak power and set the level to 10.0 ±0.5 mW by adjusting the stepped attenuator and then using the RF OUTPUT control on the transmitter driver front panel as a fine adjustment.
Reconnect the cable to the input connector of the reply detector.
Trigger the oscilloscope from the test interrogator front panel jack TRIGGER and connect channel 1 to the test interrogator module front panel DETECTED REPLIES test jack using AC coupling. Check that the waveform at this point is a pair of Gaussian-shaped pulses of amplitude in the range 2.0 to 2.4 volts.
Connect the digital multimeter to XN2:14 on the test interrogator main board. Check that the DC voltage is in the range 2.0 to 2.4 volts.
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Reconnect the input cable to the peak power meter, then repeat the above procedure to set the peak power level to 100 ±5 mW.
Again reconnect the input cable to the unit under test, and at the DETECTED REPLIES test jack, check the amplitude of the pulses; they should be between 6.6 and 7.4 volts.
Measure the DC voltage at XN2:14; it should be between 6.6 and 7.4 volts.
3.4.15.4 Timing Pulses Check Connect channel 1 of the oscilloscope (externally triggered from the test jacks TRIGGER and EARTH on the test interrogator) to DETECTED REPLIES and EARTH on the test interrogator.
Measure the half-height pulse width of the second pulse of the synchronous replies. On the CTU, select Width parameter measurement. The displayed width should be should be within ±0.1 microseconds of the width measured on the oscilloscope.
On the oscilloscope, measure rise time (10% to 90%) of the second pulse of the synchronous replies. On the CTU, select Rise parameter measurement. The displayed rise time should be should be within ±0.1 microseconds of the rise time measured on the oscilloscope.
On the oscilloscope, measure fall time (90% to 10%) of the second pulse of the synchronous replies. On the CTU, select Fall parameter measurement. The displayed fall time should be should be within ±0.1 microseconds of the fall time measured on the oscilloscope.
3.4.15.5 Detector Coincidence Check Connect channel 1 of the oscilloscope to test jacks INTERROGATIONS TIMING and EARTH and channel 2 of the oscilloscope to the test jacks REPLY TIMING and EARTH on the test interrogator.
On the front panel of the test interrogator, press and hold operated the CHECK DETECTOR COINCIDENCE switch. Measure the time interval on the oscilloscope between the leading edges of the pulses on the two channels; this should be not greater than 0.1 microseconds.
3.4.15.6 Completion On the CTU, press the SELECT/OFF RESET switch.
Remove the stepped attenuator and extra cables from the RF panel and restore the original connections.
Remove the tested unit from the monitor module, and replace the original reply detector.
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3.4.16 Receiver Video 1A72520
3.4.16.1 Test Equipment Spectrum analyser. Oscilloscope. Frequency counter. Attenuator, miniature, 6 dB. Attenuator, step, 10 dB range, 1 dB steps. Attenuator, step, 110 dB range, 10 dB steps. Peak power meter. Digital multimeter. Coaxial cables and adaptors.
3.4.16.2 Setup Ensure that the RF source on the unit under test has been aligned to the station reply frequency (see Section 3.4.18).
Ensure that the IF amplifier and RF amplifier of the unit under test have been aligned (see Sections 3.4.19 and 3.4.20 respectively).
Align the test interrogator in the depot test facility to the interrogation frequency (see Appendix K).
Mount the receiver video to be tested into the depot test facility, on the transponder extender frame.
Remove the test interrogator module from the depot test facility and reconnect the output cable (to XC2) directly to the RF generator board output connector, via a 6 dB attenuator pad. Replace the test interrogator in the depot test facility.
At the RF panel, disconnect the semirigid cable at the output of the pre-selector filter (this is the cable that connects to the receiver video module).
At the depot test facility RF panel, using short RG-188 cables and minimum necessary adaptors, connect the two variable attenuators between the TEST INTRGS connector and the semirigid coaxial cable removed from the pre-selector output.
Using the peak power meter in DIRECT mode on the 10mW range, measure the RF pulse-pair signal amplitude just before the semirigid cable; with the tens attenuator at 0 dB, adjust the units attenuator until the power level is 1.0 ±0.1 mW. This attenuator setting (which should be about 4 or 5 dB) is the reference 0 dBm value.
The equipment setup is shown in Figure 3-9.
Connect the RF output from the variable attenuator to the receiver video under test. Set the tens attenuator to 110 dB (to give a level of -110 dBm) and switch on the power to the module under test.
Remove the cover from the IF amplifier and, using a digital multimeter, check that:
a. at XT10, the DC voltage is 5.0 ±0.1 volts - adjust R50, ON CHANNEL preset, if necessary to achieve this;
b. at XT13, the DC voltage is 6.0 ±0.1 volts - adjust R15, AGC preset, if necessary to achieve this;
c. set the DC voltage at XT6 on the IF amplifier to 4.0 ±0.1 volts by adjusting the, GAIN preset, R29.
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Figure 3-9 Test Setup for Receiver Video Module
3.4.16.3 Performance Tests Set the tens attenuator to 30 dB, to give a level of -30 dBm.
Connect the oscilloscope trigger input to the TRIGGER jack on the test interrogator module front panel and set the timebase to 2 microseconds/division.
Connect the oscilloscope probe to the DETECTED LOG VIDEO and adjacent EARTH test jacks on the receiver video front panel and check that the signal is as shown below.
Set the tens attenuator to 100 dB and increase the units attenuator by 5 dB to give –95 dBm input. Check that the "peak tangential noise" input condition is met, as shown below.
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Peak tangential noise condition is when the noise peaks on the bottom of the pulse coincide with the noise peaks on either side of the pulse: the peak tangential noise sensitivity is the input level to achieve this condition, in this case -95 dBm.
Set the units attenuator to the reference value, and the tens attenuator to 90 dB to give -90 dBm input level, and observe the small noisy pulse; increase the input signal level in 10 dB steps and check that there are equal increases in pulse amplitude up to -10 dBm input.
Increase the input level to 0 dBm (attenuators switched to reference value) and note that the pulse is substantially flattened on top. Again reduce the input level to -15 dBm (tens attenuator to 10 dB and units attenuator increased by 5 dB above the reference value) and check that the pulse now shows no signs of flattening.
Both conditions specified above (peak tangential noise input condition, and no pulse flattening) should be met, as shown below. If they are not met, then the IF amplifier should be checked as described in Section 3.4.19.
In the figure above, the noise level shown is at -95 dBm and the intermediate steps are 10 dB increments from -95 dBm to -15 dBm.
Return the input level to -30 dBm. Connect the oscilloscope probe to the ON CHANNEL VIDEO test jack and check that the signal is as shown below.
Reset the oscilloscope timebase to 1 millisecond/division and check random 15 volts noise pulses as well as the "on channel" signal pulses.
Connect a frequency counter to the front panel ON CHANNEL VIDEO test jack. Select a counter timebase of 1 second. Remove the signal pulses by setting the variable attenuators to maximum (120 dB).
Check that the noise count displayed on the frequency counter is between 20 and 200 pulses per second. If it is not, then make a gain adjustment to IF amplifier preset R29 to achieve this count, ensuring that the voltage at XT6 stays within the limits of 4.0 ±0.2 volts.
Readjust the oscilloscope to 2 microseconds/division timebase and decrease the attenuation until the signal pulse re-appears.
Set the attenuator so that the pulse is just solid and note the dB value; this should correspond to a level equal to, or below, -95 dBm.
Connect the peak power meter to the RF OUTPUT connector XC1 of the RF source board. The RF output level should be within the range +5 to +7 dBm. If it exceeds +7 dBm, reduce the output by turning the RF source output capacitor C26 clockwise (i.e.,
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inwards). If the level is less than this +5 dBm, then refer to Section 3.4.18 to retune the module.
Remove the peak power meter from XC1 and reconnect the RF source to the RF amplifier via the RF filter.
Connect the peak power meter to XC2 of the receiver video module.
Tune the RF filter capacitors C1 and C2 for maximum output on the power meter.
Measure the output power, which should be +12.5 dBm ±1.5 dB.
Connect the multimeter to the front panel LOCAL OSC LEVEL test jack; the signal should be 2.0 ±1.0 volts.
Connect the multimeter to the front panel RF LEVEL test jack; the signal should be 3.0 ±1.5 volts.
Connect the spectrum analyser via the 10 dB attenuator to XC2 of the receiver video module. Set the analyser controls as follows:
Attenuator 20 dB Bandwidth 30 kHz Display 50 MHz/division (or full sweep) Sweep time 2 seconds (0.2 seconds/division)
Observe the displayed spectrum and set the LEVEL control on the spectrum analyser for a reference level of 0 at the wanted centre frequency. Check that the levels at frequencies offset from the centre by the crystal frequency are at least 65 dB below the reference. Also check, using full sweep display, that all other spectral components present are at least 65 dB below the reference. If the module fails this test then the RF source and the RF filter may require retuning. Refer to the RF source procedure (Section 3.4.18) for details.
Connect the frequency counter, through a 10 dB attenuator to the RF output, and measure the actual frequency at the output. If the actual frequency is outside the allowed range then the RF source may require retuning. Refer to the RF source procedure (Section 3.4.18) for details.
At the completion of this sequence, switch the depot test facility rack off. Remove the transponder extender frame and the unit under test. Restore the receiver video (modified) to the depot test facility. Remove the test interrogator and restore the connections to the switched attenuator. Switch the rack on and check that it operates normally.
3.4.17 Main PWB Assembly Receiver Video 1A72521
3.4.17.1 Test Equipment Oscilloscope. Digital multimeter. Frequency counter. Small alligator clip (to short two adjacent test points on the unit under test). Stopwatch
3.4.17.2 Initial Setup Switch the depot test facility rack off and remove the receiver video from the transponder subrack.
Remove the ribbon cable connector from connector XN2 on the rear of the receiver video main board and remove this printed wiring board assembly from the receiver
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video. Assemble the receiver video main board to be tested onto the receiver video. Connect the ribbon cable connector to connector XN2 on the rear of the unit under test. Replace the receiver video into the transponder subrack using the transponder extender frame.
Switch the rack on. On the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
Using the digital multimeter, check that the voltage between test jacks +15V and EARTH is in the range 14.25 to 15.75 volts.
On the unit under test, set the switches as follows:
SWITCH FUNCTION SETTING
S1 BEACON DELAY, COARSE (on front panel) 9
S2 BEACON DELAY, FINE (on front panel) 4
S3 REPLY PULSE SPACING (on front panel) 8
S4 SELECT ENCODER MODE X
S5 SELECT DECODER MODE X
S6 SET LDES PERIOD 6
S7 SET DEAD TIME 6
S8 SDES OFF
S9 LDES OFF
S11 IDENT (on front panel) NORMAL
Set the ident CODE ELEMENT switches S13, S14. S15 and S16 as follows:
a. Convert the required ident letters into International Morse Code, using the following table.
LETTER MORSE SYMBOL LETTER MORSE SYMBOL
A dot dash N dash dot B dash dot dot dot O dash dash dash C dash dot dash dot P dot dash dash dot D dash dot dot Q dash dash dot dash E dot R dot dash dot F dot dot dash dot S dot dot dot G dash dash dot T dash H dot dot dot dot U dot dot dash I dot dot V dot dot dot dash J dot dash dash W dot dash dash K dash dot dash X dash dot dot dash L dot dash dot dot Y dash dot dash dash M dash dash Z dash dash dot dot
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b. Set the switches using the following code (shading indicates switch position).
EXAMPLE: For ident code AWA, switch settings are:
Set 6 dB offset by connecting the digital multimeter to test points XT6 and XT13 and adjusting ADJUST 6 dB OFFSET (R45) to set the displayed voltage to 0.23 ±0.01 volts.
Connect the frequency counter (set to period mode with a resolution of 1 millisecond) to test points XT20 and XT17 (COMMON). Adjust IDENT CODE SPEED (R37) to set the measured period to 125 ±5 milliseconds.
Connect the counter (set to period mode with a resolution of 1 millisecond) to test points XT7 and XT1 7 (COMMON). Adjust IDENT REPTN RATE (R39) to set the measured period to 667 ±25 milliseconds.
3.4.17.3 Decoder Checks On the CTU, select Hi Eff parameter measurement at a TI RATE of 1 kHz.
Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH.
Connect channel 2 of the oscilloscope to test jacks ON CHANNEL VIDEO and EARTH.
On the channel 1 display on the oscilloscope check that rounded top pulses are present in pairs. The amplitude of the displayed synchronous video pulses should be 1.8 ±0.5 volts with respect to the 0 volts reference.
On the channel 2 display on the oscilloscope check that square top pulse pairs are present in line with the channel 1 pulses.
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Move channel 2 of the oscilloscope to test jack DOUBLE PULSE DECODER OUT. The oscilloscope display should show a single square pulse positioned immediately after the second video pulse.
Move channel 2 of the oscilloscope to test jack TRIGS TO MODULATOR. The oscilloscope display should show a pulse pair positioned about 50 microseconds after the second video pulse.
Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks REPLY TIMING and EARTH also on the test interrogator.
Connect channel 2 of the oscilloscope to test jacks REPLY ACCEPT GATES and EARTH on the test interrogator.
On the oscilloscope, check that the centre of the first REPLY ACCEPT GATES pulse aligns, within ±0.5 microseconds, with the leading edge of the first REPLY TIMING pulse. (If this alignment is outside the specified limits, adjust BEACON DELAY, COARSE and FINE controls on the front panel of the unit under test to achieve the required alignment.)
On the CTU, select Delay parameter measurement. Adjust BEACON DELAY, COARSE and FINE controls on the front panel of the unit under test to achieve a displayed delay of 50.0 ±0. 1 microseconds.
On the oscilloscope, cheek that the centre of the second REPLY ACCEPT GATES pulse aligns, within ±0.5 microseconds, with the leading edge of the second REPLY TIMING pulse. (If this alignment is outside the specified limits, adjust REPLY PULSE SPACING control on the front panel of the unit under test to achieve the required alignment.)
On the CTU, select Spacing parameter measurement. Adjust the REPLY PULSE SPACING control on the front panel of the unit under test to achieve a displayed pulse spacing of 12.0 ±0.1 microseconds.
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On the CTU, select D.Rate parameter measurement. The displayed decoded rate (from the unit under test) should be in the range 990 to 1000 Hz.
On the test interrogator, switch and hold TEST TRANSPONDER DECODING, ACCEPT to +1 microsecond. The displayed decoded rate should be greater than 700 Hz. Release the switch.
On the test interrogator, switch and hold TEST TRANSPONDER DECODING, ACCEPT to -1 microsecond. The displayed decoded rate should be greater than 700 Hz. Release the switch.
On the test interrogator, switch and hold TEST TRANSPONDER DECODING, REJECT to +2 microseconds. The displayed decoded rate should be less than 50 Hz. Release the switch.
On the test interrogator, switch and hold TEST TRANSPONDER DECODING, REJECT to -2 microseconds. The displayed decoded rate should be less than 50 Hz. Release the switch.
3.4.17.4 Over Interrogation Check a. On the CTU select Hi Eff parameter measurement.
b. Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DETECTED LOG VIDEO and EARTH on the unit under test. Measure the pulse peak amplitude (with respect to mean noise baseline). The pulse peak amplitude should be not less than 1.1 volts.
c. While observing the oscilloscope display, press and hold TI RATE, 10 kHz on the
CTU. Measure the pulse peak amplitude (with respect to mean noise baseline). The pulse peak amplitude should be not less than 0.7 volts. (This proves correct operation of the AGC circuit in reducing interrogations.)
d. On the CTU, the displayed efficiency should be less than 30%. On the unit under test, confirm that the REPLIES INHIBITED indicator is flashing at about 2 Hz. Release the switch.
e. Short test points XT21 and XT22 to disable the AGC control to the IF amplifier. On the CTU, press and hold TI RATE, 10 kHz. The displayed efficiency should be less then 30%.
f. On the oscilloscope display, the pulse peak amplitude should not have changed from the value in step b. Release the switch.
3.4.17.5 Dead Time Check Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test jacks DEAD TIME and EARTH on the unit
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under test. The duration of the displayed pulse will have random variations. Check that the pulse duration remains in the range 58 to 73 microseconds.
3.4.17.6 Long Distance Echo Suppression Check On the CTU, select Hi Eff parameter measurement at a TI RATE of 1 kHz.
On the unit under test, switch LDES to ON.
Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test points XT13 and XT21 (GND). On the oscilloscope, measure the peak interrogation pulse voltage; it should be 2.70 ±0.50 volts.
Connect channel 2 of the oscilloscope to test points XT9 and XT21 (GND). While observing the oscilloscope display, adjust LDES LEVEL (R46) to set the long distance echo suppression level to 0.10 to 0.15 volts less than the voltage measured in the previous step.
Move channel 2 of the oscilloscope to test jacks DEAD TIME and EARTH. The duration of the displayed pulse will have random variations. Check that the pulse duration remains in the range 115 to 140 microseconds.
On the CTU, select Lo Eff parameter measurement. On the oscilloscope, check that the pulse duration remains in the range 58 to 73 microseconds.
On the unit under test, switch LDES to OFF.
3.4.17.7 Short Distance Echo Suppression Check On the CTU, select Hi Eff parameter measurement.
Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator) to test points XT13 and XT21 (GND) on the unit under test. Connect channel 2 of the oscilloscope to test jacks SDES PULSE and EARTH. On the oscilloscope, check that the displayed XT1 3 waveform is similar to that shown in the figure below for SDES OFF.
Switch SDES to ON. On the oscilloscope, check that an SDES pulse is now present and that the displayed XT13 waveform has the leading edge of the second pulse masked out in line with the SDES pulse as shown in the figure above for SDES ON. (The SDES pulse has a nominal width of 2.5 microseconds and is delayed a nominal 14 microseconds from the TRIGGER pulse.)
3.4.17.8 Squitter Check On the CTU, select Tx.Rate parameter measurement at a TI RATE of 1 kHz. The displayed transmit rate should be in the range 990 to 1000 Hz.
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Switch and hold the front panel TEST switch to INHIBIT INTERROGATIONS. On the CTU, the displayed transmit rate should be in the range 940 to 950 Hz. Release the switch.
On the CTU, change the TI RATE to 100 Hz. The displayed transmit rate should be in the range 940 to 950 Hz.
Switch and hold the TEST switch to REPLY RATE MONITOR TEST. On the CTU, the displayed transmit rate should be in the range 805 to 810 Hz. Release the switch.
3.4.17.9 Ident Check On the CTU, select Ident Source as Mon 1. (This function is available under the Misc menu on the CTU Test Facility when Maintenance mode is off. Ensure Maintenance mode is switched back on.)
On the CTU, press MONITOR ALARM to switch this function from INHIBIT to NORMAL. Ident should be transmitted within 5 seconds.
Using a stopwatch, check that the ident messages are transmitted at a rate of once every 40 ±5 seconds.
On the CTU, select Tx.Rate parameter measurement.
Switch IDENT to CONTINUOUS. On the CTU, the displayed transmit rate should be in the range 1345 to 1355 MHz. Switch IDENT back to NORMAL.
3.4.17.10 Replies Inhibit Check On the CTU, select Tx.Rate parameter measurement. Check that the displayed transmit rate is in the range 990 to 1000 Hz.
On the monitor, switch MONITOR OUTPUTS to FAILED. Using a stopwatch, measure the time delay until the displayed transmit rate on the CTU fails to below 5 Hz. This time delay should be in the range 60 to 70 seconds. On the unit under test, confirm that the REPLIES INHIBITED indicator is steady on.
On the transponder power supply switch TRANSPONDER DC POWER to ON. Confirm that the REPLIES INHIBITED indicator is now off.
On the CTU, confirm that the displayed transmit rate is again in the range 990 to 1000 Hz.
3.4.18 RF Source 1A72522
3.4.18.1 Test Equipment Oscilloscope. Spectrum analyser. Frequency counter. RF millivoltmeter. Attenuator, miniature, 10 dB. Test crystals (refer Section 3.4.18.3, step 1).
3.4.18.2 Setup Switch the depot test facility off. Extend the receiver video using the transponder extender frame. Remove the lid from the RF source diecast box.
Replace the RF source board from the depot test facility with the RF source to be tested (after first removing the coaxial cable connected to the output connector XC1, (if any), the two screws securing the printed wiring board to the box, the two screws securing the coaxial connector bracket to the box - located beside the output connector - and the two
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leads supplying power to the unit). Note the colour coding of the two power leads to ensure that they are re-connected with the correct polarity.
Reconnect the two power leads. Replace the two screws securing the RF source to the box and the two screws securing the coaxial connector bracket to the box.
Connect the RF millivoltmeter to the output connector, XC1, of the RF source.
Switch the depot test facility on. On the transponder power supply front panel, switch
TRANSPONDER DC POWER to ON.
Using channel 1 of the oscilloscope (internally triggered), check that the voltages on the power supply leads to the RF source (connect the oscilloscope earth lead to the RF source diecast box) are at 15.0 ±1.0 volts and 0 volts.
3.4.18.3 Alignment To fully test and prove an RF source, the tests of this section should be performed at the minimum, middle and maximum reply frequencies, 962 MHz, 1088 MHz and 1213 MHz respectively. However, if the RF source is only to be realigned for its operational reply frequency, the tests of this section need only be performed at this operational frequency.
1. Install the oscillator crystal in the RF source. The crystal frequency is one-twelfth of the station reply frequency.
Example: Channel 84X reply frequency = 1171 MHz hence crystal frequency = 1171/12 = 97.5833 MHz
2. On the RF source, set capacitors C8, C12 and C18 to mid-range, as shown below, so that clockwise movement will increase frequency.
3. Move channel 1 of the oscilloscope to the test point XT1 on the RF source
and tune the core in L1 for peak indication on the oscilloscope, checking that a smooth peak is obtained [approximately 2 volts].
4. Check that the oscillator is operating at the crystal frequency by using a one-turn coupling loop connected to the frequency counter and loosely coupled to Ll. (if the frequency is out of range, then retune L1 for correct mode and then re-peak (after first removing the loop).
5. Move channel 1 of the oscilloscope to test point XT2 on the RF source. Tune C8 to give peak indication [approximately 0.6 volts].
6. Move channel 1 of the oscilloscope to test point XT3 on the RF source. Tune C12 to give peak indication [approximately 2.5 volts].
7. Move channel 1 of the oscilloscope to test point XT4 on the RF source. Tune C18 to give peak indication [approximately 1.8 volts].
8. Carefully adjust trimmer C26 (through the end hole in the box of the RF source) to give maximum power display on the RF millivoltmeter. The RF output level should not be less than +5 dBm.
9. Remove the RF millivoltmeter from XC1 and replace it with the spectrum analyser.
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10. Set the spectrum analyser controls as follows:
Attenuator 20 dB Bandwidth 300 kHz Display 50 MHz/division (or full sweep).
11. Observe the displayed spectrum and set the LEVEL control on the spectrum analyser for a reference level of 0 dB at the wanted centre frequency (962, 1088, 1213 MHz or operational reply frequency). Check that the levels at frequencies offset from the output by multiples of the crystal frequency are equal to, or below, the following limits:
± Fx 34 dBr ± 2Fx 24 dBr ± 3Fx 20 dBr ± 6 Fx and beyond 10 dBr
where Fx is the crystal frequency. Also check, using full sweep display, that no abnormal spectra are present.
If the crystal frequency harmonics specification is not met directly, it may be achieved by a slight detuning of capacitors C18 and/or C26, ensuring at the same time that the output level does not decrease by more then 0.3 dB.
12. Remove the spectrum analyser from XC1 and replace it with the frequency counter (through a 10 dB attenuator). The measured output reply frequency should be within ±20 kHz of the nominal frequency of step 1.
3.4.18.4 Completion After having performed the above tests at the required frequencies, switch the depot test facility off, remove the RF source under test from the diecast box on the receiver video, and restore the depot test facility RF source back into its diecast box, ensuring that all screws and electrical connections are correctly replaced and securely tightened.
Replace the lid of the diecast box. Note that the lid is deliberately warped to ensure good RF sealing. Tighten the screws firmly.
Restore the RF source under test to its diecast box, ensuring that all screws the lid are correctly replaced and the screws securely tightened.
Remove the transponder extender frame and install the receiver video back in the depot test facility.
3.4.19 IF Amplifier 1A72523
3.4.19.1 Test Equipment Oscilloscope. Signal generator. Pulse generator. Digital multimeter. Stopwatch. Attenuator, miniature, 10 dB. Mixers for pulse modulation; Qty 2. Power supply, regulated, 30 volts (required for bench test only). Resistor, fixed, 365 kilohm (or close value), 400 mW. Coaxial cables and adaptors. Tuning tools.
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3.4.19.2 Setup The IF amplifier board can be conveniently tested in a working depot test facility in the receiver video module, so that DC supplies on the correct connectors are available. It must be connected in place of the original IF amplifier, and the whole module should be mounted on an extender frame. If the unit is to be tested on a bench setup, connector details for XN1 are given in Figure 3-11. The IF amplifier must be well grounded to a metal plate if tested in this manner.
Set all variable resistors to mid-travel and all inductor cores to flush with the tops of the formers.
Place jumper of XN2 in the MAN position.
Switch the transponder supply TRANSPONDER DC POWER switch to ON.
Check the supply voltage with the multimeter; it should be 15.0 ±0.1 volts.
Measure the +6 volts supply at test point XT4; should be 6.00 ±0.15 volts.
Measure the GAIN CONTROL voltage at test point XT1 and adjust SET GAIN (R29); this should vary between +6.9 ±0.2 and +4.2 ±0.2 volts. Leave SET GAIN at maximum voltage (clockwise).
Measure DC voltage on test point XT3; it should be 6.3 ±0.2 volts.
3.4.19.3 No Signal Checks Connect the oscilloscope, set to 500 mV/division, DC coupled, to XT3 and back off the DC offset to check the noisy base line near the top of the display.
Reduce SET GAIN (R29) to minimum (counter-clockwise) and note that the noise reduces in amplitude, noting also that the signal is negative going.
Temporarily provide a short circuit across R30 and note that the noise reduces even further.
Remove the short circuit and reset SET GAIN to maximum gain. Measure and record the peak-to-peak noise amplitude; it should not exceed 300 mV.
3.4.19.4 IF Checks Connect the test system as in Figure 3-10 with the signal generator set to -90 dBm at 63.00 MHz and set the pulse generator to provide +4 volts single pulse at 1 kHz PRF with 5 microseconds width to modulate the 63 MHz signal. Synchronise the oscilloscope to the pulse generator.
Connect the modulated signal to XC1 of the unit under test, using the short coaxial RG-188 cable.
Observe the XT3 signal on the oscilloscope and increase the signal generator output level until the pulse is visible above the noise (still negative-going), as below.
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Adjust the tuning of L5 and L7 to peak the pulse, then adjust C1 also to peak the pulse. Repeat this tuning procedure to ensure peaking.
Turn SET GAIN (R29) to minimum (counter-clockwise) and adjust the oscilloscope for the noise base just at the top line of the screen as below; then reset SET GAIN to maximum.
Adjust the signal generator output level for an accurate 1 volt peak pulse, with respect to the top graticule line, then increase the level by 3.0 dB.
Increase the signal generator frequency until the pulse amplitude is again 1 volt and record the frequency, fi+.
Decrease the frequency below 63 MHz to give a 1 volt pulse again and note the frequency, fi-.
Calculate fi+ minus fi-; this difference (3 dB bandwidth) should be between 1.5 and 1.9 MHz.
Reset the frequency to 63.00 MHz. Remove the mixers from the signal generator output and connect the signal generator directly to the IF amplifier, to give unmodulated 63 MHz. Readjust the output level to give 1 volt below the top graticule line on the oscilloscope. Note the generator output in dBm.
Reconnect the mixers as before and increase the generator output until the pulse on the oscilloscope has a 1 volt amplitude. Note the new generator output in dBm. The difference between these two noted values (in dBm) is the mixer-modulator insertion loss in dB. Call this value M dB.
For this 1 volt peak pulse, note the signal generator output level in dBm (this will be referred to as level A1).
Increase the level to give a 2 volts peak pulse and note the level in dBm (A2).
Again increase the level for a 3 volts pulse and note the level in dBm (A3).
Calculate A1 minus A2, and A2 minus A3; the difference between these two values should be less than 5 dB.
Increase the amplifier input level to -10 dBm (signal generator level = (M - 10) dBm) and measure the pulse amplitude, which should be greater than 3.0 volts peak.
Increase the level to 0 dBm (signal generator level = M dBm) and again measure the amplitude; this should not be less than 3.1 volts peak.
Decrease the signal generator output to -100 dBm (signal generator level = (M -90 dBm) and check that the pulse is still visible through the noise (approximately equal). Measure the peak-to-peak noise voltage, which should not exceed 200 mV peak-to-peak.
3.4.19.5 Narrow Band Checks With the oscilloscope set to 500 mV DC, monitor the DC voltage on XT8.
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Adjust L4 tuning core into the coil so that it is 2 or 3 turns below being flush with the top of the former. With the digital multimeter, measure the DC voltage on XT8; it should be between 0.70 and 0.76 volts.
Adjust the tuning core of L4 counter-clockwise until the voltage is seen to jump to between 0.9 and 1.2 volts. Note the core position. Continue adjusting the core counter-clockwise until either a voltage peak or 2.0 volts is reached, whichever occurs first; leave the core in this position. Check that the core has been rotated more than one half turn beyond the position of the voltage jump observed above.
NOTE Tuning must be done with the core being in the position stated above. Do not exceed the voltage stated for XT8, otherwise a spurious mode of oscillation may be induced.
Check that the final voltage on XT8 is between 1.2 and 2.1 volts. Switch the power supply off and on at least three times, and check that the XT8 voltage returns to the same value each time.
Monitor XT6 waveform on the oscilloscope, on the 1 volt DC range, and increase the 63.00 MHz level to -60 dBm ((M-60) dBm from generator).
Detune L3 by removing the adjuster core almost completely, peak the pulse by tuning L6 (it may be necessary to temporarily increase the oscilloscope gain) then retune L3 to peak and note the pulse amplitude above the noise average.
Change the frequency to 63.5 MHz and note the amplitude at the middle of the pulse, then to 62.5 MHz and again note the amplitude; equalise the pulses by retuning L3. This pulse level should be less than 0.5 of the amplitude noted in the previous step.
Reset the frequency to 63.0 MHz.
With two oscilloscope probes on 1 volt DC range, connect both to XT9 and adjust controls to view both traces coincidentally.
Reconnect one probe to XT10 and adjust ON CHAN THRESH (R50) for 5.0 volts. Observe noise and pulse on XT9: adjust ON CHAN THRESH so that XT10 level cuts through the main pulse and some of the peaks of the noise, as below.
Retune the signal generator to 62.1 MHz and confirm that most of the pulse left is below the level of the noise peaks, then repeat at 63.9 MHz. A typical waveform is shown dotted in the figure above. Reset the frequency to 63.0 MHz.
Reconnect the XT10 probe, set to 5 volts DC range, to XT11 and check the ON CHANNEL signal; this should be a square 15 volts pulse with very few random noise pulses, as shown below
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Reduce the signal generator output level and note that the square pulse starts to break up, as shown below; increase the output until the pulse is just free of breakup and record the threshold input signal level in dBm, which should be below a level of -93 dBm ((M-93) dBm at the signal generator).
Increase the input level to -10 dBm (M-10 dBm at the signal generator) and check that the ON CHANNEL pulse is still solid; ignore any increase of noise.
Reconnect the oscilloscope probe from XT9 to XT12 and check that the DETECTED LOG VIDEO pulse falls completely within the width of the ON CHANNEL pulse on XT11 at all input levels from -10 to -90 dBm. Leave the signal generator level at M-30 dBm.
Transfer the oscilloscope probe from XT11 to XT12 also and reset to 1 volt DC range. Expand the timebase to 1 microsecond/division and check the leading edges of the two pulses, then superimpose the traces to ensure no timing or shape differences.
Reconnect one probe to XT3, AC couple and invert: adjust the vertical gain, if necessary, and shift so that the half-pulse amplitude is at the horizontal centre line.
Adjust the oscilloscope channel displaying XT12 waveform to centre the half amplitude points also; measure the delay between XT3 and XT12 pulses on the centre line and record this value. The delay should be 1.65 ±0.1 microseconds, as shown below. Disconnect the oscilloscope probes.
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3.4.19.6 AGC Checks Remove the mixers from the signal generator and connect the signal generator directly to the IF amplifier. Set the signal generator for 63 MHz at a level of -110 dBm. Reconnect the jumper on XN2 to AGC position.
Connect the multimeter to XT13 and measure the voltage above earth; adjust preset SET AGC (R15) to give +6.0 volts. The supply must be +15.0±0.05 volts, and steady.
Connect an oscilloscope probe (1 volt DC range) to XT1 and check that the DC level is 6.9 ±0.3 volts.
Increase the signal generator output level slowly until the voltage starts to fall on its own; note the signal level for the AGC threshold, which should be below a level of -93 dBm.
Increase the generator output again and note the steady decrease in XT1 voltage until it flattens at about 2.5 volts, then starts to drop rapidly and lose control; note the signal level just before it loses lock, which should be above a level of -30 dBm.
Reset the signal generator to M-10 dBm and replace the mixers. Check that the pulses appear correctly at XT3, with the oscilloscope on 500 mV DC range, as previously.
Connect a 365 kilohm resistor from test point XT5 to +15 volts supply (far end of R11 is the closest available) and measure the time elapsed for the pulse amplitude to reduce to the minimum level; the period should be 4 ±1 seconds.
Note the final output pulse amplitude (A4) to be used as a reference.
Disconnect the 365 kilohm resistor from the +15 volts supply and check that the full pulse returns in less than 1 second.
Reduce the signal generator output level until the XT3 amplitude equals A4; the amount that the signal generator level has been reduced below the initial M-10 dBm level should be greater than 65 dB.
3.4.19.7 Final Checks Observe the XT3 waveform on the 200 mV AC range and increase the signal input until the "peak tangential noise" input condition is reached. This is the level at which the noise peaks on the bottom of the pulse coincide with the noise peaks on either side of the pulse, as shown below. The signal generator output level at which this occurs should be equal to or below a level of M-92 dBm.
Check that the output signals are connected via XN1, by monitoring with the oscilloscope at the module front panel test jacks:
DETECTED LOG VIDEO signal as on XT12 ON CHANNEL VIDEO signal as on XT11.
Switch off power, remove the test cables and replace the cover with the screws.
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Figure 3-10 Test Setup for IF Amplifier Checks
Figure 3-11 Power and Output Cable for IF Amplifier Checks
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3.4.20 RF Amplifier 1A72524
3.4.20.1 Test Equipment Spectrum analyser. Signal generator; Qty 2 Digital multimeter. Peak power meter.
3.4.20.2 Setup Switch the test facility rack off. Place the receiver video on the transponder extender frame. Replace the RF amplifier in the receiver video of the test facility with the RF amplifier to be tested. Ensure that all screws and connections are restored. Switch the rack on.
3.4.20.3 DC Voltages Switch on the unit by setting the TRANSPONDER DC POWER switch on the transponder power supply to ON.
Using a digital multimeter, measure the DC voltage at the following points
R1/R3 junction 8.7 ±0.5 volts V2/R2 junction 0.7 ±0.1 volts R4/R6 junction 8.7 ±0.5 volts V5/R5 junction 0.7 ±0.1 volts
Check for zero volts at XC1, XC2, XC3 and XC4.
3.4.20.4 Power Stage Check Set up the equipment as in Figure 3-12. Connect the CW output of the signal generator to XC3 on the RF amplifier. Connect a 50 ohms load to XC2 and power meter to XC4. Set the signal generator frequency to 950 MHz and level to +3 dBm.
Measure the output power; it should be +12.5 ±1.5 dBm (12.6 to 25.1 mW).
Connect XC4 to the spectrum analyser. Set the spectrum analyser to centre frequency 1000 MHz and span at least 1000 MHz and measure any spurious components present. All spurious components should be more than 55 dB below the signal.
NOTE Ensure that no spurious components are originating in the signal generator.
Using a digital multimeter measure the DC voltage at XS3, which should be 0.25 ±0.07 volts. If the voltage is not within the limits specified, it may be achieved by changing the length of the anode lead on diode V7. Shortening the lead should reduce the detector output.
Measure the DC voltage at XS4; it should be 1.3 ±0.5 volts.
Repeat these measurements with the signal generator frequency to 1100 MHz and then to 1220 MHz. The measured voltages should remain within the stated limits.
3.4.20.5 Local Oscillator Leakage Check Reconnect the test equipment as follows:
• 50 ohms termination to XC1.
• Signal generator to XC3, frequency 1100 MHz; level +3 dBm.
• Spectrum analyser to XC2.
• 50 ohms termination to XC4.
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Measure the level of 1100 MHz signal on the analyser at XC2; it should be less than -15 dBm.
Set the analyser to sweep at least zero to 1500 MHz and check for any spurious components; all spurious components should be below -70 dBm. Again note the output spectrum of the signal generator.
3.4.20.6 Low Noise Amplifier and Mixer Calibration For this test it is necessary to have two signal generators, one of which has been calibrated and characterised across the band 950-1250 MHz and at 63 MHz at a level of -20 dBm.
Connect the calibrated signal generator to the spectrum analyser with the level set to -20 dBm.
Set the spectrum analyser as follows:
Centre frequency 1100 MHz Span 400 MHz Resolution bandwidth 1 MHz Video bandwidth 1 MHz Reference level -10 dBm Log scale 1 dB/division Sweep time 500 milliseconds.
Measure and record the levels indicated on the analyser at each of 1025 MHz, 1055 MHz, 1087 MHz, 1120 MHz, 1150 MHz and 63 MHz.
If the tests are being carried out at a single frequency, the correction factors and measurements need only be done at that frequency (the transmit and local oscillator frequency).
Calculate the 63 MHz correction factor, F63, for each RF frequency, from:
F63 = (analyser reading (RF) - analyser reading (63))
for example: if analyser reading (RF) = -20.1 dBm, and the reading for 63 MHz = -20.8 dBm, then
F63 = (-20.1 - (-20.8)) dB
= 0.7 dB
Connect the calibrated signal generator to XC1 and spectrum analyser to XC2. Connect the second signal generator to XC3, at a level of +3 dBm.
Set the calibrated signal generator level to -20 dBm. Set the frequencies as in the table below and for each frequency measure the 63 MHz signal level from XC2 as displayed on the analyser. At each frequency, the difference between the 63 MHz level and the corresponding RF level measured above gives the gain from RF to IF.
Calculate the gain at each frequency from the level measured on the analyser. Use the formula:
Gain = (63 MHz level - RF level + F63) dB
for example, if the measured RF level at 11 50 MHz is -20.1 dBm, the 63 MHz level is -9.3 dBm and the 63 MHz correction factor for 1150 MHz is 0.7 dB, then the gain is:
Gain = (-9.3 - (-20.1) +0.7) dB = (10.8 + 0.7) dB = 11.5 dB
The gain at all frequencies should be within the limits 12.0 ±1.2 dB.
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FREQUENCY at XC1 (MHz)
FREQUENCY at XC3 (MHz)
1025 962
1055 992
1087 1024
1120 1183
1150 1213
Figure 3-12 Test Setup for RF Amplifier Checks
3.4.21 Transponder Power Supply 1A72525 Since the transponder power supply contains no electronic circuitry in addition to that contained on the transponder power supply main board, no additional tests are required to those specified for that assembly in Section 3.4.22
3.4.22 Main PWB Assembly Transponder Power Supply 1A72526
3.4.22.1 Test Equipment Oscilloscope. Digital multimeter: Qty 2. Load resistor 54 ohms, 2%, 35 watts. Load resistor 100 ohms, 2%, 20 watts. Load resistor 400 ohms, 2%, 5 watts.
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Connector, plug, 4-pin. Current limit select-on-test resistors for R40: 51 ohms, 56 ohms, 62 ohms, 68 ohms, 75 ohms and 1.5 kilohm.
3.4.22.2 Setup With the depot test facility operating, on the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
A means is required to connect different loads to the HT supply output. Two ways of doing this are:
a. loosen the screws to either of the electrolytic capacitors C1 or C2 and attach two leads to which any, or all, of the load resistors may be connected, or
b. attach leads through a 4-pin plug connector to the 4-pin connector XN9 (POWER SUPPLY CONNECTOR 2) on the transponder subrack motherboard. The inner two pins are the positive connection to the HT supply; the outer two pins are the common earth connection.
Connect the 400 ohms load resistor to the HT supply output connections.
Remove the transponder power supply, receiver video and the transmitter driver from the depot test facility.
If a resistor is not already fitted for R40 on the unit under test, temporarily connect a 68 ohms resistor.
Place the transponder extender frame in position of the transponder power supply. Plug the transponder power supply board to be tested into the transponder extender frame. The receiver video and transmitter driver modules remain disconnected.
On the test interrogator front panel, set the switch MONITOR & INTERROGATOR DC POWER to ON.
On the monitor front panel, set switch MONITOR OUTPUTS to NORMAL.
Set the TRANSPONDER DC POWER switch to ON, and check that the red TEST indictor is on.
Check that the relay K1 is activated by confirming that the green DC POWER ON indicator is on.
3.4.22.3 HT Supply Tests
3.4.22.3.1 Regulator Oscillator Tests Connect channel 1 of the oscilloscope (set to AUTO INTERNAL CHANNEL 1 trigger and POSITIVE slope) to test points XT9 (OSC) and XT10 (EARTH) on the unit under test. Confirm that a signal is present at XT9 with a waveform similar to the waveform below, with a period in the range 26.5 to 34.0 microseconds and a pulse width of less than 1.0 microsecond.
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3.4.22.3.2 Current Limit Setup 1. Connect the 54 ohms load resistor in parallel with the 400 ohms load resistor
at the HT supply output.
2. Connect the multimeter, on 200 volts DC range, to test jacks +24V IN and EARTH.
3. Switch and hold the TEST/FLOAT switch of the AC power supply to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 21.0 ±0.1 volts.
4. Connect the multimeter to test jacks HT and EARTH.
5. Adjust HT VOLTAGE (R26) to produce a multimeter reading of 42.0 ±0.1 volts.
6. Connect the second multimeter, on 2 volts range, to test jacks SUPPLY CURRENT, + and -. The input current drawn by the transponder power supply board, in amperes, is 10 times this multimeter reading, in volts. The input current under this conditions should be not more than 2.6 amperes (not more 0.26 volts on the multimeter).
7. R40 on the unit under test is to be chosen to meet both the following conditions:
a. with only the 54 ohms and 400 ohms load resistors connected to the HT output, shorting R40 should cause a measured increase in HT supply output voltage of less than 0.1 volts; and
b. with all three load resistors (54 ohms, 100 ohms and 400 ohms) connected in parallel to the HT output, the input current drawn by the transponder power supply board should be not more than 3.2 amperes (not more than 0.32 volts on the multimeter).
Five standard values for R40 are 51 ohms, 56 ohms, 62 ohms, 68 ohms and 75 ohms. If a value between the standard values is required, use the higher valued resistor and connect a 1.5 kilohm resistor in parallel with it.
8. When the required value for R40 is determined, solder the selected value for R40 into the unit under test.
9. Repeat steps 7.a and 7.b to ensure that the conditions are still met.
10. Release the TEST/FLOAT switch of the AC power supply.
3.4.22.4 Performance Tests Ensure that only the 100 ohms and 400 ohms load resistors are connected to the HT supply output.
Connect the multimeter, on 200 volts range, to test jacks +24V IN and EARTH.
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Switch and hold the TEST/FLOAT switch of the AC power supply to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 24.0 ±0.1 volts.
Connect the multimeter, on 200 volts range, to test jacks HT and EARTH.
Adjust HT VOLTAGE (R26) to produce multimeter readings of 39.8 ±0.1 volts and 52.2 ±0.1 volts to prove that control of the HT supply output is available over this range.
Disconnect the 100 ohms load resistor from the HT supply output, and add the 54 ohms load resistor to the 400 ohms load resistor at the HT supply output.
Adjust HT VOLTAGE to produce a multimeter reading of 42.0 ±0.1 volts.
Connect the second multimeter, on 2 volts range, to test jacks SUPPLY CURRENT + and -. The input current drawn by the transponder power supply board should be not more than 2.3 A (not more than 0.23 volts on the multimeter).
Disconnect the 54 ohms load resistor from the 400 ohms load resistor at the HT supply output. The HT supply output should not increase to more than 44.0 volts.
Add the 100 ohms load resistor across the 400 ohms load resistor at the HT supply output. The HT supply output should be not more than 43.0 volts.
Disconnect the 100 ohms load resistor from and add the 54 ohms load resistor to the 400 ohms load resistor at the HT supply output.
Move the second multimeter, on 200 volts range, to test jacks +24V IN and EARTH.
Adjust the FLOAT 1 VOLTAGE of the AC power supply to give an input voltage of 30.0 ±0.1 volts.
The HT supply output should be not more than 42.3 volts.
Adjust the FLOAT 1 VOLTAGE of the AC power supply to give an input voltage of 22.0 ±0.1 volts.
The HT supply output should be not more than 41.8 volts.
Adjust the FLOAT 1 VOLTAGE of the AC power supply to give an input voltage of 24.0 ±0.1 volts.
Connect channel 1 of the oscilloscope (set to AUTO INTERNAL CHANNEL 1 trigger and POSITIVE Slope) to test points XT4 (TPS_HT) and XT1 (EARTH). Confirm that a signal is present at XT4 with a waveform similar to the waveform below. The measured peak-to-peak ripple voltage (excluding spikes) should be not more than 50 mV. The measured peak-to-peak spike voltage should be not more than 150 mV. (The amplitude of the leading spike is dependent on the position of the oscilloscope probe leads. To minimise pick-up, the oscilloscope probe leads may need to be connected directly to XT4, without using the slip-on probe tip. Ground the probe sleeve directly on the printed wiring board with a short length of wire or braid.)
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On the CTU front panel, select Drv.HT from the PS.Volt menu. The displayed reading on the CTU should be 42.0 ±0.4 volts.
Release the TEST/FLOAT switch of the AC power supply.
3.4.22.5 +15V Supply and +18V Supply Tests Connect the multimeter, on 200 volts range, to test jacks +24V IN and EARTH.
Switch and hold the TEST/FLOAT switch of the AC power supply to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 24.0 ±0.1 volts.
Connect the second multimeter, on 20 volts range, to test jacks +15V and EARTH. The voltage should be in the range 14.6 volts to 15.4 volts.
Move the second multimeter, on 20 volts range, to test jacks +18V and EARTH. The voltage should be in the range 17.4 volts to 18.6 volts.
Switch TRANSPONDER DC POWER to OFF.
Restore the receiver video and the transmitter driver back into the transponder subrack.
On the receiver video front panel, set switch IDENT to NORMAL.
On the transmitter driver front panel, set switch DRIVER DC POWER to NORMAL.
Switch TRANSPONDER DC POWER to ON.
Adjust the FLOAT 1 VOLTAGE of the AC power supply to give an input voltage of 30.0±0.1 volts.
The reading on the multimeter monitoring the +18V output should be in the range 17.4 volts to 18.6 volts.
Move the second multimeter, on 20 volts range, to test jacks +15V and EARTH. The voltage should be in the range 14.6 volts to 15.6 volts.
Adjust the FLOAT 1 VOLTAGE of the AC power supply to give an input voltage of 22.0 ±0.1 volts.
While holding TI RATE, 10 kHz pressed, the reading on the multimeter monitoring the +15V supply output should be in the range 14.4 volts to 15.4 volts. Release the 10kHz switch.
Move the second multimeter, on 20 volts range, to test jacks +18V and EARTH. While holding TI RATE, 10 kHz pressed, the measured voltage of the +18V supply output should be in the range 17.2 volts to 18.4 volts. Release the 10 kHz switch.
Adjust the FLOAT 1 VOLTAGE of the AC power supply to give an input voltage of 24.0 ±0.1 volts.
On the CTU front panel, select TP.18V from the PS.Volt menu. The displayed reading on the CTU should be within ±0.2 volts of the reading on the multimeter monitoring the +18V supply output.
Move the second multimeter, on 20 volts range, to test jacks +15V and EARTH.
On the CTU front panel, select TP.15V from the PS.Volt menu. The displayed reading on the CTU should be within ±0.1 volts of the reading on the multimeter monitoring the +15V supply output.
Release the TEST/FLOAT switch of the AC power supply.
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3.4.22.6 Control Signals On the test interrogator front panel, set the switch MONITOR & INTERROGATOR DC POWER to NORMAL.
Switch TRANSPONDER DC POWER to NORMAL. Check that:
a. On the unit under test, both DC POWER ON (green) and TEST (red) indicators are off.
b. On the CTU, the MODULES TEST indicator is off.
c. On the unit under test, relay K1 is released.
Switch TRANSPONDER DC POWER to OFF. Check that:
a. On the unit under test, the DC POWER ON (green) indicator is off and the TEST (red) indicator is on.
b. On the CTU, the MODULES TEST indicator is on.
c. On the unit under test, relay K1 is released.
Switch TRANSPONDER DC POWER to ON. Check that:
a. On the unit under test, both DC POWER ON (green) indicator and TEST (red) indicator are on.
b. On the CTU, the MODULES TEST indicator is on.
c. On the receiver video, the REPLIES INHIBITED indicator is off.
On the CTU front panel, press the MAINTENANCE key to turn its indicator off.
Switch TRANSPONDER DC POWER to NORMAL. Check on the receiver video that the REPLIES INHIBITED indicator is now off.
On the CTU, press SELECT MAIN, NO 1. Check that:
a. On the unit under test, the DC POWER ON (green) indicator is on and the TEST (red) indicator is off.
b. On the CTU, the MODULES TEST indicator is off.
c. On the unit under test, relay K1 is activated.
After having performed the above tests, remove the transponder extender frame and install the transponder power supply belonging to the depot test facility back in the transponder subrack.
3.4.23 Transmitter Driver 1A72530
3.4.23.1 Test Equipment Oscilloscope. Digital multimeter. Peak power meter. Attenuator, power, 30 dB. Attenuator, medium, 20 dB. SMA connector torque wrench. Cables and adaptors.
3.4.23.2 Setup NOTE The alignment procedure involves temporary changes to the connections to the
sub-modules of the transmitter driver. To ensure correct alignment and
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subsequent correct operation, ensure that each RF connector is securely tightened (use a torque wrench for SMA connectors) following its connection.
When making measurements of the peak RF power, correction needs to be made for the errors in the peak power meter and for the actual losses in any attenuators at the input to the peak power meter. This requires that the peak power meter and any attenuators used be characterised at the frequency of operation and these corrections applied to the meter readings.
CAUTION The sensor on the peak power meter is sensitive to overload, and is easily damaged. To prevent expensive delays and repairs from being incurred, ensure that the correct specified attenuator is connected to the peak power meter sensor before connecting to the RF source to be measured.
The unit under test is normally aligned at a reply frequency of 1215 MHz. However, if alignment and testing is required at the operational reply frequency, the tests below need only be performed at this operational frequency. Tune the receiver video in the depot test facility for the test and alignment frequency(ies) - see Section 3.4.18 if an RF Source is to be aligned; see Appendix K if the tests are being performed at the depot test facility.
With the depot test facility operating, on the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
On the unit under test, set the and controls switches as follows:
RF OUTPUT (on front panel) fully clockwise, DRIVER DC POWER (on front panel) to OFF, ALC LOOP (S2 on pulse shaper board) to OPEN, ALC (S3 on pulse shaper board) to VIDEO, MED COLL (S4 on pulse shaper board) to DC.
On the pulse shaper board of the unit under test, adjust the following controls all fully counter-clockwise:
MOD PULSE AMPLITUDE (R58), 1W PULSE (R85), EXCITER DC (R97), and MED POWER DRIVER DC (R115).
On the unit under test, check that the 50 ohms termination E1 is connected to PORT 3 of circulator W1. Check that termination E2 is connected to PORT 2 of circulator W2.
At the depot test facility, remove the transmitter driver. Place the transponder extender frame in the position of the transmitter driver. Plug the unit under test into the transponder extender frame.
On the test interrogator front panel, set the switch MONITOR & INTERROGATOR DC POWER to ON.
On the monitor front panel, set switch MONITOR OUTPUTS to NORMAL.
On the receiver video front panel, set the IDENT switch to CONTINUOUS.
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On the front panel of the unit under test, set the DRIVER DC POWER switch to ON, and check that the DC POWER ON and TEST indicators are on.
Connect the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to VIDEO OUT on the peak power meter to check the pulse shape.
Connect the multimeter (on 200 volts range) to test jacks HT and EARTH on the transponder power supply front panel. The measured voltage should be 42.0 ±0.2 volts. (If out of range, set the voltage within the specified range by adjusting HT VOLTAGE (R26) on the transponder power supply main board.)
3.4.23.3 Exciter Alignment On the transponder power supply, switch TRANSPONDER DC POWER to OFF.
Connect a calibrated 20 dB attenuator to RF IN on the peak power meter.
Disconnect the coaxial cable from the output of the exciter and connect a short coaxial cable from the exciter output connector to the IN connector on the 20 dB attenuator.
Connect the multimeter (on 200 volts range) to test points XT7 and XT8 (COMMON) on the pulse shaper board.
On the transponder power supply, switch TRANSPONDER DC POWER to ON.
While monitoring both the multimeter and the peak power meter, adjust EXCITER DC (R97) to produce a multimeter reading of 32.0 ±0.2 volts. The peak power meter reading should not exceed 40 mW (or 4.0 watts if the reading is corrected for the 20 dB attenuator).
While monitoring the peak power meter, adjust 1W PULSE (R85) to produce a peak power meter reading of 60.0 ±0.5 mW (or 6.00 ±0.05 watts if the reading is corrected for the 20 dB attenuator) to confirm that this output power can be achieved.
While monitoring the peak power meter, adjust EXCITER DC (R97) to produce a peak power meter reading of 50.0 ±0.5 mW (or 5.00 ±0.05 watts if the reading is corrected for the 20 dB attenuator).
On the transponder power supply, switch TRANSPONDER DC POWER to OFF.
Disconnect the test coaxial cable from the output of the exciter to the IN connector on the 20 dB attenuator and reconnect the coaxial cable that connects the output of the exciter to the input of the medium power driver.
3.4.23.4 Medium Power Driver Alignment Replace the 20 dB attenuator connected to the input of the peak power meter with the 30 dB attenuator.
Disconnect the coaxial cable from the input of the power modulation amplifier and reconnect it (with suitable adaptors) to the IN connector on the 30 dB attenuator connected to the peak power meter.
On the transponder power supply, switch TRANSPONDER DC POWER to ON.
While monitoring the peak power meter, adjust MED POWER DRIVER DC (R115) to produce a peak power meter reading of 28.0 ±0.5 mW (or 28.0 ±0.5 watts if the reading is corrected for the 30 dB attenuator).
NOTE If the power output specified above cannot be achieved with 5 watts from the exciter, it is permissible to return to Section 3.4.23.3 and adjust EXCITER DC (R97) to produce an exciter output power of 6.0 watts. Do this ONLY if the specified power cannot be obtained with 5 watts drive.
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While monitoring the peak power meter, adjust MED POWER DRIVER DC (R115) to produce a peak power meter reading of 25.0 ±0.5 mW (or 25.0 ±0.5 watts if the reading is corrected for the 30 dB attenuator).
On the transponder power supply, switch TRANSPONDER DC POWER to OFF.
Disconnect the coaxial cable from the IN connector on the 30 dB attenuator and reconnect it to the input of the power modulation amplifier.
3.4.23.5 Power Modulation Amplifier Alignment On the 1kW RF amplifier, disconnect the coaxial cable from the INPUT connector, and connect the cable (with suitable adaptors) to the IN connector on the 30 dB attenuator connected to the peak power meter.
On the transponder power supply, switch TRANSPONDER DC POWER to ON.
While monitoring the peak power meter, adjust POWER MOD AMP DC (R69) to produce a peak power meter reading of 60.0 ±0.5 mW (or 60.0 ±0.5 watts if the reading is corrected for the 30 dB attenuator).
On the transponder power supply, switch TRANSPONDER DC POWER to OFF.
On the circulator W2, swap the connections to ports 1 and 3 (i.e., the output of the power modulation amplifier to port 1 of the circulator; port 3 of the circulator to connector XC2 (RF DRIVE PULSE); extender coaxial cables will probably be required).
On the transponder power supply, switch TRANSPONDER DC POWER to ON.
The reading on the peak power meter should be not more than 1.0 mW (or not more than 1.0 watt if the reading is corrected for the 30 dB attenuator).
On the transponder power supply, switch TRANSPONDER DC POWER to OFF.
On the circulator W2, swap the connections to ports 1 and 3 (i.e., the output of the power modulation amplifier to port 3 of the circulator; port 1 of the circulator to connector XC2 (RF DRIVE PULSE); remove the extender coaxial cables if used).
On the transponder power supply, switch TRANSPONDER DC POWER to ON.
While monitoring the peak power meter, adjust POWER MOD AMP DC (R69) to produce a peak power meter reading of 50.0 ±0.5 mW (or 50.0 ±0.5 watts if the reading is corrected for the 30 dB attenuator).
Observe the waveform on the oscilloscope (the video output from the peak power meter). Check that any tilt on the top of the waveform (see figure below) should have a peak-to-peak value not more than 10 % of the mean pulse height.
Check that the space between the two pulses is 1.5 ±0.1 microseconds. (If it is not, then set it within this limit using the preset BACK PORCH (R36) on the pulse shaper board).
Connect channel 2 of the oscilloscope to test jacks DRIVER LEVEL and EARTH. The displayed waveform (see figure above) should have an amplitude (when measured with respect to the 0 volts reference) in the range 3.0 to 4.0 volts.
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On the CTU front panel, select TD.Drv from the Level menu. The displayed reading on .the CTU should be in the range 2.1 to 2.9 volts.
On the transponder power supply, switch TRANSPONDER DC POWER to OFF.
Set RF OUTPUT fully counter-clockwise.
After having performed the above tests, remove the transponder extender frame and install the transmitter driver belonging to the depot test facility back in the transponder subrack.
3.4.24 Pulse Shaper PWB Assembly 1A72531
3.4.24.1 Test Equipment Oscilloscope. Digital multimeter. Test clip lead, 300 ±20 mm long, with alligator clips both ends.
3.4.24.2 Setup With the depot test facility operating, on the CTU, press the following front panel keys in the specified sequence (as required):
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
Remove the transmitter driver from the depot test facility.
Place the transponder extender frame in the transmitter driver position in the transponder. Plug the pulse shaper board to be tested into the transponder extender frame (without the transmitter driver module).
On the test interrogator front panel, set the switch MONITOR & INTERROGATOR DC POWER to ON.
On the monitor front panel, set switch MONITOR OUTPUTS to NORMAL.
On the receiver video front panel, set the IDENT switch to CONTINUOUS.
On the unit under test, set the following variable resistors fully counter-clockwise:
R3, R5, R7, R9, R11, R13, R17, R36, R53, R58, R62, R69, R85, R97, R115.
and set fully clockwise:
R54.
Set the option switches as follows:
DRIVER DC POWER (S1) to OFF (towards H1), ALC LOOP (S2) to OPEN, ALC (S3) to VIDEO, MED COLL (S4) to DC.
Set link X1 (POWER) to the 1kW position.
On the transponder power supply front panel, switch TRANSPONDER DC POWER to ON.
Check that the green DC POWER ON indicator (H1) is on.
Check that the red TEST indicator (H2) is on.
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3.4.24.3 Rectangular Modulation Test Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to test jack SQUARE MODULATION (XA1) and the earth lead to EARTH (XA6).
Measure the peak voltage of the pulses at XA1. This voltage should be in the range 3.0 volts to 4.5 volts.
Adjust 1W PULSE (R85) fully clockwise while observing the output of XA1 on the oscilloscope. The peak voltage of the pulse should increase smoothly to 22.0 ±3.0 volts. Adjust 1W PULSE for a peak voltage of 16.0 ±0.5 volts.
Measure the time period between the two pulses. This time period should be in the range 1.7 to 2.2 microseconds.
Adjust BACK PORCH (R36) fully clockwise. The time period between the two pulses should decrease to not more than 0.5 microseconds. Set BACK PORCH for a 1.7 ±0.1 microseconds time period between the two pulses and measure the total duration of the double pulse, which should be 22.5 ±1.0 microseconds.
Move channel 1 of the oscilloscope to the lower end of R18 (earth to test point XT2). The amplitude of the rectangular pulse should be 15.0 ±1 .0 volts, and its duration should exceed the double pulse duration, measured above, by 5.5 ±2.5 microseconds.
3.4.24.4 Driver Level Monitor Tests On the transponder power supply front panel, switch TRANSPONDER DC POWER to OFF.
Unplug the receiver video, but leave it located in the transponder subrack.
On the transponder power supply front panel, switch TRANSPONDER DC POWER to ON.
Connect the multimeter (set to 20 volts range) to test jacks FUNCTION GENERATOR (XA2) and EARTH (XA7). Set INTEGRATOR BALANCE (R17) fully counter-clockwise; the multimeter reading should be 2.4 ±0.1 volts. Then set INTEGRATOR BALANCE fully clockwise; the multimeter reading should now be 3.5 ±0.2 volts. Adjust INTEGRATOR BALANCE to give a multimeter reading of 2.50 ±0.5 volts.
On the CTU front panel, select TD.Drv from the Level menu. The displayed reading on the CTU should be not more than 0.8 volts.
Connect the test clip lead between the back of test jack FUNCTION GENERATOR (XA2) and the top of resistor R100. The displayed reading on the CTU should be 1.6 ±0.2 volts.
On the transponder power supply front panel, switch TRANSPONDER DC POWER to OFF.
Plug the receiver video back into the transponder subrack.
On the transponder power supply front panel, switch TRANSPONDER DC POWER to ON.
Ensure R3, R5, R7, R9, R11, R13 are all set fully counter-clockwise. The displayed reading on the CTU should be not more than 3.6 volts.
Adjust R3 to produce a displayed reading on the CTU of 3.6 ±0.1 volts.
Connect both channel 1 and channel 2 of the oscilloscope (still externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to test jacks FUNCTION GENERATOR (XA2) and EARTH (XA7). Ensure that the two
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oscilloscope probes connected to channels 1 and 2 of the oscilloscope are calibrated similarly by ensuring that the displayed waveforms for these two channels are identical.
Measure the peak height of the waveform on the oscilloscope with respect to the 0 volts reference. It should be 5.6 ±0.5 volts.
Move channel 2 of the oscilloscope to test jack DRIVER LEVEL (XA5). Confirm that the two waveforms on the oscilloscope are identical (except for some possible high frequency noise).
Move channel 2 of the oscilloscope to XN2:15 (DETECTED DRIVER RETURN) (ground to test point XT2). Confirm that the two waveforms on the oscilloscope are identical (except for some possible high frequency noise).
3.4.24.5 Function Generator Test 1. Connect the multimeter (on 20 volts range) across R102 (COMMON to bottom
end). Ensure that the PULSE SHAPE presets R3, R5, R7, R9, R11, R13 are all set fully counter-clockwise. Adjust INTEGRATOR BALANCE (R17) to produce a multimeter reading of 5.5 ±0.1 volts.
2. Adjust R3 fully clockwise. The multimeter reading should be in the range 6.50 to 7.10.
3. Adjust R3 fully counter-clockwise.
4. Adjust R5 fully clockwise. The multimeter reading should be in the range 5.90 to 6.50.
5. Adjust R5 fully counter-clockwise.
6. Adjust R7 fully clockwise. The multimeter reading should be in the range 6.70 to 7.50.
7. Adjust R7 fully counter-clockwise.
8. Adjust R9 fully clockwise. The multimeter reading should be in the range 6.70 to 7.50.
9. Adjust R9 fully counter-clockwise.
10. Adjust R11 fully clockwise. The multimeter reading should be in the range 7.10 to 8.60.
11. Adjust R11 fully counter-clockwise.
12. Adjust R13 fully clockwise. The multimeter reading should be in the range 7.10 to 8.60.
13. Adjust R13 fully counter-clockwise.
14. Adjust R3 to give a multimeter reading of 5.8 ±0.1 volts.
15. Adjust R5 to give a multimeter reading of 6.3 ±0.1 volts.
16. Adjust R7 to give a multimeter reading of 7.1 ±0.1 volts.
17. Adjust R9 to give a multimeter reading of 8.3 ±0.1 volts.
18. Adjust R11 to give a multimeter reading of 10.0 ±0.1 volts.
19. Adjust R13 to give a multimeter reading of 10.6 ±0.1 volts.
The procedure of steps 14 to 19 has to be performed in the specified order. If a mistake was made in the alignment, the procedure has to be repeated from step 14 (after first readjusting R3, R5, R7, R9, R11, R13 all fully counter-clockwise).
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20. Confirm that the two waveforms on the oscilloscope (connected to XN2:15 and the DRIVER LEVEL test jack XA5) are identical (except for some possible high frequency noise).
21. Measure the peak height of the waveform on the oscilloscope with respect to the 0 volts reference. It should be 10.8 ±0.5 volts.
22. Adjust INTEGRATOR BALANCE (R17) to set the trailing edge of the waveform on the oscilloscope to be level with the leading edge.
3.4.24.6 Shaped Pulse Modulation and TD_MOD_LVL Tests On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to ON.
Move channel 1 of the oscilloscope to test jacks SHAPED MODULATION (XA3) and EARTH (XA7); disconnect channel 2.
Measure the voltage at test jack SHAPED MODULATION (XA3). This should be a DC level in the range 5.0 to 7.0 volts.
Connect the test clip lead between the ANODE end of V13 and test point XT8 (EARTH). Using the oscilloscope, measure the voltage at test jack SHAPED MODULATION (XA3). This should be a DC level of not more than 2.5 volts.
Remove the test clip lead between the ANODE end of V13 and test point XT8 (EARTH).
Adjust PEDESTAL VOLTAGE (R53) fully clockwise. Using the oscilloscope, measure the voltage at the SHAPED MODULATION test jack (XA3). This should be a DC level of at least 17.0 volts.
Adjust PEDESTAL VOLTAGE (R53) to produce a DC level of 17.0 ±1.0 volts on the oscilloscope display.
Connect the test clip lead between the ANODE end of V13 and test point XT8 (EARTH). Using the oscilloscope, measure the voltage at the SHAPED MODULATION test jack (XA3). This should be a DC level in the range 10.0 to 13.0 volts.
Remove the test clip lead between the ANODE end of V13 and test point XT8 (EARTH).
On the CTU front panel, select TD.Mod from the Level menu. The displayed reading on the CTU should be in the range 1.50 to 1.75 volts.
Connect the oscilloscope to the test jack SHAPED MODULATION (XA3) and adjust MOD PULSE AMPLITUDE (R58) clockwise whilst observing the oscilloscope. A pulse should develop from the base line, and should increase in height with the top eventually flattening off. Ensure that a pulse with a flattened top was achieved.
Adjust MOD PULSE AMPLITUDE (R58) counter-clockwise until the pulse just regains its pointed shape. The pulse peak voltage should be in the range 39 volts to 41 volts.
Adjust MOD PULSE AMPLITUDE (R58) to produce a pulse peak voltage of 35.0 ±1.0 volts.
The displayed reading on the CTU should be in the range 3.2 to 3.5 volts.
3.4.24.7 ALC Loop Check On the unit under test, set:
ALC SOURCE (S3) to VIDEO, ALC LOOP (S2) to CLOSED, ALC LEVEL (R62) to fully counter-clockwise.
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Measure the peak pulse voltage at SHAPED MODULATION test jack XA3 (as displayed on the oscilloscope - with respect to the 0 volts reference). This voltage should be not more than 18 volts (low amplitude pulses may not be visible above the DC baseline).
While monitoring the waveform on the oscilloscope, adjust ALC LEVEL fully clockwise. Check that the baseline voltage remains constant within 0.1 volts during this test.
Measure the peak pulse voltage at SHAPED MODULATION test jack (as displayed on the oscilloscope - with respect to the 0 volts reference). This voltage should be at least 38.0 volts.
Set ALC LEVEL for a peak pulse voltage of 35.0 ±1.0 volts on the oscilloscope.
3.4.24.8 Second Pulse Equalising Test Adjust 2ND PULSE EQUALISING (R54) fully clockwise. On the oscilloscope (still connected to SHAPED MODULATION test jack XA3), compare the height of the first pulse with the height of the second pulse; the two pulse peaks should be within 0.1 volts of each other.
Adjust 2ND PULSE EQUALISING fully counter-clockwise. Compare the height of the first pulse with the height of the second pulse; the height of the first pulse should be greater than the height of the second by at least 2.0 volts.
Adjust 2ND PULSE EQUALISING so that the heights of the two pulses are the same (to within 0.1 volts).
3.4.24.9 Medium Power Driver Supply Test Connect the multimeter (on 200 volts range) to pin 12 of connector XN2 (on the wiring side of the printed wiring board) and test point XT6 (COMMON).
Set MED POWER DRIVER DC (R115) fully counter-clockwise. The multimeter voltage reading should be not greater than 13.0 volts.
Set MED POWER DRIVER DC fully clockwise; the multimeter voltage reading should be at least 37.0 volts.
Adjust MED POWER DRIVER DC to give a multimeter voltage reading of 24.0 ±0.1 volts.
Set switch MED COLL (S4) to MODULATION. The multimeter voltage reading should be in the range 16.0 to 18.0 volts.
3.4.24.10 Exciter Supply Test Connect the multimeter (on 200 volts range) to test points XT7 and XT8 (COMMON).
Adjust EXCITER DC (R97) fully clockwise; the multimeter voltage reading should be at least 34.0 volts.
Set EXCITER DC fully counter-clockwise; the multimeter voltage reading should be not more than 13.0 volts.
Adjust EXCITER DC to give a voltage of 24.0 ±0.1 volts.
3.4.24.11 Power Modulation Amplifier Supply Test Connect the multimeter (on 200 volts range) to test points XT5 and XT8 (COMMON)
Adjust POWER MOD AMP DC (R69) fully clockwise; the multimeter voltage reading should be at least 37.0 volts.
Set POWER MOD AMP DC fully counter-clockwise; the multimeter voltage reading should be not more than 24.0 volts.
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Adjust POWER MOD AMP DC to give a voltage of 24.0 ±0.1 volts.
3.4.24.12 VC1 Supply and BIAS Test On the transponder power supply front panel, switch TRANSPONDER DC POWER to ON.
Switch DC POWER (S1) to NORMAL (away from LED H1), ALC LOOP (S2) to CLOSED and ALC SOURCE (S3) to DETECTED RF. Check that the red TEST indicator (H2) is off.
Check that the red TEST indicator (H2) is on for each of the following combination of switch settings:
DC POWER (S1) ALC LOOP (S2) ALC SOURCE (S3) OFF CLOSED DETECTED RF
NORMAL OPEN DETECTED RF NORMAL CLOSED VIDEO
Move the POWER link (X1) to the 150W position. Set switch ALC SOURCE (S3) to the DETECTED RF position; check that the red TEST indicator (H2) is on.
Set switch DC POWER (S1) to NORMAL, ALC LOOP (S2) to CLOSED and ALC SOURCE (S3) to VIDEO; check that the red TEST indicator (H2) is off.
Return the POWER link (X1) to the 1kW position.
Connect the multimeter (on 200 volts range) to test points XT10 and XT8 (COMMON).
Switch DRIVER DC POWER (S1) to NORMAL and check that the red TEST indicator (H2) is off; the multimeter voltage reading (voltage at XT10) should be 16.3 ±0.5 volts.
Connect the multimeter (on 200 volts range) to the +ve end of capacitor C41 and to test point XT8 (COMMON); the multimeter voltage reading should be 1.5 ±0.2 volts.
Switch DRIVER DC POWER to OFF.
3.4.24.13 Completion After having performed the above tests, on the transponder power supply front panel, switch TRANSPONDER DC POWER to OFF.
On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to OFF.
Remove the transmitter driver from the transponder extender frame and the transponder extender frame from the depot test facility. Disconnect the ribbon cable from the unit under test connector XN2, and remove the unit under test from the transmitter driver.
Assemble the pulse shaper board (belonging to the depot test facility) to the transmitter driver belonging to the depot test facility. Connect the ribbon cable from the RF modules to connector XN2 of the pulse shaper board. Install the transmitter driver into the transponder subrack.
On the transponder power supply front panel, switch TRANSPONDER DC POWER to NORMAL.
On the test interrogator front panel, set the MONITOR & INTERROGATOR DC POWER switch to NORMAL.
On the receiver video front panel, set the IDENT switch to NORMAL.
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3.4.25 Exciter 1A72532
3.4.25.1 Test Equipment Signal generator. Digital multimeter. Peak power meter. Oscilloscope. Current probe.
3.4.25.2 Test Overview This section comprises preliminary check, an alignment procedure and a sequence of tests repeated at three frequencies of 1215, 1090 and 950 MHz. The testing sequence to be followed is:
a. Perform the preliminary checks.
b. Peak tune the amplifier at 1215 MHz; then equalise the response over the frequency band.
c. Measure amplifier performance at the three frequencies in the band.
3.4.25.3 Preliminary Checks Select the diode test range on the multimeter and measure the continuity between connector XN1:9 and ground (negative meter lead to ground). Check that a meter reading equivalent to the forward resistance of a silicon diode is obtained.
With the negative meter lead to ground, check that no continuity is present at each of the following points:
XN1:1 XN1:3 XN1:5
3.4.25.4 DC Checks Fit the exciter board in place of the board in the depot test facility transmitter driver:
a. Remove the module from the depot test facility and remove the cover of the exciter.
b. Disconnect the input and output coaxial cables and the 10-pin connector and, by removing the six screws retaining the printed wiring board, take it out of the box.
c. Install the board on test into the box, using the same screws, and connect the 10-pin connector.
d. Replace the transmitter driver module, using the transponder extender frame, into the correct position in the depot test facility.
With the power switched off, connect the other instruments as shown in Figure 3-13. The small RF test items (i.e., load attenuator and peak power sensor) can be placed on the top of the extender frame.
Set the signal generator output to off, then switch the transmitter driver module DRIVER DC POWER switch to NORMAL.
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Figure 3-13 Exciter Test Setup
Check that the following voltages are present on the amplifier under test:
V1 base bias (R1) 0.8 ±0.1 volts DC V1 collector (R2) 16.3 ±1.5 volts DC
Adjust the controls on the pulse shaper board of the transmitter driver to give the following signals on the amplifier under test:
a. Set V3, V4 collector supply (as measured at XN1:1) to 15.0 ±0.2 volts peak pulse by adjusting 1W PULSE (R85).
b. Set V5, V6 collector supply (as measured at XN1:2) to 32.0 ±0.5 volts DC by adjusting EXCITER DC (R97).
3.4.25.5 Alignment With the drive voltage set as above, set the signal generator to 1215 MHz and a level of +10 dBm (10 mW), but do not yet apply RF drive to the amplifier under test (that is, leave the generator RF output off).
Set the controls on the peak power meter as follows:
READING OFFSET 20 dB RANGE 100 mW MODE DIRECT CORRECTION to suit sensor
Connect the termination unit of the current probe to channel 1 of the oscilloscope. Set the current probe sensitivity to 2 mA/mV and the oscilloscope sensitivity to 20 mV/division, so that the display represents 40 mA/division.
Clip the current probe on to the current loop leading to collectors V3 and V4 of the exciter under test. Check that the arrow on the probe is pointing towards the transistors V3 and V4.
Check the combined current pulse of V3 and V4 (in the absence of RF drive) and with a collector voltage of 16.3 volts (set as before). The current pulse should be greater than 30 mA, but less than 140 mA (refer to the conversion factor of the current probe).
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On the signal generator, set the RF switch to ON. Using the correct alignment tool, proceed to tune the 1 watt stage by trimming C5, C17, C 15 and C21 in succession, and repeating the process, until there is no further increase obtainable in the current. Check that the maximum current obtained is greater than 200 mA, but less than 500 mA.
Remove the current probe from the first loop, and clip it on to the loop supplying the current to transistors V5 and V6. Trim C26 and C30 in succession, and repeat the process, until there is no further increase obtainable in the current. Check that the maximum current obtained is greater than 300 mA, but less than 650 mA.
Observe on channel 2 of the oscilloscope, the peak of the detected RF pulse while trimming C33 and C34 in succession. Repeat the process several times, until no further increase can be obtained in the pulse amplitude. Check the output power on the peak power meter and ensure that 5 watts power is achievable by varying the 1W PULSE control on the pulse shaper board. Check that the pulse amplitude at the collectors of V3 and V4 required to give 5 watts output is not greater than 16 volts.
Set the signal generator frequency to 950 MHz, the output level remaining at +10 dBm. Check that 5 watts output power is achievable by varying the 1W pulse control on the pulse shaper board. Check that the pulse amplitude required to get 5 watts is not greater than 16 volts.
Set the signal generator frequency to 1090 MHz, the output level remaining at +10 dBm. Check that it is possible to adjust the output power to 5 watts by varying 1W PULSE (R85) on the pulse shaper board. Check that the pulse amplitude required to get 5 watts is not greater than 16 volts.
Remove the exciter board from the box in the transmitter driver module and install it in its original box; replace the original board in the module.
3.4.26 Medium Power Driver 1A72533
3.4.26.1 Test Equipment Oscilloscope. Current probe. Signal generator. Digital multimeter. Attenuator, medium, 10 dB: Qty 2. Attenuator, power, 20 dB. Dual directional coupler. Peak power meter and sensor. Coaxial detector. Resistor, 4.75 kilohm, 400 mW. Adaptor, 50 ohms, SMA (female) - SMA (female). Termination, 50 ohms, 1 watt. Calibration link (semi-flexible cable, 100 mm long, SMA(F) - SMA(F).
3.4.26.2 Preliminary Electrical Tests The medium power driver to be tested, is fitted in place of the unit in the depot test facility transmitter driver module, as follows:
1. Remove the module from the depot test facility and remove the cover of the medium power driver.
2. Disconnect the input and output coaxial cables and the 4-pin connector and, by removing the three screws visible through the PWBs, take the complete medium power driver out of the module.
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3. Install the unit on test into the module, using the same screws, and connect the 4-pin connector
4. Replace the transmitter driver module, using the extender frame, into the correct position in the depot test facility.
5. Using the digital multimeter, check that the input microstrip circuit is grounded.
6. Using the digital multimeter, check that the output microstrip circuit is isolated from ground.
7. Disconnect the link between the DC control board (terminal X2) and the RF board.
8. Set switch MED COLL (S4) on the pulse shaper board to DC, switch ALC LOOP (S2) to OPEN and switch ALC (S3) to VIDEO, then set the front panel DRIVER DC POWER switch to NORMAL, and set the TRANSPONDER DC POWER to ON. Measure the HT voltage on X5; it should be 42 ± 0.2 volts.
9. While monitoring the voltage at X2 with the digital multimeter, slowly increase MED POWER DRIVER DC (R115) control on the pulse shaper board from minimum to maximum. Check that the voltage at X2 increases with the increase of the control voltage.
10. The voltage at X2 must be less than 6 volts below the voltage on XN1 pin C.
11. Set the front panel DRIVER DC POWER switch to OFF.
12. Replace the link removed in step 7.
3.4.26.3 Calibration Procedure This section details a calibration procedure at the depot test facility frequency. The RF test equipment (directional coupler with detectors, load attenuators and peak power sensor) can be placed on the top of the extender frame.
The coaxial cable from the exciter unit output to the directional coupler input may be as long as necessary, but the cable from the coupler to the unit on test should be as short as possible, as also should be the cable from the medium power driver to the 20 dB attenuator before the power meter.
CAUTION The power sensor diode of the peak power meter is easily destroyed, so check that the 30 dB of attenuation is connected in front of the power sensor.
Arrange the test setup as shown in Figure 3-14 with the SMA calibration link connected in circuit instead of the medium power driver which is to be tested. Remove the 10 dB attenuator at the peak power sensor, and connect the sensor directly to the 20 dB attenuator.
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Figure 3-14 Medium Power Driver Test Setup
Switch on the mains to all the test equipment, with the transmitter driver DRIVER DC POWER switch remaining set to OFF.
Set the depot test facility transmit frequency to 1213 MHz.
Set the oscilloscope sweep time to 1 microsecond per division and trigger the oscilloscope from the receiver video TRIGS TO MODULATOR test jack.
On the peak power meter, set the correction to that stated on the correction table for frequencies up to 2 GHz. Set the reading offset to 20 dB and the range switch to 100 mW. Set the peak power meter to measure in COMPARE mode. Adjust the COMPARE LEVEL controls on the peak power meter to give a meter reading which corresponds to 4.0 watts into the 20 dB attenuator. The actual meter reading will depend on the exact attenuation of the 20 dB attenuator, and it is important that its calibration be taken into account when deriving the meter reading. As an example, the figures below show the correct meter reading for various values of attenuation:
Pinput (watts) ATTENUATION Pmeter (watts) 4.00 19.7 4.29
4.00 19.8 4.19
4.00 19.9 4.09
4.00 20.0 4.00
4.00 20.1 3.91
4.00 20.2 3.82
4.00 20.3 3.73
With the meter set to the appropriate value, there will be a horizontal trace on oscilloscope channel 2, which represents a true 4.0 watts into the 20 dB attenuator.
Switch the transmitter driver DRIVER DC POWER switch to NORMAL.
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Adjust 1W PULSE (R85) level control on the pulse shaper board until the main body of the pulse lies on the 4.0 watts horizontal trace on the oscilloscope (that is, ignore any initial spike in the pulse). If the top of the main body of the pulse slopes, then take an average level.
Once 4 watts of power is available, measure the output from the HP detector on the second oscilloscope and record the peak pulse voltage to the nearest 20 mV. This value then becomes the '4W available' calibration at this frequency. (The detector output is a negative-going pulse.)
Switch the transmitter driver DRIVER DC POWER switch to OFF. Replace the 10 dB attenuator between the peak power sensor and the 20 dB attenuator.
3.4.26.4 Amplifier Test Procedure Arrange the test setup as shown in Figure 3-14, with the medium power driver on test in circuit in place of the SMA calibration link. Set the RANGE switch on the peak power meter to 100 mW and the MODE switch to DIRECT. Check that there is a total of 30 dB attenuation between the amplifier and peak power sensor.
The reading offset should be switched to 30 dB and the correction set for 2 GHz from the correction table on the peak power sensor.
Observe the output power from the medium power driver on channel 2 of the oscilloscope.
Observe the output from the detector on channel 1 of the oscilloscope and adjust 1W PULSE (R85) to bring the displayed pulse level to the '4 watts available' level.
Measure the output power on the peak power meter; this should be at least 25 watts peak.
Switch the transmitter driver DRIVER DC POWER switch to OFF.
Connect the current probe to the oscilloscope channel 1 and set the sensitivity to read 8.0 amperes full scale (0.1 volts/10 mA/mV); clip the current probe to the link from X2 to the RF board.
On the pulse shaper board check that switch MED COLL (S4) is set to DC.
Switch the transmitter driver DRIVER DC POWER switch to ON and check that the current pulse shape is as shown below, the peak current should be 1.9 to 2.7 amperes for the 25 watts output.
Adjust MED POWER DRIVER DC (R115) and check that the channel 1 waveform varies as indicated below.
Reset the controls and switch on the main board to their original conditions.
Switch the transmitter driver DRIVER DC POWER switch to OFF, remove the unit on test and replace the original unit in the module.
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3.4.27 Power Modulation Amplifier 1A72534
3.4.27.1 Test Equipment Oscilloscope. Current probe. Signal generator. Digital multimeter. Attenuator, medium, 10 dB: Qty 2. Attenuator, power, 30 dB. Dual directional coupler. Peak power meter and sensor. Coaxial detector. Capacitor, electrolytic, 100 uF, 100 volts: Qty 2. Resistor, 4.75 kilohm, 400 mW. Adaptor, 50 ohms, SMA (female) - SMA (female). Termination, 50 ohms, 1 watt. Connector, plug, 4-pin. Calibration link (semi-flexible cable, 100 mm long, SMA(F) - SMA(F).
3.4.27.2 Preliminary Electrical Tests For this test, the power modulation amplifier to be tested should be placed on a bench top adjacent to the depot test facility.
Remove the transmitter driver module from the depot test facility and set the following switched on the pulse shaper board:
ALC LOOP (S2) to OPEN ALC (S3) to VIDEO MED COLL (S4) to DC.
Replace the transmitter driver module, using the extender cradle, into the correct position in the depot test facility.
On the amplifier under test, use the digital multimeter, check that the two input microstrip circuits are grounded.
Use the digital multimeter to check that the two output microstrip circuits are isolated from ground.
Disconnect the link between the DC control board (terminal X2) and the RF board.
Attach leads (minimum of 1.0 mm2) through a 4-pin plug connector to the 4-pin connector XN9 (POWER SUPPLY CONNECTOR 2) on the transponder subrack motherboard in the depot test facility. The inner two pins are the positive connection to the HT supply; the outer two pins are the common earth connection.
Connect the negative lead to the body of the amplifier under test, and connect the positive lead to pins C and D of the 4-pin connector XN1.
Switch the transponder power supply front panel switch TRANSPONDER DC POWER to ON and measure HT voltage at the input of the amplifier on test (XN1:C); it should be 42 ±0.2 volts.
Measure the voltage at X2 with the digital multimeter; this voltage must be less than 6 volts below the voltage on XN1:C.
On the transponder power supply front panel, set TRANSPONDER DC POWER switch to OFF.
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3.4.27.3 Test Overview This section details a calibration and test procedure which must be performed at depot test facility frequencies of 1150 MHz and 1213 MHz.
3.4.27.4 Calibration Procedure CAUTION The power sensor diode of the peak power meter is easily destroyed, so
check that at least 30 dB of attenuation is always connected in front of the power sensor.
Figure 3-15 Power Modulation Amplifier Test Setup
At the back if the 1kW power amplifier, remove the type-N coaxial plug at the INPUT connector. Using a type-N elbow and adaptors, connect a suitable cable from the input cable just removed to the test equipment as shown in Figure 3-15. This allows RF drive, for the amplifier under test, to be obtained from the transmitter driver in the depot test facility.
Arrange the test setup as shown in Figure 3-15 with the SMA calibration link connected in circuit instead of the power modulation amplifier which is to be tested. Remove the 10 dB attenuator at the peak power sensor, and connect the sensor directly to the 30 dB attenuator.
Set the depot test facility transmit frequency to 1150 MHz.
Switch on the mains to all the test equipment, with the transmitter driver DRIVER DC POWER switch remaining set to OFF
Switch TRANSPONDER DC POWER to ON.
Set the oscilloscope sweep time to 1 microsecond per division and trigger the oscilloscope from the receiver video TRIGS TO MODULATOR test jack.
On the peak power meter, set the correction to that stated on the correction table for frequencies up to 2 GHz. Set the reading offset to 30 dB and the range switch to 100 mW. Set the peak power meter to measure in COMPARE mode.
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Adjust the COMPARE LEVEL controls on the peak power meter to give a meter reading which corresponds to 50.0 watts into the 30 dB attenuator. The actual meter reading will depend on the exact attenuation of the 30 dB attenuator, and it is important that its calibration be taken into account when deriving the meter reading. As an example, the figures below show the correct meter reading for various values of attenuation.
Pinput (watts) ATTENUATION Pmeter (watts)
50.0 29.7 53.6
50.0 29.8 52.4
50.0 29.9 51.2
50.0 30.0 50.0
50.0 30.1 48.9
50.0 30.2 47.8
50.0 30.3 46.7
With the meter set to the appropriate value, there will be a horizontal trace on oscilloscope channel 2, which represents a true 50.0 watts into the 30 dB attenuator.
Set the transmitter driver DRIVER DC POWER switch to NORMAL.
Observe the forward power pulse on channel 1 of the oscilloscope.
Adjust the output power by varying POWER MOD AMP DC (R69) on the pulse shaper board (with the MED COLL switch S4 switched to DC) until the main body of the pulse lies on the 50.0 watts horizontal trace on the oscilloscope (that is, ignore any initial spike in the pulse). If the top of the main body of the pulse slopes, then take an average level.
When 50 watts of power is available, measure the output from the detector on the oscilloscope and record the peak pulse voltage to the nearest 20 mV. This value then becomes the '50 watts available' calibration at this frequency. (The detector output may be a negative-going pulse.)
Set the transmitter driver DRIVER DC POWER switch to OFF. Replace the10 dB attenuator between the peak power sensor and the 30 dB attenuator.
3.4.27.5 Amplifier Test and Tuning Procedure Disconnect the link between the DC control board and the RF board, and connect the positive output of the HT supply to the point on the RF board where the link was connected. Connect two 100 uF electrolytic capacitors within 100 mm of the amplifier under test, as shown in Figure 3-15. Switch the TRANSPONDER DC POWER to ON and check that the HT supply is 42.0 ±0.2 volts.
With the test setup as shown in Figure 3-15, connect the power modulation amplifier on test in place of the SMA calibration link. Set the RANGE switch on the peak power meter to 100 mW and the MODE switch to DIRECT. Check that there is a total of 40 dB attenuation between the amplifier and peak power sensor.
The reading offset should be switched to 40 dB and the correction set for 2 GHz from the correction table on the peak power sensor.
Observe the output power pulse from the power modulation amplifier on channel 2 of the oscilloscope.
Observe the output from the detector on channel 1 of the oscilloscope and adjust the input signal level by varying POWER MOD AMP DC (R69) until the 50 watts reference level is attained.
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a. At 1150 MHz only When the '50W available' calibration point has been reached at the input, adjust capacitor C4 on the amplifier under test to give the maximum output amplitude.
b. At all test frequencies, including 1150 MHz: Measure the output power on the peak power meter. This must be at least 185 watts peak.
Connect a probe to the amplifier peak detector output on pin XN1:A and check the detected pulse on channel 1 of the oscilloscope. Adjust the RF input to the amplifier so that the output power is 185 watts. The amplitude of the pulse must be within the limits inferred by the following table when the amplifier output is 185 watts peak.
FREQUENCY (MHz)
DETECTOR OUTPUT
(Vpk)
960 5.0 ±1.0
1090 5.3 ±1.0
1150 6.0 ±1.0
1213 6.3 ±1.0
Readjust POWER MOD AMP DC (R69) to give 100 watts output power.
Set the transmitter driver DRIVER DC POWER switch to OFF.
Connect the current probe to the oscilloscope channel 1 and set the sensitivity to read 20 amperes full scale (0.5 volts/1 0 mA/mV): clip the current probe to the link from X2 to the RF board.
Switch on the DRIVER DC POWER and check the current pulse shape, noting the peak current, which should be 7.5 to 9.5 amperes for the 100 watts output; see the figure below.
Adjust the front panel RF OUTPUT control and check that the channel 1 waveform varies as indicated below.
Reset the controls and switch on the main board to their original conditions.
Set the transmitter driver DRIVER DC POWER switch to OFF. Remove the unit on test and replace the original unit in the module.
Replace the link between the RF board and DC control board in the amplifier under test.
3.4.28 1kW RF Power Amplifier 1A72535
3.4.28.1 Test Equipment Oscilloscope. Digital multimeter. Peak power meter. Attenuator, power, 30 dB. Attenuator, medium, 20 dB. Spectrum analyser.
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Directional coupler. Current probe. SMA connector torque wrench. Cables and adaptors.
3.4.28.2 Setup NOTE The alignment procedure involves temporary changes to the RF connections to
some of the modules in the depot test facility. To ensure correct alignment and subsequent correct operation, ensure that each RF connector is securely tightened (use a torque wrench for SMA connectors) following its connection.
When making measurements of the peak RF power, correction needs to be made for the errors in the peak power meter and for the actual losses in any attenuators at the input to the peak power meter. This requires that the peak power meter and any attenuators used be characterised at the frequency of operation and these corrections applied to the meter readings.
CAUTION The sensor on the peak power meter is sensitive to overload, and is easily damaged. To prevent expensive delays and repairs from being incurred, ensure that the correct specified attenuator is connected to the peak power meter sensor before connecting to the RF source to be measured.
The unit under test is normally aligned at a reply frequency of 1215 MHz. However, if alignment and testing is required at the operational reply frequency, the tests below need only be performed at this operational frequency. Tune the receiver video in the DME rack for the test and alignment frequency(ies) - see Section 3.4.18 if an RF source is to be aligned; see Appendix K if the tests are being performed at the depot test facility. If necessary, align the transmitter driver for the test and alignment frequency(ies) - see Section 3.4.23.
With the depot test facility operating, on the CTU, press the following front panel keys in the sequence:
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to OFF.
On the pulse shaper board in the transmitter driver module, set the following switches:
ALC LOOP (S2) to OPEN ALC (S3) to VIDEO MED COLL (S4) to DC.
On the depot test facility, lower the hinged front panel of the 1kW PA power supply to provide access to the connections to the 1kW RF amplifier. Disconnect the two multi-pin connectors and the two RF connectors.
At the rear of the depot test facility, remove the four screws securing the cover of the 1kW RF amplifier. Remove the cover. Remove the four screws securing the 1kW RF amplifier to the rack. Remove the two screws attaching the rack earthing bars (one each side of the rack) to the 1kW RF amplifier. Carefully remove the 1kW RF amplifier. (When temporarily storing this unit, do not place the 1kW RF amplifier so that it rests on its RF connectors.)
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Install the unit under test in the depot test facility in place of the removed 1kW RF amplifier. Secure the unit under test to the two earthing bars (one each side of the rack). Secure the unit under test to the depot test facility. (Do not install the cover to the unit under test at this stage.)
Figure 3-16 1kW RF Power Amplifier Test Setup
Connect the two multi-pin connectors to the unit under test. (Access is provided from the front of the depot test facility after lowering the hinged front panel of the 1kW PA power supply.)
Connect the RF cable (from the transmitter driver in the transponder subrack) to the INPUT connector of the unit under test.
At the OUTPUT connector of the unit under test, connect the following items of test equipment, as shown in Figure 3-16.
a. INPUT of the 30 dB attenuator to OUTPUT of the unit under test (a right angle adaptor may be required);
b. INPUT of the 20 dB attenuator to OUTPUT of the 30 dB attenuator;
c. TX (or INPUT) of the directional coupler to OUTPUT of the 20 dB attenuator; and
d. RF IN of the sensor of the peak power meter to LOAD (or OUTPUT) of the directional coupler.
Connect an RF cable from the COUPLER connector on the directional coupler to RF IN on the spectrum analyser.
Initially set the spectrum analyser controls as follows:
Centre frequency 1215 MHz Bandwidth 100 kHz Scan width 1 MHz per division Input attenuation 0 dB Scan time 0.1 seconds per division
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Video filter Off Log scan sensitivity to suit.
On the test interrogator front panel, set the switch MONITOR & INTERROGATOR DC POWER to ON.
On the monitor front panel, set switch MONITOR OUTPUTS to NORMAL.
On the receiver video front panel, set the IDENT switch to CONTINUOUS.
Extend the transmitter driver using the transponder extender frame.
On the transmitter driver front panel, set switch DRIVER DC POWER to NORMAL.
On the pulse shaper board of the transmitter driver, adjust the following controls fully counter-clockwise:
PEDESTAL VOLTAGE (R53), MOD PULSE AMPLITUDE (R58).
On the transponder power supply front panel, set switch TRANSPONDER DC POWER to ON.
Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to VIDEO OUT on the peak power meter to check the pulse shape.
Carefully raise the hinged front panel of the 1kW PA power supply (to provide access to the controls and test jacks on the front panel) ensuring that no test cables have potential for being damaged.
On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to ON.
Connect the multimeter (on 200 volts range) to test jacks HT and EARTH on the 1kW PA power supply front panel. The measured voltage should be 50.0 ±0.2 volts. (If out of range, set the voltage within the specified range by adjusting R112 on the regulator board of the 1kW PA power supply.)
Connect channel 2 of the oscilloscope (other connections unchanged) to test jacks SHAPED MODULATION and EARTH on the transmitter driver front panel.
Confirm that the peak power meter reading is not more than 5.0 mW (or not more than 500.0 watts if the reading is corrected for the 50 dB attenuator).
3.4.28.3 Amplifier Performance Tests CAUTION DO NOT AT ANY TIME let the peak power exceed 2 kW (20 mW on the
peak power meter).
1. While monitoring the peak power meter, to ensure that its reading does not exceed 5.0 mW (or 500.0 W if the reading is corrected for the 50 dB attenuator), slowly increase PEDESTAL VOLTAGE (R53) on the pulse shaper board of the transmitter driver to produce a base voltage of 17.0 ±0.5 volts as displayed on channel 2 of the oscilloscope.
2. While monitoring the peak power meter, slowly increase MOD PULSE AMPLITUDE (R58) control on the pulse shaper board of the transmitter driver to produce a peak power meter reading of 18 ±0.5 mW (or 1800 ±50 watts if the reading is corrected for the 50 dB attenuator). Be sure to take into account the true calibrated attenuation of the 30 dB and 20 dB attenuators. The table below may be used to determine the required reading of the peak power meter for 1800 watts peak power.
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CALIBRATED ATTENUATOR LOSS
METER READING (in mW) FOR 1.8 kW
49.0 22.7
49.1 22.1
49.2 21.6
49.3 21.1
49.4 20.7
49.5 20.2
49.6 19.7
49.7 19.3
49.8 18.8
49.9 18.4
50.0 18.0
50.1 17.6
50.2 17.2
50.3 16.8
50.4 16.4
50.5 16.0
50.6 15.7
50.7 15.3
50.8 15.0
50.9 14.6
51.0 14.3
3. While observing channel 1 of the oscilloscope, make successive small changes to the PEDESTAL VOLTAGE (R53) and MOD PULSE AMPLITUDE (R58) presets to achieve a pulse shape as close as possible to that shown in the figure below (with a pulse width in the range 3.50 to 3.75 microseconds, and rise and fall times in the range 1.80 to 2.50 microseconds), while maintaining the 1.8 kW peak power. (The PEDESTAL VOLTAGE (R53) adjustment should be used mainly to ensure a smooth transition from the shaped pulse to the base line.) Do not let the peak power exceed 2 kW.
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4. On the spectrum analyser, tune in the pulse spectrum. Change the SCAN WIDTH to 200 kHz per division. Set the 0 dB reference to the peak of the displayed spectrum. At 800 kHz either side of the frequency of the peak response, read the spectral response in dB below the 0 dB reference. The magnitude of this difference should not be less than 50 dB (step 3 may need to be repeated to achieve this result).
5. Change the SCAN WIDTH to 5 MHz per division and reset the 0 dB reference to the peak of the displayed spectrum. Confirm that there are no responses between ±2 MHz and ±50 MHz which are above a level which is 65 dB below the 0 dB reference level. (Responses above the specified level which can be shown to not be generated in the unit under test are not to be considered.)
6. Using the current probe, measure the peak currents in the RF power transistors of the 250W RF amplifiers, A1 through A10. The peak currents should be less than 20.0 amperes.
3.4.28.4 Level Monitors Move channel 2 of the oscilloscope to test jacks POWER AMP OUTPUT and EARTH on the front panel of the 1kW PA power supply. The oscilloscope channel 2 display should be similar to the oscilloscope channel 1 display, with a peak amplitude in the range 6.0 to 8.0 volts.
Move channel 2 of the oscilloscope to test jacks POWER AMP DRIVER and EARTH on the front panel of the 1kW PA power supply. The oscilloscope channel 2 display should be similar to the oscilloscope channel 1 display, but with the pulse riding on a rectangular pedestal. The peak amplitude should be is the range 7.5 to 9.5 volts.
Move channel 2 of the oscilloscope to test jacks POWER AMP MODULATOR and EARTH on the front panel of the 1kW PA power supply. The oscilloscope channel 2 display should be similar to the oscilloscope channel 1 display, but with the pulse riding on a rectangular pedestal. The peak amplitude should be in the range 3.0 to 7.0 volts.
3.4.28.5 Completion After having performed the above tests, on the transponder power supply front panel, switch TRANSPONDER DC POWER to OFF.
On the 1kW PA power supply front panel, switch AMPLIFIER DC POWER to OFF.
On the depot test facility, lower the hinged front panel of the 1kW PA power supply. Disconnect the test equipment connected to the OUTPUT connector, the two multi-pin connectors and the RF cable connected to the INPUT connector of the unit under test.
At the rear of the depot test facility, remove the four screws securing the unit under test to the depot test facility. Remove the two screws attaching the depot test facility earthing bars (one each side of the rack) to the unit under test. Carefully remove the unit under test.
Install the 1kW RF amplifier back in the depot test facility and secure it to the two earthing bars (one each side of the rack). Secure the 1kW RF amplifier to the depot test facility. Install and secure the cover to the 1kW RF amplifier.
Reconnect the two multi-pin connectors and the two RF connectors to the 1kW RF amplifier.
If no further testing of 1kW RF amplifiers is required, the controls on the pulse shaper board of the transmitter driver need to be readjusted for the 1kW RF amplifier installed. The procedures to do this are contained in the detailed beacon alignment procedures
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contained in Section 3.3 (specifically the appropriate steps of Sections 3.3.9.1, 3.3.9.2 and 3.3.10.1).
Remove the transponder extender frame from the depot test facility. Install the transmitter driver into the transponder subrack.
On the transponder power supply front panel, switch TRANSPONDER DC POWER to NORMAL.
On the test interrogator front panel, set the switch MONITOR & INTERROGATOR DC POWER to NORMAL.
On the receiver video front panel, set the IDENT switch to NORMAL.
3.4.29 Power Divider 1A72536
3.4.29.1 Test Equipment Spectrum analyser. Signal generator. Directional coupler. Attenuator, miniature, 30 dB. Attenuator, miniature, 10 dB: Qty 2. Oscilloscope. Digital voltmeter. Connector, coaxial, panel, SMA(F). Termination, coaxial, SMA(M): Qty 9. Coaxial cables and adaptors.
3.4.29.2 Return Loss Measurement Connect the equipment and calibrate as detailed in Section 3.4.1.5.1, and calibrate using the SMA adaptor.
Remove the 50 ohms reference termination and connect the test port to the directional coupler.
While measuring the return loss at one port, ensure that the other nine ports are terminated with 50 ohms.
Measure the return loss at each of the ports XC1 through XC10 over the frequency range 950 to 1250 MHz; it should be not less than 15 dB.
3.4.29.3 Insertion Loss Measurement Set up and calibrate the equipment as detailed in Section 3.4.1.5.2.
Remove the SMA adaptor and connect the input 10 dB attenuator to XC2 and the output 10 dB attenuator to XC3. Terminate connectors XC1 and XC4 through XC10 with 50 ohms loads and measure the insertion loss over the range 950 to 1250 MHz. Similarly measure the insertion loss from XC2 to each of the connectors XC5 through XC10 and XC1 ensuring that connectors other than the one under test are terminated.
The insertion loss at each connector except XC1 should be 13 ±1 dB. Additionally, the insertion losses at two connectors connected to the same 2-way combiner (e.g., XC3 and XC4) should be within 1 dB of each other. With the input attenuator connected to XC3 and the output attenuator connected to XC1, the insertion loss should also be 13 ±1 dB.
3.4.29.4 10 dB Attenuator and Detector Connect the test setup as shown in Figure 3-17.
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Set the signal generator to an output of +13 dBm.
Using the SMA panel receptacle, connected to the SMA(M) cable, feed the RF signal from the signal generator to the short coupled line on the divider unit by pressing the centre contact of the SMA panel receptacle on to the 50 ohms terminated end of the coupled line and the body to the ground plane as shown in Figure 3-17.
Measure the voltage at XC11; this should be 100±10 mV.
Figure 3-17 Attenuator and Detector Test Setup
3.4.30 Power Combiner 1A72537
3.4.30.1 Test Equipment Spectrum analyser. Signal generator. Directional coupler. Attenuator, miniature, 30 dB. Attenuator, miniature, 10 dB: Qty 2. Oscilloscope. Digital voltmeter. Special detector test cable; see Figure 3-18. Connector, coaxial, panel, SMA(F). Termination, coaxial, SMA(M): Qty 9. Coaxial cables and adaptors.
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Figure 3-18 Detector Test Cable
3.4.30.2 Test Arrangements For return loss measurement, connect and calibrate the test equipment as in Section 3.4.1.5.1.
For insertion loss measurement, connect and calibrate the test equipment as in Section 3.4.1.5.2.
3.4.30.3 Two-way Splitter Measure the return loss at each of the ports XC13, XC1 and XC2 over the frequency range 900 to 1250 MHz. While measuring the return loss at one port, ensure that the other two ports are terminated with 50 ohms. The return loss should not be less than 15 dB.
Setup the equipment for insertion loss measurement as detailed in Section 3.4.1.5.2. Connect the 10 dB attenuator from the signal generator to XC13 and, connecting the other 10 dB attenuator to each of the connectors XC1 and XC2, measure the insertion loss through the splitter over the frequency range 900 to 1250 MHz. It should be not greater than 3.8 dB.
3.4.30.4 Eight-Way Combiner Measure the return loss at each of the connectors XC3 through XC11 over the frequency range 900 to 1250 MHz. Ensure that all the connectors other than the one under test are terminated with 50 ohms. The return loss at each port should be not less than 15 dB.
Connect the 10 dB attenuator from the signal generator to XC11 and the other 10 dB attenuator to XC3. Terminate connectors XC4 through XC10 with 50 ohms loads and measure the insertion loss over the frequency range 900 to 1250 MHz. Similarly measure the insertion loss from XC11 to each of the connectors XC5 through XC10 ensuring that the connectors other than the one under test are terminated.
The insertion loss at each connector should be 9.8 ±1 dB. Additionally, the insertion losses at two connectors connected to the same 2-way combiner (e.g., XC3 and XC4) should be within 1 dB of each other.
3.4.30.5 Attenuator and Detector Connect the test setup as shown in Figure 3-19, with the signal generator SMA(M) cable connected to the detector test cable shown in Figure 3-18.
Set the signal generator to an output of +13 dBm.
Using the detector test cable, feed the RF signal from the signal generator to the short coupled line on the combiner unit. To do this, insert this cable beneath the metal screen, so that the centre conductor contacts the middle of the coupled line, and the outer
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conductor is earthed to the screen, as shown in Figure 3-19. Measure the voltage at XC12; it should be 100 ±10 mV.
Figure 3-19 10 dB Attenuator and Detector Test Setup
3.4.31 1kW PA Power Supply 1A72540
3.4.31.1 Test Equipment Oscilloscope. Digital multimeter. Variable load resistor, 8 to 20 ohms, 250 watts rating.
3.4.31.2 Alignment Alignment of the 1kW PA power supply is performed by carrying out the required alignment procedures for its component assemblies Control and Status PWB Assembly 1A72541 and DC-DC Converter PWB Assembly 1A72542.
If a complete 1kW PA power supply is to be tested, switch off circuit breaker 1kW POWER AMP on the power distribution panel, remove the 1kW PA power supply from the depot test facility and replace it with the unit to be tested. Connect only the input power leads (positive to XB1/1, negative to XP2) but NOT the output power leads.
3.4.31.3 Control Circuit Checks Power on the beacon using the distribution panel.
On the 1kW PA power supply set the AMPLIFIER DC POWER switch to OFF. Check that the front panel green indicators DC POWER ON and HT ON are both off and that the red TEST indicator is on.
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Set the AMPLIFIER DC POWER switch to the ON position, and check that the green DC POWER ON and HT ON indicators are both on.
3.4.31.4 Relay and Voltage Checks Using the multimeter set to DC volts and the 200 volts range, measure across XB1:6 (0 volts) and XB1:5 (HT). The meter reading should be 50.0 ±0.5 volts; if it is not, refer to Section 3.4.33.
Connect channel 1 of the oscilloscope (set to AUTO INTERNAL CHANNEL 1 trigger and positive slope) to connectors XB1:6 (ground) and XB1:5.
Check that the peak-to-peak ripple and noise present on the power supply output is less than 100 mV peak-to-peak.
3.4.31.5 Load Tests Connect the variable load, set to its maximum resistance (of at least 20 ohms) to the output terminals XB1:5 (positive) and XB1:6 (negative), through an ammeter (digital multimeter set on 10A range).
Adjust the resistance of the variable load to give an ammeter reading of 3.5 ±0.1 amperes. On the oscilloscope, connected as in Section 3.4.31.4, check that the ripple and noise present on the power supply output is less than 100 mV peak-to-peak.
3.4.31.6 Completion Switch circuit breaker 1kW POWER AMP off. Remove the unit under test and replace the 1kW PA power supply belonging to the depot test facility back in the rack. Ensure that all cables are securely fastened. Switch on circuit breaker 1kW POWER AMP and check that the depot test facility operates normally
3.4.32 Control and Status PWB Assembly 1A72541
3.4.32.1 Test Equipment Oscilloscope. Digital multimeter: Qty 2.
3.4.32.2 Setup With the DME operating, on the CTU, press the following front panel keys in the sequence:
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
Switch circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel to off.
Lower the front panel of the 1kW PA power supply, disconnect the two cable connectors to the control and status board, remove its retaining screws and remove the control and status board.
Install the control and status board to be tested in place of the removed unit, ensuring that the retaining screws and cable connectors are securely replaced.
Switch on circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel.
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3.4.32.3 Control Circuitry Tests Switch AMPLIFIER DC POWER on the 1kW PA power supply front panel to NORMAL.
On the CTU, press the SELECT MAIN NO 1 key.
On the CTU, select PwrOut parameter measurement at a TI RATE of 1 kHz. The displayed transmitted output power should be 1.2 ±0.1kW.
On the 1kW PA power supply front panel, check that the indicators are as follows:
a. H3, HT ON (green) is on;
b. H2, TEST (red) is off; and
c. H1, DC POWER ON (green) is on.
Switch AMPLIFIER DC POWER on the 1kW PA power supply front panel to OFF.
On the 1kW PA power supply front panel, check that the indicators are as follows:
a. H3, HT ON (green) is off;
b. H2, TEST (red) is on; and
c. H1, DC POWER ON (green) is off.
On the CTU, select PwrOut parameter measurement. The displayed transmitted output power should be less than 0.1kW.
Switch AMPLIFIER DC POWER on the 1kW PA power supply front panel to ON.
On the 1kW PA power supply front panel, check that the indicators are as follows:
a. H3, HT ON (green) is on;
b. H2, TEST (red) is on; and
c. H1, DC POWER ON (green) is on.
On the CTU, select PwrOut parameter measurement. The displayed transmitted output power should be 1.2 ±0.1kW.
Switch AMPLIFIER DC POWER on the 1kW PA power supply to OFF.
3.4.32.4 HT OUT Monitoring For this test, disconnect the HT supply from the 1kW PA, by removing the connector at XN2 on the 1kW power amplifier.
Switch AMPLIFIER DC POWER on the 1kW PA power supply front panel to ON.
Connect the multimeter, on 200 volts range, to test jacks HT OUT and EARTH on the unit under test (on the 1kW PA power supply front panel). The measured voltage should be 50.0 ±0.2 volts.
On the CTU, select PS.Volt then PA.HT measurement. The displayed voltage should be 50.0 ±0.5 volts.
Remove the cover from the DC-DC converter of the 1kW PA power supply. Adjust R112 on the DC-DC converter slowly counter-clockwise until indicator HT ON turns off. The multimeter reading should be 48.5 ±0.1 volts. (If this reading is outside limits, slightly adjust R45 so that this and the following requirement can both be met with the same setting of R45).
Adjust R112 on the DC-DC converter slowly clockwise until indicator HT ON turns on and then off. The multimeter reading should be 51.9 ±0.1 volts. (If this reading is outside limits, slightly adjust R45 so this and the previous requirement can both be met with the same setting of R45).
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Adjust R112 on the DC-DC converter to give a multimeter reading of 50.0 ±0.1 volts. Replace the cover of the DC-DC converter of the 1kW PA power supply.
Connect the multimeter, on 20 volts range, to test jacks +15V and EARTH (on the 1kW PA power supply front panel). The measured voltage should be 15.0 ±0.8 volts.
Switch AMPLIFIER DC POWER on the 1kW PA power supply to OFF.
Reconnect the HT supply to the 1kW power amplifier.
Switch AMPLIFIER DC POWER on the 1kW PA power supply to ON.
Connect the multimeter, on 200 mV range, to test jacks SUPPLY CURRENT + and SUPPLY CURRENT - (on the 1kW PA power supply front panel). The measured voltage should be in the range 4.0 to 7.0 mV.
3.4.32.5 RF Amplifier Monitoring Tests Connect channel 1 of the oscilloscope (externally triggered from test jacks TRIGS TO MODULATOR and EARTH on the receiver video front panel) to test jacks SHAPED MODULATION and EARTH on the 1kW PA power supply front panel. The displayed waveform should be dual, shaped pulses with an amplitude in the range 25 to 35 volts.
Move channel 1 of the oscilloscope to test jacks POWER AMP DRIVER and EARTH on the 1kW PA power supply front panel. The displayed waveform should be dual, shaped pulses (on pedestals) with an amplitude in the range 3.5 to 7.5 volts.
Connect channel 2 of the oscilloscope to the top end of R24 (near N5) on the unit under test. The two waveforms on the oscilloscope should be the same.
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On the CTU, select PA.Drv Level measurement. The displayed power amplifier driver level should be in the range 2.0 to 4.8 volts.
Move channel 1 of the oscilloscope to test jacks POWER AMP OUTPUT and EARTH on the 1kW PA power supply front panel. The displayed waveform should be dual, shaped pulses with an amplitude in the range 4.0 to 7.5 volts.
Move channel 2 of the oscilloscope to the top end of R18 (near N4) on the unit under test. The two waveforms on the oscilloscope should be the same.
On the CTU, select PA.Out Level measurement. The displayed power amplifier driver level should be in the range 2.0 to 4.8 volts.
Move channel 1 of the oscilloscope to test jacks POWER AMP MODULATOR and EARTH on the 1kW PA power supply front panel. The displayed waveform should be dual, shaped pulses (on pedestals) with an amplitude in the range 2.0 to 6.5 volts.
Move channel 2 of the oscilloscope to the top end of R30 (near N6) on the unit under test. The two waveforms on the oscilloscope should be the same.
On the CTU, select PA.Mod Level measurement. The displayed power amplifier driver level should be in the range 1.0 to 3.5 volts.
3.4.32.6 Completion Switch off circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel.
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Remove the unit under test from the 1kW PA power supply and restore the control and status board belonging to the depot test facility, ensuring that all the retaining screws and cable connectors are securely replaced.
Switch on circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel.
Ensure that the depot test facility is operating normally.
3.4.33 DC-DC Converter PWB Assembly 1A72542
3.4.33.1 Test Equipment Oscilloscope. Digital multimeter: Qty 2. Variable load resistor, 8 to 20 ohms, 250 watts rating.
3.4.33.2 Setup With the DME operating, press the following CTU front panel keys in the sequence:
LOCAL, SELECT MAIN, OFF/RESET, MAINTENANCE (if MAINTENANCE indicator is not on), RECYCLE (if RECYCLE indicator is not off), MONITOR ALARM (if MONITOR ALARM INHIBIT indicator is not on).
Switch off circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel.
On the front panel of the 1kW PA power supply switch AMPLIFIER DC POWER to OFF.
Lower the front panel of the 1kW PA power supply, disconnect and remove the DC- DC converter using the procedures of Section 4.1.1.7.
Install the DC-DC converter to be tested in place of the removed unit, ensuring that the retaining screws and cable connectors are securely replaced. However DO NOT connect the heavy output leads to XP5 and XP6.
Connect the variable load resistor, set to maximum (20 ohms) to terminals XP5 and XP6.
Remove the cover from the regulator diecast box. On the regulator board, adjust variable resistor R112 fully clockwise.
On the unit under test, disconnect the driver outputs, XP9, XP10, XP12 and XP13, from the regulator.
Switch on circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel.
On the front panel of the 1kW PA power supply, switch AMPLIFIER DC POWER to ON.
3.4.33.3 Regulator
3.4.33.3.1 Oscillator Tests Connect channel 1 of the oscilloscope (set to AUTO INTERNAL CHANNEL 1 trigger and POSITIVE slope) to the connection lead XP11 (CRO TRIGGER) on the regulator (connect the oscilloscope GN D lead to any point on the metalwork).
Confirm that a signal is present at XP11 with a waveform similar to the CRO TRIGGER waveform shown in the figure below, with a period in the range 16.0 to 20.5 microseconds.
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3.4.33.3.2 15 Volts Supply Tests Measure the voltage at test point XT3 on the regulator. It should be within the range 14.3 to 15.7 volts.
3.4.33.3.3 Output Waveforms Connect channels 1 and 2 of the oscilloscope (externally triggered to connection lead XP11 of the regulator) to connection leads XP9 and XP10 of the regulator. Superimpose the two waveforms on the oscilloscope. They should be identical and have the general shape as shown for No 1 DRIVE OUTPUT in the above figure.
Using the oscilloscope, confirm that the ON TIME is in the range 15.0 to 20.0 microseconds, the OFF TIME is in the range 16.5 to 21.5 microseconds and the AMPLITUDE is in the range 14.0 to 16.0 volts.
Move channels 1 and 2 of the oscilloscope to connection leads XP12 and XP13 of the regulator. Superimpose the two waveforms on the oscilloscope. They should be identical and have the general shape as shown for No 2 DRIVE OUTPUT in the above figure.
Using the oscilloscope, confirm that the ON TIME is in the range 15.0 to 20.0 microseconds, the OFF TIME is in the range 16.5 to 21.5 microseconds and the AMPLITUDE is in the range 14.0 to 16.0 volts.
Confirm that the timing of the CRO TRIGGER signal is as shown in the above figure. Confirm the half-height PULSE WIDTH of the CRO TRIGGER waveform is in the range 0.2 to 1.3 microseconds.
3.4.33.4 Output Voltage Adjustment Range On the front panel of the 1kW PA power supply, switch AMPLIFIER DC POWER to OFF.
On the regulator, adjust variable resistor R112 fully counter-clockwise.
Reconnect the driver outputs, XP9, XP10, XP12 and XP13, from the regulator.
Adjust the load resistor for its maximum resistance (at least 18 ohms) and connect it, through an ammeter (multimeter on 10 amperes range), to connectors XP5 and XP6.
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On the front panel of the 1kW PA power supply, switch AMPLIFIER DC POWER to ON.
With the multimeter connected to the rack BATTERY terminals, switch and hold the TEST/FLOAT switch on AC power supply to TEST, and adjust the FLOAT 1 VOLTAGE control on the control module of the AC power supply to produce a multimeter reading of 22.0 ±0.1 volts. This TEST/FLOAT switch is to be held in this position until instructed to be released.
Connect the multimeter (on 100 volts range) to connectors XP5 (+ve) and XP6 (-ve). The voltmeter reading should be in the range 40 V to 48 volts
While monitoring the multimeter reading, adjust R112 to give an output voltage of 47.8 ±0.1 volts to prove that this voltage can be preset.
Readjust R112 to give an output voltage of 52.2 ±0.1 volts to prove that this voltage can be preset.
3.4.33.5 Primary Current Limit Preset While monitoring the reading on the multimeter (connected to XP5 and XP6), adjust R112 to give an output voltage of 50.0 ±0.1 volts. While monitoring the ammeter reading, adjust the load resistor to give an output current of 5.2 ±0.1 amperes. Readjust R112, if necessary, to give an output voltage of 50.0 ±0.1 volts. On the AC power supply, the ammeter reading should be less than 16.7 amperes.
While monitoring the ammeter reading, adjust the load resistor to give an output current of 4.5 ±0.1 amperes. The output voltage (as indicated on the multimeter) should be in the range 49.5 to 49.8 if the current limiting select on test resistor R115 on the regulator is set correctly (nominally 200 ohms).
If this voltage is greater than 49.8 volts, R115 needs to be reduced in value. If the voltage is less than 49.5 volts, R115 needs to be increased in value. Select a value for R115 in the resistance range 150 to 274 ohms, 5%, 400 mW. If a new value of R115 is fitted, repeat the measurement and validate that the voltage is in the required range.
While monitoring the multimeter reading, adjust the load resistor (decrease its resistance) to give an output voltage of 40.0 ±0.2 volts. The output current (on the ammeter) should be less than 4.9 amperes.
While monitoring the ammeter reading, adjust the load resistor (increase its resistance) to give an output current of 3.7 ±0.1 amperes. The output voltage (on the multimeter) should be 50.0 ±0.1 volts.
3.4.33.6 Input Regulation 1. With the operating configuration as at the end of Section 3.4.33.5 (that is, input
voltage 22.0 ±0.1 volts; output voltage 50.0 ±0.1 volts; output current 3.7 ±0.1 amperes) note the actual output voltage.
2. With the multimeter connected to the rack BATTERY terminals and switch TEST/FLOAT on AC power supply held to TEST, adjust the FLOAT 1 VOLTAGE control on the control module of this AC power supply to produce a multimeter reading of 28.0 ±0.1 volts. Note the output voltage. Calculate the difference between this voltage and the voltage measured at step 1. The difference should be less then 0.3 volts.
3.4.33.7 Output Regulation 1. With the operating configuration of step 2 of Section 3.4.33.6 (that is, input
voltage 28.0 ±0.1 volts, output voltage 50.0 ±0.1 volts, output current 3.7 ±0.1 amperes) note the actual output voltage.
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2. Adjust the load resistor to decrease the output current to 2.8 ±0.1 amperes. Note the output voltage. Calculate the difference between this voltage and the voltage measured at step 1. The difference should be less than 0.2 volts.
3.4.33.8 Input Current Monitor On the front panel of the 1kW PA power supply, switch AMPLIFIER DC POWER to OFF.
Disconnect the ammeter from the output of the unit under test and reconnect the load resistor to connectors XP5 and XP6.
At connector XP1, disconnect the two leads. Connect the ammeter (on 10 amperes range) between these two leads (connected together) and XP1.
On the front panel of the 1kW PA power supply, switch AMPLIFIER DC POWER to ON.
Adjust the load resistor to give an input current (on the ammeter) of 7.0 ±0.1 amperes. Connect the multimeter, on 200 mV range, to test jacks SUPPLY CURRENT + and SUPPLY CURRENT - on the 1kW PA power supply front panel. The measured voltage should be 7.0 ±0.1 mV.
3.4.33.9 Completion Switch off circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel.
Release the TEST/FLOAT switch on the AC power supply.
Remove the unit under test from the 1kW PA power supply and restore the DC-DC converter belonging to the depot test facility, ensuring that all the retaining screws and cable connectors are securely replaced.
Switch on circuit breakers CTU & TRANSPONDER and 1kW POWER AMP on the power distribution panel.
On the front panel of the 1kW PA power supply, switch AMPLIFIER DC POWER to NORMAL.
Ensure that the depot test facility is operating normally.
3.4.34 Preselector Filter 1A72546
3.4.34.1 Test Equipment Spectrum analyser. Signal generator. Directional coupler. Attenuator, miniature, 30 dB. Attenuator, miniature, 10 dB: Qty 2. Oscilloscope. Coaxial cables and adaptors.
3.4.34.2 Filter Tuning Procedure - 1020 MHz
3.4.34.2.1 Setup Connect the equipment for insertion loss measurement as detailed in Section 3.4.1.5.2.
Set the spectrum analyser for:
Centre frequency: 1020 MHz Span: 10 MHz/division
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Sweep time: 10 millisecond/division Amplitude scale: 10 dB/division Resolution bandwidth: 1 MHz Reference level: 0 dBm
Set the signal generator to 1020 MHz and +10 dBm output.
Connect the preselector filter as the unit under test.
Tune the preselector A and C adjusters together, keeping them equal distances out from the body, until a response is visible on the spectrum analyser display; then tune the adjusters for a peak at 1020 MHz. Adjusters will be close to fully in at this frequency (that is, clockwise end of travel).
Tune adjuster B for peak at 1020 MHz.
3.4.34.2.2 Return Loss Measurement Measure the return loss at the input of the preselector filter, using the procedure detailed in Section 3.4.1.5.1. This must be 20 dB minimum over a bandwidth of ±1 MHz on either side of the centre frequency of 1020 MHz. If it is not, slightly tune the adjusters A, B and C to achieve this.
3.4.34.2.3 Insertion Loss Measurement Set up the equipment and measure the insertion loss of the preselector filter at 1020 MHz as detailed in Section 3.4.1.5.2 It should not be greater than 1.6 dB.
By retuning the signal generator determine the frequencies, on either side of the centre frequency, where the response is 0.2 dB below the peak. This bandwidth should not be less than ±0.5 MHz.
Similarly, determine the frequencies at which the level is 1 dB below the peak; the limits are ±1 MHz to ±2 MHz.
Check the bandwidth at -60 dB; it should be ±20 MHz to ±30 MHz.
Measure the level 63 MHz away on either side of 1020 MHz; it should be more than 70 dB down with respect to the peak.
3.4.34.3 Filter Tuning Procedure - 1160 MHz Repeat the procedure in Section 3.4.34.2 with the signal generator and spectrum analyser tuned to 1160 MHz. The same limits apply.
In this case the filter adjusters will be withdrawn from the body.
3.4.34.4 Filter Tuning Procedure - Station Frequency Repeat the procedure in Section 3.4.34.2 with the signal generator and spectrum analyser tuned to the station interrogation (airborne) frequency. The same limits apply.
3.4.35 RF Panel PWB Assembly Single DME 1A72547 Although this assembly is a LRU, it is not subject to a separate test procedure but is included in the overall depot test facility test procedures. It is a very simple circuit, and functionality could be independently verified (if required) using a multimeter with reference to the circuit diagram.
3.4.36 RF Panel PWB Assembly Dual DME 2A72547 Although this assembly is a LRU, it is not subject to a separate test procedure but is included in the overall depot test facility test procedures. It is a very simple circuit, and
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functionality could be independently verified (if required) using a multimeter with reference to the circuit diagram.
3.4.37 Power Distribution Panel Single DME 1A72549
3.4.37.1 Test Equipment Digital multimeter.
3.4.37.2 Continuity Checks Set the circuit breakers on the unit under test as indicated in the table below, and for each series of settings check for continuity or lack of continuity (YES or NO) between the nominated pins of connector XN1. The "chassis" connection indicates a lug screwed to the chassis.
CIRCUIT BREAKERS CONTINUITY ON OFF FROM TO CONNECTION
z4 z32 YES
z4 chassis YES
z4 d14 NO
d6 z20 NO
Z8 d18 NO
Z8 d22 NO
CTU & TRANSPONDER
1kW POWER AMP
z8 z12 NO
z4 z32 YES
z4 chassis YES
z4 d14 NO
d6 z20 YES
Z8 d18 NO
Z8 d22 NO
1kW POWER AMP
CTU & TRANSPONDER
Z8 z12 NO
z4 z32 YES
z4 chassis YES
z4 d14 NO
d6 z20 NO
Z8 d18 YES
Z8 d22 YES
CTU & TRANSPONDER
1kW POWER AMP
Z8 z12 YES
z4 z32 YES
z4 chassis YES
CTU & TRANSPONDER
1kW POWER AMP
z4 d14 YES
3.4.38 Power Distribution Panel Dual DME 2A72549
3.4.38.1 Test Equipment Digital multimeter
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3.4.38.2 Continuity Checks Set the circuit breakers on the unit under test as indicated in the table below, and for each series of settings check for continuity or lack of continuity (YES or NO) between the nominated pins of connector XN1. The “chassis" connection indicates a lug screwed to the chassis.
CIRCUIT BREAKERS CONTINUITY ON OFF FROM TO CONNECTION
z4 z32 YES z4 chassis YES z4 d14 NO d6 Z20 NO d10 d18 NO d10 d22 NO d10 d26 NO d10 z12 NO d10 z16 NO
ALL
z8 z28 NO z4 z32 YES z4 chassis YES z4 d14 NO d6 z20 YES d10 d18 NO d10 d22 NO d10 d26 NO d10 z12 NO d10 z16 NO
1kW PWR AMP 1
ALL OTHERS
Z8 z28 NO z4 z32 YES z4 chassis YES z4 d14 NO d6 z20 NO d10 d18 NO d10 d22 NO d10 d26 NO d10 z12 NO d10 z16 NO
1kW PWR AMP 2
ALL OTHERS
Z8 z28 YES z4 z32 YES z4 chassis YES z4 d14 NO d6 z20 NO d10 d18 YES d10 d22 YES d10 d26 YES d10 z12 NO d10 z16 NO
CTU ALL OTHERS
z8 z28 NO z4 z32 YES z4 chassis YES z4 d14 NO d6 z20 NO
TPNDR 1 ALL OTHERS
d10 d18 NO
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CIRCUIT BREAKERS CONTINUITY ON OFF FROM TO CONNECTION
d10 d22 NO d10 d26 NO d10 z12 YES d10 z16 NO z8 z28 NO z4 z32 YES z4 chassis YES z4 d14 NO d6 z20 NO d10 d18 NO d10 d22 NO d10 d26 NO d10 z12 NO d10 z16 YES
TPNDR 2 ALL OTHERS
Z8 z28 NO z4 z32 YES z4 chassis YES
ALL NONE
z4 d14 YES
3.4.39 Control and Test Unit 1A72550
3.4.39.1 Introduction The CTU assembly consists of three circuit assemblies; these are the processor board, the front panel board, and the RCMS interface board. To test and align the processor board, see Section 3.4.40. To test and align the front panel board, see Section 3.4.41. To test and align the RCMS interface board, see Section 3.4.42.
The following procedures in this section provide a confidence check on the CTU assembly as a whole. These procedures would normally be done after the three main assemblies of the CTU have been tested and aligned.
3.4.39.2 Test Equipment Digital multimeter.
3.4.39.3 Setup Switch the CTU & TRANSPONDER circuit breaker off, and remove the CTU from the depot test facility. On the processor board of the unit under test, set switches S1:8 and S2:4 to the ON position, noting their original positions. Install the CTU to be tested in the depot test facility using the extender cards.
CAUTION Make sure that the CTU is properly supported so that it cannot fall from the extender cards.
Switch the CTU & TRANSPONDER circuit breaker on; after a short delay (about 2 seconds) the CTU should start up in the same configuration it had before it was last powered down.
Check the green 'heartbeat' indicators on the processor board, the front panel board, and the RCMS interface board. Each of these should be flashing at a rate of about once per second.
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3.4.39.4 DC-DC Converter Output Measure the voltage between pins 3 and 4 of XN1 in the CTU module; this should be in the range 5.15 to 5.25 volts.
If the measured voltage is not within the required range, then the resistor connected between the +5V and the TRIM pins on the DC-DC converter will need to be changes, as follows:
a. If the voltage is in the range 5.00 to 5.15 volts, replace the trimming resistor with a 121 kilohm resistor.
b. If the voltage is in the range 5.25 to 5.40 volts, replace the trimming resistor with a 562 kilohm resistor.
Repeat the voltage measurement to check that the voltage is within the required range.
Switch the CTU & TRANSPONDER circuit breaker off, remove the CTU from the extender cards, and replace the CTU directly into its rack frame. Switch the CTU & TRANSPONDER circuit breaker on.
3.4.39.5 LCD Display and Softkeys Select the maintenance off mode; the LCD should display:
LDB-102 DME Param Level PS.Volt Status Misc
Select each submenu in turn, and compare with the listing given in Figure A-2 in Appendix A. Use ESC to return to the top level menu.
Select the maintenance on mode; the LCD should display:
LDB-102 DME - Maintenance Mode Ch.1
3.4.39.6 Front Panel Controls and Indicators Check Select LOCAL operation; the yellow indicator above this switch should now be on. The green indicator above the REMOTE switch should be off.
Select transponder OFF/RESET; the yellow indicator above the OFF/RESET switch should be on, and the green SELECT MAIN indicators above the NO 1 and NO 2 switches should be off.
Select REMOTE operation, the green indicator above this switch should now be on. The yellow indicator above the LOCAL switch should be off. The red MAINTENANCE and MONITOR ALARM INHIBIT indicators should be off.
Select maintenance mode; the MAINTENANCE indicator should stay off, and the >> Select LOCAL First << error message should be flashed three times on the bottom line of the LCD display.
CAUTION Ensure that the high power 50 ohms RF load is attached to the transponder output before proceeding to the next step.
Select LOCAL operation, MONITOR ALARM INHIBIT and SELECT MAIN NO 1 operation. Check that the DME switches on and operates normally.
3.4.39.7 CTU Bus Interface to Test Interrogator and Monitor Modules Press the ESC key, and then press 'Params', 'NEXT', 'NEXT', 'NEXT', 'R cal' softkey sequence. The LCD should display:
Rate Cal. = 5000 Hz (±1 Hz).
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Press the Wall softkey. The LCD should display:
Volt Cal. = 5.00 volts (±0.1 volts).
Using the front panel softkeys, select each DME parameter in turn to display the measured result. Check that the displayed values are within the limits stated in the table in Section A.1.7 in Appendix A.
3.4.39.8 CTU Direct Interface to the Transponder Modules CAUTION Ensure that the 50 ohms RF load is attached to the transponder output
before proceeding to the next step.
Make sure that all the module test switches are in the NORMAL position, and the red CTU MODULES TEST indicator is off. Select LOCAL, MONITOR ALARM INHIBIT, and SELECT MAIN, OFF/RESET operation. Make sure that the green power indicators on all the transponder modules are off.
Select LOCAL, MONITOR ALARM INHIBIT, and SELECT MAIN NO 1 operation. Check that the green transponder module power indicators on the five modules in the transponder subrack and on the 1kW PA power supply are on.
3.4.39.9 Control System Check As a more complete check of the CTU control functions, perform the procedures described in Section 3.3.18 “Control System - Single DME".
3.4.39.10 Restore Operation Turn the CTU circuit breaker off, then remove the unit under test from the depot test facility. Make sure that switch S1:8 and switch S2:4 on the processor board are returned to their previously noted positions. Reinstall the original CTU, making sure that it is properly seated. Switch the CTU & TRANSPONDER circuit breaker on; after a short delay (about 2 seconds) the CTU should start up in the same configuration it had before it was last powered down.
3.4.40 CTU Processor PWB Assembly 1A72552
3.4.40.1 Test Equipment Oscilloscope. Digital multimeter. Alligator clip.
3.4.40.2 Setup Switch the CTU & TRANSPONDER circuit breaker off. Remove the CTU from the depot test facility. Undo the four screws securing the CTU processor board to the CTU chassis. Undo the three electrical connectors and remove the CTU processor board. Install the processor board to be tested to the CTU chassis, following the reverse of the above procedure.
Install the CTU using two Eurocard extenders. Make sure that the CTU is properly supported so that it cannot fall from the extender cards. Make sure that switch S1:8 is in the ON position.
Switch the CTU & TRANSPONDER circuit breaker on. After a short delay the CTU should start up in the same configuration it had before it was last powered down.
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3.4.40.3 Power Supplies Using a digital multimeter check the following voltages:
CONNECTOR PINS VOLTAGE (volts)
2c +5.0 ±0.5
3a, 3c +23 ±5
XN1
1a, 1c, 10a, 10c, 30a, 30c, 31a, 31c, 32a, 32c
Ground
18c +5.3 ±0.5 XN2
1a, 1c, 2a, 4c, 5c, 6a, 7a, 9c, 10c, 12a, 13a, 19a, 21c, 25a, 27a, 29c, 30c, 31a, 31c, 32a, 32c
Ground
39,40 +5.0 ±0.5
43,44 +23 ±5
XN3
1, 2, 3, 4, 7, 9, 12, 14, 17, 19, 47, 48, 49, 50
Ground
26 +5.0 ±0.5 XN4
1, 2, 5, 7, 10. 12, 15. 17, 29. 36, 39. 48, 52, 55, 57, 59, 60
Ground
4 +5.0 ±0.5
1 +23 ±5
XN11
2, 3 Ground
3.4.40.4 Self Test LED Indicators The heartbeat indicator HBEAT (H6) should flash at a rate of about once a second. The RAM OK indicator (H8) and the ROM OK indicator (H4) should both be continually lit.
3.4.40.5 Watchdog
3.4.40.5.1 Reset Line Using an alligator clip, short pins 1 and 2 of XN9 together. Set the oscilloscope to 2 volts/division and connect the probe to N2:16. The signal at this pin should be normally high and should pulse low every 1.6 seconds for a period of 50 milliseconds. Remove the alligator clip from XN9.
3.4.40.5.2 +24 Volts Monitor On the AC power supply, hold the TEST/FLOAT switch to TEST. Adjust the FLOAT 1 VOLTAGE so that the voltage at XN1:3c is 22.0 ±0.1 volts. Set the oscilloscope to 2 volts/division and connect the probe to N2:10. Using a small screwdriver, adjust preset the low volts preset R32 fully counter-clockwise. The signal on the oscilloscope should be high. Slowly adjust R32 until the signal on the oscilloscope changes from high to low. Return the 24 volts supply to the normal operating voltage.
3.4.40.6 External Oscillator Signal Set the oscilloscope to 2 volts/division and 0.5 millisecond/division. Connect the probe to D31:13. The waveform on the oscilloscope should be a square wave between ground and 5 volts with a frequency of 1220 ±61 Hz.
3.4.40.7 Ident Buzzer If the RECYCLE indicator is lit press the RECYCLE key and the indicator should be turned off.
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If the REMOTE indicator is lit press the LOCAL key; the LOCAL indicator should be lit and the REMOTE indicator should be turned off.
If the MAINTENANCE indicator is lit press the MAINTENANCE key and the indicator should be turned off.
If the MONITOR ALARM INHIBIT indicator is lit press the MONITOR ALARM key and the indicator should be turned off.
If either the SELECT MAIN, NO 1 or NO 2 indicator is on press the OFF/RESET key. The indicator which is lit should be turned off, and the OFF/RESET indicator should be lit instead.
Press the ESC key. The LCD should display the top level menu with the first line of the LCD being
LDB 102 DME.
Press the rightmost softkey three times, which should result in the Ident Source menu being displayed. Select 2440 Hz as the ident source. The buzzer on the CTU processor board should activate. Select OFF as the ident source to turn the buzzer off.
3.4.40.8 Completion Restore the CTU processor board from the depot test facility back to the CTU, using the procedures of Section 3.4.40.2. Ensure correct CTU operation.
3.4.41 CTU Front Panel PWB Assembly 1A72553
3.4.41.1 Test Equipment Digital multimeter.
3.4.41.2 Setup Turn the CTU & TRANSPONDER circuit breaker off. Remove the CTU from the depot test facility. Replace the CTU front panel board on the CTU with the unit to be tested (see Section 4.1.1.6 for guidance).
Reinstall the CTU using two Eurocard extenders. Make sure that the CTU is properly supported so that it cannot fall from the extender cards.
Switch the CTU & TRANSPONDER circuit breaker on. After a short delay the CTU should start up in the same configuration it had before it was last powered down.
3.4.41.3 Power Supplies Using a digital multimeter, check the following voltages:
CONNECTOR/ DEVICE PINS VOLTAGE (volts)
39, 40 +5.0 ±0.5
43, 44 +23 ±5 XN1
1, 2, 3,4 7, 9, 12, 14, 17, 19, 47, 48, 49, 50 Ground
D1 7 +5.0 ±0.5
3.4.41.4 Heartbeat LED The heartbeat indicator (H14) should be flashing at a rate of about once a second.
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3.4.41.5 Pushbuttons
3.4.41.5.1 DME Control Buttons Press the RECYCLE key a number of times to toggle its indicator. Leave it with its indicator off.
Press the LOCAL key a number of times to toggle its indicator. Leave it with its indicator off.
Press the MAINTENANCE key a number of times to toggle its indicator. Leave it with its indicator off.
Press the MONITOR ALARM key a number of times to toggle its indicator. Leave it with its indicator off.
If either the SELECT MAIN, NO 1 or NO 2 indicator is on press the OFF/RESET key. The indicator which is lit should be turned off, and the OFF/RESET indicator should now be fit instead.
Press the SELECT MAIN, NO 2 key, check that the message:
Not available on single DME
is shown on the display.
Press the SELECT MAIN, NO 1 key, check that the DME switches on, and the NO 1 indicator is lit.
3.4.41.5.2 Softkeys Press the ESC key. The LCD should display the top level menu with the first line of the LCD being
LDB 102 DME.
Press the first softkey located just below the LCD. The LCD should display the next level of the menu. Press the ESC key and the LCD should display the top level menu again. Repeat for the other four softkeys.
3.4.41.5.3 TI RATE Buttons Press the MAINTENANCE key and its ON indicator should be lit. The top line of the LCD should display
Maintenance Mode
Press the first softkey which corresponds to Ch.1. The top right hand corner of the LCD should display 100.
Press the 1 kHz N key. With each press of the key the frequency displayed should toggle between 1 and 100.
Press the 10 kHz key. While the key is pressed the display should show 10. When the key is released the display should show the previously active state (100 or 1).
3.4.41.6 ALARM DELAY Switch Use a small screwdriver to turn the actuator of the ALARM DELAY switch. The ALARM DELAY indicator should be on only if a delay of less than 4 seconds is selected.
3.4.41.7 View Angle Adjust Use a small screwdriver to adjust preset R1. The view angle of the LCD should vary with the setting of R1.
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3.4.41.8 Completion Restore the CTU front panel board from the depot test facility back to the CTU using the procedure of Section 3.4.41.2.
3.4.42 RCMS Interface PWB Assembly 1A72555
3.4.42.1 Test Equipment Digital multimeter.
3.4.42.2 Setup Switch the CTU & TRANSPONDER circuit breaker off. Remove the CTU from the depot test facility. Undo the four screws securing the RCMS interface board to the CTU chassis. Undo the two electrical connectors and remove the RCMS interface board. Install the unit under test to the CTU chassis following the reverse of the above procedure. Reinstall the CTU using two Eurocard extenders. Make sure that the CTU is properly supported so that it cannot fall from the extender cards.
Switch the CTU & TRANSPONDER circuit breaker on. After a short delay the CTU should start up in the same configuration it had before it was last powered down.
3.4.42.3 Power Supplies Using the multimeter check the following voltages:
CONNECTOR PINS VOLTAGE (volts)
XN1 1a, 1c, 25c Ground
XN2 18c +5.3 ±0.5
39, 40 +5.0 ±0.5
43, 44 +23 ±5
XN3
1, 2, 3, 4, 7, 9, 12, 14, 17, 19, 47, 48, 49, 50
Ground
3.4.42.4 Heartbeat LED The heartbeat indicator, H1, should flash at a rate of about once per second.
3.4.42.5 Relays Ensure that the depot test facility is operating on normal mode (that is, all green indicators on the monitor are on, and NORMAL and NO 1 ON indicators on the CTU STATUS display are on) in LOCAL control.
Ensure RECYCLE is off.
On the External I/O PWB Assembly 1A72257 at the rear of the rack, check the continuity of the connections on the following terminal blocks.
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FUNCTION CONNECTED NOT CONNECTED
LOC CTRL C-NO C-NC
BATT CH NORM 1 C-NO C-NC
AC PWR NORM C-NO C-NC
SEC ALM C-NC C-NO
NO 1 ON C-NO C-NC
SHUTDOWN C-NC C-NO
NORMAL C-NO C-NC
MON ALM C-NC C-NO
MAINT C-NC C-NO
BATT CH NORM 2 C-NC C-NO
PRI ALM C-NC C-NO
NO 2 ON C-NC C-NO
TRANSFER C-NC C-NO
Switch the CTU & TRANSPONDER circuit breaker off.
On the CTU processor board, switch S1:8 to OFF (to set for DUAL operation). Switch the CTU & TRANSPONDER circuit breaker on.
On the CTU, press the following front panel keys:
SELECT MAIN, OFF/RESET MAINTENANCE (ON indicator to be on) MONITOR ALARM (INHIBIT indicator to be on) SELECT MAIN NO 2 REMOTE
The DME will attempt to power up with No.2 transponder as main. Since there is no second transponder in the depot test facility, the monitor will detect primary faults. However, since the monitor alarms are inhibited, no transfer will take place.
On the External I/O PWB Assembly 1A72557 at the rear of the rack, check continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
LOC CTRL C-NC C-NO
SEC ALM C-NO C-NC
NO 1ON C-NC C-NO
NORMAL C-NC C-NO
MON ALM C-NO C-NC
MAINT C-NO C-NC
PRI ALM C-NO C-NC
NO 2 ON C-NO C-NC
On the AC power supply, remove the front cover and disconnect the cable connector to TB/3 (the multi-way connector for status indication). On the External I/O PWB Assembly 1A72557 at the rear of the rack, check continuity of the connections on the following terminal blocks.
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FUNCTION CONNECTED NOT CONNECTED
BATT CH NORM 1 C-NC C-NO
AC PWR NORM C-NC C-NO
Restore the connector to TB/3 and replace the power supply front cover.
On the CTU, press the following front panel keys:
LOCAL (LOCAL indicator to be on), MAINTENANCE (ON indicator to be on), MONITOR ALARM (INHIBIT indicator to be off).
Since the monitor alarms are no longer inhibited, the CTU will initiate a transfer to No.1 transponder. On the External I/O PWB Assembly 1A72557 at the rear of the rack, check continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
NO 1ON C-NO C-NC
TRANSFER C-NO C-NC
On the monitor, switch MONITOR OUTPUTS to FAILED. This will cause the CTU to shut down the DME.
On the External 1/0 PWB Assembly 1A72557 at the rear of the rack, check continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
SHUTDOWN C-NO C-NC
3.4.42.6 Transponder 2 Interface Switch the CTU & TRANSPONDER circuit breaker off.
At the rear of the rack, remove the ribbon cable connector from CTU CONNECTOR (XN6) on the transponder subrack motherboard, and plug the connector labelled SECOND TRANSPONDER (on the unattached ribbon cable) into XN6.
Switch the CTU & TRANSPONDER circuit breaker on.
The DME should power up in normal mode (that is, all green indicators on the monitor are on, and NORMAL and NO 1 ON indicators on the CTU STATUS display are on) with No.2 transponder indicating as the operating transponder.
On the CTU select Param Delay measurement. The delay should be 50.0 ±0.2 microseconds.
On the CTU select PS.Volt TP.18V to measure the transponder power supply 18 volts supply; it should be 18.0 ±0.1 volts.
3.4.42.7 Completion On the CTU, press the front panel softkeys in the following order:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1.
Switch the CTU & TRANSPONDER circuit breaker off.
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At the rear of the rack, remove the ribbon cable connector SECOND TRANSPONDER and restore the original cable connector to XN6 on the transponder subrack motherboard.
On the CTU processor board, set switch S1:8 back to ON (to restore SINGLE operation).
Restore the RCMS interface board from the depot test facility back to the CTU and restore the CTU to the subrack.
Switch the CTU & TRANSPONDER circuit breaker on.
The DME should power up in normal mode (that is, all green indicators on the monitor are on and NORMAL and NO 1 ON indicators on the CTU STATUS display are on) with No. 1 transponder indicating as the operating transponder.
3.4.43 External I/O PWB Assembly 1A72557
3.4.43.1 Test Equipment Digital multimeter. Resistor, 180 ohms, 4 watts Resistor, 47 ohms, 3 watts.
3.4.43.2 Setup At the rear of the rack, remove all cables from the External I/O PWB Assembly 1A72557. Undo the mounting screws and remove the external I/O board; replace it with the unit under test, installing cables only to XN6 and XN8 terminal blocks.
3.4.43.3 Modem 12 Volts Supply Check Power on the rack using the power distribution panel.
Connect a 47 ohms resistor between XN3:1 and XN3:10.
Using the voltmeter set to DC 200 volts range, measure the voltage across C1; it should be 24.0 ±0.5 volts. If necessary, set the voltage to within this range by adjusting the FLOAT 2 preset control on the AC power supply control board.
Using the voltmeter set to DC 20 volts range, measure the voltage across C2: it should be 12.0 ±0.6 volts.
3.4.43.4 Protected 24 Volts Supply Check Connect a 180 ohms resistor between XB1:6 and XB11:6.
Using the voltmeter set to DC 200 volts range, measure the voltage between XB1:6 and XB11:6; it should be not more than 1.0 volt below the input voltage measured across C1.
Place the multimeter set to DC 200 mA range between XB1:6 and ground. The meter reading should be 20 ±5 mA.
Remove the 47 ohms and 180 ohms resistors.
3.4.43.5 Status Outputs Ensure that the depot test facility is operating on normal mode (that is, all green indicators on the monitor are on and NORMAL and NO 1 ON Indicators on the CTU STATUS display are on) in LOCAL control.
Ensure RECYCLE is off.
HA72500 SECTION 3
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Check the continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
LOC CTRL C-NO C-NC
BATT CH NORM 1 C-NO C-NC
AC PWR NORM C-NO C-NC
SEC ALM C-NC C-NO
NO 1 ON C-NO C-NC
SHUTDOWN C-NC C-NO
NORMAL C-NO C-NC
MON ALM C-NC C-NO
MAINT C-NC C-NO
BATT CH NORM 2 C-NC C-NO
MAINS OK C-NO C-NC
PRI ALM C-NC C-NO
NO 2 ON C-NC C-NO
TRANSFER C-NC C-NO
Switch the CTU & TRANSPONDER circuit breaker off.
On the CTU processor board, switch S1:8 to OFF (to set for DUAL operation). Switch the CTU & TRANSPONDER circuit breaker on.
On the CTU, press the following front panel keys:
SELECT MAIN, OFF/RESET MAINTENANCE (ON indicator to be on) MONITOR ALARM (INHIBIT indicator to be on) SELECT MAIN NO 2 REMOTE
The DME will attempt to power up with No.2 transponder as main. Since there is no second transponder in the depot test facility, the monitor will detect primary faults. However, since the monitor alarms are inhibited, no transfer will take place.
Check continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
LOC CTRL C-NC C-NO
SEC ALM C-NO C-NC
NO 1ON C-NC C-NO
NORMAL C-NC C-NO
MON ALM C-NO C-NC
MAINT C-NO C-NC
PRI ALM C-NO C-NC
NO 2 ON C-NO C-NC
HA72500 SECTION 3
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Disconnect the cable connector to XN2 and check the continuity of the connections on the following terminal blocks
FUNCTION CONNECTED NOT CONNECTED
BATT CH NORM 1 C-NC C-NO
AC PWR NORM C-NC C-NO
Restore the normal cable connector to XN2.
Check continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
BATT CH NORM 1 C-NO C-NC
AC PWR NORM C-NO C-NC
MAINS OK C-NO C-NC
On the CTU, press the following front panel keys as required to give the condition indicated:
LOCAL (LOCAL indicator to be on), MAINTENANCE (ON indicator to be on). MONITOR ALARM (INHIBIT indicator to be off).
Since the monitor alarms are no longer inhibited, the CTU will initiate a transfer to No. 1 transponder. Check continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
NO 1 ON C-NO C-NC
TRANSFER C-NO C-NC
On the monitor, switch MONITOR OUTPUTS to FAILED. This will cause the CTU to shut down the DME.
Check continuity of the connections on the following terminal blocks.
FUNCTION CONNECTED NOT CONNECTED
SHUTDOWN C-NO C-NC
3.4.43.6 Completion On the CTU, press the front panel keys in the following order:
SELECT MAIN, OFF/RESET, SELECT MAIN NO 1
Switch the CTU & TRANSPONDER circuit breaker off.
At the rear of the rack, remove the unit under test and restore the external I/O board from the depot test facility, along with all its connections.
On the CTU processor board, set switch S1:8 back to ON (to restore SINGLE operation).
Switch the CTU & TRANSPONDER circuit breaker on.
The DME should power up in normal mode (that is, all green indicators on the monitor are on and NORMAL and NO 1 ON indicators on the CTU STATUS display are on) with No. 1 transponder indicating as the operating transponder.
HA72500 SECTION 4
4-i
SECTION 4
MAINTENANCE PROCEDURES
HA72500 SECTION 4
4-ii
TABLE of CONTENTS
4. MAINTENANCE PROCEDURES ...............................................................4-1 4.1 REMOVAL & REPLACEMENT OF LINE-REPLACEABLE UNITS (LRU) 4-1
4.1.1 Replacement/Removal Instructions.............................................................4-1 4.1.1.1 SMA Connectors ................................................................................4-1 4.1.1.2 PWB Assemblies (General) ................................................................4-1 4.1.1.3 RF Modules in Transponder Plug-in Modules
(excluding 1A72533 and 1A72534) ..................................................4-1 4.1.1.4 Medium Power Driver 1A72533 and Power Modulation Amplifier
1A72534 .............................................................................................4-1 4.1.1.5 RF Modules in 1kW RF Power Amplifier ............................................4-2 4.1.1.6 Switched Attenuator 1A69737 ............................................................4-2 4.1.1.7 CTU Front Panel PWB Assembly 1A72553........................................4-2 4.1.1.8 DC-DC Converter PWB Assembly 1A72542 ......................................4-2 4.1.1.9 Preselector Filter 1A72546 and Directional Coupler 1A/2A69755......4-2 4.1.1.10 Control Card, AC Power Supply 3A71130..........................................4-2
4.1.2 Fault Location ..............................................................................................4-3 4.1.2.1 General Troubleshooting Guidance....................................................4-3 4.1.2.2 Fault Finding Procedures ...................................................................4-6
4.1.3 LRU Post-Replacement Tests ...................................................................4-11 4.2 WAVEFORMS 4-18 4.3 SPECIAL MAINTENANCE PROCEDURES 4-41
4.3.1 Stripline Printed Wiring Boards..................................................................4-41 4.3.1.1 Positioning of Ceramic Chip Capacitors ...........................................4-41 4.3.1.2 Soldering ..........................................................................................4-42 4.3.1.3 Cleaning ...........................................................................................4-47
4.3.2 Conformal Coating.....................................................................................4-47 4.3.3 RF Transistor Replacement.......................................................................4-48
4.3.3.1 Tools Required .................................................................................4-48 4.3.3.2 Preparation of Unit............................................................................4-48 4.3.3.3 Removal of Device ...........................................................................4-48 4.3.3.4 Inserting the New Device..................................................................4-49
HA72500 SECTION 4
4-iii
LIST of FIGURES
Figure 4-1 Signal Flow Block Diagram.....................................................................4-5 Figure 4-2 Lateral Positioning of Chip Capacitors .................................................4-41 Figure 4-3 Longitudinal Positioning of Chip Capacitors .........................................4-41 Figure 4-4 Chip Capacitor Soldering Requirements ..............................................4-42 Figure 4-5 Soldering of Through Board Mounted Chip Capacitors........................4-43 Figure 4-6 Part Placement .....................................................................................4-44 Figure 4-7 Maximum/Minimum Solder Conditions .................................................4-44 Figure 4-8 Lead Placement Conditions..................................................................4-45 Figure 4-9 Lead Soldering Conditions ...................................................................4-45 Figure 4-10 Minimum Clearance of Sealed Components ........................................4-46 Figure 4-11 Multiple Lead Termination Requirements.............................................4-46
LIST of TABLES
Table 4-1 LRU Post-Replacement Tests ..................................................................4-11
HA72500 SECTION 4
4-1
4. MAINTENANCE PROCEDURES 4.1 REMOVAL & REPLACEMENT OF LINE-REPLACEABLE UNITS (LRU)
4.1.1 Replacement/Removal Instructions The DME LDB-102 contains a number of line replaceable units (LRUs) which can be replaced during field servicing. A list of LRUs can be found in Section 3.4.
The following sections describe the procedure for removing units. Units may be refitted by following the reverse procedure.
4.1.1.1 SMA Connectors Most RF LRUs are connected using SMA coaxial connectors. These may be disconnected using the 8 mm open-ended spanner provided in the DME Test Accessory Kit. When reconnecting SMA connectors, ensure that the connectors are properly aligned and not cross-threaded. The connector nut should be tightened to a torque of 0.5 newton-metres (4.5 inch-pounds), which is equivalent to a light hand pressure on the spanner provided.
4.1.1.2 PWB Assemblies (General) a. Disconnect all external connectors.
b. Remove the printed wiring board (PWB) fixing screws, and withdraw the PWB.
4.1.1.3 RF Modules in Transponder Plug-in Modules (excluding 1A72533 and 1A72534)
a. Remove the plug-in module main PWB, following the procedure described in Section 4.1.1.2; this gives access to the RF module fixing screws.
b. Disconnect all external connectors to the RF module, removing the box lid if necessary.
c. Remove the module fixing screws, and withdraw the module.
4.1.1.4 Medium Power Driver 1A72533 and Power Modulation Amplifier 1A72534
a. Disconnect all external connectors.
b. Remove the lid from the box.
c. Remove the three module fixing screws from inside the box, and withdraw the unit.
NOTE When removing the power modulation amplifier from the 1kW RF Power Amplifier 1A72535, it is necessary to remove the fixing screws and move the box before disconnecting the 4-pin connector and the coaxial cables, because of the space restrictions around the box.
HA72500 SECTION 4
4-2
4.1.1.5 RF Modules in 1kW RF Power Amplifier This procedure applies to Power Divider 1A72536, Power Combiner 1A72537 and 250W RF Power Amplifier 1A69783 (procedure for Power Modulation Amplifier 1A72534 is given in 4.1.1.3).
a. Disconnect all external connectors.
b. Remove the fixing screws and withdraw the unit.
CAUTION When disconnecting the ‘flexible’ semirigid coaxial cables, do not strain the cables more than is necessary to permit removal of the unit being serviced. If straining of these cables is necessary, do so evenly along the length of each cable, and avoid straining the cable close to the connectors, as fatigue failure may result.
4.1.1.6 Switched Attenuator 1A69737 a. Disconnect all external connectors.
b. Remove the two fixing screws, and withdraw the unit.
4.1.1.7 CTU Front Panel PWB Assembly 1A72553 a. Disconnect all external connectors.
b. Remove the CTU Processor PWB Assembly 1A72552, and the RMS Interface PWB Assembly 1A72555, following the procedure described in Section 4.1.1.2.
c. Remove the six fixing screws for the front panel. The CTU front panel and CTU front panel PWB assembly can then be lifted away separately from the CTU module chassis.
4.1.1.8 DC-DC Converter PWB Assembly 1A72542 a. Hinge open the front panel of the 1kW Power Supply Frame 1A72503.
b. Disconnect all external connectors to the DC-DC converter.
c. Remove the four screws which fasten the large heatsinks to the 1kW PA power supply frame. The DC-DC converter complete with the two large heatsinks can then be lifted away.
d. Remove the three screws which fasten each heatsink to the DC-DC converter, and remove the heatsinks.
4.1.1.9 Preselector Filter 1A72546 and Directional Coupler 1A/2A69755 a. Disconnect all external connectors.
b. Remove the four fixing screws, and withdraw the unit.
4.1.1.10 Control Card, AC Power Supply 3A71130 a. Remove the front panel to give access to the AC power supply.
b. Withdraw the control card from the power supply. It is a plug-in card, located approximately centrally.
HA72500 SECTION 4
4-3
4.1.2 Fault Location This section describes the various methods that may be used for troubleshooting should a fault occur in an LDB-102 DME. The first section gives guidance of a general nature, to outline the various facilities available to assist fault location. The second section gives detailed instructions for signal tracing within the DME equipment.
4.1.2.1 General Troubleshooting Guidance Should a DME beacon develop a fault, it is best serviced by replacing the defective module, or subassembly, with an operational unit. These replaceable assemblies are called line-replaceable units (LRUs).
The following guidance information is given to assist technical personnel locate a defective LRU after a DME beacon has shut down or registered a fault. The facilities discussed below may be used either individually or in combination to isolate the defective unit.
a. System Block Diagrams Two levels of block diagram are included in the DME handbook to show the signal flow through the equipment. These are:
1. System Block Diagrams:
Single see Figure 2-1. Dual see Figure 2-2. Test Facility see Figure K-2.
2. Signal Flow Block Diagram; see Figure 4-1.
This last drawing indicates the divisions between modules and subassemblies, and the signal flow between then. It eases the task of tracing a signal through a particular subsystem for fault location purposes.
b. Test Facility The test facility, which is part of the CTU, allows rapid measurement of the main beacon parameters and internal signal levels. During troubleshooting, the parameter values and signal voltage levels may be compared with the values recorded at station commissioning. In many cases, this will isolate a fault to a specific module.
Refer to Appendix A, Section A.3, for operating instructions of the Test Facility.
c. Front Panel Test Jacks Each of the transponder modules has a number of front panel test jacks to allow rapid checking of significant signals and voltages. In most cases, the information available from the test jacks is sufficient to determine if a module is functioning correctly.
Section 4.2 lists the test point signal waveforms and voltages that should be present in a normally functioning DME rack. Comparison of these signals with those measured on the equipment under test will help isolate a faulty unit.
HA72500 SECTION 4
4-4
d. Alarm Register The CTU includes a group of indicators to show the alarms that were present when a transponder transfer shutdown occurred. When technical personnel visit a DME which has shut down due to a fault, the alarm register should be examined before switching on the beacon again. The alarms indicated will show which parameters were out of tolerance, and this often suggests which subsystem is at fault.
In a dual DME, the alarm register can be accessed to show the faults associated with each transponder. This is explained in Appendix A.3.
HA72500 SECTION 4
4-5
Figure 4-1 Signal Flow Block Diagram
HA72500 SECTION 4
4-6
4.1.2.2 Fault Finding Procedures In the event of a failure in the LDB-102 DME beacon, the adoption of the following procedures will help isolate the fault to a particular area, so that replacement of the appropriate line-replaceable unit (LRU) can restore operation of the equipment with minimum interruption to service.
These procedures trace the signal firstly through the interrogation and receiver chain, and then through the transmitter chain. The test interrogator is used as a source of test signals for the transponder, and it is essential to obtain interrogations at the correct level from the test interrogator in order to check operation of the receiver and video signal processing.
Test jacks are provided on the module front panels to facilitate troubleshooting. The typical waveforms measured on these test points are given in Section 4.2. Reference is made to these waveforms during the signal tracing procedures.
4.1.2.2.1 Conditions for Tests 1. Operate the equipment in the MAINTENANCE mode, as described in Appendix
A.1 for a single DME, and A.2 for a dual DME.
2. For a dual DME, the defective transponder will be operated as the standby. On the RF panel at the rear of the rack, connect the test interrogator of the standby transponder to the second directional coupler, so that it can be used to interrogate the standby transponder. This is described in Appendix A.2.5.1.
3. On the standby monitor of a dual DME, switch the MONITOR OUTPUTS switch to the FAILED position (this takes the monitor 'off-line').
4. On the CTU, select MONITOR ALARM to INHIBIT. For a single DME, press the SELECT MAIN, NO 1 switch. For a dual DME, press the SELECT MAIN, NO 1 or NO 2 switch for the transponder that will be operating normally (for example, if transponder 2 is under investigation, then select NO 1 as the operating transponder so that transponder 2 becomes the standby).
5. On the transponder power supply, switch TRANSPONDER DC POWER to ON.
6. On the CTU, select Hi Eff (High Level Efficiency) measurement to set the interrogation level to -70 dBm.
4.1.2.2.2 Interrogation and Receiver Chain With the DME operating in the MAINTENANCE mode, perform the following check sequence:
1. Trigger the oscilloscope from the TRIGGER test jack on the test interrogator Failure of the oscilloscope to trigger reveals the absence of a signal from the test interrogator module.
In this case, either the test interrogator main board, or the complete test interrogator module (equipped with the appropriate crystals and tuned to the correct frequency) should be replaced.
2. Set the oscilloscope sensitivity to 2 volts/division and the timebase to 2 microseconds/division, and check the waveform at the DETECTED INTERROGATIONS test jack on the test interrogator. Compare the displayed waveform with that in Waveform 17.
If the displayed waveform is significantly different to the reference waveform, a failure in the test interrogator is indicated; either the entire module, or separate LRUs, should be replaced.
HA72500 SECTION 4
4-7
3. Set the oscilloscope to 0.5 volts/division and 5 microseconds/division, and check the waveform at the DETECTED LOG VIDEO test jack on the receiver video. Compare the displayed waveform with that in Waveform 37.
If the waveforms are significantly different, malfunction of the receiver video is indicated. Either the entire module, or separate LRU, should be replaced with appropriate assemblies tuned to the correct frequency.
4. If, after replacement of the module or circuit board assemblies, the correct waveform is still not obtained, consult Figure 4-1 to identify the block circuitry in the failed signal path.
5. Set the oscilloscope to 0.5 volts/division and 5 microseconds/division. On the CTU, select Effncy measurement, to cause the interrogations to switch between high and low level. With only one oscilloscope channel displayed, observe the waveform on the DETECTED LOG VIDEO test jack and compare it with that in Waveform 37.
If the displayed waveform does not show the two discrete pulse amplitude levels, malfunction of the level switching in the test interrogator is indicated. Replace either the complete test interrogator, or the main board assembly and switched attenuator LRUs.
6. Display the waveforms at the DETECTED LOG VIDEO and ON CHANNEL VIDEO test jacks. Compare the displayed waveform with those shown in Waveform 36.
7. Similarly, display the waveform at the DOUBLE PULSE DECODER OUT test jack and compare with that in Waveform 33.
8. Reset the oscilloscope to 10 microseconds/division and check that the waveform at the TRIGS TO MODULATOR test jack is similar to that in Waveform 35.
Failure to obtain waveforms as above indicates a receiver video malfunction requiring replacement of the module or subassemblies.
9. Check the waveform at the DETECTED REPLIES test jack on the test interrogator and compare it with that in Waveform 16. Absence of pulses indicates a malfunction in the transmission chain.
4.1.2.2.3 Transmitter Chain The major symptom of transmitter faults will be shown on the CTU as a low output power reading. Transmitter chain faults can be isolated and corrected by the following sequence; the waveforms referred to in the test sequence are shown in Section 4.2.
The performance requirements of each step must be met before the next step in the sequence is commenced; the sequence need only be performed far enough to correct the fault.
When the transmitter output power has been restored to the correct level (either by adjustment/s or module replacement) perform the routine alignment and performance tests on the transmitted pulse power and pulse shape, making adjustments as necessary. The pulse shape of a correctly adjusted transmitter is shown in Waveform 16 and 67.
HA72500 SECTION 4
4-8
1. At the HT test jack on the front panel of the 1kW RF amplifier, check that the DC supply to the 1kW RF amplifier is within the range 49.5 to 50.5 volts.
This voltage is supplied by the DC-DC converter. If this voltage is only slightly out of tolerance, it may be corrected by adjustment of the converter output voltage control R112 (located under the cover of the metal box housing the regulator board).
If this voltage is more than 3 volts out of range, then replace the DC-DC converter in the 1kW PA power supply.
2. Trigger the oscilloscope from the TRIGS TO MODULATOR test jack on the receiver video. Display the waveform at the SHAPED MODULATION test jack on the transmitter driver, and compare the displayed waveform with that shown in Waveform 51. Check that the pulse amplitude is within the normal amplitude range stated against Waveform 51; the 1kW PA power supply must be within limits for this pulse to be correct.
If the amplitude exceeds this range, and there is low (or zero) output from the transmitter, then it is probably due to the automatic level control (ALC) trying to correct the low output condition. If this pulse is absent, or significantly below the stated range, then it indicates a fault on the pulse shaper board, which should be replaced.
3. Display the waveform at the DRIVER LEVEL test jack on the transmitter driver. If the drive waveform amplitude is within the limits stated against Waveform 52, then it indicates that the transmitter driver is satisfactory and is providing drive to the 1kW RF power amplifier. Proceed to step 9 to continue the signal tracing.
If the waveform amplitude is below the limits stated, then check the performance of the transmitter driver units, as detailed in steps 4 to 8.
4. Extend the transmitter driver using the transponder extender frame. Switch on power to the transponder, switch DRIVER DC POWER to NORMAL, and check that the following supply voltages are within the limits stated:
Test Point Limits (volts DC) Transponder power supply +15 V
+18V HT
15.0 ±0.5 18.0 ±1.0 42.0 ±1.0
Transmitter driver +15 V 15.0 ±0.5
Pulse shaper board XT10 XT4 XT7 XT9 XT5
16.3 ±1.0 11 to 15, rectangular pulse 20 to 32 25 to 35 28 to 37
If any of these voltages are out of tolerance, then replacement of the transponder power supply or pulse shaper board may be necessary. For alignment of the pulse shaper board, refer to Section 3.2.7.
5. Remove the cover from the exciter unit and clip the current probe around the wire loop supplying current to the collectors of transistors V5 and V6. Check that the collector current waveform is within the limits stated against Waveform 54.
HA72500 SECTION 4
4-9
If the waveform is low in amplitude, check firstly that the input drive from the receiver video is correct, as described in Section 3.2.6, then check the alignment of the exciter as described in Section 3.2.7. If this fails to correct the current waveform, then replace the exciter board.
6. Remove the cover from the medium power driver and clip the current probe around the wire supplying collector current to the RF amplifier subassembly. Check that the collector current waveform is within the limits stated against Waveform 55.
If the waveform is low in amplitude, then it indicates either insufficient drive, from the exciter, or a fault in the medium power driver itself. Replace each subassembly in turn to determine the defective unit.
7. Remove the cover from the power modulation amplifier and clip the current probe around the wire supplying collector current to the RF amplifier subassembly. Check that the collector current waveform is within the limits stated against Waveform 56.
If the waveform is low in amplitude, then it indicates either insufficient drive from the medium power driver, or a fault in the power modulation amplifier itself. Replace each subassembly in turn to determine the defective unit.
8. If any units have been replaced or adjusted, repeat the check described in Step 3 above. If the waveform amplitude is now within the stated limits, then replace the covers on the units in the transmitter driver, then replace the module in the rack.
9. On the 1kW RF amplifier, display the waveform from the POWER AMP MODULATOR test jack and check that it is within the limits stated against Waveform 60.
If the waveform is low in amplitude, and if it has been previously determined that the RF drive and the modulation to the 1kW RF amplifier are correct, then a fault in the 1kW power modulation amplifier is indicated. Remove the cover from the 1kW RF amplifier and replace the power modulation amplifier.
10. On the 1kW RF amplifier, display the waveform from the POWER AMP DRIVER test jack and check that it is within the limits stated against Waveform 62.
If the waveform is low in amplitude, then a fault in the 1kW amplifier driver stage is indicated; this function is provided by the 250W amplifier units A1 and A2, in the 1kW RF amplifier. Remove the cover from the 1kW RF amplifier and determine the defective unit by checking the collector current of each driver stage. Clip the current probe around the red supply lead, connecting to the amplifier module, and check the waveform amplitude with the limits stated against Waveform 66. A low amplitude collector current indicates the defective unit, which should be replaced.
11. On the 1kW RF amplifier, display the waveform from the POWER AMP OUTPUT test jack and check that it is within the limits stated against Waveform 61.
If the waveform is low in amplitude, a defective power output stage is indicated, and the particular unit may be isolated by the procedure below.
HA72500 SECTION 4
4-10
Remove the cover from the 1kW RF amplifier and clip the current probe, in turn, around the red supply lead to each of the amplifiers A3 to A10. Display the current waveform and check that it is within the limits stated against Waveform 64. There may be considerable variation in the current amplitude for the individual power amplifiers A3 to A10, but a defective unit is usually indicated by a current much lower than the others. Any defective units should be replaced.
This completes the signal tracing troubleshooting procedures. If any module or subassembly has been replaced during these procedures, then perform the relevant LRU Post- Replacement Tests, as listed in Section 4.1.3.
HA72500 SECTION 4
4-11
4.1.3 LRU Post-Replacement Tests This section details the tests and/or adjustments required to be made to an operational beacon following the replacement of any module or subassembly. The information is presented in tabular form, and:
a. contains a brief statement of the parameter or performance function required to be checked, or adjustments required to be made, as applicable, in sequence user order; and also
b. cites the relevant section of this handbook in which the detailed procedure for the required check, measurement, or adjustment may be found.
If any module or subassembly is replaced during servicing, then the procedure listed for that unit MUST be performed to restore the beacon to operational status. It is implicit that all other units in the beacon are in normal working order.
Table 4-1 LRU Post-Replacement Tests
MODULE OR SUBASSEMBLY
PARAMETER TO BE CHECKED or ADJUSTMENT TO BE MADE
REFER to SECTION
1A69737 Attenuator
High and low switching of interrogations 3.2.4.13.2
1A69755 2A69755 Directional Coupler
1 2 3
Final receiver checks Calibrate Final check
3.2.4.13.2 3.2.4.10.5 3.2.4.18
1A69873 250W RF Amplifier
1 2 3 4
Check Transmitter Pulse Parameters (If pulse parameters out of tolerance, then perform output pulse alignment) Transponder delay Final check
3.2.4.10.1 to 3.2.4.10.4 (3.2.4.9) 3.2.4.13 3.2.4.18
3A71130 AC Power Supply or Control Card for AC Power Supply
1 2 3 4 5
Printed wiring board link settings Powering rack High voltage adjust Low voltage alarm adjust DC supply adjustment
3.3.3.11 3.2.4.3 3.2.4.16.5 3.2.4.16.6 3.2.4.16.8
1A72510 Monitor Module
1 2 3 4
Set internal preset switches for station fault limits Calibrate Peak Power Monitor Check Monitor fault limits and fault indications Final check
3.2.4.2.8 or Appendix A.5.3 3.2.4.15.6 3.2.4.15 3.2.4.18
1A72511 Monitor Main PWB
Perform all checks listed for Monitor Module, 1A72510
1A72512 Peak Power Monitor
1 2
Check signal amplitude at Monitor ERP MONITOR test jack Calibrate peak power monitor
4.2 Waveform 13.2.4.15.6
HA72500 SECTION 4
4-12
MODULE OR SUBASSEMBLY
PARAMETER TO BE CHECKED or ADJUSTMENT TO BE MADE
REFER to SECTION
1A72514 Test Interrogator Module
1 2 3 4 5 6 7 8 9 10 11 12
Install crystals for interrogate frequencies Set internal preset switch S4 for X or Y channel Set front panel switches REPLY GATE DELAY to settings recorded for the station Align RF Generator for operation at the station frequency (if not pre-aligned) Check RF Generator crystal frequencies Check RF Generator output pulse amplitude and shape Check RF Generator test frequencies Check signal timing parameters Calibrate Peak Power Display Set REPLY ACCEPT GATES Check high and low level switching of interrogations Final check
3.2.4.1.2 3.2.5 3.2.4.4.5 3.2.4.4.1, 3.2.4.4.2 3.2.4.4.3 3.2.4.4.6 3.2.4.10.5 3.2.4.11.2 steps 2 to 5 3.2.4.13.2 3.2.4.18
1A72515 Test Interrogator Main PWB
1 2 3 4 5 6 7
Set preset switch S4 for X or Y channel Set front panel switches REPLY GATE delay to setting recorded for the station Check RF Generator output pulse amplitude and shape Check signal timing parameters Set REPLY ACCEPT GATES Check high and low level switching of interrogations Final check
3.2.4.4.1, 3.2.4.4.2 3.2.4.4.6 3.2.4.11.2 steps 2 to 5 3.2.4.13.2 3.2.4.18
1A72516 RF Generator
1 2 3 4 5 6
Install crystals for interrogate frequencies Align RF Generator Check RF Generator crystal frequencies Check RF Generator output pulse amplitude and shape Check test frequencies Final check
3.2.4.1.2 3.2.5 3.2.4.4.5 3.2.4.4.1, 3.2.4.4.2 3.2.4.4.3 3.2.4.18
1A72517 RF Filter
1 2
Align RF Filter Check receiver video module RF levels
3.2.6 steps11 to 13 3.2.4.5 steps 4, 5
1A72518 Modulator and Detector
1 2 3
Check and adjust RF Generator output pulse amplitude and shape Check signal timing parameters Final check
3.2.4.4.1, 3.2.4.4.2 3.2.4.4.6 3.2.4.18
1A72519 Reply Detector
1 2 3 4 5
Check detector coincidence Calibrate peak power display Check Reply Delay measurement. (This should be within 0.1 microseconds of the normal value for the station) Check pulse shape measurement Final check
3.2.4.4.6 step 3 3.2.4.10.5 3.2.4.13.1 3.2.4.15.9 3.2.4.18
HA72500 SECTION 4
4-13
MODULE OR SUBASSEMBLY
PARAMETER TO BE CHECKED or ADJUSTMENT TO BE MADE
REFER to SECTION
1A72520 Receiver Video Module
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Install crystal for reply frequency Set internal switches S4 and S5 for X or Y channel Set code switches for station ident code Select SDES and LDES OFF or ON as required for the station Set internal DEAD TIME and LDES PERIOD switches to standard setting of 6, or to setting recorded for the station Set front panel BEACON DELAY and SPACING (SEPARATION) switches to settings recorded for the station Align RF source for operation of the station frequency (if not pre-aligned) Check RF source crystal frequency and check RF level Align RF Filter Adjust 6 dB offset Set ON-CHANNEL threshold Check receiver sensitivity Check receiver bandwidth Check receiver selectivity Check decoding window Check reply rate Set dead time Set LDES threshold (if LDES is used) Check SDES (if used) Check station ident code Set reply delay Perform final receiver checks Final check
3.2.4.1.2 3.2.4.2.4 3.2.4.2.4 3.2.6 3.2.4.5 3.2.6 steps11 to 13 3.2.4.7 3.2.4.11.1 3.2.4.11 steps 2, 3 3.2.4.11.4 3.2.4.11.5 3.2.4.11.6 3.2.4.11.8 3.2.4.11.9 3.2.4.12.1 3.2.4.12.2 3.2.4.14.1 3.2.4.13.1 3.2.4.13.2 3.2.4.18
1A72521 Receiver Video Main PWB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Set internal switches S4 and S5 for X or Y channel Set code switches for station ident code Select SDES and LDES OFF or ON as required for the station Set internal DEAD TIME and LDES PERIOD switches to standard setting of 6, or to setting recorded for the station Set front panel BEACON DELAY and SPACING (SEPARATION) switches to settings recorded for the station Adjust 6 dB offset Check receiver sensitivity Check decoding window Check reply rate Set dead time Set LDES THRESHOLD (if LDES is used) Check SDES (if used) Check station ident code Set Reply Delay Final check
3.2.4.2.4 3.2.4.2.4 3.2.4.7 3.2.4.11 steps 2, 3 3.2.4.11.6 3.2.4.11.8 3.2.4.11.9 3.2.4.12.1 3.2.4.12.2 3.2.4.14.1 3.2.4.13.1 3.2.4.18
1A72522 RF Source
1 2 3 4 5
Install crystal for reply frequency Align RF Source for operation at the station frequency (if not pre-aligned) Check RF source crystal frequency and check RF level Check receiver sensitivity Final check
3.2.4.1.2 3.2.6 3.2.4.5 3.2.4.11.3 3.2.4.18
HA72500 SECTION 4
4-14
MODULE OR SUBASSEMBLY
PARAMETER TO BE CHECKED or ADJUSTMENT TO BE MADE
REFER to SECTION
1A72523 IF Amplifier
1 2 3 4 5 6 7 8 9 10 11 12
Set AGC link XN2 to AGC position Align IF amplifier (if not pre-aligned) Set ON-CHANNEL threshold Adjust 6 dB offset Check receiver sensitivity Check receiver bandwidth Check receiver selectivity Check decoding window Check CW protection Set reply delay Perform final receiver checks Final check
3.2.9 3.2.4.11.1 3.2.4.7 3.2.4.11 steps 2, 3 3.2.4.11.4 3.2.4.11.5 3.2.4.11.6 3.2.4.11.7 3.2.4.13.1 3.2.4.13.2 3.2.4.18
1A72524 RF Amplifier
1 2 3 4
Check RF output level Check tuning of Preselector Filter Check receiver sensitivity Final check
3.2.4.5 steps 4, 5 3.2.4.6 3.2.4.11.3 3.2.4.18
1A72525 Transponder Power Supply
1 2 3
Check the HT voltage and adjust if necessary Check regulated supply voltages, +15 volts and +18 volts Final check
3.2.4.8 steps 4, 7 3.2.4.6 3.2.4.18
1A72526 Transponder Power Supply Main PWB
Perform all checks listed for Transponder Power Supply Module, 1A72525
1A72530 Transmitter Driver
1 2 3 4 5 6 7
Set internal switches to alignment positions Align Transmitter Driver for operation at the station frequency (if not pre-aligned) Adjust Transmitter Driver for correct drive to RF Power Amplifier Align Transmitter output pulse Adjust ALC for correct power out Check Transmitter output pulse amplitude and shape Final check
3.2.4.2.5 3.2.7 3.2.4.8 3.2.4.9.1 3.2.4.9.2 3.2.4.10 steps 1 to 4 3.2.4.18
1A72531 Pulse Shaper PWB Assembly
1 2 3 4 5 6 7 8
Set PWB switches to alignment positions Align function generator for nominal pulse shape (if not pre-aligned) Adjust Transmitter Driver for correct drive to RF Power Amplifier. Note: This is necessary only if PWB has never been aligned. Adjust Transmitter Driver for correct drive to RF Power Amplifier Align Transmitter output pulse Adjust ALC for correct power out Check Transmitter output pulse amplitude and shape Final check
3.2.4.2.5 3.2.8 3.2.7 3.2.4.8 3.2.4.9.1 3.2.4.9.2 3.2.4.10 steps 1 to 4 3.2.4.18
HA72500 SECTION 4
4-15
MODULE OR SUBASSEMBLY
PARAMETER TO BE CHECKED or ADJUSTMENT TO BE MADE
REFER to SECTION
1A72532 Exciter
1 2 3 4 5 6 7
Set Pulse Shaper Board switches to alignment positions Set Exciter supply voltages to initial values Align Exciter Adjust drive to Medium Power Driver Adjust ALC for correct power out Adjust ALC for correct power out Final check
3.2.7.1 step 3 3.2.7.1 steps 1, 2 then steps 5 to 10 3.2.7.2 steps 1 to 5 3.2.7.2 step 6 3.2.4.9.2 3.2.4.10 steps 1 to 4 3.2.4.18
1A72533 Medium Power Driver
1 2 3 4 5 6
Set Pulse Shaper Board switches to alignment positions Set supply voltage to Medium Power Driver Adjust drive to Power Modulation Amplifier Adjust ALC for correct power out Check Transmitter output pulse amplitude and shape Final check
3.2.7.1 step 3 3.2.7.1 steps 1, 2, 10 3.2.7.2 steps 7, 8 3.2.4.9.2 3.2.4.10 steps 1 to 4 3.2.4.18
1A72534 Power Modulation Amplifier
A 1 2 3 4 5 6 7
FOR POWER MODULATION AMPLIFIER IN TRANSMITTER DRIVER MODULE. Set Pulse Shaper Board switches to alignment positions Set supply voltage to Power Modulation Amplifier Adjust drive to the Power Modulation Amplifier Adjust drive to the RF Power Amplifier Adjust ALC for correct power out Check Transmitter output pulse amplitude and shape Final check
3.2.7.1 step 3 3.2.7.1 steps 1, 2, 10. 3.2.7.2 steps 7, 8 3.2.4.8 3.2.4.9.2 3.2.4.10 steps 1 to 4 3.2.4.18
B 1 2 3 4 5
FOR POWER MODULATION AMPLIFIER IN 1kW POWER AMPLIFIER. Adjust Transmitter Driver for correct drive to 1kW Power Amplifier. Align transmitter output pulse. Adjust ALC for correct power out. Check Transmitter output pulse amplitude and shape. Final check.
3.2.4.8 3.2.4.9.1 3.2.4.9.2| 3.2.4.10 steps 1 to 4 3.2.4.18
1A72535 1kW Power Amplifier
1 2 3 4 5
Adjust Transmitter Driver for correct drive to 1 kW PA. Align 1 kW Power Amplifier. Adjust ALC for correct power out. Check transmitter output pulse amplitude and shape. Final check.
3.2.4.8.1 3.2.4.9.1 3.2.4.9.2 3.2.4.10 steps 1 to 4 3.2.4.18
1A72536 Power Divider
1 2 3 4
Prepare Transmitter Driver for 1 kW PA alignment. Adjust ALC for correct power out. Check transmitter output pulse amplitude and shape. Final check.
3.2.4.8.1 steps 1 to 9 3.2.4.9.2 3.2.4.10 steps 1 to 4 3.2.4.18
1A72537 Power Combiner
1 Perform all checks listed for Power Divider, 1A72536.
HA72500 SECTION 4
4-16
MODULE OR SUBASSEMBLY
PARAMETER TO BE CHECKED or ADJUSTMENT TO BE MADE
REFER to SECTION
1A72540 1 kW PA Power Supply
1 2 3 4 5 6
Check power switching to 1kW Power Amplifier. Check LED indicators. Check voltage at HT test jack and adjust if necessary. Check Transmitter output power. Check 1kW PA detected signals at front panel test jacks (confirm that these are unchanged from normal station values). Final check.
4.9.1 steps 4, 5 3.2.4.9.1 steps 4, 5 3.2.4.10.2 4.2 3.2.4.18
1A72541 Control and Status PWB
1 2 3 4 5 6
Check power switching to 1kW Power Amplifier. Check LED indicators. Check Transmitter output power. Check 1 kW PA detected signals at front panel test jacks (confirm that these are unchanged from normal station values). Check 1 kW PA detected signals at front panel test jacks (confirm that these are unchanged from normal station values) Final check.
4.9.1 steps 4, 5 3.2.4.10.2 3.2.4.10.2 4.2 3.2.4.18
1A72542 DC-DC Converter
1 2 3
Check voltage at HT test jack and adjust if necessary. Check Transmitter output power. Final check
3.2.4.9.1 steps 4,5 3.2.4.10.2 3.2.4.18
1A72546 Preselector Filter
1 2 3
Tune Preselector Filter to station frequency Check receiver sensitivity Final check
3.2.4.6 3.2.4.11 steps 2, 3 3.2.4.18
1A72549 2A72549 Power Distribution Panel
1 2
Perform rack powering sequence Final check
3.2.4.3 3.2.4.18
HA72500 SECTION 4
4-17
MODULE OR SUBASSEMBLY
PARAMETER TO BE CHECKED or ADJUSTMENT TO BE MADE
REFER to SECTION
1A72550 Control and Test Unit
1 2 3 4 5 6 7 8 9 10
Set configuration and offset switches S1 and S2 Perform rack powering sequence Adjust low voltage shutdown level Set power-on inhibit delay S11 Adjust ident volume and set external ident level (if applicable) SINGLE DME Check control system action for: a. Normal operation b. Primary Fault c. Secondary Fault d. Recycle DUAL DME Check control system action for: a. Normal operation, No. 1 Main b. Primary fault c. Secondary fault d. Normal operation, No. 2 Main e. Primary fault f. Secondary fault g. Recycle Check Test Unit operation Confirm correct operation of remote control and status indications at remote site Final check
3.2.4.2.3 3.2.4.3 3.2.4.16.7 Appendix A.5.1.6 Appendix A.3.2.14 3.2.4.16, Part 1 3.2.4.16.1 3.2.4.16.2 3.2.4.16.3 3.2.4.16.4 3.2.4.16 Part 2 3.2.4.16.1 3.2.4.16.2 3.2.4.16.3 3.2.4.16.4 3.2.4.16.5 3.2.4.16.6 3.2.4.16.7 Appendix A.3.1.2 3.2.4.18
1A72552 Control and Test Unit Processor PWB
Perform all checks listed for Control and Test Unit 1A72550
1A72553 CTU Front Panel PWB
1 2 3
Perform rack powering sequence Confirm correct operation of each front panel switch and LED (functional check only) Final check
3.2.4.3 3.2.4.16 Part 1, Single Part 2, Dual 3.2.4.18
1A72555 RCMS Interface PWB
1 2 3
Perform rack powering sequence Confirm correct operation of remote control and status indications at remote site Final check
3.2.4.3 3.2.4.18
1A72557 External I/O PWB
1 2 3 4
Confirm correct operation of remote control and status indications at remote site Check operation of external ident interface (if used) Confirm correct indications on CTU from AC Power Supplies Final check
3.2.4.14.2 & 3.2.4.14.3 3.2.4.18
HA72500 SECTION 4
4-18
4.2 WAVEFORMS
WAVEFORM 1 Monitor
ERP PULSE XA1
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Channel 2 Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Monitor ERP PULSE jack
Typical value: 6.0 to 8.5 volts pulse on 3.5 volts DC (pulse amplitude depends on ERP RF level from antenna)
Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 2 Monitor
RISE PULSE XT3
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase:
1 microsecond/division
Mode: DC Sensitivity: 2 volts/division
S E T T I N G S
Connect to: Monitor test point XT3 Typical value: 5 volts logic levels Included reference waveforms:
Test Interrogator DETECTED REPLIES jack (upper trace)
Conditions: Beacon in normal operation
WAVEFORM 3 Monitor
10 MHz CLOCK XT4
Trigger from: Channel 1 Timebase: 100 nanoseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Monitor 10 MHz CLOCK test point
XT4 Typical value: 5 volts logic level Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-19
WAVEFORM 4 Monitor
DELAY COUNT XT5DELAY PULSE XT6
Trigger from: Test Interrogator TRIGGER jack Timebase: 1 microsecond/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division Channel 1
S E T T I N G S
Connect to: Channel 1 DELAY COUNT test point XT5 (upper) Channel 2 DELAY PULSE test point XT6 (lower)
Typical value: A correctly aligned delay monitor will have the falling edge of trace 2 occurring during second pulse of trace 1.
Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 5 Monitor
WIDTH COUNT XT7WIDTH PULSE XT11
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division Channel 1
2 volts/division Channel 2
S E T T I N G S Connect to: Monitor WIDTH COUNT test point
XT7 Monitor WIDTH PULSE test point XT11
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 6 Monitor
SPACING PULSE XT8SPACING COUNT XT14
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division both channels
S E T T I N G S
Connect to: Monitor SPACING COUNT test point XT14 Monitor SPACING PULSE test point XT8
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-20
WAVEFORM 7 Monitor
TIPRF XT9
Trigger from: Test Interrogator TRIGGER jack Timebase: 0.5 microseconds/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Monitor TIPRF test point XT9
Typical value: 5 volts logic level Included reference waveforms:
Test Interrogator TRIGGER jack
Conditions: Beacon in normal operation
WAVEFORM 8 Monitor
FALL PULSE XT10
Trigger from: Test Interrogator TRIGGER jack Timebase: 1 microsecond/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Monitor FALL PULSE test point XT10
Typical value: 5 volts logic levels Included reference waveforms:
Test Interrogator DETECTED REPLIES jack
Conditions: Beacon in normal operation
WAVEFORM 9 Monitor
Monitor WIDTH PULSE XT11
Trigger from: Test Interrogator TRIGGER jack Timebase: 1 microsecond/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Monitor WIDTH PULSE test point
XT11 (Channel 2) Typical value: 5 volts logic levels Included reference waveforms:
Test Interrogator DETECTED REPLIES jack
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-21
WAVEFORM 10 Monitor
RISE PULSE XT3RISE COUNT XT15
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division
S E T T I N G S
Connect to: Monitor RISE COUNT test point XT15 Channel 1 (upper trace) Monitor RISE PULSE test point XT3 Channel 2 (lower trace)
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 11 Monitor
FALL PULSE XT10FALL COUNT XT16
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division
S E T T I N G S
Connect to: Monitor FALL COUNT test point XT16 (upper) Monitor FALL PULSE test point XT10 (lower)
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 12 Test Interrogator
TRIGGER XA1
Trigger from: Channel 1 on oscilloscope Timebase: 0.5 microseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator TRIGGER jack
Typical value: +5 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-22
WAVEFORM 13 Test Interrogator
LDES PULSE XA2
Trigger from: Test Interrogator TRIGGER jack Timebase: 20 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video LDES PULSE jack
Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator INTERROGATIONS TIMING jack Channel 2
Conditions: 1. LDES switch ON 2. Beacon in normal operation 3. LDES period set to 7
WAVEFORM 14 Test Interrogator
REPLY ACCEPT GATES XA3
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division, delayed
sweep Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Test Interrogator REPLY ACCEPT
GATES jack Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator DETECTED REPLIES test jack
Conditions: Beacon in normal operation
WAVEFORM 15 Test Interrogator
1 µs MARKERS XA4
Trigger from: Test Interrogator TRIGGER jack Timebase: 1 microsecond/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator 1 µs MARKERS
jack Typical value: 5 volts logic levels Included reference waveforms:
Test Interrogator TRIGGER jack
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-23
WAVEFORM 16 Test Interrogator
DETECTED REPLIES XA7
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division, delayed
sweep Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator DETECTED
REPLIES jack Typical value: 6.0 to 8.5 volts pulse on 3.6 volts DC Included reference waveforms:
GND Channel 2
Conditions: Beacon in normal operation
WAVEFORM 17 Test Interrogator
DETECTED INTERROGATIONS XA8
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division Channel 1 Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: Test Interrogator DETECTED
INTERROGATIONS jack Typical value: 2.7 to 3.3 volts pulse on 3.6 volts DC Included reference waveforms:
Test Interrogator TRIGGER jack (2 volts/division)
Conditions: Beacon in normal operation
WAVEFORM 18 Test Interrogator
INTERROGATION TIMING XA11
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division Channel 2 Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Test Interrogator INTERROGATION
TIMING jack Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator DETECTED INTERROGATIONS jack Channel 1 (1 volt/division)
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-24
WAVEFORM 19 Test Interrogator
REPLY TIMING XA12
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division, delayed
sweep Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Test Interrogator REPLY TIMING jack
Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator DETECTED REPLIES jack
Conditions: Beacon in normal operation
WAVEFORM 20 Test Interrogator
REPLY TIMING XA1INTERROGATIONS TIMING XA13
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Test Interrogator INTERROGATIONS
TIMING jack Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator REPLY TIMING jack Channel 2
Conditions: Beacon in normal operation
WAVEFORM 21 Test Interrogator
M FLT REPLY XT1
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: DC Test Interrogator test point XT1
Typical value: 15 volts logic levels Included reference waveforms:
None
Conditions: 1. Beacon in Maintenance Mode 2. Select Channel 1 3. Select FLT LIMIT 4. Select TX RATE Signal is present for 10 seconds only
HA72500 SECTION 4
4-25
WAVEFORM 22 Test Interrogator
COUNTER XT2
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: COUNTER test point XT2 Channel 1
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: 1. Beacon in Maintenance Mode 2. Select Channel 1 3. Select PARAM 4. Select TX RATE
WAVEFORM 23 Test Interrogator
M FLT SPACING XT3
Trigger from: Test Interrogator TRIGGER jack Timebase: 20 microseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator test point XT3
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: 1. Beacon in Maintenance Mode 2. Select Channel 1 3. Select FLT LIMIT 4. Select TX RATE Signal is present for 10 seconds only
WAVEFORM 24 Test Interrogator
M FLT T± PRF XT4
Trigger from: Test Interrogator TRIGGER jack Timebase: 0.5 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: Test Interrogator test point XT4
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: 1. Beacon in Maintenance Mode 2. Select Channel 1 3. Select FLT LIMIT 4. Select TX RATE Signal is present for 10 seconds only
HA72500 SECTION 4
4-26
WAVEFORM 25 Test Interrogator
MICROSECOND MARKERS XT6
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Channel 1 Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator test point XT6
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 26 Test Interrogator
TIMER XT7
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator TIMER test point
XT7 Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: 1. Beacon in Maintenance Mode 2. Select Ch 1 on CTU Param, NEXT, NEXT, Width
WAVEFORM 27 Test Interrogator
TIPRF 100Hz XT8
Trigger from: Test Interrogator TRIGGER jack Timebase: 1 microsecond/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Test Interrogator TIPRF test point
XT8 100 Hz Typical value: 15 volts logic levels Included reference waveforms:
Channel 2 Test Interrogator TRIGGER jack
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-27
WAVEFORM 28 Test Interrogator
M FLT DELAY XT9
Trigger from: Test Interrogator TRIGGER jack Timebase: 0.1 milliseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator test point XT9
Typical value: 5 volts logic levels Included reference waveforms:
None
Conditions: 1. Maintenance Mode 2. Select Channel 1 3. Select FLT LIMIT Select DELAY Signal is present for 10 seconds only
WAVEFORM 29 Test Interrogator
ATTENUATOR XT10
Trigger from: Channel 1 to XT10 Timebase: 10 milliseconds/division, single DME
20 milliseconds/division dual DME Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator test point XT10
Typical value: 5 volt logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 30 Test Interrogator
1 MHz 15V XT11
Trigger from: Test Interrogator TRIGGER jack Timebase: 0.5 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Test Interrogator test point XT11
Typical value: 15 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-28
WAVEFORM 31 Test Interrogator
10 MHz 15V XT12
Trigger from: Test Interrogator TRIGGER jack Timebase: 0.1 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Test Interrogator test point XT12
Typical value: 15 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 32 Receiver Video
SDES PULSE XA1
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video SDES jack (lower
trace) Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator DETECTED INTERROGATIONS jack
Conditions: Beacon in normal operation SDES switch ON
WAVEFORM 33 Receiver Video
DOUBLE PULSE DECODER OUT XA3
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Channel 1 Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video DOUBLE PULSE
DECODER OUT jack Typical value: 15 volts logic levels Included reference waveforms:
Receiver Video DETECTED LOG VIDEO jack
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-29
WAVEFORM 34 Receiver Video
DEAD TIME XA4
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video DEAD TIME jack
Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator INTERROGATION TIMING jack Channel 2
Conditions: Beacon in normal operation DEAD TIME set to 6
WAVEFORM 35 Receiver Video
TRIGS TO MODULATOR XA5
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Channel 1 Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video TRIGS TO
MODULATOR jack Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator INTERROGATIONS TIMING jack
Conditions: Beacon in normal operation
WAVEFORM 36 Receiver Video
ON CHANNEL VIDEO XA11
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video ON CHANNEL
VIDEO jack Typical value: 15 volts logic levels Included reference waveforms:
Receiver Video DETECTED LOG VIDEO jack (0.5 volts/division)
Conditions: Beacon in normal operation Hi Eff selected
HA72500 SECTION 4
4-30
WAVEFORM 37 Receiver Video
DETECTED LOG VIDEO XA13
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Mode: DC Sensitivity: 0.5 volts/division
S E T T I N G S Connect to: Receiver Video DETECTED LOG
VIDEO jack Typical value: 1.2 volts pulse on 0.7 volts DC
(high interrogation level shown) Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 38 Receiver Video
SELECT INTERROGATION XT1
Trigger from: Receiver Video DOUBLE PULSE DECODER jack
Timebase: 10 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Channel 1 to XT1
Typical value: 15 volts logic levels Included reference waveforms:
Receiver Video DOUBLE PULSE DECODER OUT XA3 jack
Conditions: Beacon in normal operation
WAVEFORM 39 Receiver Video
SQUITTER FREQUENCY XT2
Trigger from: Receiver Video test point XT3 Timebase: 1 millisecond/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video Channel 1 to test
point XT2 SQUITTER FREQUENCY Typical value: 15 volts logic levels Included reference waveforms:
Channel 2 to Receiver Video test point XT3
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-31
WAVEFORM 40 Receiver Video
XT3
Trigger from: Channel 1 Timebase: 2 milliseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Channel 1 to Receiver Video board
test point XT3 Typical value: 15 volts logic levels Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 41 Receiver Video
BEACON DELAY O/P XT5
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Channel 1 to Receiver Video board
test point XT5 BEACON DELAY O/P Typical value: 15 volt logic levels Included reference waveforms:
Channel 2 Receiver Video DOUBLE PULSE DECODER OUT test jack
Conditions: Beacon in normal operation
WAVEFORM 42 Receiver Video
XT6
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: Channel 1 to Receiver Video board
test point XT6 Typical value: 1.6 volts peak pulse on 1.2 volts DC Included reference waveforms:
Channel 2 connected to Receiver Video test point XT13
Conditions: Beacon in normal operation Hi Eff selected
HA72500 SECTION 4
4-32
WAVEFORM 43 Receiver Video
XT8
Trigger from: Receiver Video DOUBLE PULSE DECODER OUT jack
Timebase: 1 microsecond/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Channel 1 to Receiver Video board
test point XT8 Typical value: 15 volts logic levels Included reference waveforms:
Channel 2 to Receiver Video DOUBLE PULSE DECODER OUT jack
Conditions: Beacon in normal operation
WAVEFORM 44 Receiver Video
XT11
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Mode: DC Sensitivity: Channel 1 - 1 volt/division
Channel 2 - 5 volts/division
S E T T I N G S Connect to: Channel 2 to Receiver Video board
test point XT11 Typical value: 15 volts logic levels Included reference waveforms:
Channel 1 to Receiver Video test point XT6
Conditions: Beacon in normal operation
WAVEFORM 45 Receiver Video
XT12
Trigger from: Test Interrogator TRIGGER jack Timebase: 2 microseconds/division (lower trace) Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video board test point XT12
Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator DETECTED INTERROGATIONS jack
Conditions: Beacon in normal operation SDES switch to ON
HA72500 SECTION 4
4-33
WAVEFORM 46 Receiver Video
XT13
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: Channel 1 to Receiver Video board
test point XT6 Typical value: 1.6 volts peak pulse on 1.0 volts DC Included reference waveforms:
Channel 2 connected to Receiver Video board test point XT13
Conditions: Beacon in normal operation Hi Eff selected
WAVEFORM 47 Receiver Video
XT14
Trigger from: Test Interrogator TRIGGER jack Timebase: 5 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: Channel 1 to Receiver Video board
test point XT6 Typical value: 1.6 volts peak pulse on 1.2 volts DC Included reference waveforms:
Channel 2 connected to Receiver Video test point XT13
Conditions: Beacon in normal operation Hi Eff selected
WAVEFORM 48 Receiver Video
XT20
Trigger from: Test Interrogator TRIGGER jack Timebase: 50 milliseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Receiver Video board test point XT20
Typical value: 15 volts logic levels Included reference waveforms:
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-34
WAVEFORM 49 Transmitter Driver
SQUARE MODULATION XA1
Trigger from: Test Interrogator TRIGGER jack Timebase: 10 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Transmitter Driver SQUARE
MODULATION jack Typical value: 15 volts logic levels Included reference waveforms:
Test Interrogator TRIGGER jack
Conditions: Beacon in normal operation
WAVEFORM 50 Transmitter Driver
FUNCTION GENERATOR XA2
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Transmitter Driver FUNCTION
GENERATOR jack Typical value: 5 to 10 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 51 Transmitter Driver
SHAPED MODULATION XA3
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Transmitter Driver SHAPED
MODULATION jack Typical value: 17 volts DC, 25 to 35 volts peak pulse Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-35
WAVEFORM 52 Transmitter Driver
DRIVER LEVEL XA5
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 10 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: DRIVER LEVEL jack
Typical value: 2.5 to 4.0 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 53 Pulse Shaper
SQUARE MODULATION XT4
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 10 microseconds/division Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: Pulse Shaper Board test point XT4
Typical value: 11 to 15 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 54 Exciter
V5, V6 CURRENT
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: Both channels DC Sensitivity: Channel 1: 10 volts/division
Channel 2: 200 mA/division
S E T T I N G S
Connect to: Channel 1: Collector supply lead of V5, V6 pair in exciter Channel 2: Collector supply lead of V5, V6 pair in exciter, with current probe
Typical value: Channel 1: 20 to 30 volts Channel 2: 0.4 to 0.7 amperes (Both values depend on operating frequency)
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-36
WAVEFORM 55 Medium Power Driver
COLLECTOR CURRENT
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: Both channels DC Sensitivity: Channel 1. 10 volts/division
Channel 2: 1 ampere/division
S E T T I N G S
Connect to: Channel 1: Collector supply lead of V1 in medium power driver Channel 2: Collector supply lead of V1 in medium power driver, with current probe
Typical value: Channel 1: 22 to 30 volts Channel 2: 1.9 to 2.7 amperes
Conditions: Beacon in normal operation
WAVEFORM 56 Power Modulation Amplifier
COLLECTOR CURRENT
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 2 microseconds/division Mode: DC Sensitivity: 2 amperes/division
S E T T I N G S Connect to: Collector supply lead V1 in power
modulation amplifier, with current probe
Typical value: 5 to 8 amperes Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 57 Transponder Power Supply
XT5
Trigger from: Internal, Channel 1 Timebase: 10 microseconds/division Mode: DC Sensitivity: 20 volts/division
S E T T I N G S Connect to: Transponder Power Supply test point
XT5 Typical value: 40 volts peak-to-peak Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-37
WAVEFORM 58 Transponder Power Supply
XT8
Trigger from: Internal, Channel 1 Timebase: 10 microseconds/division Mode: DC Sensitivity: 0.2 volts/division
S E T T I N G S Connect to: Transponder Power Supply test point
XT8 Typical value: 0.35 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 59 Transponder Power Supply
XT9
Trigger from: Internal, Channel 1 Timebase: 5 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: Transponder Power Supply test point
XT9 Typical value: 4 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 60 1kW RF Amplifier
POWER AMP MODULATOR XA1
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 10 microseconds/division Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: POWER AMP MODULATOR jack
Typical value: 2.0 to 6.5 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-38
WAVEFORM 61 1kW RF Amplifier
POWER AMP Output XA2
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: POWER AMP OUTPUT jack
Typical value: 4.0 to 7.5 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 62 1kW RF Amplifier
POWER AMP DRIVER XA3
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: DC Sensitivity: 1 volt/division
S E T T I N G S Connect to: POWER AMP DRIVERJACK
Typical value: 3.5 to 7.5 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 63 1kW RF Amplifier
SHAPED MODULATION XA10
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Channel 1 Mode: DC Sensitivity: 5 volts/division
S E T T I N G S Connect to: SHAPED MODULATION jack
Typical value: 17 volts DC, 25 to 35 volts peak Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-39
WAVEFORM 64 1kW RF Amplifier : 250W Output Amplifiers
COLLECTOR CURRENT
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: DC Sensitivity: 2 amperes/division
S E T T I N G S Connect to: Collector supply lead to 250W
amplifiers A3-A10, with current probe Typical value: 10 to 15 amperes peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 65 1kW RF Amplifier : Power Mod Amp
COLLECTOR CURRENT
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: DC Sensitivity: 2 amperes/division
S E T T I N G S Connect to: Collector supply lead to V1 of power
modulation amplifier in 1kW RF PA, with current probe
Typical value: 7 to 9 A pedestal, 10 to 12 A peak Included reference waveforms:
None
Conditions: Beacon in normal operation
WAVEFORM 66 1kW RF Amplifier : Drivers
DRIVER COLLECTOR CURRENT
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 5 microseconds/division Mode: DC Sensitivity: 2 amperes/division
S E T T I N G S Connect to: Collector supply lead to 250W
amplifiers A1, A2, with current probe Typical value: 1.5 to 2.5 A pedestal, 8 to 15 A peak Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-40
WAVEFORM 67 Test Interrogator
DETECTED REPLIES XA7
Trigger from: Receiver Video TRIGS TO MODULATOR test jack
Timebase: 1 microseconds/division Channel 1 Mode: DC Sensitivity: 2 volts/division
S E T T I N G S Connect to: Test Interrogator DETECTED
REPLIES jack Typical value: 6.0 to 8.5 volts pulse on 3.6 volts DC Included reference waveforms:
None
Conditions: Beacon in normal operation
HA72500 SECTION 4
4-41
4.3 SPECIAL MAINTENANCE PROCEDURES
4.3.1 Stripline Printed Wiring Boards Component replacement on the flexible stripline printed wiring boards used in the LDB-102 requires that special requirements relating to positioning of components, soldering and cleaning be observed.
4.3.1.1 Positioning of Ceramic Chip Capacitors a. Lateral Positioning.
Ceramic chips must be positioned within the track or pad boundaries or, when the pad is the same width as the chip, within 0.25 mm of true position (that is, 0.25 mm deviation each side of centre line); refer to Figure 4-2
Figure 4-2 Lateral Positioning of Chip Capacitors
b. Longitudinal Positioning.
Metallised contact ends of ceramic chip capacitors should not be positioned so that they overhang the ends of the pads; refer to Figure 4-3.
Figure 4-3 Longitudinal Positioning of Chip Capacitors
HA72500 SECTION 4
4-42
4.3.1.2 Soldering
4.3.1.2.1 Type of Solder and Flux The solder to be used for soldering ceramic chip capacitors to stripline board should be 62-36-2 (Sn-Pb-Ag) alloy. For manufacture, a solder paste of this alloy is applied by screen printing. For component replacement, a resin-cored solder wire of this alloy is to be used; a suitable type is 'Multicore' Sn62. All fluxes must be of the QQ-S-571E Type R or AS1834 type 2.
4.3.1.2.2 Soldering Surface Mounted Chip Capacitors The soldering of surface mounted chip capacitors shall be such that the end result displays good wetting (solderability) indicating good joint integrity and reliability. Solder joints are to be smooth, bright and feathered to a thin edge, indicating proper wetting action. Lead material is not to be exposed within the solder connection, and no sharp protrusions or contamination (embedded foreign material) is to be evident. The contour of the component lead must be visible. The height of the solder fillet should extend at least one-third of the chip height and not higher than the end of the chip. The soldered joint surfaces should exhibit good wettability (that is, low contact angles of the solder in contact with the joined surfaces). Figure 4-4shows these requirements, together with examples of typical soldering faults.
Figure 4-4 Chip Capacitor Soldering Requirements
HA72500 SECTION 4
4-43
4.3.1.2.3 Soldering Through Board Mounted Chip Capacitors The main criterion for a sound joint is a smooth bright joint displaying good wetting across the entire width of the metallised contact of the chip. Care must be taken that no short circuits are caused due to excessive solder. Refer to Figure 4-5.
Figure 4-5 Soldering of Through Board Mounted Chip Capacitors
4.3.1.2.4 Workmanship Care must be taken when soldering ceramic chip capacitors to stripline. Excessive temperature will cause damage to the metallised chip contacts and stripline pads. On completion of each solder joint check for evaporation of the metallised chip contacts and for lifted pads or track. Under no circumstances are ceramic chip capacitors to be touched with a soldering iron. The molten solder joint must not be disturbed while cooling; cooling should be natural, without assistance from liquid or air.
4.3.1.2.5 Placement and Soldering of Standard Components to Stripline Standard components (such as resistors, capacitors, diodes) when used in conjunction with stripline board must have the shortest possible leads to reduce inadvertent inductance.
The following are essential requirements:
a. Components must have the shortest possible leads and be as close as possible to the surface of the board.
b. Stress relief bends are not required.
c. For surface mounted ribbon leads, the soldered area between lead and land of ribbon wire leads is to be greater than the square of the lead width. After soldering, the distance from the top of the lead to the top of the land is to be less that three times the lead thickness, and the lead outlines are to be visible. Maximum and minimum lead overhang conditions are shown in Figure 4-6, and maximum and minimum solder conditions are shown in Figure 4-7.
HA72500 SECTION 4
4-44
Figure 4-6 Part Placement
Figure 4-7 Maximum/Minimum Solder Conditions
HA72500 SECTION 4
4-45
d. Surface mounted round, flat or coined leads are not to have any side overhang. The contact length of the lead is to be twice the width of the flattened leads, and twice the diameter for round leads. Lead placement requirements are shown in Figure 4-8 and soldering conditions are shown in Figure 4-9.
Figure 4-8 Lead Placement Conditions
Figure 4-9 Lead Soldering Conditions
e. Coated or sealed components (such as capacitors) must display a minimum
clearance of 0.25 mm between the solder fillet and the coating; refer Figure 4-10.
HA72500 SECTION 4
4-46
Figure 4-10 Minimum Clearance of Sealed Components
f. Multiple lead terminations are allowable within the following constraints:
1. No lead is closer than 1.25 mm to the end of the metallisation of a ceramic chip capacitor; refer to Figure 4-11.
2. Pads are of sufficient size to accommodate the number of leads; refer to Figure 4-11.
Figure 4-11 Multiple Lead Termination Requirements
HA72500 SECTION 4
4-47
4.3.1.3 Cleaning On completion of soldering, printed board assemblies should be cleaned by brush application of Freon TE35, Freon TP35 or ethyl alcohol. It should be noted that the following components and materials are adversely affected by cleaning solvents such as Freon (trichlorotriflurorethane):
a. All aluminium electrolytic capacitors where ends are not sealed with epoxy resins.
b. Variable and/or adjustable capacitors and resistors.
c. Metal oxide resistors (such as Welwyn F series).
d. Wire wound resistors (such as IRC ASW series).
e. MFD capacitors.
f. 'Styroseal' capacitors and other polystyrene capacitors of the wound film type.
g. All polystyrene materials and coatings.
h. Inductor type 222V57973 (red) or any inductor impregnated with M198 or with potted cores (such as 89V57997 and 90V57997).
i. All silicon based rubber material, or components containing it such as tantalum foil capacitors (Plessey type ETR) and miniature variable capacitors (Morganite type 81 or 83).
j. Wax and silicon greases.
k. Natural rubber and neoprene.
l. Components impregnated or coated with Dow Corning 630 Protective Coating.
4.3.2 Conformal Coating Most printed wiring boards in the DME LDB-102 equipment are coated with Dow Corning Conformal Coating 1-2577. Component replacement will breach the conformal coating, which must then be restored on completion of the repair.
Repair and restoration of conformal coating should be conducted as follows:
a. Desolder the component. Use a small soldering iron or a solder sucker device at the lowest practicable tip temperature (250 to 300 degrees C); maximum tip temperature should not exceed 300 degrees C. The coating is affected by a time-by-temperature factor, so apply heat for the shortest possible time.
b. If the conformal coating becomes discoloured or charred from desoldering, carefully scrape the affected coating away or use a rubber eraser to remove it.
c. Clean the area affected by desoldering; use Freon TP35, or equivalent. Do NOT flood or wet the conformal coating, as this may dissolve it.
d. Solder in the new component with a resin flux-cored solder wire.
e. Remove the flux residue and clean the surrounding conformal coating. Use a cotton-tipped applicator (cotton bud) moistened with Freon TP35, or equivalent, as soon as possible after soldering. Do NOT flood or wet the conformal coating, as this may dissolve it.
f. To restore the conformal coating recoat the soldered joint(s), the component leads on both sides of the board, and any bare board surfaces by brush application of Dow Corning Conformal Coating 1-2577. This material will be supplied thinned for brushing.
HA72500 SECTION 4
4-48
4.3.3 RF Transistor Replacement This section describes the preferred method for removal of RF low power and high power transistors from printed wiring boards (PWB), especially microstrip circuitry on Teflon substrate: it is assumed that the device to be removed is to be discarded as faulty, most emphasis being placed on avoiding damage to the PWB which is being re-used.
Care must be taken in component removal from any PWB to avoid the use of excessive heat, as this will reduce the adhesion of the copper track to the base material: this is especially critical in the microstrip-on-TefIon case, where the initial adhesion is lower than with fibreglass boards and the tracks rely on surface adhesion alone, having no plated-through holes which provide mechanical anchoring as well as thermal shunting.
4.3.3.1 Tools Required a. For efficient removal of surface mounted transistors, it is advisable to have two
instrument type soldering irons available, one with a small bit with a flat area, which is temperature controlled to 250 degrees Celsius, and the other with a larger flat bit to rapidly heat larger thermal masses.
b. A reel of multi-cored solder
c. Tapered nose pliers and tweezers.
d. A fine sharp blade such as a craft knife.
e. A vice or clamp for securing small assemblies.
f. Damp pad for keeping iron bit clean - important.
g. Solder sucker or solder wick braid.
4.3.3.2 Preparation of Unit a. With all external connections removed, take the LRU from its module and the
PWB, or subassembly, from the unit, if possible; see Section 4.1.1 if necessary for instructions on removal and replacement of LRU and PWB sub-assemblies.
b. Note the method used to mount the transistor, and withdraw and retain any screws or nuts used.
c. Secure the PWB or subassembly with a clamp or vice to leave both hands free.
4.3.3.3 Removal of Device a. If any surface mounted components are within 3 mm of the device joints, these
should be removed, first noting their precise positioning with respect to the transistor, for later replacing.
b. Miscellaneous chip components can be readily removed using the two-iron method - apply the iron with the larger bit to the end of the component connected to ground plane and the smaller bit to the other end; as soon as the solder has melted both ends, lift the component between the bits and quickly remove it from the heat before it loses its end cap plating.
HA72500 SECTION 4
4-49
c. If the transistor is soldered to large track areas (such as ground planes) these joints should be unsoldered first; using the larger soldering iron bit and a little fresh solder, melt the local solder and, using the solder sucker or wick, reduce the molten solder as fast and thoroughly as possible. Whilst the solder is still molten, use the sharp blade to part all transistor tabs, except one, from the copper areas: it may be necessary to complete this later. Using the smaller soldering iron bit, reduce the solder and, again using the blade, lift the tabs of the transistor connected to the microstrip tracks, then finally lift the remaining large tab.
d. Lift the device, using pliers to hold the body and the soldering iron to finally part any joints still connected.
e. Clean up all track areas by carefully using the soldering iron to reflow the solder.
4.3.3.4 Inserting the New Device a. Handle the new transistor by the body, or the tabs to be connected to ground
plane, to prevent any static discharge damage. Place it in the desired position, ensuring that the tabs are accurately aligned with the tracks, using any screws or nuts removed earlier.
b. Pressing the body down gently with an insulated tool, if needed, solder any ground plane connections first, using the soldering iron with the large bit and more solder - not too much.
c. Using the smaller bit, solder the collector (or drain) lead(s) to track(s) using minimum heat for a clean joint; then solder the base (or gate) lead(s) to the appropriate track(s).
d. Finally, any components previously removed should be carefully resoldered back in their correct positions.
e. Clean the board to remove any excess flux and inspect new joints.
f. The PWB can now be refitted into its box and the appropriate LRU tests applied.
HA72500 APPENDIX B
APPENDIX B
PHYSICAL DIMENSIONS AND MASSES
B-i
HA72500 APPENDIX B
TABLE of CONTENTS
B. PHYSICAL DIMENSIONS AND MASSES..................................................B-1 B.1 DME LDB-102 STATION (SINGLE 1kW) TYPE 1A72500 B-1 B.2 DME LDB-102 STATION (DUAL 1kW) TYPE 2A72500 B-1
B-ii
HA72500 APPENDIX B
LIST of TABLES
Table B-1 Dimensions and Masses - Single 1 kW DME............................................ B-1 Table B-2 Dimensions and Masses - Dual 1 kW DME............................................... B-1
B-iii
HA72500 APPENDIX B
B. PHYSICAL DIMENSIONS AND MASSES B.1 DME LDB-102 STATION (SINGLE 1kW) TYPE 1A72500 The dimensions and masses of the main items of the single 1kW station equipment are listed in Table B-1.
Table B-1 Dimensions and Masses - Single 1 kW DME
HEIGHT
(mm)
WIDTH
(mm)
DEPTH
(mm)
MASS
(kg)
Rack Assembly (Single 1kW DME) 1A72505 (complete with all modules and AC Power Supply)
1930 560 580 206
Antenna Cable Set for Single Installation 1A72560 7
Accessory Kit, DME Test 1A72561
Kits of various assemblies and components 3
DME Antenna Refer to separate antenna handbook
The only assemblies with masses greater than 5 kg are the following:
• Rack Frame Assembly 1A72588 (without removable modules) 100
• AC Power Supply 3A71130 64
• 1kW RF Power Amplifier 1A72535 19
• 1kW PA Power Supply 1A72540 7
B.2 DME LDB-102 STATION (DUAL 1kW) TYPE 2A72500 The dimensions and masses of the main items of the dual 1kW station equipment are listed in Table B-2.
Table B-2 Dimensions and Masses - Dual 1 kW DME
HEIGHT
(mm)
WIDTH
(mm)
DEPTH
(mm)
MASS
(kg)
Rack Assembly (Dual 1kW DME) 2A72505 (complete with all modules)
1930 560 580 185
Dual AC Power Supply System 2A69758 1060 560 560 190
Dual AC Power Supply System 3A69758 1930 560 560 220 Antenna Cable Set for Dual Installation 2A72560 7
Accessory Kit, DME Test 1A72561
Kits of various assemblies and components 3
DME Antenna Refer to separate antenna handbook
The only assemblies with masses greater than 5 kg are the following:
• Rack Frame Assembly 1A72588 (without removable modules) 100
• AC Power Supply 3A71130 64
• 1kW RF Power Amplifier 1A72535 19
• 1kW PA Power Supply 1A72540 7
B-1
HA72500 APPENDIX C
APPENDIX C
POWER AND REMOTE CONTROL
C-i
HA72500 APPENDIX C
TABLE of CONTENTS
C. POWER AND REMOTE CONTROL .......................................................C-1 C.1 POWER REQUIREMENTS AND CONSUMPTION C-1 C.2 REMOTE CONTROL AND MONITORING FACILITIES C-2
C.2.1 RCMS Control Inputs...................................................................................C-2 C.2.2 RCMS Inputs and Outputs...........................................................................C-2 C.2.3 Remote Indication Descriptions...................................................................C-4
C-ii
HA72500 APPENDIX C
LIST of TABLES
Table C-1 RCMS Control Inputs............................................................................. C-2 Table C-2 RCMS Inputs ......................................................................................... C-2 Table C-3 RCMS Outputs ...................................................................................... C-3 Table C-4 Remote Indication Functions ................................................................. C-4
C-iii
HA72500 APPENDIX C
C. POWER AND REMOTE CONTROL C.1 POWER REQUIREMENTS AND CONSUMPTION The primary source requirement is:
a. Input voltage: 200, 210, 220, 230, 240, 250 or 260 volts ±10%, single phase.
b. Input frequency: 45 to 55 Hz.
c. Consumption: 1400 VA maximum (when charging flat batteries) for single beacon; 2800 VA for dual beacon.
The battery supply requirement is:
a. Voltage: 24 volts nominal.
b. Capacity: not less than 105 AH (discharged at 10-hour rate to 1.85 volts per cell). This will give 14 hours operation at squitter rate.
c. Current consumption from a fully charged battery at 27 volts is:
Single Transponder, Single Monitor
Dual Transponder, Dual Monitor
Operating at squitter rate: 6 amperes 7 amperes
Operating at maximum replies: 12 amperes 13 amperes
C-1
HA72500 APPENDIX C
C.2 REMOTE CONTROL AND MONITORING FACILITIES
C.2.1 RCMS Control Inputs The three remote control functions (OFF, NO 1 ON, NO 2 ON) shown in Table C-1 are each activated by applying a control voltage of 24 volts DC to the relevant control inputs on the External I/O PWB 1A72557. Although these inputs are protected against reverse polarity, the correct polarity must be used to activate the input. If more than one input is active, the priority is OFF, NO 1 ON, NO 2 ON.
An input can be activated by wiring the +24 Volts Protected supply to the '+ve' terminal and earthing the '-ve' terminal. Both +24 Volts Protected and Earth are also available on the I/O PWB Assembly. The +24 Volts Protected supply can source a maximum current of 140 mA.
The loop resistance of the external input must be between 0 and 1200 ohms. The control responds to either impulse (0.2 to 2 seconds impulse duration) or continuous earthing.
Table C-1 RCMS Control Inputs
SIGNAL NAME EXTERNAL I/O BOARD CONTACTS
Negative Input Positive Input
OFF XB10:5 XB10:6
NO 1 ON XB10:3 XB10:4
NO 2 ON XB10:1 XB 10:2
C.2.2 RCMS Inputs and Outputs RCMS inputs are voltage free (dry) optically-isolated inputs to 100 volts AC, at the external I/O board. They are listed in Table C-2.
RCMS outputs are voltage free (dry) contacts, floating to 100 volts AC, at the external I/O board. They are listed in Table C-3.
Table C-2 RCMS Inputs
SIGNAL NAME EXTERNAL I/O BOARD CONTACTS
Out 1 Out 2 Comments
Master Ident Output XB1:2 XB1:1 From DME ident generator, voltage free.
Recovered Ident Key XB1:3 Recovered ident key from monitor module, open collector.
SIGNAL NAME EXTERNAL I/O BOARD CONTACTS
In 1 In 2 Comments
Associated Ident In XB1:4 To DME ground referenced (optional pullup on CTU processor board). Used when external ident keying is to be used as master.
C-2
HA72500 APPENDIX C
Table C-3 RCMS Outputs
SIGNAL NAME EXTERNAL I/O BOARD CONTACTS
Common Normally Closed Normally Open
NORMAL XB9:4 XB9:6 XB9:2
TRANSFER XB9:3 XB9:5 XB9: 1
SHUTDOWN XB8:4 XB8:6 XB8:2
LOCAL CONTROL XB3:4 XB3:6 XB3:2
NO 1 ON XB7:4 XB7:6 XB7:2
NO 2 ON XB7:3 XB7:5 XB7:1
MAINTENANCE XB3:3 XB3:5 XB3:1
MONITOR ALM INHIBIT XB2:3 XB2:5 XB2:1
PRIMARY ALARM XB6:3 XB6:5 XB6:1
SECONDARY ALARM XB6:4 XB6:6 XB6:2
BATT CHG NORM 1 XB4:4 XB4:6 XB4:2
BATT CHG NORM 2 XB4:3 XB4:5 XB4:1
AC PWR NORM XB5:4 XB5:6 XB5:2
Ground (0 volts) XB11:5,6
+24 V DC - protected XB1:5,6
C-3
HA72500 APPENDIX C
C.2.3 Remote Indication Descriptions For each remote indication, the RCMS interface provides voltage-free (dry) changeover relay contacts capable of switching 50 volts DC at 200 mA and 24 volts DC at 500 mA, surge protected and isolated to 100 volts AC.
+24 Volts Protected and Earth are also available on the External I/O PWB Assembly.
The transponder functions for which status indication is available for remote indication are listed in Table C-4.
Table C-4 Remote Indication Functions
FUNCTION PURPOSE
No. 1 On/No. 2 On Indicators which transponder is on and operating
Normal Indicates when the selected main transponder is on and operating with no faults or alarms. Will not be active if the monitor alarms are inhibited.
Transfer Indicates when the standby transponder is on and operation (dual system only).
Shutdown Indicates when the transponder(s) have been turned off by the CTU (due to a fault condition).
Maintenance Indicated when the DME is in maintenance mode or in a test condition.
Monitor Alarm Inhibit Indicates when the DME is set to ignore the alarms from the monitor(s).
Primary Alarm Indicates when the DME has a primary fault or alarm.
Secondary Alarm Indicates when the DME has a secondary fault or alarm.
Battery Charger Normal No. l/No. 2
Indicates when the battery charge conditions are normal
AC Power Normal Indicates when the input AC power is normal.
Local Control Indicates when the CTU has been put into local control mode.
Ground Ground reference for the RCMS.
+24V Protected Protected voltage source.
Ident Tone Recovered ident tone, from the selected monitor module. 600 ohms balanced line.
C-4
HA72500 APPENDIX D
APPENDIX D
SYSTEM INSTALLATION
D-i
HA72500 APPENDIX D
TABLE of CONTENTS
D. SYSTEM INSTALLATION.......................................................................D-1 D.1 INTRODUCTION D-1 D.2 INSTALLATION ITEMS REQUIRED D-2
D.2.1 Introduction..................................................................................................D-2 D.2.2 Hardware .....................................................................................................D-2 D.2.3 Tools............................................................................................................D-3 D.2.4 Test Equipment ...........................................................................................D-3
D.3 EQUIPMENT EARTHING D-3 D.4 UNPACKING AND INSPECTION OF RACK D-4
D.4.1 Unpacking....................................................................................................D-4 D.4.2 Checks after Unpacking ..............................................................................D-4
D.5 EMPLACEMENT OF DME RACK(S) D-4 D.6 AC AND DC POWER CONNECTIONS D-5
D.6.1 AC Connections...........................................................................................D-5 D.6.2 DC Connections ..........................................................................................D-5
D.7 RACK ASSEMBLY D-7 D.7.1 Module Assembly ........................................................................................D-7 D.7.2 1kW Power Amplifier Assembly...................................................................D-7 D.7.3 1kW PA Power Supply Assembly................................................................D-8
D.8 WIRING CONNECTIONS D-10 D.8.1 External Interface ......................................................................................D-10 D.8.2 Wiring for Power Supply Signals ...............................................................D-10 D.8.3 Wiring for Remote Control and Status Signalling ......................................D-10 D.8.4 Wiring to Associated VHF Navaid .............................................................D-12
D.9 ANTENNA INSTALLATION D-13 D.9.1 General......................................................................................................D-13 D.9.2 Pipe Mounting Installation .........................................................................D-13 D.9.3 Antenna Assembly and Connections.........................................................D-14
D.10 ANTENNA CABLES D-16 D.10.1 Antenna Feeder Cables.............................................................................D-16 D.10.2 ERP Monitor Cable....................................................................................D-19 D.10.3 ERP Monitor Attenuator.............................................................................D-21 D.10.4 Antenna Integrity Signal Cable ..................................................................D-22
D.11 COMPLETION D-22
D-ii
HA72500 APPENDIX D
LIST of FIGURES
Figure D-1 DC Power Connections, Single DME .................................................... D-6 Figure D-2 DC Power Connections, Dual DME....................................................... D-6 Figure D-3 1kW RF Power Amplifier Connections .................................................. D-8 Figure D-4 1kW PA Power Supply Connections ..................................................... D-9 Figure D-5 RF Feeder Connector Termination...................................................... D-17 Figure D-6 Monitor Feeder Connector Termination............................................... D-20 Figure D-7 Antenna Integrity Signal Cable Connections ....................................... D-22 Figure D-8 Rack Installation .................................................................................. D-23 Figure D-9 Rack Power Cabling - Single 1kW DME Installation ........................... D-24 Figure D-10 Rack Power Cabling - Dual 1kW DME Installation .............................. D-25 Figure D-11 Air Vent Assembly ............................................................................... D-26 Figure D-12 LDB-102 Single 1kW Rack Arrangement ............................................ D-27 Figure D-13 LDB-102 Dual 1kW Rack Arrangement............................................... D-28 Figure D-14 AC Power Supply Monitor Connections .............................................. D-29 Figure D-15 Antenna Feeder Connections - RF and Signal.................................... D-30 Figure D-16 Pipe Mount - Chu Antenna .................................................................. D-31 Figure D-17 Antenna Installation - Chu Antenna..................................................... D-32 Figure D-18 Antenna Installation - Interscan Antenna............................................. D-33 Figure D-19 Interscan Antenna Baseplate .............................................................. D-34 Figure D-20 External I/O Board Layout ................................................................... D-35 Figure D-21 dB Systems Antenna Base Connections............................................. D-36
D-iii
HA72500 APPENDIX D
D. SYSTEM INSTALLATION D.1 INTRODUCTION
REFER Figure D-9 and Figure D-10
This appendix describes the recommended procedures for installing an LDB-102 DME beacon, and is compiled in a sequence which provides the simplest installation plan. Some details will be dictated by particular site characteristics and can only be decided locally; these items, listed below, are not covered in this appendix.
Details not covered are:
a. Site preparation.
b. Assembly of antenna mast.
c. Assembly of equipment shelter.
d. Laying of power cables and control/monitoring cables.
e. Assembly and wiring of work bench, lights and power outlets in the equipment shelter.
f. Mounting and connections to the remote control facility.
If batteries other than the fully sealed type are used, it is necessary to locate them in a room separated from the main equipment; the battery room must have adequate ventilation to prevent accumulation of fumes. An alternative arrangement is to house the batteries in a suitable box outside the main shelter, again with adequate ventilation. Essential elements of equipment shelter layouts are shown in Figure D-9 and Figure D-10 for single and dual installations respectively.
D-1
HA72500 APPENDIX D
D.2 INSTALLATION ITEMS REQUIRED
D.2.1 Introduction This section lists all the major ancillary items needed for the installation of an LDB-102 DME beacon which are NOT supplied with the equipment, and references them to the section in which they are specified. The list applies to a standard beacon installation.
D.2.2 Hardware a. Power cable for mains supply connection, rated for 240 volts, 8 amperes
minimum. Conventional flexible 3-core mains cable is sufficient. (Qty 2 required for dual DME) : see Section D.6.1.
b. Power cable for connection to batteries. Recommended type is 195 x 0.25 mm, (10 sq mm) such as Hartland HC0060: see Section D.6.2
c. Battery terminal lugs to suit batteries used : see Section D.6.2.
d. Battery supply fuse (if required); if used, it is to be slow blow (delay) type, 32 amperes rating, HRC type or equivalent: see Section D.6.2
e. Antenna mounting pipe, diameter to suit antenna used : see Section D.9.
f. Antenna obstruction lights (if to be fitted) : see Section D.9
g. Mains power cable for connection to antenna obstruction lights (if fitted) : see Section D.9.
h. Cable strain bracket (if required) : see Section D.9.
i. Cable(s) for earthing rack to earth bus (not less than 20 square mm area of copper total) and lugs as necessary : see Section D.3.
j. Wooden plinth for mounting rack: see Section D.5.
k. Masonry anchors for securing plinth : see Section D.5.
l. Coach screws 120 mm long by 10 mm diameter, for securing rack to wooden plinth; Qty 4 per rack : see Section D.5.
The following are required only if the unit is NOT collocated with other equipment requiring extensive grounding; otherwise, use a common earth bus for all equipments (see Section D.3).
m. Grounding stakes, 2 metres long minimum; Qty 2 minimum.
n. Earth bus, copper bar 25 mm by 3 mm; lengths as necessary for the installation.
o. Mechanical and electrical fittings for earth bus (screws, lugs, cable).
D-2
HA72500 APPENDIX D
D.2.3 Tools As well as normal hand tools appropriate to the installation of an electronic system such as the LDB-102 DME, the following special items are required:
a. Two wrenches, 13/16 inch capacity (for termination of antenna feeder cable, as detailed in Section D.10.1).
b. Crimp tool for fixing type N connectors on type RG-223 coaxial cable (for termination of the monitor feeder cable, as detailed in Section D.10.2). Suitable tool types are Radiall R282-223 or R282-240 (for Radiall connectors); Amphenol TWIN-HEX tool, handle 227-944 and die set 227-1221-57 (for Amphenol connectors); ERMA 29010 (for both connector types).
D.2.4 Test Equipment Test equipment required for installation is specified in Section E.1 of Appendix E.
D.3 EQUIPMENT EARTHING REFER Figure D-1, Figure D-2, Figure D-9 and Figure D-10
Very good ground connections between the rack and the installation ground are essential.
It is recommended that 2-metre long copper stakes be used, with a minimum of two stakes spaced about 1750 mm apart and connected together at their tops with 25 mm by 3 mm copper bar, or very heavy PVC-covered cable. Copper braid must not be used. If the ground contains a high percentage of non-conductive elements such as silica or calcium, longer stakes should be used.
A copper earthing bar at least 25 mm by 3 mm should be fitted in the duct beneath the rack(s). The copper bar should pass through the wall of the shelter and be bolted securely to the copper bar or cable joining the ground stakes.
Connection is made from the negative battery terminal at the rear right-hand side of the rack to the earthing bar by one or more lengths of heavy duty multi-strand earthing cable fitted with lugs at each end; refer to Figure D-1 and Figure D-2. These terminals are 7.94 mm (5/16 inch) diameter. The cable (or cables) used for this should have cross-sectional area of at least 20 square mm and the run should be as short as possible. This cable will pass through the right-hand (as viewed from the rear of the rack) cable entry hole in the base of the rack.
Ensure that good electrical connections are made where the bars join and where the rack earth cables are bolted to the bar; refer to Figure D-9 Figure D-10.
D-3
HA72500 APPENDIX D
D.4 UNPACKING AND INSPECTION OF RACK
D.4.1 Unpacking REFER Appendix B
The wired DME rack and plug-in modules are packed separately, and must be re-assembled on site.
Carefully unpack the rack, modules, power supply and cables, and check for any damage that may have occurred during transit. Check that all items of equipment are present; refer to Appendix B for a list of major equipment items.
D.4.2 Checks after Unpacking a. Replace any screws or fasteners that are found lying loose inside the rack as
a result of vibration in transit.
b. Check that no module guide rails have come loose during transit.
c. Check that the following subassemblies are mounted in the rack:
1. RF Panel 1A72545 (or 2A72545 if a dual DME).
2. External I/O PWB Assembly 1A72557.
3. Transponder and CTU subracks.
d. The racks should now be secured to the plinth before further assembly.
D.5 EMPLACEMENT OF DME RACK(S) REFER Figure D-8
The equipment room/shelter should be provided with in-floor ducts for the earth bus, DC input power cables from the battery room, and AC mains power cables. If required, remote control cables can also be ducted; recommended duct size is 150 mm by 100 mm.
The rack(s) should be mounted on a wooden plinth to enable a 60 mm floor clearance; leave at least 800 mm clearance from the wall behind the rack for access. The wooden plinth(s) should be firmly attached to the floor using masonry anchors to suit the thickness of the plinth, and the rack(s) attached to them using 10 mm by 120 mm hexagon head coach screws; the mounting centres and general detail can be seen in Figure D-8.
NOTE In a dual system the AC power supplies are mounted separately and the two racks may be spaced apart. The DC power cables from the AC supplies to the main racks are best located in the underfloor duct.
D-4
HA72500 APPENDIX D
D.6 AC AND DC POWER CONNECTIONS
D.6.1 AC Connections For a single DME beacon installation, the AC mains supply cable is fed into the main rack through an elongated hole, in the base of the rack to the left of the rear door (as viewed from the rear), adjacent to the AC power supply unit. The cable connects to the 6-way mains terminal block; line colours are:
• ACTIVE - BROWN;
• NEUTRAL - BLUE;
• EARTH - GREEN/YELLOW.
In a dual system installation, two separate mains cables are required, one for each power supply. Connections are made to the 6-way mains terminal block in the power supply rack for AC power supplies Nos 1 and 2.
D.6.2 DC Connections REFER Figure D-1, Figure D-2, Figure D-9 and Figure D-10
The batteries are not normally supplied, and the final arrangement of the battery bank will depend on the type of batteries to be used.
It is recommended that the installation includes a delay fuse (32 amperes HRC, for example) in series with the batteries to prevent catastrophic short circuit conditions in the event of wiring damage; the DME equipment itself is protected by surge-proof circuit breakers.
Wiring from the battery bank to the rack should be kept as short as possible, using the recommended cable type (see Section D.2.2). It is important to keep the cable run as short as possible; the recommended cable type is rated at six times the maximum equipment operating current of 9 amperes, but even so would introduce a 0.5 volts drop over a 12-metre run.
The battery connecting cable and terminating lugs must be supplied by the user. The terminal lugs for connection to the main rack should be ring types; the terminals to which they connect at the rack end are 7.94 mm (5/16 inch) diameter.
The cable entry to the equipment rack is via the elongated hole in the base to the right-hand side of the rear door. The cable is terminated at the heavy-duty terminals marked BATTERY on the mounting bracket at the back of the main rack.
In a dual system, the DC outputs from the AC power supplies are connected to the red and black BATTERY terminals on the mounting bracket using the cable assembly supplied in the installation kit; the DC power cables will have to be cut to length and terminated with the ring lugs supplied.
See Figure D-1 and Figure D-2 for connection details.
NOTE In a single DME installation, all cables entering the rack via the access holes in the base must be routed to leave adequate clearance for the AC power supply unit, which in this type of installation is mounted in the main rack. Cables should be secured to convenient points within the rack, using cable ties.
No power should be connected to the rack until after installation is complete and beacon is ready for testing.
D-5
HA72500 APPENDIX D
Figure D-1 DC Power Connections, Single DME
Figure D-2 DC Power Connections, Dual DME
D-6
HA72500 APPENDIX D
D.7 RACK ASSEMBLY REFER Figure D-11
Assemble the air vent on top of the equipment racks as shown in Figure D-11. All mounting hardware necessary to do this is packed with the mesh sides and unit top cover.
D.7.1 Module Assembly REFER Figure D-12 and Figure D-13
Unpack each module and inspect it to check that no damage has occurred, particularly to the 96-way and RF connectors at the rear.
CAUTION Connectors are not keyed, and it is possible to plug a module into the wrong position.
Insert each module into its assigned position in the rack, as shown in Figure D-12. The module name is also printed above the 96-way connector on the subrack motherboard. This is visible from the front of the rack when the modules are removed.
NOTE In a dual system, install the modules in Transponder 1 or Transponder 2 subracks according to the serial numbers listed in the factory Test Report which accompanies the equipment.
Slide each module into the assigned position, checking that it moves freely on the guides and that it can be pushed fully home. Secure the front panel module locking screws.
D.7.2 1kW Power Amplifier Assembly REFER Figure D-3, Figure D-12 and Figure D-13
The 1kW Power Amplifier (type 1A72535) module is fitted as follows:
• Unpack the amplifier unit and remove the cover. The cover is held in place with temporary screws for shipment. Check that no damage has occurred in transit.
• Lift the amplifier into position at the rear of the rack, and rest it on the support brackets. The location of the amplifiers is shown in Figure D-12, for a single DME and in Figure D-13, for a dual DME. Ensure that the type N coaxial connectors are to the top.
• Secure the amplifier in the rack with the four M6 screws and flat washers, as shown in Figure D-3.
• Connect the DC power and signal connectors, XN1 and XN2, on the amplifier heatsink, as shown in Figure D-3.
• Connect the coaxial cables to the RF Input and RF Output connectors on the heatsink, as shown in Figure D-3. Ensure that these connectors are firmly tightened by hand.
• Fit the cover over the amplifier unit, securing it with four M6 screws and washers. Tighten the screws fully to ensure that the RF gasket is properly compressed.
D-7
HA72500 APPENDIX D
Figure D-3 1kW RF Power Amplifier Connections
WARNING Ensure that the cover of the 1kW RF power amplifier is correctly refitted as operating the amplifier without it may cause harmful levels of RF radiation.
D.7.3 1kW PA Power Supply Assembly The 1kW PA Power Supply (type 1A72540), comprising the Control and Status Board (type 1A72541) and DC Converter (type 1A72542), is packed separately as a complete assembly. To fit the 1kW PA Power Supply, proceed as follows:
• Unpack the Power Supply assembly and inspect it for damage.
NOTE Be very careful when resting this assembly on a flat surface to avoid damage to the components projecting from the edge of the Control and Status Board.
• Release the screws securing the 1kW PA Power Supply hinged panel and lower it to the open position.
• Place the 1kW PA Power Supply on the open panel as shown in Figure D-4, being careful to align the projecting components (on the Control and Status Board) with the apertures in the panel.
• Secure the assembly to the panel with the screws provided.
D-8
HA72500 APPENDIX D
• Connect the wires and cables from the rack wiring harness as follows:
a. 25-way D connector to XN1 on the Control and Status Board.
b. Red lead (labelled “to 1kW PA PS-1") to XB1:1.
c. Orange and black leads (labelled "to XB1 1A72540") to XB1:5 and XB1:6 respectively.
d. Black lead (labelled "to XP2 1A72542") to post XP2 on the DC Converter.
These connections are shown in Figure D-4.
• Close and fasten the hinged panel.
Figure D-4 1kW PA Power Supply Connections
D-9
HA72500 APPENDIX D
D.8 WIRING CONNECTIONS
D.8.1 External Interface All external signal connections to the DME rack are made to the External I/O PWB Assembly 1A72557, which is mounted on the upper left-hand side of the DME rack as viewed from the rear. This includes AC power supply status signals, beacon remote control, and beacon status signals.
D.8.2 Wiring for Power Supply Signals REFER Figure D-14
The AC power supply provides status signals via the multi-way plug on the Power Supply to XN2 on the External I/O Board.
In a single DME, this cable (Cable Assembly 72558-2-55) is already fitted to the rack.
For a dual DME, the signal cable (Cable Assembly 69758-3-26) must be connected from the two 16-way terminal blocks in the rack housing the power supply units, to XN2 on the external I/O board in the DME rack. (in the case of a dual DME using a single AC power supply, there will be only one 16-way terminal block in the power supply rack.) The signal cable supplied has the 9-way D connector already fitted. Make the connections shown in Figure D-14 for the interwiring between the AC power supply and the DME.
D.8.3 Wiring for Remote Control and Status Signalling REFER Figure D-20
For remote control and status monitoring of the DME, connections are made to terminal blocks XB2 - XB10 on the External I/O PWB at the rear of the rack.
The following remote control inputs are available:
• OFF/RESET
• DME NO 1 ON
• DME NO 2 ON
The following remote status indications are available:
• NORMAL
• TRANSFER
• SHUTDOWN
• NO 1 ON
• NO 2 ON (Dual only)
• PRIMARY FAULT
• SECONDARY FAULT
• BATTERY CHARGER 1 NORMAL
• BATTERY CHARGER 2 NORMAL (Dual only)
• MAINS OK
• LOCAL CONTROL
• MONITOR ALARM INHIBITED
D-10
HA72500 APPENDIX D
In addition, the recovered 1350 Hz ident tone is available for connection to an external 600 ohms balanced line.
The connections to the terminal block for remote control and status signalling are shown in Figure D-20, and the electrical requirements of the interface are given in Appendix C.2.
To connect the remote control and status signal cable proceed as follows:
1. Feed the appropriate multicore cables through the left side (viewed from the rear) elongated hole in the base of the rack.
2. Run the cables up the side of the rack to the External I/O Board, fastening the cables to the rack frame using cable ties. Keep these cables away from the DME rack wiring to prevent coupling of voltage surges should a lightning strike occur on the remote lines.
3. Connect the cables to the relevant terminal block contacts on the External I/O Board. The layout and connection for this board are shown in Figure D-20. In this figure, the left column of function designations is associated with the left half of the terminal block. For example, the DME NORMAL function is connected to terminal block XB9, terminals 2, 4 and 6 with the normally open relay contact on 2, the common contact on 4 and the normally closed contact on 6.
4. For remote signalling of the mains power status, make the connection to the MAINS OK terminals (XB5:1, 3 and 5) and not AC PWR NORM. The MAINS OK terminals are directly connected to the mains relay in the AC power supply.
5. The remote control inputs (to XB10) require a switched positive voltage of at least 12 volts to activate the function. If this voltage is not available from the external signalling system, +24 volts DC may be obtained from terminal block XB1: 5 and 6. To use this voltage, make a connection to the common contact of the relays in the external signalling unit, then connect the switched voltage to the '+' terminal of each remote input on XB10. Connect the “-“ terminal of each remote input to ground, on XB11: 5 and 6, to complete the circuit.
NOTE The remote control inputs, and the remote signalling outputs, are not protected beyond the 100 V AC isolation specified in Appendix C.2. If these terminals are connected directly to external lines where there is a possibility of lightning induced surges, then external surge protection must be provided in order to protect the DME.
6. If the external remote signalling system requires either a switched positive voltage or a closure to ground to assert a signal, these may be obtained from the terminal blocks. A +24 volts DC voltage is available at XB1: 5 and 6 and ground is available at XB11: 5 and 6. If either of these is required, make a "daisy chain" connection to the common contact of each status signalling function used.
7. An additional signalling function, FUSE FAIL, is available from each AC power supply for external use if required. This is available at terminals 7 and 8 of the 16-way terminal block in the DME Power Supply rack. For this function, the connections must be made in the Power Supply rack.
D-11
HA72500 APPENDIX D
D.8.4 Wiring to Associated VHF Navaid REFER Figure D-20
If the DME is collocated with an associated VHF navaid, such as a Doppler VOR or ILS, connections must be made between the two navaids to ensure synchronised ident generation (as specified in the ICAO requirements). For this purpose, the LDB-102 DME provides for:
• ASSOCIATED IDENT IN (from the VHF Navaid)
• ASSOCIATED IDENT OUT (to the VHF Navaid)
The electrical requirements of the ident interface are specified in Appendix C, but it should be noted that:
a. The Associated Ident In requires a closure to ground to signal an ident “mark” (dot or dash).
b. The Associated Ident Out provides a floating closure for an ident “mark” which is polarity sensitive.
To connect the wiring for the associated VHF navaid, proceed as follows:
1. Feed the interconnecting cables through the left side (viewed from the rear) elongated hole in the base of the rack.
2. Run the cables up the side of the rack to the External I/O Board, fastening the cables to the rack frame using cable ties.
3. Connect the wires to the relevant terminal block contacts on the External I/O Board, the layout and connections of which are shown in Figure D-20. Connect the “ident out" wiring to XB1:1 and 2, observing the polarity indications. Connect the "ident in" to XB1:4.
4. If the external ident source switches between ground and a positive voltage, then remove the link on pins XN10 of the CTU Processor Board.
If the external ident source simply provides a switched closure to ground, then the XN10 link must be left in place in order to provide a voltage pull-up.
D-12
HA72500 APPENDIX D
D.9 ANTENNA INSTALLATION
D.9.1 General The Chu antenna type CA3167, supplied fully assembled, has an overall length of 2.7 metres (106.3 inches) and a mass of 45 kg (99.2 pounds); it mounts on a 114.4 mm (4.5 inches) diameter steel pipe which is supplied and erected by the user. The overall length includes the obstruction lights, which are normally not supplied; these lights should be fitted before mounting the antenna.
Alternatively, an Interscan DME/N antenna type 230-7340, may be supplied. It is also fully assembled, and mountable on a 114.4 mm (4.5 inches) diameter steel pipe which is supplied and erected by the user. The overall length includes the obstruction lights, which are normally not supplied; these lights should be fitted before mounting the antenna according to the instructions given in the DME/N Antenna Handbook.
Another antenna supplied with the LDB-102 is the dB Systems type dBS 5100A. It is supplied fully assembled and, with its base adaptor fitted, mounts on a steel pipe of diameter 100 to 105mm, which must be supplied and erected by the user. The mounting pipe is smaller than that used with the two earlier antennas. The dBS antenna is approximately 2.7 metres long, including the base adaptor and optional obstruction light. Details for installing this antenna are given in the dBS Antenna Technical Handbook, supplied with the antenna.
D.9.2 Pipe Mounting Installation REFER Figure D-16, Figure D-17 and Figure D-18
The height of the antenna installation must be such that it is above any local obstruction (such as DVOR antennas, if collocated) or equipment buildings. Choose an appropriate pipe length, to give adequate antenna height, and ensure rigid mounting of the pipe base. An entry hole for the antenna cables is recommended as shown in Figure D-17 and Figure D-18.
If the pipe is fastened to the side of a building and projects more than 1 metre above the point of fixing, then guying or strutting must be provided to prevent wind gust resonance.
If a free-standing mast is to be used, ensure it is sufficiently rigid to prevent deflection or vibration of the antenna under the maximum wind speeds expected at the site.
The pipe mount for the antenna should be pre-assembled on to the pipe as shown in Figure D-16 or Figure D-18 (as applicable, depending on the type supplied) before the pipe is erected, and the antenna mounted onto the pipe after erection; if this cannot be done then, the antenna could be fitted to the mast before erection and carefully lifted with the mast. The installation procedure adopted will depend on individual site limitations.
The recommended routing of the antenna cables is to support them overhead between the mast and the shelter roof overhang. This method is preferable when low-loss 'Heliax' type cable is used, to reduce length and to minimise cable handling and bending; see Figure D-17 and Figure D-18.
It is also recommended that the antenna cables be routed inside the antenna pipe to the antenna connectors, as shown in Figure D-17 and Figure D-18. This gives the cables protection from the weather. If this cannot be done, then the cables may be routed on the outside of the pipe or mast, provided they are securely fastened at regular intervals.
D-13
HA72500 APPENDIX D
D.9.3 Antenna Assembly and Connections
D.9.3.1 Chu Antenna REFER Figure D-17
If the antenna is lifted on to the pre-erected mast and pipe adapter, special care must be taken to protect the exposed connectors on the base. Particularly, take care not to damage the gasket.
Remove the cover plate on the adapter to gain access to the antenna connectors.
D.9.3.2 Interscan Antenna REFER Figure D-18
The mast requires a mounting adapter to be fitted to it, onto which the antenna base casting is then bolted. Full instructions for installing this antenna are given in the Interscan DME/N Antenna Handbook.
The lighting rod cable passes out from the antenna body through the baseplate. It is best connected to earth via the antenna mast. Accordingly, cut the cable to the length required and terminate with an appropriate lug to connect to one of the 10 mm diameter bolts that mount the antenna base to the mast adapter; see Figure D-18.
D.9.3.3 Cables Route the antenna cables through the mounting pipe (or on the outside of the mast, as suitable) and connect them to the antenna, observing the connector designations on the antenna base. For further details on connecting and terminating the cables, refer to Section D.10.
If the cable drop distance exceeds 3 metres, a cable strain bracket must be fitted.
External cables must be secured to the pipe mast at 1-metre intervals, and then supported back to the shelter by the nominated method.
D.9.3.4 dB Systems Antenna This antenna requires a base adaptor to secure it to the mounting pipe. Full instructions for mounting the antenna are given in the dBS Antenna Technical Handbook.
The mounting arrangement and cabling is the same as that shown in Figure D-18, except that there is no antenna continuity monitor cable, and no separate lightning conductor cable. The lightning conduction path is through the body of the antenna, to the base adaptor and to the mounting pipe. It is the responsibility of the user to ensure that the mounting pipe is properly earthed to provide a low impedance path for lightning strike currents. Ensure that the bolts securing the antenna to its base adaptor, and the bolts clamping the base adaptor to the mounting pipe, are all properly tightened to give a good electrical connection.
The antenna cables comprise the RF Input cable, one or two monitor cables (single or dual DME), and the obstruction light power cable. Route these cables through the mounting pipe and connect them to the appropriate connector on the base of the antenna, as shown in Figure D-21, and as described in the following sections of this handbook. Detailed wiring connections for the obstruction light are given in the dBS Antenna Technical Handbook. For estimating the ERP Monitor signal level in section D.10.3, use a value of 25dB for the nominal coupling of the monitor ports in the dBS antenna.
D-14
HA72500 APPENDIX D
There is no antenna continuity monitor in this antenna, so this particular function in the DME Monitor must be inhibited to prevent an erroneous fault indication. A special plug is provided for this purpose. It is called a “DME Antenna DC Monitor Substitute” (part no. 72560-4-07), and is supplied in the DME Antenna Cable Set. Fit this plug to connector XN2, on the RF Panel Board Assembly, at the top rear of the DME cabinet (refer Figure D-15).
D-15
HA72500 APPENDIX D
D.10 ANTENNA CABLES There are a number of cables which must be connected between the DME rack and the DME antenna. These are:
• Antenna Feed Cable
• ERP Monitor Cable (quantity 2 used in Dual DME)
• DC Continuity Monitor Cable (Interscan antenna only)
• Obstruction Light Cable (for optional obstruction lights)
The first three of these cables, complete with their associated connectors, are supplied in the Antenna Cable Set, type 1A72560 (single) or 2A72560 (dual).
The obstruction light cable must be supplied by the user.
Each of the cables supplied has a connector fitted at one end only, the second being fitted on-site after the cable is cut to suit the distance between the equipment rack and the antenna.
D.10.1 Antenna Feeder Cables REFER Figure D-5 and Figure D-15.
The low-loss antenna feed cable (supplied) should be cut to the minimum practicable length for the installation, to allow maximum radiated power.
The cable is already terminated with a connector at one end. This end should be connected to the antenna when the cable is installed. The other connector, supplied with the cable but not terminated, must be attached to the rack end following EXACTLY the instructions given in Figure D-5.
When the antenna is installed and the cable routed, the rack end of the cable is fed through the grommet in the top cover of the rack.
NOTE It will be necessary to remove this grommet whilst feeding the large connector through. Slip it over the cable end, and replace it in the hole.
Attach the coaxial right-angled adapter (supplied in the Antenna Cable Set) to the ANTENNA output on the back of the RF panel and connect to it the feed cable, as shown in Figure D-15.
D-16
HA72500 APPENDIX D
Figure D-5 RF Feeder Connector Termination (Sheet 1 of 2)
INSTALLATION INSTRUCTIONS
TYPES L44F L44J, L44M, L44N, L44NT, L44P, L44R, L44T, L44U, L44W, L44EN and L44EW CONNECTORS
FOR LDF4-50 HELIAX COAXIAL CABLE
TOOLS AND MATERIALS REQUIRED FOR ASSEMBLY File, flat Hacksaw, fine-toothed blade Knife Wire brush, small Scale, 6 in. (150 mm)
Gauge, 1/16 in., (provided) Soft solder Soldering gun Rosin flux Damp cloth
Garnet cloth Solvent, comothene, vythene, or other non-flammable cleaning fluid Wrenches: (2) 13/16 in.
READ INSTRUCTIONS THOROUGHLY BEFORE ASSEMBLY STEP 1. Prepare cable. End of cable must be straight for at least 10 in. (254 mm). Remove jacket to approximate dimension shown. Use knife. Deburr sharp end of cut outer conductor.
STEP 2. Make second jacketing cut. Scribe line on ridge of exposed corrugated outer conductor. Line must be at least 13/32 in. (10 mm) from end of cable. Remove jacket to dimension shown using straight edged piece of heavy paper wrapped around cable to guide cut.
STEP 3. Install gasket. Clean outer conductor with GASKET solvent. Add thin O-ring gasket to second fully exposed corrugation groove from jacket. Apply thin coating of silicone grease to outer surface of gasket and gasket lead chamfer in clamping nut using finger tip.
STEP 4. Add clamping nut and cut cable. Push clamping nut on cable. Use twisting motion to assure spring contacts snap into groove. Refer to cutaway view in Step 6. Grip clamping nut with one hand and align edge with scribed line, then carefully cut outer conductor and foam dielectric material flush with end of clamping nut exposing inner conductor. Make shallow cut; do not damage inner conductor. Use hacksaw with fine-toothed blade or model maker's saw.
D-17
HA72500 APPENDIX D
Figure D-5 RF Feeder Connector Termination (Sheet 2 of 2)
L44EN, L44EW, L44J, L44NT, L44T, L44W = 7/32” (5mm) L44P, L44U = 5/16” (8mm)
L44R = 3/8” (10mm) L44F = 7/16” (11mm)
STEP 5. Trim inner conductor. Cut inner conductor to length shown. Use file to deburr cut end of inner conductor.
STEP 6. Detach foam dielectric. Separate ail foam dielectric completely from edge of outer conductor to assure good electrical contact with outer body. Refer to enlarged cutaway view in Step 7 which illustrates positive grip of outer conductor between clamping nut and outer body. Use tip of knife and work around entire circumference. Remove burrs from inside edge of outer conductor with knife. Use wire brush to remove copper particles from foam.
STEP 7. Inspect contact surface. Thread outer body to clamping nut and tighten with wrenches. Turn outer body only; do not turn clamping nut. Disassemble connection to inspect for good metal-to-metal contact. Cut foam dielectric flush with edge of flared outer conductor.
STEP 8. Add inner connector and outer body. Clean inner conductor. For all connectors except L44F, slip inner connector onto ' inner conductor. Use gauge as indicated. Solder connector to conductor while pressing connector against gauge. Cool with damp cloth then clean with garnet cloth. Make certain connector is straight, i.e., square to flared outer conductor. Place thick O-ring gasket into groove in clamping nut. Add thin coating of silicone grease to outer surface of gasket. For all connectors, thread outer body onto clamping nut and tighten. For L44F, add inner connector and solder per above.
STEP 9. L44T assembly. Apply thin coating of silicone grease to both O-ring gaskets, and place one gasket onto extension insulator. Slip assembly into outer body. See that gasket is properly seated inside. Place other gasket into groove in stud head. Care fully screw stud head onto inner connector and tighten.
STEP 10. L44T assembly. Lock stud head in place with setscrew. Add connecting strap or wire connection, flat washer, shake proof lockwasher and cap nut as shown. Tighten cap nut. For protection against corrosive atmospheres, apply silicone grease over entire connection.
D-18
HA72500 APPENDIX D
D.10.2 ERP Monitor Cable REFER Figure D-6 and Figure D-15
The antenna includes provision for sampling the effective radiated power (ERP) of the transmitter signal. In a dual DME, two ERP monitors are used. The monitor cables(s), supplied with a coaxial connector fitted to one end, should be cut to the appropriate length and installed with the terminated end connected to the antenna. After the cable is installed, terminate the cut end with the type N connector supplied in the Antenna Cable Set. Termination details for the connectors are shown in Figure D-6. Be sure adequate slack is allowed to connect the cables to the ERP connectors, as shown in Figure D-15.
Feed the equipment end of the cable through one of the grommets in the top of the rack and connect it to the ERP MONITOR connector on the rear of the Transponder 1 subrack, via an attenuator if necessary; see Figure D-15. The other cable (in a dual system) goes to the ERP MONITOR connector on the rear of the Transponder 2 subrack.
In a 1kW DME beacon, it is usually necessary to install an attenuator in series with the monitor cable to avoid an excessive signal level to the DME monitor. The presence of the attenuator depends on the monitor cable length and the monitor signal coupling within the antenna. Details for determining the need for this attenuator are given in Section D.10.3. Coaxial Type-N, 10 dB attenuators are supplied in the Antenna Cable Set.
No attenuator is required with a low power beacon.
D-19
HA72500 APPENDIX D
Figure D-6 Monitor Feeder Connector Termination
AMPHENOL TYPE RADIALL TYPE
NOTE: Stripping dimensions vary, depending on the type of connector supplied.
1. Slide the ferrule over the cable.
2. Strip one end of the cable only, as above. Ensure that there are no nicks in the braid or the conductor.
3. Crimp the centre contact. Using the appropriate crimping tool
4. Slide the cable and contact into the body. Ensure that the milled back end of the connector is positioned between the dielectric and the braid.
5. Push the dielectric of the cable home into the body.
6. Crimp. Using the appropriate crimping tool
7. Fit over the ferrule, using heatshrink tubing 6 mm by 25 mm long.
D-20
HA72500 APPENDIX D
D.10.3 ERP Monitor Attenuator Some installations may need a different attenuation value to enable correct monitoring of the antenna radiated power. The monitor detector has a range of 10 dB, from +10 to +20 dBm, within which the normal input level must fall; however, the actual power arriving from the monitor antenna will depend on several factors - such as signal frequency, signal feeder loss, monitor feeder loss, monitor antenna coupling, and radiated power.
An example of how the required attenuation value can be calculated is as follows:
a. Signal frequency = 1200 MHz
b. Signal feeder length = 20 metres Signal feeder unit loss = 9.5 dB/100 metres at 1200 MHz (LDF4-50) Therefore signal feeder loss = 1.9 dB
c. Monitor feeder length = 20 metres Monitor feeder unit loss = 59.0 dB/100 metres at 1200 MHz (RG-223) Therefore monitor feeder loss =11.8dB
d. Monitor antenna coupling =21.0 dB at 1200 MHz
Output power =1200 watts = 60.8 dBm approx. Therefore Power at monitor input = 60.8 - 1.9 - 11.8 - 21.0 = 26.1 dBm
Monitor window is +10 to +20 dBm, with a nominal level of +15 dBm. Therefore Attenuation needed = 26.1 - 15 dBm = 9.1 dB say 10 dB
Because the monitor window is so wide, the situation for an installation will be that an attenuator is either not needed or, if needed, a 10 dB attenuator will be suitable. A 10 dB type N attenuator is supplied as part of the Antenna Cable Set.
D-21
HA72500 APPENDIX D
D.10.4 Antenna Integrity Signal Cable REFER Figure D-15
NOTE This cable assembly is required only if the Interscan DME antenna is used. It allows monitoring of the DC continuity of the antenna by means of the Antenna Integrity Monitor in the DME.
All parts required for the cable assembly are contained in the cable accessories kit supplied as part of the Antenna Cable Set (type 1A72560 for a single DME installation, type 2A72560 for a dual DME installation).
The 2-core flexible cable will need to be cut to the appropriate minimum practical length and terminated at both ends, as shown in Figure D-7 below.
Figure D-7 Antenna Integrity Signal Cable Connections
Feed the cable through the unused third grommetted hole in the rack top cover and connect it to connector XN2 on the RF Panel PWB, as shown in Figure D-15.
D.11 COMPLETION When all the work in the preceding sections has been completed, check the following items before proceeding with the beacon alignment:
1. All modules correctly inserted in rack.
2. 1kW Power Amplifier and associated power supply correctly wired.
3. DC power wiring and batteries correctly connected.
4. VHF navaid ident interface connected (if used).
5. Antenna feed cable and adaptor connected and connectors tightened.
6. Antenna ERP monitor cables connected and connectors tightened.
The Beacon is now ready for testing and alignment; the procedures for this are described in Section 3.2, On-site Performance Testing.
D-22
HA72500 APPENDIX D
Figure D-8 Rack Installation
D-23
HA72500 APPENDIX D
Figure D-9 Rack Power Cabling - Single 1kW DME Installation
D-24
HA72500 APPENDIX D
Figure D-10 Rack Power Cabling - Dual 1kW DME Installation
D-25
HA72500 APPENDIX D
Figure D-11 Air Vent Assembly
D-26
HA72500 APPENDIX D
Figure D-12 LDB-102 Single 1kW Rack Arrangement
D-27
HA72500 APPENDIX D
Figure D-13 LDB-102 Dual 1kW Rack Arrangement
D-28
HA72500 APPENDIX D
Figure D-14 AC Power Supply Monitor Connections
D-29
HA72500 APPENDIX D
Figure D-15 Antenna Feeder Connections - RF and Signal
D-30
HA72500 APPENDIX D
Figure D-16 Pipe Mount - Chu Antenna
D-31
HA72500 APPENDIX D
Figure D-17 Antenna Installation - Chu Antenna
D-32
HA72500 APPENDIX D
Figure D-18 Antenna Installation - Interscan Antenna
D-33
HA72500 APPENDIX D
Figure D-19 Interscan Antenna Baseplate
D-34
HA72500 APPENDIX D
Figure D-20 External I/O Board Layout
D-35
HA72500 APPENDIX D
Figure D-21 dB Systems Antenna Base Connections
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D-36
HA72500 APPENDIX E
APPENDIX E
TEST EQUIPMENT
E-i
HA72500 APPENDIX E
TABLE of CONTENTS
E. TEST EQUIPMENT ....................................................................................E-1 E.1 PERFORMANCE TESTING E-1 E.2 BEACON ALIGNMENT E-3 E.3 LRU TESTING E-5 E.4 INSTALLATION E-9
E-ii
HA72500 APPENDIX E
LIST of TABLES
Table E-1 Recommended Test Equipment for On-site Maintenance......................... E-1 Table E-2 Test Equipment for Beacon Alignment ...................................................... E-3 Table E-3 Recommended Test Equipment for LRU Testing...................................... E-5
E-iii
HA72500 APPENDIX E
E. TEST EQUIPMENT E.1 PERFORMANCE TESTING Table E-1 lists the basic equipment required to perform the performance testing of Section 3.2. If alignment or testing of the transmitter sections of the DME is required, the additional special items listed will also be required.
Table E-1 Recommended Test Equipment for On-site Maintenance
ITEM QTY CHARACTERISTICS SUITABLE TYPE/MODEL
Accessory kit 1 DME Test Accessory Kit
This comprises an extender frame for the transponder subrack, two extender cards for the CTU subrack, test cables and basic tools. One kit is supplied with each DME rack.
1A72561
Digital multimeter 1 Voltage range: Accuracy:
2 to 50 volts full scale 0.5%
Fluke 8010A
Oscilloscope 1 Vertical channels: Bandwidth: Sensitivity: Sweep: Probes:
2 At least 20 MHz 10 mV to 2 volts/division 20 nsecs to 50 msecs/div 10:1
Tektronix 2225
Current probe 1 Frequency range: Sensitivity: 10 Coupling:
120 Hz to 20 MHz mA/mV AC only
Tektronix P6021
Frequency counter
1 Frequency range: Frequency accuracy:Input sensitivity: Input impedance:
10 Hz to 120 MHz 5 ppm 50 mV >10 kilohms
Leader LDR-824
Detector, coaxial 1 Frequency: Sensitivity: Maximum input: Impedance: VSWR: Termination:
950 to 1250 MHz -10dBm +20 dBm 50 ohms < 1.2 to 4 GHz 4.7 kilohms
Hewlett Packard 8473, with termination
The detector plus termination must be calibrated for output voltage against signal input at a frequency of 1100 MHz, over a signal range of -10 to +20 dBm
E-1
HA72500 APPENDIX E
The following additional items are required for transmitter alignment/tests
Peak power meter
1 Frequency range: Input power: Input impedance: Level accuracy (at 1100 MHz, from 10 to 50 mW) Frequency response (from 950 to 1250 MHz):
950 to 1300 MHz 1 to 100 MW 50 ohms, VSWR <1.2 ±0.1 dB Less than ±0.05 dB
Hewlett Packard 8900D meter, with 84811A sensor
If the above accuracy requirements are tighter than the makers' specification, it is acceptable to have the instrument characterised for corrections to the meter readings.
Attenuator, power 1 Attenuation: Power rating: Impedance: Return loss: Frequency response (950 to 1250 MHz): Calibration accuracy:
30.0 ±0.5 dB 50 watts average (2kW pk) 50 ohms, N type (M-F) > 20 dB < +0.05 dB ±0.1 dB required
Weinschel 24-30-43
Attenuator, medium
1 Attenuation: Power rating: Impedance: Return loss: Frequency response (950 to 1250 MHz): Calibration accuracy:
20.0 +0.5 dB 1 watt average 50 ohms, N type (M-F) > 20 dB < ±0.05 dB ±0.1 dB required
Weinschel 50-20
E-2
HA72500 APPENDIX E
E.2 BEACON ALIGNMENT Table E-2 lists the items required to perform the beacon alignment of Section 3.3.
Table E-2 Test Equipment for Beacon Alignment
ITEM QTY CHARACTERISTICS SUITABLE TYPE/MODEL
Oscilloscope 1 Vertical channels: Bandwidth: Sensitivity: Sweep: Probes:
2 At least 20 MHz 10 mV to 2 volts/division 20 nsecs to 50 msecs/div 10:1
Tektronix 2225
Digital multimeter
1 Voltage range: Accuracy:
2 to 50 volts full scale 0.5%
Fluke 8010A
Peak power meter
1 Frequency range: Input power: Input impedance: Level accuracy: (at 1100 MHz, from 10 to 50 mW) Frequency response: (from 950 to 1250 MHz)
950 to 1300 MHz 1 to 100 mW 50 ohms, VSWR <1.2 ±0.1 dB Less than ±0.05 dB
Hewlett Packard 8900D meter, with 84811A sensor
If the above accuracy requirements are tighter than the makers' specification, it is acceptable to have the instrument characterised for corrections to the meter readings.
Power splitter (for dual beacon only)
1 Power rating: Insertion loss: Impedance: Return loss: (950- to 1250 MHz)
1 watt < 4 dB 50 ohms > 15 dB
Narda 4032C
Frequency counter
1 Frequency range: Frequency accuracy: Input sensitivity Input impedance:
10 Hz to 1300 MHz 5 ppm 0 dBm at 1300 MHz 50 ohms/> 10 kilohms
Advantest TR5823
Spectrum analyser
1 Frequency range: Frequency accuracy: Input power: Level accuracy: Level scale: Frequency response: (950 to 1250 MHz)
Up to 1300 MHz ±5 MHz -70 to +10 dBm ±1 dB Log, 2 dB and 10 dB/div < ±0.05 dB
Hewlett Packard 8590A
Attenuator, step
Frequency range: Attenuation accuracy: Impedance: Return loss: (950 to 1250 MHz)
950 to 1350 MHz +0.5, -0.2 dB 50 ohms > 20 dB
1 Attenuation range: > 100 dB, 10 dB steps Hewlett Packard 8496B
1 Attenuation range: > 10 dB, 1 dB steps Hewlett Packard 8494B
E-3
HA72500 APPENDIX E
ITEM QTY CHARACTERISTICS SUITABLE TYPE/MODEL
Attenuator, power
1 Attenuation: Power rating: Impedance: Return loss: Frequency response: (950 to 1250 MHz) Calibration accuracy:
30.0 ±0.5 dB 50 watts average (2kW pk) 50 ohms, N type (M-F) > 20 dB < ±0.05 dB ±0.1 dB required
Weinschel 24-30-43
Attenuator, medium
1 Attenuation: Power rating: Impedance: Return loss: Frequency response: (950 to 1250 MHz)
20.0 ±0.5 dB 1 watt average 50 ohms, N type (M-F) > 20 dB < ±0.05 dB
Weinschel 50-20
1 Connectors: SMA(F) - SMA(F) Suhner 31SMA50-01
Adaptor, coaxial
1 Connectors: N(F) - BNC(M) Suhner 33BNC-N50-1
1 Connectors: SMA(M) - SMA(F) right angle Suhner 53SMA-50-01
1 Connectors: SMA(F) -- N(M) Suhner 33N-SMA50-1
1 Connectors: N(F) - N(F) Suhner 31N50-02Test cable 1 RG-188A/U, 600 mm, with SMA(M) each end 1 RG-58A/U, 1 m, with SMA(M) - BNC(M) 3 RG-188A/U, 300 mm, with SMA(M) each end 1 RG-188A/U, 100 mm, with SMA(M) each end 1 RG-213, 600 mm, with N(M) each end 1 Sucoform 141 or UT-141A semirigid, 1.2 m, SMA(M) one
end and N(M) at the other end; loss 0.5 ±0.1 dB
Stopwatch 1 Antenna integrity monitor test fixture
1
E-4
HA72500 APPENDIX E
E.3 LRU TESTING Table E-3 lists the items of test equipment, cables and miscellaneous components required to perform the alignment and testing of line replaceable units (LRU) as specified in Section 3.4.
Table E-3 Recommended Test Equipment for LRU Testing
ITEM QTY CHARACTERISTICS SUITABLE TYPE/MODEL
Signal generator
2 Frequency range: Level range:
100 kHz to 1300 MHz -133 to +13 dBm
Supplied as part of Depot Test Facility
Pulse generator
1 Pulse period: Pulse width: Amplitude: Trigger:
50 nsecs to 10 secs 25 nsecs to 100 msecs 15 volts External and internal
Hewlett Packard 8011A
Digital multimeter
2 Voltage range: Accuracy: Current range: Accuracy: Resistance range: Accuracy:
2 to 50 volts full scale 0.5% 1 mA to 10 A 1% 10 ohms to 200 kilohms 0.7%
Fluke 8010A
Oscilloscope 1 Vertical channels: Bandwidth: Sensitivity: Sweep: Probes:
2 At least 20 MHz 10 mV to 2 volts/division 20 nsecs to 50 msecs/div 10:1
Tektronix 2225
Peak power meter
1 Frequency range: Input power: Input impedance: Level accuracy: (at 1100 MHz, from 10 to 50 mW) Frequency response: (from 950 to 1250 MHz)
950 to 1300 MHz 1 to 100 mW 50 ohms, VSWR <1.2 ±0.1 dB Less than ±0.05 dB
Hewlett Packard 8900D meter, with 84811A sensor
If the above accuracy requirements are tighter than the makers' specification, it is acceptable to have the instrument characterised for corrections to the meter readings.
RF millivolt meter
1 Frequency range: Input range: Input impedance:
950 to 1300 MHz 1 mV to 3 volts full scale 50 ohms or high
Boonton 92EA
Frequency counter
1 Frequency range: Frequency accuracy: Input sensitivity: Input impedance:
10 Hz to 1300 MHz 5 ppm 0 dBm at 1300 MHz 50 ohms/> 10 kilohms
Advantest TR5823
Spectrum analyser
1 Frequency range: Frequency accuracy: Input power: Level accuracy: Level scale: Frequency response: (950 to 1250 MHz)
Up to 1350 MHz ±5 MHz -70 to +10 dBm ±1 dB Log, 2 dB and 10 dB/div < ±0.05 dB
Hewlett Packard 8590A
E-5
HA72500 APPENDIX E
ITEM QTY CHARACTERISTICS SUITABLE TYPE/MODEL
Current probe, with passive termination, clip-on type, AC coupled
1 Bandwidth: Peak current: Sensitivity:
120 Hz to 20 MHz 15 amperes 2 mA/div or 10 mA/div
Tektronix P6021
Detector, coaxial
2 Frequency: Sensitivity: Maximum input: Impedance: VSWR: Termination:
950 to 1250 MHz -10 dBm +20 dBm 50 ohms < 1.2 to 4 GHz 4.7 kilohms
Hewlett Packard 8473, with termination
Directional coupler
1 Frequency range: Coupling: Directivity: VSWR:
950 to 1300 MHz 20 dB ±0.5 dB > 40 dB 1.15:1, 50 ohms
Hewlett Packard 776D
Attenuator, step
Frequency range: Attenuation accuracy: Impedance: Return loss: (950 to 1250 MHz)
DC to 1300 MHz +0.5, -0.2 dB 50 ohms > 20 dB
1 Attenuation range: > 110 dB, 10 dB steps Hewlett Packard 8496B
1 Attenuation range: > 11 dB, 1 dB steps Hewlett Packard 8494B
Attenuator, power
1 Attenuation: Power rating: Impedance: Return loss: Frequency response: (950 to 1250 MHz) Calibration accuracy:
30.0 ±0.5 dB 50 watts average (2kW pk)50 ohms, N type (M-F) > 20 dB < ±0.05 dB ±0.1 dB required
Weinschel 24-30-43
Attenuator, medium
Power rating: Impedance: Return loss: Frequency response: (950 to 1250 MHz)
1 watt average 50 ohms, N type (M-F) > 20 dB < ±0.05 dB
2 Attenuation: 20.0 ±0.5 dB Weinschel 50-20 2 Attenuation: 10.0 ±0.5 dB Weinschel 50-10 1 Attenuation: 6.0 ±0.2 dB Weinschel 50-6 1 Attenuation: 3.0 ±0.2 dB Weinschel 50-3 Attenuator, miniature
Power rating: Impedance: Return loss: Frequency response: (950 to 1250 MHz)
1 watt average (10 W peak) 50 ohms, SMA type (M-F) > 20 dB < ±0.05 dB
1 Attenuation: 30.0 ±0.5 dB Microlab AG-30F 2 Attenuation: 10.0 ±0.5 dB Microlab AG-10F 1 Attenuation: 6.0 ±0.5 dB Microlab AG-6F
E-6
HA72500 APPENDIX E
Termination, coaxial
Power rating: Impedance: VSWR:
1 watt, average 50 ohms < 1.05
9 Connector: SMA (M) Suhner 65SMA-50-0-1
1 Connector: SMA (F) Suhner 65SMA-50-0-31
1 Connector: N (M) Suhner 65N-50-0-1 1 Connector: SMA (M) Suhner
64SMA-50-0-1 Short circuit, coaxial
1 Connector: SMA (F) Suhner 63SMA-50-0-1
1 Connectors: SMA(F) - SMA(F) Suhner 31SMA-50-0-1
Adaptor, coaxial
1 Connectors: SMA(M) - N(M) Suhner 32N-SMA-50-0-1
1 Connectors: SMA(M) - N(F) Suhner 33SMA N-50-1
1 Connectors: SMA(F) - N(M) Suhner 33N-SMA-50-1
1 Connectors: N(M) - N(M) Suhner 32N-50-0-1 1 Connectors: N(F) - N(F) Suhner 31N-50-0-2 Torque wrench
1 For SMA connectors Suhner 74Z-0-0-21
Power supply 1 Output voltage: Output current: Ripple and noise:
15 volts DC, regulated 100 mA < 0.1 volts peak-to-peak
Double balanced mixer
2 Frequency: 50 to 60 MHz Mini Circuits ZFM-31-1
1 RG-213 cable, 100 mm, N(M) - N(M) Cables, coaxial 2 RG-213 cable. 800 mm, N(M) - N(M) 1 RG-188 cable, 100 mm, N(M) - SMA(M) 2 RG-188 cable, 200 mm, N(M) - SMA(M) 2 RG-188 cable, 800 mm, N(M) - SMA(M) 1 RG-188 cable, 800 mm, N(M) - SMA(F) 1 RG-188 cable, 100 mm, N(F) - SMA(M) 2 RG-58A/U cable, 1 metre, BNC(M) - BNC(M) 1 'Sucoform' 141 semiflexible cable, 1200 mm, N(M) -
SMA(M); loss = 0.5 ±0.1 dB
Connector, coaxial
1 SMA(F) panel receptacle Huber and Suhner 23-SMA-50-0-52/199
Connector 1 Plug, 4-pin Klippon 12593.69 Calibration link
1 'Sucoform' 141 semiflexible cable, 100 mm, SMA(F) - SMA(F)
Cable, power 1 Red and black, 2 metres, 35 amperes rating, PVC 195/0.25 mm: connector one end (supplied with rack)
Anderson No 1300
Detector test cable for power combiner
1 'Sucoform' 141 semiflexible cable, as detailed in Section 3.4.30
Test clip lead 1 300 ±20 mm long, with alligator clips both ends
E-7
HA72500 APPENDIX E
Alligator clips 2 Small, to be used for shorting test points together 10 6 ohms ±10%, 100 watts, wire wound, adjustable Resistors,
power 1 54 ohms ±2%, 35 watts, wire wound, fixed (2x27 ohms 20 watts in series)
1 100 ohms ±2%, 20 watts, wire wound, fixed 1 400 ohms ±2%, 5 watts, wire wound, fixed Resistors 1 62 ohms, ±1%, 400 mW, metal film 1 68 ohms, ±1%, 400 mW, metal film 1 75 ohms, ±1%, 400 mW, metal film 1 1.5 kilohms, ±1%, 400 mW, metal film 1 365 kilohms, ±1%, 400 mW, metal film Load resistors
1 Resistance range: Resolution: Current rating:
0.7 to 3.0 ohms 0.01 ohms 35 amperes
1 Resistance range: Resolution: Current rating:
8 to 20 ohms 0.25 ohms 5 amperes
1 Resistance range: Resolution: Current rating:
54 ohms 2% 35 watts
1 Resistance range: Resolution: Current rating:
100 ohms 2% 20 watts
1 Resistance range: Resolution: Current rating:
400 ohms 2% 5 watts
Antenna integrity monitor test fixture
1
The following items are supplied with each DME rack in Accessory Kit 1A72561 Extender cradle
1 Fits LDB-102 modules within rack 1A72562
Card extender
2 Eurocard extenders, dual 64-way VERO 09-0108E
Extender, AC Power supply
1 Fits AC Power Supply Control Card Ericsson ROF131391/1
E-8
HA72500 APPENDIX E
E.4 INSTALLATION The test equipment and accessories required for installation are identical with those required for performance testing, and are listed in Section E.1.
As well as normal hand tools appropriate to the installation of an electronic system such as the LDB-102 DME, the following special items are required.
ITEM QTY TYPE/PERFORMANCE
Wrenches 2 13/16 inch capacity Crimp tool for fitting connectors to RG-223 cable
1 Depends on type of connector supplied:
ERMA 29010 For either type of connector Radiall R282-223 or
R282-240 For Radiall connectors
Amphenol TWIN-HEX tool (handle 227-944 and die set 227-1221-57)
For Amphenol connectors
E-9
HA72500 APPENDIX A
A-i
APPENDIX A
OPERATING INSTRUCTIONS
HA72500 APPENDIX A
A-ii
TABLE of CONTENTS
A. OPERATING INSTRUCTIONS...................................................................A-1 A.1 OPERATING INSTRUCTIONS - SINGLE DME A-1
A.1.1 Introduction.................................................................................................. A-1 A.1.2 Application of Power.................................................................................... A-2 A.1.3 Local Operation ........................................................................................... A-3 A.1.4 Remote Operation ....................................................................................... A-4 A.1.5 Maintenance Operation ............................................................................... A-5 A.1.6 Recycle Operation ....................................................................................... A-5 A.1.7 Typical Test Results ....................................................................................A-6 A.1.8 Operating Notes ..........................................................................................A-7
A.2 OPERATING INSTRUCTIONS - DUAL DME A-8 A.2.1 Introduction.................................................................................................. A-8 A.2.2 Application of Power.................................................................................... A-9 A.2.3 Local Operation ......................................................................................... A-10 A.2.4 Remote Operation ..................................................................................... A-11 A.2.5 Maintenance Operation ............................................................................. A-12 A.2.6 Recycle Operation ..................................................................................... A-16 A.2.7 Operating Notes ........................................................................................ A-16 A.2.8 Typical Test Results ..................................................................................A-17
A.3 CTU FACILITIES AND OPERATING PROCEDURE A-18 A.3.1 CTU Front Panel Controls ......................................................................... A-18 A.3.2 CTU Front Panel Indicators ....................................................................... A-33
A.4 OPERATOR CONTROLS AND INDICATORS A-36 A.5 MODULE PRESET CONTROLS, SWITCHES, LINKS AND INDICATORS A-41
A.5.1 CTU Internal Controls................................................................................ A-41 A.5.2 CTU Internal Displays................................................................................ A-44 A.5.3 Transponder Internal Controls................................................................... A-49
A.6 DEPOT TEST FACILITY OPERATION A-57
HA72500 APPENDIX A
A-iii
LIST of FIGURES
Figure A-1 CTU Front Panel.................................................................................. A-19 Figure A-2 Menu Structure in Operational Modes................................................. A-24 Figure A-3 Menu Structure in Maintenance Mode................................................. A-25 Figure A-4 CTU Processor Board - Control and Indicator Locations .................... A-46 Figure A-5 CTU Front Panel Board - Control and Indicator Locations .................. A-47 Figure A-6 CTU RCMS Interface Board - Control and Indicator Locations ........... A-48
LIST of TABLES
Table A-1 Switch Setting Checklist - Single System.................................................. A-1 Table A-2 Switch Setting Checklist - Dual System..................................................... A-8 Table A-3 Transponder Front Panel Controls and Indicators................................... A-36 Table A-4 CTU Processor Board Option Switch Settings ........................................ A-42 Table A-5 CTU Processor Board Test Jumpers....................................................... A-43 Table A-6 Internal Controls : Monitor Module 1A72510 ........................................... A-49 Table A-7 Internal Controls : Test Interrogator 1A72514 ......................................... A-51 Table A-8 Internal Controls : Receiver Video 1A72520 ........................................... A-52 Table A-9 Internal Controls : Transponder Power Supply 1A72525 ........................ A-54 Table A-10 Internal Controls : Transmitter Driver 1A72530 ................................... A-55 Table A-11 Internal Controls: 1kW PA Power Supply 1A72540............................. A-56
HA72500 APPENDIX A
A-1
A. OPERATING INSTRUCTIONS A.1 OPERATING INSTRUCTIONS - SINGLE DME
A.1.1 Introduction The procedures in this section detail the steps required to place a DME beacon (single configuration) into operation. Each mode of operation is described separately and some guidance is given concerning action required when abnormal performance occurs.
For in-depth explanation of the various controls, indicators, and facilities, refer to the following sections:
• CTU Facilities and Operating Procedure: Section A.3;
• Operator Controls and Indicators: Section A.4;
• Module Preset Controls, Switches, Links and Indicators: Section A.5.
The checklist in Table A-1 gives the required switch settings of the front panel switches prior to placing the beacon into operation. These settings are independent of the final mode of operation of the beacon.
Table A-1 Switch Setting Checklist - Single System
MODULE/UNIT CONTROL/INDICATOR SETTING/INDICATIONAC Power Supply POWER OFF
1kW POWER AMP OFF Power Distribution Panel
CTU & TRANSPONDER OFF Monitor MONITOR OUTPUTS NORMAL Test Interrogator MONITOR AND INTERROGATOR DC
POWER NORMAL
Transponder Power Supply
TRANSPONDER DC POWER NORMAL
Transmitter Driver DRIVER DC POWER NORMAL Receiver Video IDENT NORMAL 1kW PA Power Supply AMPLIFIER DC POWER NORMAL
HA72500 APPENDIX A
A-2
A.1.2 Application of Power a. On the AC power supply, set the POWER switch to ON. Check that the front
panel voltmeter indicates a voltage of 27.0 ±0.5 volts.
b. On the power distribution panel, set both circuit breakers on. After a short delay (about 10 seconds), check that the following CTU front panel indicators are on:
AC PWR NORM BATT CH1 LOCAL (press LOCAL pushbutton if the indicator is
off) SELECT MAIN, OFF/RESET (press OFF/RESET pushbutton if the indicator
is off) Check that the following CTU front panel indicators are off:
TEST section: MODULES ANT RELAY POWER section: BATT CH2 BATT LOW DME CONTROL section: RECYCLE (press RECYCLE pushbutton if the indicator
is on) REMOTE (press LOCAL pushbutton if the indicator is
on) MAINTENANCE (press MAINTENANCE pushbutton if the
indicator is on) MONITOR ALARM (press MONITOR ALARM INHIBIT pushbutton
if the indicator is on) SELECT MAIN NO1 (press OFF/RESET pushbutton if the indicator
is on) SELECT MAIN NO2 STATUS section: NO1 ON NO2 ON NORMAL TRANSFER SHUTDOWN MAINTENANCE
If the indications are contrary to the above, refer to Section A.1.8 below.
HA72500 APPENDIX A
A-3
A.1.3 Local Operation
A.1.3.1 Switch-on Procedure a. Set the front panel controls initially as in Section A.1.1.
b. Apply power to the beacon as in Section A.1.2.
c. On the CTU, press the LOCAL control source pushbutton. This selects normal operation in the 'local' mode and the LOCAL indicator should be on.
d. On the CTU, press the SELECT MAIN, NO1 pushbutton. This activates the rack in its normal operating mode. The following indications should result:
1. SELECT MAIN, NO1 indicator on.
2. NO1 ON status indicator on (this is an internal CTU preset control, adjustable from 2 to 20 seconds for a cold standby and fixed at 2 seconds for a warm standby; see A.5.1.6 for details).
3. NORMAL status indicator on, after the selected POWER ON inhibit time. This indicates that the monitor is powered, and no faults are detected.
4. All the ALARM REGISTER indicators off immediately, and stay off unless a fault is present.
e. Check that no unit or module has a red indicator on. A red indicator on indicates that a test switch is not in the NORMAL position, or a fault is present.
NOTE A monitor module self test occurs every 15 seconds (±2 seconds), and will produce a momentary PRIMARY fault display on the monitor module. This is normal operation.
A.1.3.2 Switch-off Procedure On the CTU, press the SELECT MAIN, OFF/RESET pushbutton. The indicators in the STATUS section should go off, after a short delay. The OFF/RESET indicator should be on, and the SELECT MAIN, NO1 and NO2 indicators should be off.
A.1.3.3 Reset Procedure To reset the beacon following a shutdown, due to an alarm condition, press the SELECT MAIN, OFF pushbutton, and then press the SELECT MAIN, NO1 pushbutton. (Response should be the same as Section A.1.3.1d.)
HA72500 APPENDIX A
A-4
A.1.4 Remote Operation
A.1.4.1 At the DME Site a. Set the front panel switches initially as in Section A.1.1.
b. Apply power to the beacon as in Section A.1.2.
c. On the CTU press the SOURCE, REMOTE pushbutton. The SOURCE, LOCAL indicator should be off, and the SOURCE, REMOTE indicator should be on. This selects normal operation in the 'remote' mode.
A.1.4.2 At the Remote Site Check that the AC PWR NORM and BATT CHG remote indicators are on.
A.1.4.2.1 Switch-on Procedure At the remote control panel, select DME NO1 ON. Correct operation will be indicated by the DME NORMAL indicator and RACK ON indicator (if used) turning on. At the DME site, indications should be as in Section A.1.3.1d, except that REMOTE should be on.
A.1.4.2.2 Switch-off Procedure At the remote control panel, select DME OFF/RESET. The DME NORMAL indicator and the DME NO1 ON indicator (if used) should turn off.
A.1.4.2.3 Reset Procedure If a beacon shutdown occurs due to an alarm, the DME NORMAL indicator should turn off, and the SHUTDOWN indicator should turn on.
To reset the beacon, select DME OFF/RESET, and then select DME NO1 ON again.
HA72500 APPENDIX A
A-5
A.1.5 Maintenance Operation The 'maintenance' mode would normally be used during servicing or alignment of the DME rack. In a single beacon installation, the 'maintenance' mode is essentially the same as the 'normal' mode, except that more extensive tests are available from the CTU, and the high test interrogation rate switches are enabled.
A.1.5.1 Switch-on Procedure a. Set the front panel switches initially as in Section A.1.1.
b. Apply power to the beacon as in Section A.1.2.
c. On the CTU, press the MAINTENANCE pushbutton. This selects 'maintenance' operation in the ‘local ‘mode. The LOCAL and MAINTENANCE indicators should be on.
d. On the CTU, press the SELECT MAIN, NO1 pushbutton. This activates the rack in its maintenance operating mode. The following indications should result:
1. SELECT MAIN, NO1 indicator on.
2. NO1 ON status indicator on.
3. MAINTENANCE status indicator on.
4. All the ALARM REGISTER indicators off immediately, and stay off unless a fault is present.
A.1.5.2 Switch-off Procedure On the CTU, press the SELECT MAIN, OFF/RESET pushbutton. The indicators in the STATUS section should go off, after a short delay. The OFF/RESET indicator should be on, and the SELECT MAIN, NO1 and NO2 indicators should be off.
A.1.5.3 Reset Procedure To reset the beacon following a shutdown due to an alarm, press the SELECT MAIN, OFF/RESET pushbutton, and then press the SELECT MAIN, NO1 pushbutton.
A.1.6 Recycle Operation The recycling facility allows the beacon to automatically restart after a failure. Following a shutdown due to an alarm, the beacon should attempt three restarts. If normal operation ensues, then the beacon should remain on. If there are four shutdowns within a 5-minute period, then the beacon will remain off, until it is manually reset.
a. The RECYCLE facility is 'enabled' when the RECYCLE indicator is on. On the CTU, press the RECYCLE pushbutton to toggle between the 'enable' and 'disable' of this facility.
b. The number of restarts is recorded on the restart counter. The restart counter is displayed on the CTU's test display when the Misc softkey is pressed, from the top level of the operational mode menu.
HA72500 APPENDIX A
A-6
A.1.7 Typical Test Results The table below shows the normal readings which would be indicated on the Test Facility of the CTU, in an operating rack. For operation of the test facility of the CTU refer to Section A.3.1.2.
PARAMETER LOWER LIMIT UPPER LIMIT NOTES X 49.8 µs 50.2 µs
DELAY Y 55.8 µs 56.2 µs X 11.9 µS 12.1 µs
SPACING Y 29.9 µs 30.1 µs
POWER OUT 1.1 kW 1.3 kW EFFICIENCY 70% 100% Typical reply efficiency is 90% unless
interrogation rate is high. Decoded Pulse Rate 95 pps 2850 pps Varies with interrogation rate. Tx Pulse Rate 940 pps 2850 pps Varies with interrogation rate. Pulse Width 3.2 µs 3.8 µs Pulse Rise Time 1.9 µs 2.5 µs Pulse Fall Time 1.9 µs 2.5 µs RV Local Oscillator 1.0 volts 3.0 volts RV RF Drive 1.5 volts 4.5 volts TD Drive 1.5 volts 2.5 volts TD Modulation 1.5 volts 3.5 volts PA Modulation 1.0 volts 3.5 volts PA Drive 2.0 volts 4.8 volts PA Output 2.0 volts 4.8 volts TI Interrogation Level
2.7 volts 3.3 volts
Auxiliary 24 V 21 volts DC 28 volts DC Varies with battery voltage. Power Amplifier HT 49.5 volts DC 50.5 volts DC Transponder 15 V 14.6 volts DC 15.6 volts DC Transponder 18 V 17.2 volts DC 18.6 volts DC Driver HT 41.6 volts DC 42.4 volts DC
HA72500 APPENDIX A
A-7
A.1.8 Operating Notes For a full definition of the CTU controls and indicators, refer to Section A.3. The following notes are given to assist the operator when an abnormal indication occurs on the CTU:
a. If the AC PWR NORM or BATT CHG1 indicators are not on after the power distribution panel circuit breakers are closed, then the operation of the AC power supply should be checked for the presence of AC mains and correct DC output voltage.
b. If the BATT LOW indicator turns on after the power distribution panel circuit breakers are closed, then the rack DC supply is too low for proper operation, and the transponder will not switch on. The DC output from the AC power supply and the battery voltage should be checked.
c. If the CTU fault indicator in the ALARM REGISTER turns on after the power distribution panel circuit breakers are closed, then the controller circuits are not operating correctly. Reset the system by switching the CTU & TRANSPONDER circuit breaker to off and then on again. If the CTU fault indicator is still on, or flashing, then the CTU module should be replaced.
d. If any of the ALARM REGISTER, PRIMARY or SECONDARY indicators turn on following switch-on, then one of the transponder operating parameters is out of tolerance; if this parameter is a primary fault, the transponder should be shut down after the ALARM DELAY period. The indicators in the ALARM REGISTER can be used as a guide to locating the cause of the fault condition, after the transponder has shutdown. (See also Section 4.1.2 for LRU fault location).
HA72500 APPENDIX A
A-8
A.2 OPERATING INSTRUCTIONS - DUAL DME
A.2.1 Introduction The procedures in this section detail the steps required to place a DME beacon (dual configuration) into operation. Each mode of operation is described separately and some guidance is given concerning action required when abnormal performance occurs.
For in-depth explanation of the various controls, indicators, and facilities, refer to the following sections:
• CTU Facilities and Operating Procedures: Section A.3.
• Operator Controls and Indicators: Section A.4.
• Module Preset Controls, Switches, Links and Indicators: Section A.5.
The checklist in Table A-2 gives the required switch settings of the front panel switches prior to placing the beacon into operation. These settings are independent of the final mode of operation of the beacon.
Table A-2 Switch Setting Checklist - Dual System
MODULE/UNIT CONTROL/INDICATOR SETTING/INDICATION AC Power Supplies POWER OFF Power Distribution Panel All circuit breakers OFF RF Panel Antenna Relay Control Switch NORMAL Monitors MONITOR OUTPUTS NORMAL Test Interrogators MONITOR AND
INTERROGATOR DC POWER
NORMAL
Transponder Power Supplies TRANSPONDER DC POWER NORMAL Transmitter Drivers DRIVER DC POWER NORMAL Receiver Videos IDENT NORMAL 1kW PA Power Supplies AMPLIFIER DC POWER NORMAL
HA72500 APPENDIX A
A-9
A.2.2 Application of Power a. On both AC power supplies, set the POWER switch to ON. Check that the front
panel voltmeters indicate a voltage of 27.0 ±0.5 volts.
b. On the power distribution panel, set all circuit breakers to on. After a short delay (about 10 seconds), check that the following CTU front panel indicators are on:
AC PWR NORM BATT CHG1 BATT CHG2 LOCAL (press LOCAL pushbutton if the indicator is off) SELECT MAIN, OFF/RESET (press OFF/RESET pushbutton if the indicator is off)
Check that the following CTU front panel indicators are off:
TEST section:
MODULES ANT RELAY
POWER section:
BATT LOW
DME CONTROL section:
RECYCLE (press RECYCLE pushbutton if the RECYCLE indicator is on)
REMOTE (press LOCAL pushbutton if the REMOTE indicator is on)
MAINTENANCE (press MAINTENANCE pushbutton if the indicator is on)
MONITOR ALARM (press MONITOR ALARM INHIBIT pushbutton if the indicator is on)
SELECT MAIN NO1 (press OFF/RESET pushbutton if the indicator is on) SELECT MAIN NO2 (press OFF/RESET pushbutton if the indicator is on)
STATUS section:
NO1 ON NO2 ON NORMAL TRANSFER SHUTDOWN MAINTENANCE
If the indications are contrary to the above, refer to Section A.2.8 below.
HA72500 APPENDIX A
A-10
A.2.3 Local Operation
A.2.3.1 Switch-on Procedure a. Set the front panel controls initially as in A.2.1.
b. Apply power to the beacon as in A.2.2.
c. On the CTU, press the LOCAL control source pushbutton. This selects normal operation in the ‘local ‘mode and the LOCAL indicator should be on.
d. On the CTU, press the SELECT MAIN, NO1 or NO2 pushbutton. This activates the rack in its normal operating mode. The following indications should result:
1. SELECT MAIN, NO1 or NO2 indicator on.
2. NO1 ON or NO2 ON status indicator on (this is an internal CTU preset control, adjustable from 2 to 20 seconds for a cold standby and fixed at 2 seconds for a warm standby; see A.5.1.6 for details).
3. NORMAL status indicator on, after the selected POWER ON inhibit time. This indicates that the monitor is powered, and no faults are detected.
4. All the ALARM REGISTER indicators off immediately, and stay off unless a fault is present.
e. Check that no unit or module has a red indicator on. A red indicator on indicates that a test switch is not in the NORMAL position, or a fault is present.
NOTE A monitor module self test occurs every 15 seconds (±2 seconds), and will produce a momentary PRIMARY fault display on the monitor module. This is normal operation.
A.2.3.2 Switch-off Procedure On the CTU, press the SELECT MAIN, OFF/RESET pushbutton. The indicators in the STATUS section should go off, after a short delay. The OFF/RESET indicator should be on, and the SELECT MAIN, NO1 and NO2 indicators should both be off.
A.2.3.3 Transfer Indication If the main transponder has been switched off due to an alarm, the NORMAL and SHUTDOWN status indicators will be off, and if the standby transponder is currently operating, the TRANSFER indicator will be on. The faults that were present at the time of the transfer action are displayed on the ALARM REGISTER indicators.
A.2.3.4 Shutdown Indication If the main transponder and the standby transponder have both been switched off due to an alarm, the NORMAL and TRANSFER status indicators will be off and the SHUTDOWN indicator will be on. The faults that were present at the time of the shutdown action are displayed on the ALARM REGISTER indicators.
A.2.3.5 Reset Procedure To reset the beacon following a shutdown or transfer, due to an alarm condition, press the SELECT MAIN, OFF/RESET pushbutton, and then press the SELECT MAIN, NO1 or NO2 pushbutton (response should be the same as A.2.3.1d).
HA72500 APPENDIX A
A-11
A.2.4 Remote Operation
A.2.4.1 At the DME Site a. Set the front panel switches initially as in A.2.1.
b. Apply power to the beacon as in A.2.2.
c. On the CTU press the SOURCE, REMOTE pushbutton. The SOURCE, LOCAL indicator should be off, and the SOURCE, REMOTE indicator should be on. This selects normal operation in the ‘remote' mode.
A.2.4.2 At the Remote Site Check that the AC PWR NORM and BATT CHG NORM remote indicators are on.
A.2.4.2.1 Switch-on Procedure At the remote control panel, select DME NO1 ON or DME NO2 ON. Correct operation will be indicated by the DME NORMAL indicator and DME NO1 ON or DME NO2 ON indicator (if used) turning on. At the DME site, the indications should be the same as those in A.2.3.1d, except that the REMOTE indicator should be on.
A.2.4.2.2 Switch-off Procedure At the remote control panel, select DME OFF/RESET. The DME NORMAL indicator and the DME NO1 ON indicator (if used) should turn off.
A.2.4.2.3 Transfer Indication If the main transponder has switched off due to an alarm, the DME NORMAL and DME SHUTDOWN status indicators will be off, and if the standby transponder is currently operating, the DME TRANSFER indicator will be on.
A.2.4.2.4 Shutdown Indication If the main transponder and the standby transponder have switched off due to an alarm, the DME NORMAL and DME TRANSFER status indicators will be off, and the DME SHUTDOWN indicator will be on.
A.2.4.2.5 Reset Procedure To reset the beacon, select DME OFF/RESET, and then select DME NO1 ON or DME NO2 ON again.
HA72500 APPENDIX A
A-12
A.2.5 Maintenance Operation The 'maintenance' mode would normally be used during servicing or alignment of the DME rack. In a dud,] beacon installation, the 'maintenance' mode allows one of the transponders to be operated separately as a single transponder while the other transponder is used for maintenance tasks. Operating in this mode, if the MONITOR ALARM is selected to be NORMAL, only primary faults will be recognised, and shutdown is the only action that will be performed. More extensive tests are also available on the CTU, and the TI RATE 1 kHz and 10 kHz switches are enabled.
NOTE Only the monitor/test interrogator installed in the operating transponder will be used to monitor that transponder. In other words, only single monitoring is used in maintenance mode.
A.2.5.1 Switch-on Procedure
A.2.5.1.1 Switch-on Procedure 1 This procedure applies when Transponder 1 is to be connected to the antenna, and Transponder 2 is to be connected to the dummy load for maintenance or alignment.
a. Set the front panel controls initially as in A.2.1.
b. Perform the following RF wiring changes on the RF panel, noting the original wiring configuration:
1. Make sure a 10 dB attenuator is attached to connector FWD-A on upper Directional Coupler (1A69755).
2. Make sure a 50 ohms termination is attached to connector REV-A on the upper directional coupler.
3. Move the coaxial cable connected to FWD-B on the lower Directional Coupler (2A69755) to connect from the 10 dB attenuator on TI-2 REPLY DET to connector FWD-B on the upper directional coupler. A longer coaxial cable may be necessary.
4. Leave the coaxial cable connected from the 10 dB attenuator on TI-1 REPLY DET to connector FWD-D on the lower directional coupler.
5. Move the coaxial cable connected to FWD-C on the lower directional coupler, to connect from FWD-C on the upper directional coupler to TI-2 TEST INTRGS. A longer coaxial cable may be necessary.
6. Leave the coaxial cable from connector FWD-E on the lower directional coupler to TI-1 TEST INTRGS,
7. Connect a coaxial cable from connector ERP IN on the rear of the lower transponder subrack to the 10 dB attenuator on connector FWD-A on the upper directional coupler.
HA72500 APPENDIX A
A-13
c. The following table lists the settings of the front panel switches, of Transponder 2, prior to placing the beacon in maintenance operation. These settings are independent of the final mode of operation of the beacon.
UNIT SWITCH SETTING AC Power Supplies AC POWER OFF RF Panel Antenna Relay Control
Switch NORMAL
Power Distribution Panel All circuit breakers OFF Test Interrogator Modules MONITOR AND
INTERROGATOR DC POWER
ON
Transponder Power Supplies
TRANSPONDER DC POWER
ON
Transmitter Driver Modules DRIVER DC POWER ON 1kW PA Power Supplies AMPLIFIER DC POWER ON
d. Apply power to the beacon as in A.2.2.
e. On the CTU, press the MAINTENANCE pushbutton. This selects 'maintenance' operation in the ‘local ‘mode. The LOCAL and MAINTENANCE indicators should be on.
f. On the CTU, press the SELECT MAIN, NO1 pushbutton. This activates the rack in its maintenance operating mode. The following indications should result:
1. SELECT MAIN, NO1 indicator on.
2. NO1 ON status indicator on.
3. MAINTENANCE status indicator on.
4. All the ALARM REGISTER indicators off immediately, and stay off unless a fault is present.
A.2.5.1.2 Switch-on Procedure 2 This procedure applies when Transponder 2 is to be connected to the antenna, and Transponder 1 is to be connected to the dummy load for maintenance or alignment.
a. Set the front panel controls initially as in A.2.1.
b. Perform the following RF wiring changes on the RF panel, noting the original wiring configuration:
1. Make sure a 10 dB attenuator is attached to connectors FWD-A on the upper Directional Coupler (1A69755).
2. Make sure a 50 ohms termination is attached to connector REV-A on the upper directional coupler.
3. Move the coaxial cable connected to FWD-D on the lower Directional Coupler (2A69755) to connect from 10 dB attenuator on TI-1 REPLY DET to connector FWD-B on the upper directional coupler.
4. Leave the coaxial cable connected from the 10 dB attenuator on TI-2 REPLY DET to connector FWD-B on the lower directional coupler.
HA72500 APPENDIX A
A-14
5. Move the coaxial cable connected to FWD-E on the lower directional coupler, to connect from FWD-C on the upper directional coupler to TI-1 TEST INTRGS.
6. Leave the coaxial cable from connector FWD-C on the lower directional coupler to TI-2 TEST INTRGS.
7. Connect a coaxial cable from connector ERP IN on the rear of the upper transponder subrack to the 10 dB attenuator on connector FWD-A on the upper directional coupler.
c. The following table lists the settings of the front panel switches, of Transponder 1, prior to placing the beacon in maintenance operation. These settings are independent of the final mode of operation of the beacon.
UNIT SWITCH SETTING AC Power Supplies AC POWER OFF RF Panel Antenna Relay Control Switch NORMAL Power Distribution Panel All circuit breakers OFF Test Interrogator Modules MONITOR AND
INTERROGATOR DC POWER ON
Transponder Power Supplies TRANSPONDER DC POWER ON Transmitter Driver Modules DRIVER DC POWER ON 1kW PA Power Supplies AMPLIFIER DC POWER ON
d. Apply power to the beacon as in A.2.2.
e. On the CTU, press the MAINTENANCE pushbutton. This selects 'maintenance' operation in the ‘local ‘mode. The LOCAL and MAINTENANCE indicators should be on.
f. On the CTU, press the SELECT MAIN, NO2 pushbutton. This activates the rack in its maintenance operating mode. The following indications should result:
1. SELECT MAIN, NO2 indicator on.
2. NO2 ON status indicator on.
3. MAINTENANCE status indicator on.
4. All the ALARM REGISTER indicators off immediately, and stay off unless a fault is present.
A.2.5.2 Switch-off Procedure On the CTU, press the SELECT MAIN, OFF/RESET pushbutton. The indicators in the STATUS section should go off, after a short delay. The OFF/RESET indicator should be on, and the SELECT MAIN, NO1 and NO2 indicators should both be off.
A.2.5.3 Reset Procedure To reset the beacon following a shutdown due to an alarm, press the SELECT MAIN, OFF/RESET pushbutton, and then press the SELECT MAIN, NO1 or NO2 pushbutton.
HA72500 APPENDIX A
A-15
A.2.5.4 Restore RF Wiring Procedure If steps A.2.5.1.1 or A.2.5.1.2 have been performed, the RF wiring needs to be restored for normal dual operation, by performing the following steps:
1. Make sure that 10 dB attenuators are attached to connectors TI-1 REPLY DET, TI-2 REPLY DET, on the RF panel, and FWD-A on both directional couplers.
2. Leave 50 ohms terminations on connectors REV-A on both directional couplers.
3. Remove any coaxial cable connected to FWD-B and FWD-C of the upper directional coupler.
4. Make sure that a coaxial cable is connected from FWD-D on the lower directional coupler to the 10 dB attenuator on TI-1 REPLY DET on the RF panel.
5. Make sure that a coaxial cable is connected from FWD-B on the lower directional coupler to the 10 dB attenuator on TI-2 REPLY DET on the RF panel.
6. Make sure that a coaxial cable is connected from FWD-E on the lower directional coupler to TI-1 TEST INTRGS on the RF panel.
7. Make sure that a coaxial cable is connected from FWD-C on the lower directional coupler to TI-2 TEST INTRGS, on the RF panel.
8. Re-install the original wiring associated with connectors ERP IN on the rear of the transponder subracks
HA72500 APPENDIX A
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A.2.6 Recycle Operation The recycling facility allows the beacon to automatically restart after a failure. Following a shutdown due to an alarm, the beacon should attempt three restarts. If normal operation ensues, then the beacon should remain on. If there are four shutdowns within a 5-minute period, then the beacon will remain off, until it is manually reset.
a. The RECYCLE facility is 'enabled' when the RECYCLE indicator is on. On the CTU, press the RECYCLE pushbutton to toggle between the 'enable' and 'disable' of this facility.
b. The number of restarts is recorded on the RESTART counter. The RESTART counter is displayed on the CTU test display when the Misc softkey is pressed, from the top level of the operational mode test menu.
A.2.7 Operating Notes For a full definition of the CTU controls and indicators, refer to Section A.3.
The following notes are given to assist the operator when an abnormal indication occurs on the CTU:
a. If the AC PWR NORM, BATT CHG1 or BATT CHG2 indicators are not on after the power distribution panel circuit breakers are closed, then the operation of the AC power supplies should be checked for the presence of AC mains and correct DC output voltage.
b. If the BATT LOW indicator turns on after the power distribution panel circuit breakers are closed, then the rack DC supply is too low for proper operation, and the transponder will not switch on. The DC output from the AC power supplies and the battery voltages should be checked.
c. If the CTU fault indicator, in the ALARM REGISTER, turns on after the power distribution panel circuit breakers are closed, then the controller circuits are not operating correctly. Reset the system by switching the CCTU & TRANSPONDER circuit breakers to off and then on again. If the CTU fault indicator is still on, or flashing, then the CTU module should be replaced.
d. If any of the ALARM REGISTER, PRIMARY or SECONDARY indicators turn on following switch-on, then one of the transponder operating parameters is out of tolerance; if this parameter is a primary fault, the transponder should shut down after the ALARM DELAY period. The indicators in the ALARM REGISTER can be used as a guide to locating the cause of the fault condition, after the transponder has shut down. (See also Section 4.1.2 for LRU fault location)
HA72500 APPENDIX A
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A.2.8 Typical Test Results The table below shows the normal readings which would be indicated on the Test Facility of the CTU, in an operating rack. For operation of the Test Facility of the CTU refer to Section A.3.1.2.
PARAMETER LOWER LIMIT UPPER LIMIT NOTES X 49.8 µs 50.2 µs
DELAY Y 55.8 µs 56.2 µs X 11.9 µS 12.1 µs
SPACING Y 29.9 µs 30.1 µs
POWER OUT 1.1 kW 1.3 kW EFFICIENCY 70% 100% Typical reply efficiency is 90%unless
interrogation rate is high. Decoded Pulse Rate 95 pps 2850 pps Varies with interrogation rate. Tx Pulse Rate 940 pps 2850 pps Varies with interrogation rate. Pulse Width 3.2 µs 3.8 µs Pulse Rise Time 1.9 µs 2.5 µs Pulse Fall Time 1.9 µs 2.5 µs RV Local Oscillator 1.0 volts 3.0 volts RV RF Drive 1.5 volts 4.5 volts TD Drive 1.5 volts 2.5 volts TD Modulation 1.5 volts 3.5 volts PA Modulation 1.0 volts 3.5 volts PA Drive 2.0 volts 4.8 volts PA Output 2.0 volts 4.8 volts TI Interrogation Level
2.7 volts 3.3 volts
Auxiliary 24 V 21 volts DC 28 volts DC Varies with battery voltage. Power Amplifier HT 49.5 volts DC 50.5 volts DC Transponder 15 V 14.6 volts DC 15.6 volts DC Transponder 18 V 17.2 volts DC 18.6 volts DC Driver HT 41.6 volts DC 42.4 volts DC
HA72500 APPENDIX A
A-18
A.3 CTU FACILITIES AND OPERATING PROCEDURE The major human interface to the DME LDB-102 is provided by the Control and Test Unit (CTU). Although the implementation of some commands input via the CTU is installation-specific (that is, depending on the facilities and configuration of the particular installation) all the facilities provided by the CTU are explained here in order to give a detailed overview of the operational control facilities available.
This procedure assumes that each individual module of the DME has been correctly configured and setup in accordance with the alignment and adjustment procedures described in Section 3 of this handbook.
A.3.1 CTU Front Panel Controls REFER Figure A-1.
The controls on the CTU front panel can be divided into two groups; control switches and test switches.
CONTROL SWITCHES TEST SWITCHES ALARM DELAY Five multifunction test switches, beneath
display, software programmable RECYCLE TIRATE 1 kHz
LOCAL 10 kHz SOURCE
REMOTE ESCape
MAINTENANCE MONITOR ALARM
OFF/RESET NO 1 SELECT MAIN NO 2
HA72500 APPENDIX A
A-19
Figure A-1 CTU Front Panel
HA72500 APPENDIX A
A-20
A.3.1.1 CTU Front Panel Control Switches - Description of Operation Each CTU front panel control switch has an indicator associated with it, indicating the current setting of that particular switch. These do not indicate the current state of the DME. This can be determined using the status indicators described in Section A.3.2.1.
The most recent settings of these switches are stored in EEPROM. Therefore, when power is restored after any type of power interruption to the CTU the switch settings (and hence the state of the DME) will return to those which were in use immediately before the power interruption occurred.
A.3.1.1.1 ALARM DELAY Switch The ALARM DELAY switch is a recessed 10-position rotary switch with positions labelled 1 through 10. This switch selects the delay in seconds from the moment a fault is first detected by the CTU until action is taken. The fault must be present for the duration of this period in order for the CTU to take action following the expiry of the delay period.
The ALARM DELAY indicator will be lit if an alarm delay of less than 4 seconds is selected. This indicates that abbreviated postfault measurements will be performed if the RMM System option is installed.
The CTU will respond immediately to changes in the position of this switch.
A.3.1.1.2 RECYCLE Switch The RECYCLE switch is a pushbutton switch that toggles between two settings: ON and OFF. When recycle is selected, the CTU will attempt to restart the main transponder 30 seconds after a complete DME shutdown. If more than three restart attempts occur within a 5-minute period, the DME will be permanently shut down. When recycle is not selected, no restart will be attempted if the DME is shut down. When the DME is permanently shut down, it can only be restarted by firstly selecting OFF on the SELECT MAIN switches (either locally or remotely, depending upon the setting of the SOURCE switches).
The CTU will respond immediately to the operation of this switch.
A.3.1.1.3 SOURCE Switches The SOURCE switches are two pushbutton switches labelled LOCAL and REMOTE. These settings are mutually exclusive (either LOCAL is selected or REMOTE is selected - they can never be both on or both off).
When set to remote mode, the DME will accept commands only from a remote source (either an RCMS interface or an optional RMM system if installed - this is set during system configuration). In this mode, any attempts to change the SELECT MAIN, MAINTENANCE or MONITOR ALARM switches will result in a <<< Select LOCAL first >>> message on the lower line of the CTU front panel display. The current setting of the SELECT MAIN switches will remain unchanged when REMOTE is selected.
When set to local mode, the DME will allow the MAINTENANCE, MONITOR ALARM or SELECT MAIN switches to be used. Any commands received from the remote source will be ignored and, in the case of an RMM system, an error message will be returned to the remote system.
The CTU will respond immediately to the operation of these switches. Their current selection cannot be changed remotely.
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If the MAINTENANCE switch is ON, attempting to select REMOTE will result in a message << Turn MAINTENANCE off first >> being displayed. If the MONITOR ALARM switch is set to INHIBIT, attempting to select REMOTE will result in the message << Turn MON INHIBIT off first >> being displayed.
A.3.1.1.4 MAINTENANCE Switch The MAINTENANCE switch is a pushbutton switch that toggles between two settings: ON and OFF. The CTU will only respond to input from this switch when the SOURCE switches are set to LOCAL. MAINTENANCE may be selected if the DME is on or off. It may be turned off at any time by pressing the MAINTENANCE switch; it cannot be changed remotely.
When the MAINTENANCE switch is ON, a dual DME is prevented from transferring to the standby transponder, thus allowing the standby transponder to be tested without alarms being generated by h modules. The main transponder may remain on-air, but will be shut down if a primary fault occurs.
The 1kHz and 10 kHz interrogation rates (TI RATE) are only available when MAINTENANCE is ON.
A.3.1.1.5 MONITOR ALARM Switch The MONITOR ALARM switch is a pushbutton switch that toggles between two settings: INHIBIT and NORMAL. The CTU will only respond to input from this switch when the SOURCE switches are set to LOCAL. Failure to do this will result in the <<< Select LOCAL first >>> message on the lower line of the CTU front panel display. It may be turned off at any time by pressing the MONITOR ALARM switch; it cannot be changed remotely.
When the MONITOR ALARM switch is set to NORMAL, the DME is able to transfer or shut down should the monitored parameters warrant such action. When this switch is set to INHIBIT, transfer and shutdown are prevented since the CTU will ignore the fault lines from all monitor modules. When set to INHIBIT, it also prevents ident from being transmitted.
A.3.1.1.6 SELECT MAIN Switches The SELECT MAIN switches are three pushbutton switches labelled OFF, NO1 and NO2. These settings are mutually exclusive (one and only one of them can be on at any given time). These switches can only be used when the SOURCE switches are set to LOCAL. Failure to do this will result in the <<< Select LOCAL first >>> message on the lower line of the CTU front panel display. The settings of these switches can be changed remotely when the remote mode is selected.
When OFF is selected, all modules in the transponder subracks are turned off (unless they are being forced on by their front panel switches being in the TEST position). When NO1 is selected, Transponder 1 is selected as the main transponder (and Transponder 2 is selected as the standby transponder in a dual DME). When NO2 is selected in a dual DME, Transponder 2 is selected as the main transponder and Transponder 1 is selected as the standby transponder. In a single transponder DME, the message <<< Not available for single >>> will be displayed on the lower line of the CTU front panel display.
Note that these switches do not indicate which transponder is currently operating (for example, even though NO1 is selected as main, the DME may have transferred to the standby transponder due to fault conditions). The currently operating transponder may be determined from the NO1 ON and NO2 ON status indicators, as described in Section A.3.2.1.
HA72500 APPENDIX A
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A.3.1.2 Test Facility - Description of Operation REFER Figure A-1.
The test facility of the CTU is located in the top half of the CTU front panel. It provides facilities which allow the user to measure various parameters, sample status lines, and control and display some minor functions on the DME transponder(s). In maintenance mode (see Section A.3.1.1.4) these facilities can also measure the more important fault limits of the available monitor module(s).
The front panel controls and displays associated with the test facility consist of:
a. A 2x40-character liquid crystal display (LCD), which performs the following:
• On the top line of the LCD, status messages and measurement results are displayed.
• On the bottom line of the LCD, labels for the five multifunction pushbuttons are displayed. This forms the basis of the menu system described below. If a measurement is being performed, the corresponding switch label will flash.
• On the bottom line of the LCD, error messages are displayed. These are flashed four times at one-second intervals before returning to the previous display.
b. Five multifunction pushbuttons mounted directly below the LCD display, which are used to select the action, or select the next menu indicated by the label above it. These may also be referred to as 'softkeys' throughout the remainder of this Appendix.
c. ESC (escape) pushbutton, which is used to return to the top level menu.
d. Two TI RATE pushbuttons which select the pulse repetition frequency of the test interrogator module. The two buttons are:
• 1kHz. Toggles the test Interrogation rate (TIPRF) of the test interrogator between 1kHz and 50 Hz (dual DME) or 100 Hz (single DME). This button can only be operated while the CTU is in maintenance mode and the test interrogator/ monitor modules to be affected has been selected at the top menu. The active TIPRF rate will be displayed in the top right hand corner of the test display once the test interrogator/monitor module has been selected from the menu.
• 10 kHz. Is only active while held pressed and selects the 10 kHz test interrogation rate of the test interrogator module. When the button is released the test interrogation rate returns to the previously active rate (50 Hz, 100 Hz, or 1 kHz). This button can only be operated while the CTU is in maintenance mode and the test interrogator/monitor module to be affected has been selected at the top menu. The active TIPRF rate will be displayed in the top right hand corner of the test display once the test interrogator/monitor module has been selected from the menu.
If either of these buttons are pressed when MAINTENANCE switch is OFF, the message <<< Select MAINTENANCE first >>> will be displayed on the lower line of the CTU front panel display.
HA72500 APPENDIX A
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A.3.1.3 Test Facility - Menu System
A.3.1.3.1 Menu System - Introduction REFER Figure A-2 and Figure A-3.
The menu system on the CTU allows the implementation of a multifunction test control system with the minimum of controls and prompts the user with the allowable combinations. The menus are arranged in an hierarchical system, and the behaviour, display and choices offered by the menus are modified if maintenance mode is selected.
When the MAINTENANCE switch is not selected (MAINTENANCE indicator is off) the system is in an operational mode. The menu structure is as shown in Figure A-2 and the user is allowed to:
a. Perform and display measurements from both transponder monitoring systems (test interrogator/monitor modules) at the same time. The name of the parameter being measured, the measured value for each channel (transponder), the unit of measurement and the pulse repetition rate of the test interrogator are shown on the top line of the front panel display. A typical parameter display is as shown below (but with the tiprf field blank). The tiprf is displayed only in maintenance mode.
Name Ch1 Ch2 unit tiprf
Delay = 50.1 50.1 µs 100
b. Perform and display measurements that do not interfere with the operation of the transponder.
c. Display and reset the number of transponder restarts that have occurred.
d. Modify the display on the alarm register to display only those alarms that apply to a particular transponder. (Otherwise the alarms from both transponders are ORed together for the display.)
e. Select the ident source or test tone for the internal CTU speaker.
f. Select the ident source for external audio drive.
g. Test the CTU front panel LED indicators.
h. Display the software version installed in the CTU.
When MAINTENANCE is selected ON, the MAINTENANCE indicator is on and equipment is in the maintenance mode. The menu structure is as shown in Figure A-3 and the user is allowed to:
a. Perform and display measurements from the selected transponder monitoring system (test interrogator/monitor module), with the parameter display appearing as shown above (but with only one parameter value displayed - that from the selected monitoring system). Tiprf is displayed in this mode.
b. Perform and display measurements that may interfere with the operation of the transponder (for example – 1 kHz and 10 kHz test interrogation rate tests).
c. Perform the monitor module fault limit tests, which interfere with the normal operation of the DME
HA72500 APPENDIX A
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Figure A-2 Menu Structure in Operational Modes
HA72500 APPENDIX A
A-25
Figure A-3 Menu Structure in Maintenance Mode
HA72500 APPENDIX A
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A.3.1.3.2 Menu System in Operational Mode
A.3.1.3.2.1 Measurement Class Selection (Top Level Menu)
LDB-102 DME CTU Display
Param Level PS.Volt Status Misc. Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Change display to the first of four parameter select menus (see A.3.1.3.2.2.1).
b. Change display to first of two signal level select menus (see A.3.1.3.2.3.1).
c. Change display to power supply select menu (see A.3.1.3.2.4).
d. Change display to status select menu (see A.3.1.3.2.5).
e. Change display to first of three miscellaneous selection menus (see A.3.1.3.2.6.1).
A.3.1.3.2.2 Transponder Parameter Selection
A.3.1.3.2.2.1 Parameter Select - First Menu
CTU Display
Spacing Delay Pwr.Out Effncy NEXT Keys a. b. c. d. e.
Actions performed (for each of the monitor/test interrogator modules fitted) when the corresponding softkey is pressed
a. Measure and display 'Spacing' parameter.
b. Measure and display 'Delay' parameter.
c. Measure and display 'Power Out' parameter.
d. Measure and display 'Efficiency' parameter.
e. Change display to second parameter select menu (see A.3.1.3.2.2.2).
A.3.1.3.2.2.2 Parameter Select - Second Menu
CTU Display
D.Rate Tx.Rate PREV NEXT Keys a. b. c. d. e.
Actions performed (for each of the monitor/test interrogator modules fitted) when the corresponding softkey is pressed:
a. Measure and display 'Decoded Rate' parameter.
b. Measure and display 'Transmit Rate' parameter.
c. No action.
d. Change display to first parameter select menu (see A.3.1.3.2.2.1).
e. Change display to third parameter select menu (see A.3.1.3.2.2.3).
HA72500 APPENDIX A
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A.3.1.3.2.2.3 Parameter Select - Third Menu
CTU Display
Width Rise Fall PREV NEXT Keys a. b. c. d. e.
Actions performed (for each of the monitor/test interrogator modules fitted) when the corresponding softkey is pressed:
a. Measure and display 'Transmit Pulse Width' parameter.
b. Measure and display 'Transmit Pulse Rise Time' parameter.
c. Measure and display 'Transmit Pulse Fall Time' parameter.
d. Change display to second parameter select menu (see A.3.1.3.2.2.2).
e. Change display to fourth parameter select menu (see A.3.1.3.2.2.4).
NOTE It is the characteristics of the second transmitted pulse that are measured and displayed
A.3.1.3.2.2.4 Parameter Select - Fourth Menu
CTU Display
V Cal R cal T cal PREV Keys a. b. c. d. e.
Actions performed (for each of the monitor/test interrogator modules fitted) when the corresponding softkey is pressed:
a. Measure and display ‘Voltage Test Signal' parameter.
b. Measure and display 'Rate Check Signal' parameter.
c. Measure and display 'Time Check Signal' parameter.
d. Change display to third parameter select menu (see A.3.1.3.2.2.3).
e. No action.
HA72500 APPENDIX A
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A.3.1.3.2.3 Transponder Signal Level Selection
A.3.1.3.2.3.1 Signal Level Select - First Menu
CTU Display
RV.Osc RV.RF TD.Drv TD.Mod NEXT Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Measure and display 'Oscillator RF Level' parameter, from receiver video module(s).
b. Measure and display ‘Tx RF Drive Level' parameter, from receiver video module(s).
c. Measure and display ‘TD Drive Level' parameter, from transmitter driver module(s).
d. Measure and display 'Pulse Modulation Level' parameter, from transmitter driver module(s).
e. Change display to second signal level select menu (see A.3.1.3.2.3.2).
A.3.1.3.2.3.2 Signal Level Select - Second Menu
CTU Display
PA.Mod PA.Drv PA.Out TI.RF PREV Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Measure and display 'RF Modulation Level' parameter, from Power Amplifier Module(s).
b. Measure and display 'RF Drive Level' parameter, from Power Amplifier Module(s).
c. Measure and display 'Power Output RF Level' parameter, from Power Amplifier Module(s).
d. Measure and display 'RF Drive Level' parameter, from Test Interrogator Module(s).
e. Change display to first signal level select menu (see A.3.1.3.2.3.1).
HA72500 APPENDIX A
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A.3.1.3.2.4 Power Supply Voltage Selection
CTU Display
AUX.24V PA.HT TP.15V TP.18V Drv.HT Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Measure and display ‘+24 Volt input Supply' parameter, from monitor module(s).
b. Measure and display ‘Power Amplifier HT Supply' (nominal 50 volts) parameter, from 1kW PA power supply module(s).
c. Measure and display ‘+15 Volts Transponder Supply' parameter, from transponder power supply module(s).
d. Measure and display ‘+18 Volts Transponder Supply' parameter, from transponder power supply module(s).
e. Measure and display ‘Driver HT Transponder Supply' (nominal 42 volts) parameter, from transponder power supply module(s).
A.3.1.3.2.5 Status Selection
CTU Display
MON PS RV PS TI PS RV TRIG Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Sample and display ‘Monitor Power Status' parameter, from monitor module(s).
b. Sample and display 'Receiver Video Power Status' parameter, from monitor module(s).
c. Sample and display ‘Test Interrogator Power Status' parameter, from test interrogator module(s).
d. Sample and display 'Receiver Video Triggers Normal Status' parameter, from monitor module(s).
e. No action.
HA72500 APPENDIX A
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A.3.1.3.2.6 Miscellaneous Selection
A.3.1.3.2.6.1 Miscellaneous - First Menu Restart count = xxx
CTU Display Reset Alarm1 Alarm2 NEXT
Keys a. b. c. d. e. (where 'xxx' is the restart count)
Actions performed when the corresponding softkey is pressed:
a. Change display to submenu, to ask the user 'Are you sure T; if the response is 9 yes' then reset the' RESTART COUNT' both in RAM and EEPROM, otherwise return to this menu.
b. No action.
c. On the alarm register, display only those alarms that apply to Transponder 1 while this button is held down.
d. On the alarm register, display only those alarms that apply to Transponder 2 while this button is held down.
e. Change display to second miscellaneous select menu (see).
A.3.1.3.2.6.2 Miscellaneous - Second Menu
CTU Display LEDTst Version PREV NEXT
Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. While the pushbutton is pressed, switch on all the CTU front panel LED indicators, returning to the previous display when the pushbutton is released.
b. Display the version number of the software installed in the CTU (component reference D17 on the CTU processor board).
c. No action.
d. Change display to first miscellaneous select menu (see A.3.1.3.2.6.1).
e. Change display to third miscellaneous select menu (see A.3.1.3.2.6.3).
A.3.1.3.2.6.3 Miscellaneous - Third Menu Ident Source : xxx
CTU Display Mon 1 Mon 2 2240Hz OFF PREV
Keys a. b. c. d. e. (where 'xxx' is the current audio source for the internal CTU speaker)
Actions performed when the corresponding softkey is pressed:
a. Select the Monitor 1 audio source.
b. Select the Monitor 2 audio source.
c. Select 2240 Hz as the audio source.
d. Turn audio source off.
e. Change display to second miscellaneous select menu (see A.3.1.3.2.6.2).
HA72500 APPENDIX A
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A.3.1.3.3 Menu System in Maintenance Mode
A.3.1.3.3.1 TI/Monitor Selection (Top Level Menu)
LDB-102 DME - Maintenance Mode CTU Display
Ch.1 Ch.2 Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Select test interrogator/monitor module No. 1 to be used for subsequent measurements, enable high test interrogation rates, and change display to maintenance measurement class select menu (see A.3.1.3.3.2).
b. Select test interrogator/monitor module No. 2 to be used for subsequent measurements, enable high test interrogation rates, and change display to maintenance measurement class select menu (see A.3.1.3.3.2).
NOTE This option is only offered if 'dual' operation is selected on option switch S1 on the CTU processor board - see Section A.5.1.1. If 'single' operation is selected, no action is performed.
c. No action.
d. No action.
e. No action.
A.3.1.3.3.2 Measurement Class Selection
CTU Display
Param Level PS.Volt Status F1tLimit Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Change display to first parameter select menu, same menu as when maintenance is not selected, except that only one value is measured and displayed (see A.3.1.3.2.2.1). For the 'Efficiency' measurement submenu of the 'Param' selection, see A.3.1.3.3.2.2.
b. Change display to first signal level select menu, same menu as when maintenance is not selected, except that only one value is measured and displayed (see A.3.1.3.2.3.1).
c. Change display to first power supply select menu, same menu as when maintenance is not selected, except that only one value is measured and displayed (see A.3.1.3.2.4).
d. Change display to first status select menu, same menu as when maintenance is not selected, except that only one value is measured and displayed (see A.3.1.3.2.5).
e. Change display to monitor fault limit select menu (see A.3.1.3.3.2.1).
HA72500 APPENDIX A
A-32
A.3.1.3.3.2.1 Monitor Fault Limit Select Menu When an option is selected from this menu the selected fault limit test will be performed once, on the selected monitor module, and the results will be displayed. Upper limit will be displayed on the left hand side of the display, and the lower limit will be displayed on the right hand side. If no limit is applicable to the parameter selected, 'N/A' will be displayed.
CTU Display
Delay Spacing Effncy Tx.Rate Ant.Pwr Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Perform the Delay fault limit test once.
b. Perform the Spacing fault limit test once.
c. Perform the Efficiency fault limit test once.
d. Perform the Transmit Rate fault limit test once.
e. Perform the Antenna Power fault limit test once.
A.3.1.3.3.2.2 Efficiency Reading Select Menu
1kHz CTU Display
Effncy Hi Eff Lo Eff PREV Keys a. b. c. d. e.
Actions performed when the corresponding softkey is pressed:
a. Perform a normal Efficiency measurement, alternating high and low level test interrogations, using the selected test interrogator/monitor modules.
b. Perform an Efficiency measurement, using high level only test interrogations, in the selected test interrogator/monitor modules.
c. Perform an Efficiency measurement, using low level only test interrogations, in the selected test interrogator/monitor modules.
d. Return to the first parameter select menu (see A.3.1.3.2.2.1).
e. No action.
HA72500 APPENDIX A
A-33
A.3.2 CTU Front Panel Indicators REFER Figure A-1.
A.3.2.1 Status Indicators There are six status indicators on the CTU front panel:
• NO1 ON (green). Will be lit if Transponder 1 is powered on and is the currently operating transponder. This does not indicate that Transponder 1 is selected as main.
• NO2 ON (green). Will be lit if Transponder 2 is powered on and is the currently operating transponder. This does not indicate that Transponder 2 is selected as main.
• NORMAL (green). The DME will be in the normal state when the selected main transponder (that is, the transponder selected using the SELECT MAIN switches) is on and operating. The DME is not in the normal state if the MONITOR ALARM switch is set to INHIBIT or the MAINTENANCE switch is ON or if any alarms are present.
• TRANSFER (yellow). The DME will be in the transfer state if it is a dual DME and the standby transponder is on and operating (the standby transponder is the transponder that is not selected as main on the SELECT MAIN switches).
• SHUTDOWN (red). The DME will be in the shutdown state when all transponders are off due to a fault condition and the SELECT MAIN switches are set to either NO1 or NO2. This is an alarm condition.
• MAINTENANCE (red). The DME will be in the maintenance mode when the MAINTENANCE switch is set to ON. Only when this indicator is lit is the DME actually in the maintenance mode - under certain conditions there may be a slight delay between the setting of the MAINTENANCE switch and the DME entering or leaving the maintenance mode.
Three of these indicators (NORMAL, TRANSFER, and SHUTDOWN) are mutually exclusive - only one of these may be on at any given time (although they may all be off in the case of the selected main transponder being on and operating with monitor alarms inhibited, or if selected OFF at the SELECT MAIN switches).
HA72500 APPENDIX A
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A.3.2.2 Power Status Indicators There are four POWER status indicators on the CTU front panel:
• BATT LOW (red). Low battery voltage is detected by comparing the 24 volts auxiliary supply against a predefined threshold (an internal CTU setting - see Section A.5.1.2). If a transponder is on, and low battery voltage is detected, the transponder will be shut down to prevent the batteries discharging completely.
• BATT CHG 1 (green). If battery charger 1 is on and operating then this status indicator is on. One of the battery chargers must be 'normal' for the CTU to power up the transponders, after a 'battery low voltage' shutdown.
• BATT CHG 2 (green). If battery charger 2 is on and operating then this status indicator is on.
• AC PWR NORM (green). If AC power is being applied to battery charger 1, then this status indicator will be on.
A.3.2.3 Test Status Indicators There are two TEST status indicators on the CTU front panel:
• MODULES (red). Will be on if any one of the transponder modules has its control switch out of the NORMAL position.
• ANT RELAY (red). Will be on if the antenna control switch is not in the NORMAL position. The antenna test switch is located on the RF panel behind the CTU, and can be accessed from the rear of the rack.
HA72500 APPENDIX A
A-35
A.3.2.4 Alarm Register The ALARM REGISTER display indicates the faults (in all transponders) that were present at the time the most recent shutdown or transfer decision was made by the CTU.
The alarms corresponding to individual transponders can be selected from the menu system (see Section A.3.1.3.2.6.1).
In a single DME, the alarms shown on this display are derived from the monitor faults.
In a dual DME, the alarms shown on this display are the result of the monitor 'voting' specified on the internal option switch S2 on the CTU processor board (see Table A-4). This display is cleared when the main transponder is selected from the OFF state.
There are 12 alarm register indicators on the CTU front panel; all of them are red.
INDICATOR COLOUR FAULT TYPE DESCRIPTION DELAY Red Primary Monitor delay fault status from both
transponders SPACING Red Primary Monitor spacing fault status from both
transponders EFFICIENCY Red Secondary Monitor efficiency fault status from both
transponders TX RATE Red Secondary monitor transmit rate fault status from both
transponders POWER Red Secondary Monitor RF power fault status from both
transponders IDENT Red Secondary Monitor ident fault status from both
transponders PULSE SHAPE Red Secondary Monitor pulse shape fault status from both
transponders ANTENNA Red Secondary Monitor antenna fault status from both
transponders PRIMARY Red Primary Primary fault status from both transponders;
ORed from the primary faults SECONDARY Red Secondary Secondary fault status from both
transponders; ORed from the secondary faultsMONITOR Red Primary Monitor delay fault status from both
transponders CTU Red Primary CTU watchdog or software fault
A.3.2.5 Control Switch Indicators Each of the front panel control switches described in Section A.3.1.1 has an indicator associated with it to indicate the state of the controls, whether the DME is under remote or local control.
HA72500 APPENDIX A
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A.4 OPERATOR CONTROLS AND INDICATORS Information on CTU controls and indicators are contained in Sections A.3.1 and A.3.2 respectively. The front panel controls and indicators on the main transponder modules are listed in Table A-3, following.
Table A-3 Transponder Front Panel Controls and Indicators MAJOR ASSEMBLY/
SUBASSEMBLY CONTROL/INDICATION FUNCTION DETAILS
TYPE No. NAME TYPE LEGEND FUNCTION/SETTING/INDICATION FAILED All monitor outputs are set to
their fault condition (high) which invokes a FAILED condition for all front panel indicators and all fault lines read by the CTU. The TEST indicator is turned on.
1A72510 Monitor Module
Toggle switch
MONITOR OUTPUTS
NORMAL Monitor module operates normally and TEST indicator is off.
Green LED DELAY Green LED SPACING Green LED EFFICIENCY Green LED RATE Green LED POWER Green LED IDENT Green LED ANTENNA Green LED SHAPE
When on, indicates that the named parameter is within preset limits.
Yellow LED SELF TEST Indicates that the CTU is performing a Monitor Self Test, during which the CTU will look for the two primary parameters in the fault state.
Red LED PRIMARY Indicates that one or both of the primary parameters (Delay or Spacing) are outside preset limits.
Yellow LED SECONDARY Indicates that one or more of the six secondary parameters (Efficiency, Rate, RF Power, ident, Antenna, Shape) are outside preset limits.
Red LED TEST Indicates that the MONITOR OUTPUTS switch is not in the NORMAL position.
Green LED POWER ON Indicates that DC power is applied to the monitor.
Test jack ERP PULSE Detected pulse waveform of transmitted pulse - sampled near the antenna and fed into the ERP IN connector.
Test jack ERP EARTH Earth reference for the ERP PULSE test jack signal.
Test jack +15V Buffered output of the internally generated +15 volts.
Test jack +5V Buffered output of the internally generated +5 volts.
Test jack EARTH Common earth of the power supplies, the internally generated supplies, and all input and output signals.
HA72500 APPENDIX A
A-37
1A72514 Test
Interrogator Red LED TEST Indicates that the MONITOR AND
INTERROGATOR DC POWER switch is not in the NORMAL position.
Green LED DC POWER ON Indicates that DC power is applied to the monitor and test interrogator.
Pushbutton switch
CHECK DETECTOR COINCIDENCE
Connects the output of the RF generator into the reply detector, bypassing the transponder. Is used to check that the detector stages in the transponder have the same delay. The signals at the INTERROGATIONS TIMING and REPLY TIMING test jacks should match each other when this switch is pressed. This switch will interfere with the normal operation of the monitor module connected to the test interrogator under test.
+2µs
Toggle switch, centre off
TEST TRANSPONDER DECODING
REJECT
-2µs
Afters the interrogating pulse spacing outside acceptable limits to test the transponder pulse decoder rejection.
+1µs
Toggle switch, centre off
ACCEPT
-1µs
Alters the interrogating pulse spacing within acceptable limits to test the transponder pulse decoder acceptance.
REPLY GATE DELAY
Sets accept gate timing; variable between 0 and 60 microseconds.
16-way rotary switches COARSE 16 microseconds increments.
FINE 1 microsecond increments. Toggle
switch, centre off
MONITOR AND INTERROGATOR DC POWER
ON The power supply output is connected to the test interrogator and monitor regardless of other power sources.
OFF The power supply is disconnected from the test interrogator and monitor.
NORMAL The test interrogator circuitry is connected to the power supply if the input signal TI-ON from the CTU is active (high) or TRANSPONDER POWER on the transponder power supply is switched ON. Otherwise, the module's circuitry is isolated from the power supply.
Test jack TRIGGER Buffered version of test interrogator output TI-PRF; can be used to trigger an oscilloscope.
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack REPLY ACCEPT GATES
Buffered pulse from the parameter extractor circuitry, defining a time slot in which the received reply pulse should be present (15 volts, 6 microseconds wide).
Test jack 1 µs MARKERS Buffered output from the timer circuitry (5 volts, 1 microsecond period).
Test jack +15V Buffered +15V internal supply (15 volts). Test jack +5V Protected +5V internal supply (5 volts). Test jack DETECTED
REPLIES Buffered output of the reply detector, which is a detected pulse envelope representing the RF pulses transmitted from the transponder.
HA72500 APPENDIX A
A-38
Test jack DETECTED INTERRO-GATIONS
Buffered detected pulse envelope representing the RF pulse generated by the test interrogator for test interrogation.
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack INTERROGATIONS TIMING
Output pulses from the RF generator detector.
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack REPLY TIMING Buffered output pulses of the reply detector. 1A72520 Receiver
Video Yellow LED REPLIES
INHIBITED Flashes on and off when the receiver video is being over-interrogated.
On continuously when replies are inhibited. Red LED TEST Indicates that the IDENT switch is not in the
NORMAL position. Green LED DC POWER ON Indicates that DC power is applied to the
module. COARSE
16-position switches
BEACON DELAY FINE
Sets the Delay parameter of the receiver video.
16-position switch
REPLY PULSE SEPARATION
Sets the Spacing parameter of the receiver video.
Toggle switch centre off
IDENT NORMAL Normal mode of operation.
OFF No ident is generated. CONTINUOUS Ident is generated
continuously. INHIBIT INTERROGATIONS
All interrogations are inhibited. Toggle switch, spring loaded to centre off
TEST REPLY RATE MONITOR
Transponder replies are inhibited, and squitter reduced to 810 Hz.
Test jack SDES PULSE Buffered output from the double pulse decoder, which gives the short distance echo suppression pulse to the on-channel gating logic (15 volts, 2.5 microseconds wide, one pulse per correctly decoded pulse pair).
Test jack LDES PULSE Buffered output from the dead time suppressor showing the period of long distance echo suppression and when it is active (15 volts, selectable length, selectable trigger level).
Test jack DOUBLE PULSE DECODER OUT
Buffered output of the double pulse decoder indicating a pulse pair has been correctly decoded (15 volts, 2.5 microseconds wide, one pulse per each valid interrogation).
Test jack DEAD TIME Buffered output from the dead time generator shows the period of dead time and when it is active (15 volts, selectable length).
Test jack TRIGS TO MODULATOR
Buffered output from the double pulse encoder buffer to the transmitter driver. This output is normally high, and goes low during TX MODULATION TRIGGERS (0-15 volts, 2.5 microseconds wide pulses in pulse pairs separated by 12 or 36 microseconds, minimum rate 945 PPPS, maximum rate 3000 PPPS).
Test jack LOCAL OSC LEVEL
DC output proportional to the drive level out of the RF source.
Test jack +15V Buffered output from the +1 5V regulator.
HA72500 APPENDIX A
A-39
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack RF LEVEL DC output proportional to the output TX RF DRIVE.
Test jack ON CHANNEL VIDEO
Buffered output of the narrow band detected on-channel gate from the IF amplifier (15 volts pulses forming an envelope around the detected log video pulses, normally 3 microseconds wide).
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack DETECTED LOG VIDEO
Buffered output from the wideband logarithmic amplifiers of the IF amplifier.
Green LED POWER ON Indicates that power is applied to the module.
1A72525 Transponder Power Supply Red LED TEST Indicates that the TRANSPONDER POWER
switch is not in the NORMAL position. Toggle
switch, centre off
TRANSPONDER DC POWER
ON All supply outputs are on, regardless of CTU commands. This is required during testing and maintenance.
OFF All power supply outputs are oft. NORMAL Power supply outputs are under
CTU control. Test jack +24V IN The input voltage from the power
supply/battery. Test jack HT HT output to the Transmitter Driver
1A72530. Test jack +15V +15 volts output to the Transmitter
Driver1A72530. Test jack EARTH Ground reference for +24V IN, HT, +1 8V
and+15V, which is connected to the power +24V IN return.
Test jack +18V +18 volts output to the Transmitter Driver1A72530.
Test jack SWITCHED +24V
The switched +24 volts output.
Test jack SUPPLY CURRENT+
Test jack SUPPLY CURRENT-
These test jacks are connected to either side of a resistor in series with the input +24V IN. The + is connected to the higher voltage side of the resistor, and the - jack to the lower voltage side (100 mV/ampere).
1A72530 Transmitter Driver
Green LED DC POWER ON Indicates that 15 volts output from the transponder power supply is applied to the module.
Red LED TEST Indicates that the DRIVER DC POWER switch is not in the NORMAL position or that internal switches S2 and S3 are incorrectly set.
Variable resistor
RF OUTPUT Adjusts the RF from the module.
Toggle switch
DRIVER DC POWER
OFF Turns off the pulse modulation to the second stage of the exciter.
NORMAL Normal operation. Test jack SQUARE PULSE
MODULATION A buffered low-level modulation pulse output representing the signal from the pulse shaper to the second stage of the exciter.
Test jack FUNCTION GENERATOR
The buffered output of the pulse-shaping integrator on the pulse shaper.
Test jack SHAPED PULSE MODULATION
A buffered high-level modulation output representing the signal from the pulse shaper to the modulation stage.
Test jack +15V The buffered input + 15V supply.
HA72500 APPENDIX A
A-40
Test jack EARTH Common earth of all supply voltages and outputs.
Test jack EARTH Common earth of all supply voltages and outputs.
Green LED POWER ON Indicates that DC power is supplied to the module.
1A72540 1kW PA Power Supply Red LED TEST Indicates that the AMPLIFIER POWER
switch is not in the NORMAL position. Green LED HT ON Indicates that the HT supply is available,
and within limits. Toggle
switch, centre off
AMPLIFIER POWER
ON HT output voltage is supplied to the1kW RF power amplifier regardless of the power control signal state. This is required only during testing and maintenance.
OFF There is no power output from the1kW PA power supply.
NORMAL There is HT output from the module while the power control signal from the CTU is active (high); if it is inactive (low) the HT output is set to 0 volts.
Test jack POWER AMP MODULATOR OUT
Buffered output signal from the modulation stage of the 1kW RF power amplifier.
Test jack POWER AMP OUTPUT OUT
Buffered output signal from the output stage of the1kW RF power amplifier.
Test jack POWER AMP DRIVER OUT
Buffered output signal from the driver stage of the1kW RF power amplifier.
Test jack +15V Internally generated +15V supply (15 volts). Test jack SUPPLY
CURRENT- Test jack SUPPLY
CURRENT +
These jacks are connected to either side of a resistor in series with the +24V IN supply. The + side of the jack is buffered the to jack higher voltage resistor, and the - jack to the lower voltage side (1 mV/ampere).
Test jack EARTH A ground reference for the +24V IN, HT OUT and+15V OUT supplies, which is connected to the+24V IN return.
Test jack +24VIN Buffered +24V IN power supply input. Test jack HT OUT Buffered HT output. Test jack SHAPED PULSE
MODULATION Buffered signal modulation pulse.
TPNDR2 The output of Transponder 2 is fed directly to the antenna.
2A72547 RF Panel PWB Assembly (Dual)
Toggle switch, centre off TPNDR1 The output of Transponder 1 is fed directly
to the antenna. NORMAL The CTU controls which transponder output
is fed to the antenna.
HA72500 APPENDIX A
A-41
A.5 MODULE PRESET CONTROLS, SWITCHES, LINKS AND INDICATORS This section lists all the preset controls, switches, links and indicators that are located internally on the equipment (that is, not accessible at the front panel). These are used to set up operating conditions and functional modes of the equipment either prior to commissioning or as part of alignment or adjustment procedures.
The major mode selection functions are selected by CTU internal controls, which are described in Section A.5.1. The internal indicators of the CTU are described in Section A.5.2. The internal controls for the transponder modules and boards are described in Section A.5.3.
A.5.1 CTU Internal Controls
A.5.1.1 Option Switches REFER Figure A-4.
There are two 8-way dual-in-line switches (S1 and S2) located on the CTU Processor PWB Assembly (1A72552). These switches are used to modify the CTU's behaviour for key functions, as described in Table A-4.
HA72500 APPENDIX A
A-42
Table A-4 CTU Processor Board Option Switch Settings
FUNCTION SELECTED SWITCH IF SWITCH ON IF SWITCH OFF
DESCRIPTION OF FUNCTION
S1 SW1 Normal Operation
Production Tests
Used to select normal operation of the CTU or test routines that are used (in association with a test jig) during production testing.
SW2 NMP Present
No NMP Indicates if Navaid Maintenance Processor (NMP) used in the RMM system is fitted.
NOTE If S1:2 Is set to ON (NMP Present), but no NMP Is connected, there may be a significant delay before the CTU responds to any commands.
SW3 No action Subtract from MFLT2 delay
Subtracts 0.1 microseconds from delay monitor fault limit readings (see alignment procedure) on Monitor Module 2.
SW4 No action Add to MFLT2 delay
Adds 0.1 microseconds to delay monitor fault limit readings (see alignment procedure) on Monitor Module 2.
SW5 No Statistics Menu
Delay Statistics Menu Available
Enables mean and standard deviation statistics to be accumulated for delay readings.
SW6 No action Subtract from MFLT1 delay
Subtracts 0.1 microseconds from delay monitor fault limit readings (see alignment procedure) on Monitor Module 1.
SW7 No action Add to MFLT1 delay
Adds 0.1 microseconds to delay monitor fault limit readings(see alignment procedure) on Monitor Module 1.
SW8 Single Dual Select single or dual transponder operation. S2 SW1 Main AND
Vote Main OR Vote In a dual transponder this selects the type of voting to be
used between the monitor module fault lines when the selected 'main' transponder is ON. This has no effect in a single transponder.
SW2 Standby AND Vote
Standby OR Vote
In a dual transponder, this selects the type of voting to be used between the monitor module fault lines when the designated 'standby' transponder is ON. This has no effect in a single transponder.
SW3 RMM Control
RCMS Control When remote control is selected on the front panel, this switch selects the source of that remote control.
SW4 Standby COLD
Standby WARM
In a dual transponder, this selects power OFF (for COLD) or ON (for WARM) on the transponder that is not in use. Independent of the state of this switch, power is switched OFF to the transponder(s) if there is a primary fault, or maintenance mode is selected, or the transponders are selected OFF on the CTU front panel. This switch has no effect in a single transponder.
SW5 1-element Antenna Fault Not Installed
1-element Antenna Fault Installed
Used to tell the CTU if one antenna element fault detection hardware is absent or installed. If installed, it can be used to display the fault if one is detected.
SW6 1-element Antenna Fault No Action
1-element Antenna Fault Action
Used to tell the CTU if the one antenna element fault detection hardware is to be ignored, or treated as a secondary fault.
SW7 2-element Antenna Fault Not Installed
2-element Antenna Fault Installed
Used to tell the CTU if two antenna element fault detection hardware is absent or installed. If installed, it can be used to display the fault if one is detected.
SW8 2-element Antenna Fault No Action
2-element Antenna Fault Action
Used to tell the CTU if the two antenna element fault detection hardware is to be ignored, or treated as a secondary fault.
HA72500 APPENDIX A
A-43
A.5.1.2 Low Voltage Shutdown Preset REFER Figure A-4.
This adjustable preset control (R32) is used to set the lower limit of the battery voltage for normal transponder operation. This limit is adjustable between 19 volts and 22 volts. If the battery voltage falls below this limit, the transponders are switched off. Normal operation is restored when the battery voltage rises above this limit and either battery charger is normal. There is a small amount of hysteresis in the comparator to mask noise that may be present.
A.5.1.3 Internal Speaker Volume Preset REFER Figure A-4.
This preset control (R33) is used to adjust the audio volume from the internal CTU speaker (B1), and is located on the CTU processor board. A test tone of 2440 Hz may be selected from the menu system or via link XN8 on the CTU processor board. The internal speaker is normally used for recovered ident tone.
A.5.1.4 Internal Test Jumpers REFER Figure A-4.
The internal CTU jumpers are used during production or field test procedures. XN5 and XN10 may be fitted, depending on the installation configuration. For normal operation, all other test jumpers should be removed.
Table A-5 CTU Processor Board Test Jumpers
JUMPER NAME FUNCTION XN5 MA IDENT OUTPUT If fitted, connects ASSOC_IDENT_OUT + (XB1:1 on
External I/O PWB Assembly to ground. To be fitted, as required, for Interfacing to the ident circuitry of an associated navaid.
XN6 WATCHDOG DISABLE Only fitted during fault finding - prevents watchdog circuitry from regularly resetting the processor, which may happen during faulty operation of the CTU processor.
XN7 SIGNATURE ANALYSIS
Only fitted during fault finding - causes the processor to cycle through all its addresses, without running the software in the ROM.
XN8 IDENT TEST Only fitted during fault finding - causes 2440 Hz test tone to be fed to the internal CTU speaker.
XN9 WATCHDOG TEST Only fitted during fault finding - used to test that the watchdog circuit can reset the CTU processor. When this is fitted, the processor cannot reset the watchdog circuit.
XN10 ASSOC IDENT INPUT When fitted, provides a 10 kilohms pullup on ASS0C_IDENT_IN (XB1:4 on the External I/O PWB Assembly) 20 24 volts. To be fitted, as required, for interfacing to the ident circuitry of an associated navaid.
HA72500 APPENDIX A
A-44
A.5.1.5 LCD Viewing Angle Preset REFER Figure A-5.
This preset control (R1) is located on the CTU front panel board and is used to adjust the LCD viewing angle for the best display readability. To be adjusted, if required, to give best contrast on the display when viewed from the normal angle.
A.5.1.6 Alarm Power On Inhibit Switch REFER Figure A-5.
This preset rotary switch (S11) is read by the software to determine the period to ignore transponder alarms, after a transponder has been switched on, for cold standby. The delay can be preset between 2 and 20 seconds in 2-second steps. (The delay, in seconds, is 2 times the switch setting, plus 2)
NOTE For warm standby operation the alarm power on delay is preset to 2 seconds, and is independent of this switch
A.5.1.7 External Ident Level Preset REFER Figure A-6.
This preset control (R1) is used to adjust the output audible level of the recovered ident signal. It is located on the RCMS interface board.
A.5.2 CTU Internal Displays Internal status indicators are provided to display useful information during production tests and normal operation.
A.5.2.1 CTU Processor Board REFER Figure A-4.
The indicators provided on the CTU processor board are:
• H1 Driven from A19 address line.
• H2 Driven from A16 address line.
• H3 Not used.
• H4 ROM Test OK - performed when the processor is reset.
• H5 Not used.
• H6 Heartbeat - shows operational software activity.
• H7 Not used.
• H8 RAM Test OK - performed when the processor is reset.
HA72500 APPENDIX A
A-45
•
A.5.2.2 CTU Front Panel Board REFER Figure A-5.
The indicators provided on the CTU front panel board are:
• H14 Heartbeat - shows operational software activity, and I/0 bus control of the front panel board.
A.5.2.3 CTU RCMS Interface Board REFER Figure A-6.
The indicators provided on the CTU RCMS interface board are:
• H1 Heartbeat - shows operational software activity, and I/O bus control of the RCMS interface board.
HA72500 APPENDIX A
A-46
Figure A-4 CTU Processor Board - Control and Indicator Locations
HA72500 APPENDIX A
A-47
Figure A-5 CTU Front Panel Board - Control and Indicator Locations
HA72500 APPENDIX A
A-48
Figure A-6 CTU RCMS Interface Board - Control and Indicator Locations
HA72500 APPENDIX A
A-49
A.5.3 Transponder Internal Controls This section gives details of the internal switches, presets and adjustments for each of the module assemblies.
Table A-6 Internal Controls : Monitor Module 1A72510
CONTROL FUNCTIONS SUBASSY TYPE REF LEGEND FUNCTION/SETTING/INDICATION
Preset resistor
R87 Sets the ERP monitor fault alarm reference level to 0 dB at commissioning. 1 2 3 4 5 6 7 8 ON OFF
1A72511 Main PWB Assembly, Monitor Module
8-way DIL switch
S1 PULSE WIDTH LOWER REJECT LIMIT
Multiply the required lower reject limit (in microseconds) by 10 and subtract 1. Encode the switches for this value. For a lower reject limit of 2.9 microseconds the switches are encoded for a number of 28, as shown above. 1 2 3 4 5 6 7 8 ON OFF
8-way DIL switch
S2 FALL TIME UPPER REJECT LIMIT
Multiply the required upper reject limit (in microseconds) by 10 and subtract 2. Encode the switches for this value. For an upper reject limit of 3.6 microseconds the switches are encoded for a number of 34, as shown above. 1 2 3 4 5 6 7 8 ON OFF
8-way DIL switch
S3 RISE TIME UPPER REJECT LIMIT
Multiply the required upper reject limit (in microseconds) by 10 and subtract 2. Encode the switches for this value. For an upper reject limit of 3.1 microseconds the switches are encoded for a number of 29, as shown above. 1 2 3 4 5 6 7 8 ON OFF
The Monitor Fault Limit switches S1-4 and S8-10, S12 and S13 are binary coded, with switch 1 of the DIL switches the least significant and switch 8 (or 10) the most significant. They use inverted logic, with the OFF position of the switch being active.
8-way DIL switch
S4 PULSE WIDTH REJECT WINDOW
Multiply the required upper reject limit (in microseconds) by 10 and subtract 1. Encode the switches for this value. For an upper reject limit of 4.1 microseconds the difference between the limits of 1.2 microseconds and the switches are encoded for a number of 11, as shown above. 1 2 3 4 5 6 7 8 ON OFF
S7 is not Binary coded and is active in the ON position
8-way DIL switch
S7 POWER LEVEL LOWER REJECT LIMIT
The power level corresponds to the switch setting, from -1 to -7 dB. For a lower reject limit of -3 dB the switches are set as shown above (S7:8 is not used).
HA72500 APPENDIX A
A-50
CONTROL FUNCTIONS SUBASSY
TYPE REF LEGEND FUNCTIONISETTING/INDICATION 1 2 3 4 5 6 7 8 ON OFF
1A72511 Main PWB Assembly, Monitor Module
8-way DIL switch
S8 IDENT GAP UPPER REJECT LIMIT
Subtract 2 from the required upper reject limit (in seconds). Encode the switches for this value.For an upper reject limit of 62 seconds the switches are encoded for a number of 60, as shown above. 1 2 3 4 5 6 7 8 ON OFF
8-way DIL switch
S9 DELAY REJECT WINDOW
Multiply the difference between the required upper and lower reject limits (in microseconds) by 10 and subtract 1. Encode the switches for this value. For an upper reject limit of 50.5 microseconds the difference between the limits is 1.0 microsecond and the switches are encoded for a number of 9, as shown above. 1 2 3 4 5 6 7 8 ON OFF
8-way DIL switch
S10 SPACING REJECT WINDOW
Multiply the difference between the required upper and lower reject limits (in microseconds) by 10 and subtract 1. Encode the switches for this value. For an upper reject limit of 12.5 microseconds the difference between the limits is 1.0 microsecond and the switches are encoded for a number of 9, as shown above. 1 2 3 4 5 6 7 8 9 10 ON OFF
10-way DIL switch
S12 DELAY LOWER REJECT LIMIT
Multiply the required lower reject limit (in microseconds) by 10 and subtract 1. Encode the switches for this value. For a lower reject limit of 49.5 microseconds the switches are encoded for a number of 494, as shown above. 1 2 3 4 5 6 7 8 9 10 ON OFF
10-way DIL switch
SPACING LOWER REJECT LIMIT
Multiply the required lower reject limit (in microseconds) by 10 and subtract 1. Encode the switches for this value. For a lower reject limit of 11.5 microseconds the switches are encoded for a number of 114 as shown above.
HA72500 APPENDIX A
A-51
Table A-7 Internal Controls : Test Interrogator 1A72514
CONTROL/INDICATION FUNCTION DETAILS SUBASSY TYPE REF LEGEND FUNCTION/SETTING/INDICATION
X Sets pulse spacing for X channel operation. Slide switch
S4 mode Y Sets pulse spacing for Y channel operation.
1A72515 Main PWB Assembly. Test Interrogator
Preset resistor
R7 TPNDR OP LVL CAL
Used to calibrate the transmitted pulse peak power.
Variable capacitors
C10, 14,18, 22 1A72516 RF Generator Inductor L1
Used to align the RF generator to the operating interrogator frequencies (see Section 3.4.12).
6-way DIL switch
S1 SW1 Selects interrogations at the nominal interrogation frequency.
SW2 Selects interrogations at 160 kHz above the nominal interrogation frequency.
SW3 Selects interrogations at 160 kHz below the nominal interrogation frequency.
SW4 Selects interrogations at 900 kHz above the nominal interrogation frequency.
SW5 Selects interrogations at 900 kHz below the nominal interrogation frequency.
SW6 Adds a CW signal to the interrogation pules at -10 dB. 1A72517 RF Filter
Variable capacitors
C1, C2 Used to align the RF filter (see Section 3.4.13).
R13 Pulse amplitude R20 Pulse shape
1A72518 Modulator and Detector
Preset resistors
R37 Pulse pedestal
Used to align the pulse shape of the interrogations produced by the RF generator (see Section 3.4.14).
Normal Position for normal operation. Slide switch
S1 Test Used during testing.
Test point XT1 Bias voltage Bias voltage for level detector circuitry. Test point XT2 Pk amp lvl DC voltage proportional to the peak amplitude of the
transmitted pulses. Test point XT3 Timing pulse Timing reference for the transmitted pulse. Test point XT4 Mod out Modulation pulse to RF generator. Test point XT5 Ground 0 volts reference. Test point XT6 Ground 0 volts reference.
HA72500 APPENDIX A
A-52
Table A-8 Internal Controls : Receiver Video 1A72520
CONTROL FUNCTIONS SUBASSY TYPE REF LEGEND FUNCTION/SETTING/INDICATION
Preset resistor
R37 CODE SPEED Varies the ident code speed, which is set to 8 Hz.
Preset resistor
R39 CODE REPTN Varies the ident repetition rate, which is set to 1.5 Hz.
1A72521 Main PWB Assembly, Receiver Video Preset
resistor R45 ADJUST 6 dB
OFFSET Set to 0.24 volts during factory test, but may need to be varied at module test level (see Sections 3.3.8, 3.4.17).
Preset resistor
R46 LONG DISTANCE ECHO SUPP LEVEL
Varies the LDES DC level.
X Selects X mode operation for the encoder. Slide switch
S4 SELECT ENCODER MODE Y Selects Y mode operation for the encoder.
X Selects X mode operation for the decoder. Slide switch
S5 SELECT DECODER MODE Y Selects Y mode operation for the decoder.
16-way rotary switch
S6 SET LDES PERIOD
Sets the LDES period in multiples of 12.15 microseconds.
16-way rotary switch
S7 SET DEAD TIME Sets the dead time period in multiples of 11.57 microseconds.
ON Enables SDES operation. Slide switch
S8 SDES OFF Disables SDES operation. ON Enables LDES operation. Slide
switch S9 LDES
OFF Disables LDES operation. 8-way
switch S13 to S16
CODE ELEMENT Set the ident Morse code characters.
Variable capacitors
C8, 12, 18, 26 1A72522 RF Source
Variable inductor
L1
Used to align the RF source to the operating reply frequency (see Section 3.4.18)
1A72523 IF Amplifier
Variable capacitor
C1
Preset resistors
R15, 29, 50
Variable inductors
L3, 4, 5, 6, 7
Used to align the IF amplifier (see Section 3.4.19).
HA72500 APPENDIX A
A-53
The Ident code element switches S13, S14, S15 and S16 on the Main PWB Assembly, Receiver Video set the ident code as follows:
a. Convert the required Ident letters into International Morse Code, using the following table.
LETTER MORSE SYMBOL LETTER MORSE SYMBOL A dot dash N dash dot B dash dot dot dot 0 dash dash dash C dash dot dash dot P dot dash dash dot D dash dot dot Q dash dash dot dash E dot R dot dash dot F dot dot dash dot S dot dot dot G dash dash dot T dash H dot dot dot dot U dot dot dash 1 dot dot V dot dot dot dash J dot dash dash W dot dash dash K dash dot dash X dash dot dot dash L dot dash dot dot Y dash dot dash dash M dash dash Z dash dash dot dot
b. Set the switches using the following code (shading indicates switch position).
EXAMPLE: For ident code AWA, switch settings are:
HA72500 APPENDIX A
A-54
Table A-9 Internal Controls : Transponder Power Supply 1A72525
CONTROL FUNCTIONS SUBASSY TYPE REF LEGEND FUNCTION/SETTING/INDICATION
1A72526 Main PWB Assembly, Transponder Power Supply
Preset resistor
R26 HT VOLTAGE Sets the HT output voltage to the Transmitter Driver 1A72530.
HA72500 APPENDIX A
A-55
Table A-10 Internal Controls : Transmitter Driver 1A72530
CONTROL FUNCTIONS SUBASSY TYPE REF LEGEND FUNCTION/SETTING/INDICATION
Preset resistors
R3, 5, 7, 9, 11, 13
PULSE SHAPE
These vary the slope of the segments of the function generator output from base (R3) to apex (R13).
1A72531 Pulse Shaper PWB Assembly R17 INTEGRATOR
BALANCE Adjusts the balance of the function generator integrator.
R36 BACKPORCH Adjusts the spacing between the modulation pulses.
R52 PEDESTAL VOLTAGE
Adjusts the DC level of the shaped modulation pulse.
R54 2ND PULSE EQUALISING
Adjusts the height of the second pulse of the pulse pair to equalise it with the height of the first pulse.
R58 MOD PULSE AMPLITUDE
Adjusts the amplitude of the shaped modulation pulse.
R62 ALC LEVEL (RF OUTPUT)
With S2 (ALC LOOP) in its closed position, adjusts the shaped modulation pulse amplitude.
R69 POWER MOD AMP DC
Adjusts the power modulation amplifier DC level.
R85 1W PULSE Adjusts the pulse modulation amplitude. R97 EXCITER DC Adjusts the exciter DC level. R115 MED POWER
DRIVER DC Adjusts the medium power driver DC level.
OFF Power supply to exciter is off. Toggle switch
S1 DRIVER DC POWER NORMAL Power supply to the exciter is
under CTU CLOSED Automatic level control is
enabled. Slide switch S2 ALC LOOP
OPEN Automatic level control is disabled.
VIDEO ALC maintains shaped modulation pulse amplitude (150W DME).
Slide switch S3 ALC
DETECTED RF ALC maintains output level from the 1kW RF power amplifier (1kW DME).
DC Selects a DC voltage as the collector supply for the medium power driver in high power (1kW) mode.
Slide switch S4 MED PD COLL
MODULATION Selects the shaped modulation pulse as the collector supply for the medium power driver in low power (150 W) mode.
Link X1 POWER 150W Lights TEST LED if switch S3 incorrectly set to DET RF.
1kW Lights TEST LED if switch S3 incorrectly set to VIDEO.
1A72532 Exciter
Variable capacitors
C5, 15, 17. 21, 26, 30, 33, 34.
Used to align the exciter (see Section 3.4.25).
HA72500 APPENDIX A
A-56
Table A-11 Internal Controls: 1kW PA Power Supply 1A72540 CONTROL FUNCTIONS SUBASSY
TYPE REF FUNCTION/SETTINGP/INDICATION 1A72541 Control and Status PWB Assembly
Preset resistor
R45 Varies the centre of the HT ON window between approximately 48.5 and 51.9 volts.
1A72542 DC-DC Converter PWB Assembly
Preset resistor
R16 Calibrates the input circuit monitoring of the DC-DC converter (see section 3.4.33).
1A72543 Regulator PWB Assembly
Preset resistor
R112 Sets the HT output voltage to the 1kW RF power amplifier.
HA72500 APPENDIX A
A-57
A.6 DEPOT TEST FACILITY OPERATION Operating procedures for the Depot Test Facility 3A72500 are contained in Appendix K.
HA72500 APPENDIX F
F-i
APPENDIX F
COMPONENTS SCHEDULE
HA72500 APPENDIX F
F-ii
TABLE of CONTENTS
F. COMPONENTS SCHEDULE...................................................................... F-1 F.1 COMPONENT IDENTIFICATION F-1 F.2 COMPONENT ORDERING DATA F-1 F.3 PRESENTATION OF DATA F-1 F.4 ASSEMBLY/SUBASSEMBLY IDENTITIES F-2 F.5 COMPONENT SCHEDULE LISTS F-8
F.5.1 1A69737 Attenuator..................................................................................... F-8 F.5.2 1A69755 Directional Coupler....................................................................... F-8 F.5.3 2A69755 Directional Coupler....................................................................... F-8 F.5.4 1A69757 50 Ohm Load (SMA) .................................................................... F-8 F.5.5 2A69757 50 Ohm Load (N) ......................................................................... F-9 F.5.6 2A/3A69758 Power Supply System, Dual AC ............................................. F-9 F.5.7 1A69873 250W RF Power Amplifier............................................................ F-9 F.5.8 3A71130 Power Supply 200/260 VAC, 24 VDC 30A................................... F-9 F.5.9 1A72500 DME LDB-102 Station, Single 1kW............................................ F-10 F.5.10 2A72500 DME LDB-102 Station, Dual 1kW .............................................. F-10 F.5.11 1A72505 Rack Assembly, Single 1kW DME ............................................. F-10 F.5.12 2A72505 Rack Assembly, Dual 1kW DME................................................ F-10 F.5.13 1A72510 Monitor Module .......................................................................... F-11 F.5.14 1A72511 Monitor Module Main PWB ........................................................ F-11 F.5.15 1A72512 Peak Power Monitor................................................................... F-14 F.5.16 1A72513 Transponder Subrack................................................................. F-14 F.5.17 1A72514 Test Interrogator......................................................................... F-15 F.5.18 1A72515 Test Interrogator Main PWB....................................................... F-15 F.5.19 1A72516 RF Generator ............................................................................. F-18 F.5.20 1A72517 RF Filter ..................................................................................... F-19 F.5.21 1A72518 Modulator and Detector.............................................................. F-19 F.5.22 1A72519 Reply Detector ........................................................................... F-21 F.5.23 1A72520 Receiver Video........................................................................... F-22 F.5.24 1A72521 Receiver Video Main PWB......................................................... F-22 F.5.25 1A72522 RF Source .................................................................................. F-25 F.5.26 1A72523 IF Amplifier ................................................................................. F-26 F.5.27 1A72524 RF Amplifier ............................................................................... F-28 F.5.28 1A72525 Transponder Power Supply........................................................ F-29 F.5.29 1A72526 Transponder Power Supply Main PWB...................................... F-29 F.5.30 1A72530 Transmitter Driver ...................................................................... F-31 F.5.31 1A72531 Pulse Shaper PWB .................................................................... F-32 F.5.32 1A72532 Exciter ........................................................................................ F-34 F.5.33 1A72533 Medium Power Driver................................................................. F-35 F.5.34 1A72534 Power Modulation Amplifier ....................................................... F-36 F.5.35 1A72535 1kW RF Power Amplifier ............................................................ F-36 F.5.36 1A72536 Power Divider............................................................................. F-37 F.5.37 1A72537 Power Combiner ........................................................................ F-37 F.5.38 1A72538 RF Amplifier Driver PWB............................................................ F-38 F.5.39 1A72540 1kW Power Amplifier Power Supply........................................... F-38 F.5.40 1A72541 Control and Status PWB ............................................................ F-39 F.5.41 1A72542 DC-DC Converter PWB.............................................................. F-41 F.5.42 1A72543 Regulator PWB .......................................................................... F-42 F.5.43 1A72544 1kW PA Connector PWB ........................................................... F-43 F.5.44 1A72545 RF Panel - Single DME .............................................................. F-43 F.5.45 2A72545 RF Panel - Dual DME................................................................. F-44 F.5.46 1A72547 RF Panel PWB - Single DME..................................................... F-44
HA72500 APPENDIX F
F-iii
F.5.47 2A72547 RF Panel PWB - Dual DME ....................................................... F-45 F.5.48 A72549 Power Distribution Panel - Single DME........................................ F-45 F.5.49 2A72549 Power Distribution Panel - Dual DME ........................................ F-45 F.5.50 1A72550 Control and Test Unit ................................................................. F-46 F.5.51 1A72552 CTU Processor PWB ................................................................. F-46 F.5.52 1A72553 CTU Front Panel PWB ............................................................... F-48 F.5.53 1A72555 RCMS Interface PWB ................................................................ F-49 F.5.54 1A72556 Transponder Subrack Motherboard ........................................... F-51 F.5.55 1A72557 External I/O PWB ....................................................................... F-51 F.5.56 1A72558 Rack Frame Wired - Single 1kWDME........................................ F-52 F.5.57 2A72558 Rack Frame Wired - Dual 1kW DME ......................................... F-53 F.5.58 1A72560 Antenna Cable Set for Single Installation................................... F-53 F.5.59 2A72560 Antenna Cable Set for Dual Installation ..................................... F-53 F.5.60 1A72561 Accessory Kit, DME Test ........................................................... F-54 F.5.61 1A72562 Transponder Extender Frame .................................................... F-54 F.5.62 1A72563 Special Tools and Fittings .......................................................... F-54 F.5.63 1A72564 Coaxial Cables and Accessories................................................ F-54
HA72500 APPENDIX F
F-iv
LIST of FIGURES
Figure F-1 Family Tree of DME LDB-102 Station (Single 1kW)...............................F-4 Figure F-2 Family Tree of DME LDB-102 Station (Dual 1kW) .................................F-5 Figure F-3 Rack/Module Complement of LDB-102 Single 1kW Station 1A72500 ...F-6 Figure F-4 Rack/Module Complement of LDB-102 Dual 1kW Station 2A72500......F-7
HA72500 APPENDIX F
F-1
F. COMPONENTS SCHEDULE F.1 COMPONENT IDENTIFICATION Components in the schedules included in this appendix are identified by a component reference designator or quantity (as applicable), the value/description, and a code number. A code number may define components either of one or of more than one source of manufacture as complying to the relevant specifications of that code number.
These schedules list only the most common, or preferred, source details. Manufacturer or supplier sources are identified by an abbreviated name or code group. This code group is followed by the catalogue or part designation used by the manufacturer or supplier to identify the component. All included code groups are identified in Appendix G, in which the name and address of the company represented by the code group is also given.
F.2 COMPONENT ORDERING DATA When ordering replacement components, always quote:
a. the type number of the parent unit (or subunit);
b. the component reference designator; and
c. all details which are shown in the components schedule against the component reference designator.
This information will ensure the supply of suitable substitute components should the listed components have become either obsolete or unavailable.
F.3 PRESENTATION OF DATA The system arrangement of major assemblies and subassemblies will vary with the individual configuration, facilities, and options choices that apply to each particular Installation.
The table on the following page lists the included subassemblies and shows the type configuration to which they apply.
The assemblies and subassemblies which contain maintainable components are then listed in numerical order of type number in Section F.5 in this Appendix; this arrangement is to facilitate usage and, of course, bears no relationship to the system structure of any particular configuration. The TABLE OF CONTENTS shows a full listing of all the included component schedules.
Subassemblies which are not maintainable to the component level do not have components listings included in Section F.5; in the event of failure they should be replaced as a complete assembly.
In instances where subassemblies are included as parts of higher assemblies, only the subassembly type number is identified under the higher assembly listing; refer to the table for the referenced type number for detailed components listing of that subassembly.
HA72500 APPENDIX F
F-2
F.4 ASSEMBLY/SUBASSEMBLY IDENTITIES The LDB-102 assemblies and major subassemblies are identified and listed in type number order in the following table.
The 'VERSION USED ON' column in this table indicates the type variant/s to which each assembly/subassembly is fitted. The version types referred to are:
• 1A 1A72500 DME LDB-102 Station, Single 1kW.
• 2A 2A72500 DME LDB-102 Station, Dual 1kW
• 3A 3A72500 DME LDB-102 Depot Test Facility.
The assembly/subassembly relationships of the single and dual 1kW station versions are shown in Figure F-1 and Figure F-2 respectively. The rack and assembly complement for the single 1kW station is shown in detail in Figure F-3, and that for the dual 1kW station in Figure F-4. Components schedules applicable to the Depot Test Facility are included in Appendix K.
Assembly Type Identification
ASSEMBLY/ SUBASSEMBLY VERSION USED ON
TYPE No. NAME 1A 2A 3A 1A69737 Attenuator ● ● ● 1A69755 Directional Coupler ● ● ● 2A69755 Directional Coupler ● 1A69757 50 Ohm Termination ● ● 2A69757 50 Ohm Termination ● ● ●
2/3A69758 Power Supply System, Dual AC ● 1A69873 250W RF Amplifier ● ● ● 3A71130 AC Power Supply ● ● ● 1A72500 LDB DME-102 Station (Single 1kW) ● 2A72500 LDB DME-102 Station (Dual 1kW) ● 3A72500 LDB DME-102 Depot Test Facility ● 1A72503 1kW PA Power Supply Frame NMC ● ● ● 1A72505 Rack Assembly (Single 1kW DME) ● 2A72505 Rack Assembly (Dual 1kW DME) ● 3A72505 Rack Assembly (Depot Test Facility) ● 1A72506 CTU Subrack NMC ● ● ● 1A72510 Monitor Module ● ● ● 1A72511 Main PWB Assembly, Monitor Module ● ● ● 1A72512 Peak Power Monitor ● ● ● 1A72513 Transponder Subrack ● ● ● 1A72514 Test Interrogator ● ● 2A72514 Test Interrogator (Modified) ● 1A72515 Main PWB Assembly, Test Interrogator ● ● ● 1A72516 RF Generator ● ● 2A72516 RF Generator (Modified) ● 1A72517 RF Filter ● ● ● 1A72518 Modulator and Detector ● ● ● 1A72519 Reply Detector ● ● ● 1A72520 Receiver Video ● ●
HA72500 APPENDIX F
F-3
ASSEMBLY/ SUBASSEMBLY VERSION USED ON
TYPE No. NAME 1A 2A 3A 2A72520 Receiver Video (Modified) ● 1A72521 Main PWB Assembly, Receiver Video ● ● ● 1A72522 RF Source ● ● ● 1A72523 IF Amplifier ● ● ● 1A72524 RF Amplifier ● ● ● 1A72525 Transponder Power Supply ● ● ● 1A72526 Main PWB Assembly, Transponder Power Supply ● ● ● 1A72530 Transmitter Driver ● ● ● 1A72531 Pulse Shaper PWB Assembly ● ● ● 1A72532 Exciter ● ● ● 1A72533 Medium Power Driver ● ● ● 1A72534 Power Modulation Amplifier ● ● ● 1A72535 1kW RF Power Amplifier ● ● ● 1A72536 Power Divider ● ● ● 1A72537 Power Combiner ● ● ● 1A72538 RF Amplifier Driver PWB Assembly ● ● ● 1A72540 1kW PA Power Supply ● ● ● 1A72541 Control and Status PWB Assembly ● ● ● 1A72542 DC-DC Converter PWB Assembly ● ● ● 1A72543 Regulator PWB Assembly ● ● ● 1A72544 1kW PA Connector PWB Assembly ● ● ● 1A72545 RF Panel - Single DME ● ● 2A72545 RF Panel - Dual DME ● 1A72546 Preselector Filter NMC ● ● ● 1A72547 RF Panel PWB Assembly - Single DME ● ● 2A72547 RF Panel PWB Assembly - Dual DME ● 1A72549 Power Distribution Panel - Single DME ● ● 2A72549 Power Distribution Panel - Dual DME ● 1A72550 Control and Test Unit ● ● ● 1A72552 CTU Processor PWB Assembly ● ● ● 1A72553 CTU Front Panel PWB Assembly ● ● ● 1A72555 RCMS Interface PWB Assembly ● ● ● 1A72556 Transponder Subrack Motherboard ● ● ● 1A72557 External I/O PWB Assembly ● ● ● 1A72558 Rack Frame Wired - Single 1kW DME ● 2A72558 Rack Frame Wired - Dual 1kW DME ● 3A72558 Rack Frame Wired (Test Facility) ● 1A72560 Antenna Cable Set for Single Installation ● 2A72560 Antenna Cable Set for Dual Installation ● 1A72561 Accessory Kit, DME Test ● ● ● 1A72562 Transponder Extender Frame ● ● ● 1A72563 Special Tools and Fittings ● ● ● 1A72564 Coaxial Cables and Accessories ● ● ● 1A72569 Hinge In-line NMC ● ● ●
NMC denotes there are no maintainable components, and no component schedule, for this item
HA72500 APPENDIX F
F-4
Figure F-1 Family Tree of DME LDB-102 Station (Single 1kW)
HA72500 APPENDIX F
F-5
Figure F-2 Family Tree of DME LDB-102 Station (Dual 1kW)
HA72500 APPENDIX F
F-6
Figure F-3 Rack/Module Complement of LDB-102 Single 1kW Station 1A72500
HA72500 APPENDIX F
F-7
Figure F-4 Rack/Module Complement of LDB-102 Dual 1kW Station 2A72500
HA72500 APPENDIX F
F-8
F.5 COMPONENT SCHEDULE LISTS
F.5.1 1A69737 Attenuator CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1-4 1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805 Q220 JXA-AB RESISTORS, FIXED REF CODE DESCRIPTION MFR/SUPPLIER REF R1-2 select on test SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1028850Q switching diode HP 5082-3041 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XFA 1028908D stripline launcher SUHNER 23SMA-50-0-52 XFB1, 2
1028758Q jack CAMBION 450-3704-01-03-00
XMA 1028551R coaxial receptacle SUHNER 13SMA-50-0-52
F.5.2 1A69755 Directional Coupler RESISTORS, FIXED QTY CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF 2 1028907C pill termination 50 2% KDI PST-1 CONNECTORS QTY CODE DESCRIPTION MFR/SUPPLIER REF 6 1028908D stripline launcher SUHNER 23SMA-50-0-52
F.5.3 2A69755 Directional Coupler RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF 4 1028907C pill termination 50 2% KDI PST-1 CONNECTORS QTY CODE DESCRIPTION MFR/SUPPLIER REF 8 1028908D stripline launcher SUHNER 23SMA-50-0-52
F.5.4 1A69757 50 Ohm Load (SMA) RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF 1 1050026H metal film 50 2% 250W RES-NET RPT975-250P
WARNING This resistor may contain beryllium oxide CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 69757-4-09 coaxial SMA 69757-4-09
HA72500 APPENDIX F
F-9
F.5.5 2A69757 50 Ohm Load (N) RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF 1 1050026H metal film 50 2% 250W RES-NET RPT975-250P
WARNING This resistor may contain beryllium oxide CABLE QTY CODE DESCRIPTION MFR/SUPPLIER REF
0.75m coaxial 50 ohms SUHNER EZ-141-AL-TP CONNECTORS QTY CODE DESCRIPTION MFR/SUPPLIER REF XC1 1028913J coaxial N plug OMNI SPECTRA 3001-7941-00
F.5.6 2A/3A69758 Power Supply System, Dual AC MISCELLANEOUS QTY CODE DESCRIPTION MFR/SUPPLIER REF 2 3A71130 Power supply, 200/260 VAC, 24 VDC, 30 A 3A71130 1 69758-3-22 Cable assembly 69758-3-22 3 72558-4-47 Cable assembly, earth 72558-4-47 1 72558-4-48 Cable assembly, door earth 72558-4-48 1 69758-4-24 Installation accessories kit 69758-4-24
F.5.7 1A69873 250W RF Power Amplifier CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 2 1036606W ceramic chip 47p 5% 150 VITRAMON VJ0805Q470JXB-AB INDUCTORS QTY CODE DESCRIPTION MFR/SUPPLIER REF L1, 2 57969V31 57969V31 SEMICONDUCTORS QTY CODE DESCRIPTION MFR/SUPPLIER REF V1 microwave L-band amplifier GHZ TAN250A
WARNING V1 may contain beryllium oxide CONNECTORS QTY CODE DESCRIPTION MFR/SUPPLIER REF 2 1031124M coaxial SMA jack SUHNER 23SMA-50-0-04
F.5.8 3A71130 Power Supply 200/260 VAC, 24 VDC 30A The AC Power Supply is a stand-alone equipment and is separately documented in its own handbook (see Appendix J). Refer to that handbook for details of replacement components. The major electronics subassembly in the unit is:
SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72599 Control Board, AC Power Supply 1A72599
HA72500 APPENDIX F
F-10
F.5.9 1A72500 DME LDB-102 Station, Single 1kW SUBASSEMBLIES REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF A1 1A72505 Rack Assembly (Single 1kW DME) 1A72505 A2 1A72560 Antenna Cable Set 1A72560 A3 1A72561 Accessory Kit, DME Test 1A72561 A4 DME Antenna
F.5.10 2A72500 DME LDB-102 Station, Dual 1kW SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 2A72505 Rack Assembly (Dual 1kW DME) 2A72505 A2 2A72560 Antenna Cable Set 2A72560 A3 1A72561 Accessory Kit, DME Test 1A72561 A4 DME Antenna A5 2A/3A69758 Dual AC Power Supply System 2A/3A69758
F.5.11 1A72505 Rack Assembly, Single 1kW DME SUBASSEMBLIES REF/ QTY CODE DESCRIPTION MFR/SUPPLIER REF
A1 1A72520 Receiver Video 1A72520 A2 1A72530 Transmitter Driver 1A72530 A3 1A72525 Transponder Power Supply 1A72525 A4 1A72510 Monitor Module 1A72510 A5 1A72514 Test Interrogator 1A72514 A6 1A72535 1kW RF Power Amplifier 1A72535 A7 1A72540 1kW PA Power Supply 1A72540 A8 1A72558 Rack Frame Wired - Single 1kW DME 1A72558 A9 3A71130 Power Supply, 200/260 VAC,24 VDC, 30 A 3A71130 A11 1A72550 Control and Test Unit 1A72550 A12 1A72549 Power Distribution Panel - Single DME 1A72549 2 1030559Y Attenuator 10 dB 50 ohms SMA MICROLAB/FXRAG-10F 1 1030562B Termination 50 ohms 1 watt SMA plug SUHNER 65SMA-50-0-1/111
F.5.12 2A72505 Rack Assembly, Dual 1kW DME SUBASSEMBLIES REF/ QTY CODE DESCRIPTION MFR/SUPPLIER REF
A1, 14 1A72520 Receiver Video 1A72520 A2, 15 1A72530 Transmitter Driver 1A72530 A3, 16 1A72525 Transponder Power Supply 1A72525 A4, 17 1A72510 Monitor Module 1A72510 A5, 18 1A72514 Test Interrogator 1A72514 A6, 19 1A72535 1kW RF Power Amplifier 1A72535 A7, 20 1A72540 1kW PA Power Supply 1A72540 A9 2A72558 Rack Frame Wired - Dual 1kW DME 2A72558 A11 1A72550 Control and Test Unit 1A72550 A12 2A72549 Power Distribution Panel - Dual DME 2A72549 3 1030559Y Attenuator 10 dB 50 ohms SMA MICROLAB/FXRAG-10F 2 1030562B Termination 50 ohms 1 watt SMA plug SUHNER 65SMA-50-0-1/111
HA72500 APPENDIX F
F-11
F.5.13 1A72510 Monitor Module SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72511 Main PWB Assembly, Monitor Module 1A72511 A2 1A72512 Peak Power Monitor 1A72512 CABLE ASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF 1 72510-4-13 ribbon 20-way 72510-4-13 1 72510-4-14 coaxial BNC/SMA 72510-4-14
F.5.14 1A72511 Monitor Module Main PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1-33, 35, 37-45, 49-51, 55-64. 68-71, 73, 81
1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C34, 52, 82
1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9
C36 1004863T ceramic monolyth 10n 10% 100V VITRAMON CK05BX103K C46, 48, 54, 80, 83 1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K C47, 72
1026365P metal polyester 470n 10% 63V WIMA MKS2
C53, 65-67, 74-76 1026369U metal polyester 1u 10% 50V WIMA MKS2 C77 1028394V ceramic 22p 5% 100V VITRAMON VP12BA220J C78 1028347U ceramic 33p 5% 100V VITRAMON VP12BA330J C79 1026345T metal polyester 10n 10% 63V WIMA MKS2 DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1 1030379C multiplexer PHILIPS HEF4053BD D2 3A72502 PLD monitor bus interface 3A72502 D3, 6, 7, 12, 20, 21, 25 1033775U octal buffer RCA CD74HC541E D4, 8, 16, 48 1035245R octal bus transceiver TEXAS SN74HC245N D5, 22, 27 PHILIPS HEF4051BD 1028716V multiplexer D9 4A72502 PLD monitor width counter 4A72502 D10 5A72502 PLD monitor fall counter 5A72502 D11 6A72502 PLD monitor rise counter 6A72502 D13 7A72502 PLD monitor fault driver 7A72502 D14, 15
1036477F octal D-type latch NATIONAL MM74HC573N
D17 8A72502 PLD pulse shape error counter 1 8A72502 D18, 35, 38, 41, 42 1030185R dual precision monostable PHILIPS HEF4538BD D19 9A72502 PLD monitor clock 1 9A72502 D23 10A72502 PLD pulse shape error counter 2 10A72502 D24 11A72502 PLD monitor clock 2 11A72502 D26 1032799H hex inverting Schmitt trigger NATIONAL MM74HC14N D28 1036595J 8-bit a/d converter NATIONAL ADC0820BCD D29, 32
1036730F hex non-inverting buffer NATIONAL MM74HC4050N
D30 12A72502 PLD monitor delay counter 12A72502 D31 13A72502 PLD monitor spacing counter 13A72502 D33 14A72502 PLD ident extraction 14A72502 D34, 36, 39, 43 1030186T BCD rate multiplier PHILIPS HEF4527BD D37 15A72502 PLD primary error counter 15A72502 D40 17A72502 PLD monitor ident counter 17A72502
HA72500 APPENDIX F
F-12
D44 1028410M hex inverter PHILIPS HEF4049BD D45 18A72502 PLD monitor rate counter 18A72502 D46 1028749F quad 2-input NOR PHILIPS HEF4001BD D47 19A72502 PLD ident error counter 19A72502 D49 20A72502 PLD monitor efficiency counter 20A72502 D50 1033555E hex inverter PHILIPS PC74HCU04P D51 16A72502 PLD mon inhibit device driver 16A72502 CRYSTALS REF CODE DESCRIPTION MFR/SUPPLIER REF G1 1028733N 10.0 MHz QC-49 HY-Q EE01C/QC49 INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1-8, 13
1036586Z green LED HP HLMP-3502-010
H9, 11 1036587A yellow LED HP HLMP-3400-010 H10, 12
1036588B red LED HP HLMP-3300-010
ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1 1036584X dual op amplifier RCA CA3240AE N2, 7, 9
1036504K quad comparator NATIONAL LM239N
N3, 5 1036594H precision 5V reference MAXIM REF02 N4, 8 1030766Y voltage regulator 1.2 to 33V NATIONAL LM150K N6 1036593G voltage regulator 1.2 to 37V SGS-THOMSON LM217T RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 89 1020019R wire wound 3R3 5% 5W0 IRH ASW-5 R2, 52, 86, 100, 101 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R3, 80, 85, 93,108 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R4, 6, 7, 12, 15. 23, 24, 26, 68 1008739F metal film 511 1% 0W4 ROEDERSTEIN MK2 R5, 57, 61
1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2
R8 1008773T metal film 13k 1% 0W4 ROEDERSTEIN MK2 R9, 56, 71, 90-92, 94, 103 1008794Q metal film 100k 1% 0W4 ROEDERSTEIN MK2 R10, 20, 27
1008720K metal film 82R5 1% 0W4 ROEDERSTEIN MK2
R11, 21, 22, 72, 73, 99 1029244U metal film 0R0 1% 0W4 ROEDERSTEIN MK2 R13, 17, 41, 42, 44, 54, 77 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2 R14 1008776W metal film 18k2 1% 0W4 ROEDERSTEIN MK2 R16, 37, 38, 50 1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2 R18 1008777X metal film 20k 1% 0W4 ROEDERSTEIN MK2 R19 1008802Z metal film 221k 1% 0W4 ROEDERSTEIN MK2 R28, 29, 43, 75, 97 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R30, 31
1008728U metal film 182 1% 0W4 ROEDERSTEIN MK2
R32 1008768M metal film 8k25 1% 0W4 ROEDERSTEIN MK2 R33 1008782C metal film 33k2 1% 0W4 ROEDERSTEIN MK2 R34, 35
1036495A metal film 30k1 1% 0W4 ROEDERSTEIN MK2
R36 1008780A metal film 27k4 1% 0W4 ROEDERSTEIN MK2 R39, 46, 58
1036496B metal film 10k 0.1% 0W1 PHILIPS 2322-160-41003
R40 1021552H metal film 10M 1% 0W4 ROEDERSTEIN MK2
HA72500 APPENDIX F
F-13
R45 1008763G metal film 5k11 1% 0W4 ROEDERSTEIN MK2 R47 1008751U metal film 1k62 1% 0W4 ROEDERSTEIN MK2 R48, 49, 95
1008760D metal film 3k92 1% 0W4 ROEDERSTEIN MK2
R51, 53
1008756Z metal film 2k74 1% 0W4 ROEDERSTEIN MK2
R55, 98
1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2
R59, 69, 70,102 1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2 R60 1008810H metal film 475k 1% 0W4 ROEDERSTEIN MK2 R62 1008735B metal film 365 1% 0W4 ROEDERSTEIN MK2 R63 1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2 R64, 74
1008764H metal film 5k62 1% 0W4 ROEDERSTEIN MK2
R65, 66
1008798V metal film 150k 1% 0W4 ROEDERSTEIN MK2
R67, 78. 79, 83 1008786G metal film 47k5 1% 0W4 ROEDERSTEIN MK2 R76 1008795R metal film 110k 1% 0W4 ROEDERSTEIN MK2 R81 1008761E metal film 4k32 1% 0W4 ROEDERSTEIN MK2 R82 1008749R metal film 1k3 1% 0W4 ROEDERSTEIN MK2 R84 1008733Z metal film 301 1% 0W4 ROEDERSTEIN MK2 R88 1008726R metal film 150 1% 0W4 ROEDERSTEIN MK2 R96 1021496X metal film 681k 1% 0W4 ROEDERSTEIN MK2 R104, 106
1008730W metal film 221 1% 0W4 ROEDERSTEIN MK2
R105 1008755Y metal film 2k43 1% 0W4 ROEDERSTEIN MK2 R107 1008753W metal film 2k0 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R87 1028760T Cermet 1-turn 10k 10% 0W5 BOURNS 3386F-1-103 RESISTORS, NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN1-3, 22, 33, 34 1026493D SIP 10-pin 1kx9 2% 1W25 BOURNS 4310R-101-102 RN4, 12, 18
1032352X SIP 10-pin 47kx9 2% 1W25 BOURNS 4610X-101-473
RN5-10, 15, 16, 19, 26-29, 31, 32, 36-39 1036556R SIP 10-pin 3k3x5 2% 1W25 BOURNS 4610-X-102-332 RN13, 14, 17, 20, 23-25, 30 1028389P SIP 10-pin 15kx9 2% 1W25 BOURNS 4310R-101-153 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1-4, S7-10
1026437T DIL SPST 8-way CTS 206-8-LPST
S12, 13
1036685G DIL SPST 10-way CTS 206-10-LPST
S16 1036573K toggle DPDT C&K 7201-M-D9-A-B-E SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 4. 5
1005279V zener diode 10V PHILIPS BZC79/C10
V2, 6 1026172E low power PNP transistor PHILIPS 2N2907A V3, 11, 12
1006793Q switching diode FAIRCHILD 1N914A
V7 1030394U zener diode 3V3 PHILIPS BZX79/B3V9 V8, 9 1036408F Schottky diode IRC 1N5818 V10 1004812M rectifier diode IRC 1N4004
HA72500 APPENDIX F
F-14
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XA1-5 1030153G test jack SCOTT 4879-125-0 XN1 1036519B plug 96-way SIEMENS V42254-B1400-C910 XN2 1036522E header 20-way SIEMENS V23535-A2200-A200 XT1-11, 14-16 1036570G test terminal white WILLIAM HUGHES 101 XT13 1036569F test terminal black WILLIAM HUGHES 103
F.5.15 1A72512 Peak Power Monitor CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 2, 8
1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805 Q220 JXA-AB
C3, 9 1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K C4 1026333E metal polyester 1n 10% 100V WIMA FKS2 C5, 11 1018878B ceramic monolyth 100n 10% 100V VITRAMON CK06BX104K C6, 7, 10
1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9
ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1-3 1036584X dual operational amplifier RCA CA3240AE N4 1028415T dual comparator NATIONAL LM219J RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 31 1035042W chip 110 1% 0W25 ROHM MCR18X 1100F EZH R2 1008776W metal film 18k2 1% 0W4 ROEDERSTEIN MK2 R3 1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2 R4 1008742J metal film 681 1% 0W4 ROEDERSTEIN MK2 R5 1008781B metal film 30k1 1% 0W4 ROEDERSTEIN MK2 R6 1008760D metal film 3k92 1% 0W4 ROEDERSTEIN MK2 R7, 8, 19. 21, 22, 26-28 1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2 R9, 12 1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2 R10 1021545A metal film 2M21 1% 0W4 ROEDERSTEIN MK2 R13 1008767L metal film 7k5 1% 0W4 ROEDERSTEIN MK2 R14 1008743K metal film 750 1% 0W4 ROEDERSTEIN MK2 R18, 20
1008780A metal film 27k4 1% 0W4 ROEDERSTEIN MK2
R29 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 R30 1035090Y chip 82k5 1% 0W125 ROHM MCR18X 823F EZH SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 2 1019399T hot carrier diode HP 5082-2817 or 5082-2811 V3 1026172E low power PNP transistor PHILIPS 2N2907A CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XC1 1028757P coaxial SMA jack SUHNER 21SMA-50-3-15 XN2 72512-4-24 header 2-row 10-way 72512-4-24
F.5.16 1A72513 Transponder Subrack CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72513-4-11 coaxial jack 72513-4-11 1 72513-4-12 coaxial jack 72513-4-12
HA72500 APPENDIX F
F-15
F.5.17 1A72514 Test Interrogator SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72515 Main PWB Assembly, Test Interrogator 1A72515 A2 1A72516 RF Generator 1A72516 A3 1A69737 Attenuator 1A69737 A4 1A72518 Modulator and Detector 1A72518 A5 1A72519 Reply Detector 1A72519 ATTENUATORS QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 1030202K fixed coaxial 50 ohms SMA 20dB MICROLAB/FXR AG-20F 1 1030203L fixed coaxial 50 ohms SMA 30dB MICROLAB/FXR AG-30F CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72514-4-12 coaxial BNC/SMA 72514-4-12 1 72514-4-13 coaxial BNC/SMA 72514-4-13 1 72514-4-14 coaxial SMA/SMA 72514-4-14 1 72514-4-16 single 72514-4-16
F.5.18 1A72515 Test Interrogator Main PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 48, 61, 74, 77 1004863T ceramic monolyth 10n 10% 100V VITRAMON CK05BX103K C2, 3, 5, 7, 14, 16, 18-27, 29, 30, 32-41, 43, 45-47, 49-52, 55, 57-60, 62-71, 78
1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C4 1026352A metal polyester 33n 10% 63V WIMA MKS2 C6, 17 1030190X ceramic 100p 5% 100V VITRAMON VP12BA101J C8 1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9 C9 1026365P metal polyester 470n 10% 63V WIMA MKS2 C10, 11
1036508P electrolytic tantalum 33u 20% 10V SIEMENS B45170-A1336-M9
C12, 79
1026369U electrolytic tantalum 1u 10% 50V WIMA MKS2
C13 1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4336-M9 C15 1026350Y metal polyester 22n 10% 63V WIMA MKS2 C31, 76
1028735Q ceramic monolyth 330p 10% 100V PHILIPS 2222-630-08331
C42 1028736R ceramic monolyth 470p 10% 100V PHILIPS 2222-630-08471 C44, 75
1028893M ceramic 150p 5% 100V PHILIPS 2222-678-34151
C56 1026354C metal polyester 47n 10% 63V WIMA MKS2 C72 1028394V ceramic 22p 5% 100V VITRAMON VP12BA220J C73 1028347U ceramic 33p 5% 100V VITRAMON VP12BA330J DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1, 4, 17
1028747D 1-64 bit shift register PHILIPS HEF4557BD
D2, 5, 29, 38
1028375Z dual monostable PHILIPS HEF4528BD
D3, 18, 40
1028741X 4-bit decimal counter PHILIPS HEF40160BD
D6, 41 1030379C multiplexer PHILIPS HEF4053BD D8, 42 1028716V multiplexer PHILIPS HEF4051BD D10, 20, 36, 50 1036730F hex buffer NATIONAL MM74HC4050N D12, 25, 27
1033775U octal non-inverting buffer RCA CD74HC541E
HA72500 APPENDIX F
F-16
D13, 14, 24
1036477F octal D latch NATIONAL MM74HC573N
D15 1035245R octal bus transceiver TEXAS SN74HC245N D16, 47
1032799H hex inverting Schmitt trigger NATIONAL MM74HC14N
D19 1028402D quad 2-input NAND PHILIPS HEF4011BD D21, 32, 49
1036729E hex inverter NATIONAL MM74HC4049
D26 22A72502 PLD TI bus interface 22A72502 D28 1028743Z 8-input tristate multiplexer PHILIPS HEF4512BD D30 1028401C quad XOR PHILIPS HEF4070BD D31 1028379D dual JK flip-flop PHILIPS HEF4027BD D33 21A72502 PLD TI timer counter 21A72502 D34, 35
1036502H programmable interval timer INTEL TP82C54-2
D37 1028409L hex Schmitt trigger PHILIPS HEF40106BD D39 1028378C BCD up/down counter PHILIPS HEF4510BD D43-46
1036551L 4-bit BCD down counter PHILIPS HEF4522BD
D48 1028749F quad 2-input NOR PHILIPS HEF4001BD D51, 52
1028410M hex inverter PHILIPS HEF4049BD
CRYSTALS REF CODE DESCRIPTION MFR/SUPPLIER REF G1 1028733N 10.0 MHz HY-Q EE01C/QC49 INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1 1036588B red LED HP HLMP-3300-010 H2 1036586Z green LED HP HLMP-3502-010 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1 1036118Q voltage regulator +15V NATIONAL LM140AK-15 N2 1036554P voltage regulator +5V MOTOROLA LM140AK-5.0 N3 1028415T dual comparator NATIONAL LM219J N4-7 1036504K quad comparator NATIONAL LM239N RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 19, 45, 47, 60, 61 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R2, 4, 14, 18, 25 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R3, 11, 52
1008738E metal film 475 1% 0W4 ROEDERSTEIN MK2
R5, 6 1036496B metal film 10k 0.1% 0W1 PHILIPS 2322-160-41003 R8 1036576N wire wound 6R8 5% 6W5 IRH ASW-5 R9 1036578Q wire wound 68 5% 6W5 IRH ASW-5 R10 1008766K metal film 6k81 1% 0W4 ROEDERSTEIN MK2 R18, 24, 44
1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2
R20, 21, 30, 57 1008786G metal film 47k5 1% 0W4 ROEDERSTEIN MK2 R22 1008743K metal film 750 1% 0W4 ROEDERSTEIN MK2 R23, 51
1008748Q metal film 1k21 1% 0W4 ROEDERSTEIN MK2
R36 1008790L metal film 68k1 1% 0W4 ROEDERSTEIN MK2 R27 1008798V metal film 150k 1% 0W4 ROEDERSTEIN MK2 R28, 59
1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2
R29 1008735B metal film 365 1% 0W4 ROEDERSTEIN MK2 R31, 43
1008764H metal film 5k62 1% 0W4 ROEDERSTEIN MK2
R32 1008761E metal film 4k32 1% 0W4 ROEDERSTEIN MK2
HA72500 APPENDIX F
F-17
R36, 37, 53
1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2
R38 1008782C metal film 33k2 1% 0W4 ROEDERSTEIN MK2 R40, 41, 49, 54, 55 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2 R42 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R48 1008794Q metal film 100k 1% 0W4 ROEDERSTEIN MK2 R56 1008767L metal film 7k5 1% 0W4 ROEDERSTEIN MK2 R62 1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R7 1028760T cermet 1-turn 10k 10% 0W5 BOURNS 3386F-1-103 RESISTOR NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN1, 2, 4, 10 1036531P SIP 8-pin 1kx4 2% 1W BOURNS 4608X-102-102 RN3, 6, 8, 9, 12, 15 1028389P SIP 10-pin 15kx9 2% 1W25 BOURNS 4310R-101-153 RN5, 11, 17
1036555Q SIP 8-pin 100x4 2% 1W BOURNS 4608X-102-101
RN7, 13, 14
1032352X SIP 10-pin 47kx9 2% 1W BOURNS 4610X-101-473
RN16 1036532Q SIP 8-pin 15kx4 2% 1W BOURNS 4608X-102-153 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1 1036572J pushbutton DPDT C&K 8225-S-D9-A-B-E S2, 3 1036499E toggle DPDT centre off C&K 7205-S-D9-A-B-E S4 1030651Y slide SPDT C&K 1101-M2-S3-CB-E S5, 6 1036500F rotary hex coded ELMA 07-4153 S7 1036501G toggle DPDT centre off C&K 7203-M-D9-A-B-E SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 4, 9
1026171D low power NPN transistor PHILIPS 2N2222A
V2 1030231R high power NPN transistor MOTOROLA 2N6488 V3 1026172E low power PNP transistor PHILIPS 2N2907A V5, 7, 8, 15
1036408F rectifier diode MOTOROLA 1N5818
V6, 14 1004812M rectifier diode IRC 1N4004 V10-12
1006793Q switching diode FAIRCHILD 1N914A
V13 1030394U zener diode PHILIPS BZX79/B3V9 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XA1-13
1030153G test jack SCOTT 4879-125-0
XN 1036519B plug 96-way SIEMENS V42254-B1400-C910 XN2 1036522E header 20-way SIEMENS V23535-A2200-A200 XT1-4, 6-12 1036570G test terminal white WILLIAM HUGHES 101 XT5, 13
1036569F test terminal black WILLIAM HUGHES 103
HA72500 APPENDIX F
F-18
F.5.19 1A72516 RF Generator CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 5, 11
1028736R ceramic monolyth 470p 10% 100V PHILIPS 2222-630-08471
C2, 12 1030189W ceramic 10p 5% 100V PHILIPS 2222-678-10109 C3 1028928A ceramic 15p 5% 100V VITRAMON VP12BA150JB C4 1026345T metal polyester 10n 10% 63V WIMA MKS2 C6, 24-28, 35 1036605V ceramic chip 22p 5% 50v VITRAMON VJ0805 C7 1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102 C8, 33, 37
1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K
C9 1026365P metal polyester 470n 10% 63V WIMA MKS2 C13, 15, 16, 19, 20, 32 1030190X ceramic 100p 5% 100V VITRAMON VP12BA101J C17, 36
1030211V ceramic 2p2 0p25 100V PHILIPS 2222-680-09228
C21, 23
1036651V ceramic 1p 0p25 100V PHLIPS 2222-678-03108
C29 1033084T ceramic chip 10n 10% 50V VITRAMON VJ0805Y103KXAMT C30 1030214Y ceramic chip 5p6 nom 50V VITRAMON 7800P7G02F C34 1033436A ceramic chip 100p 5% 50V VITRAMON VJ0805A101JXAMT CAPACITORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C10 1005194C PTFE film 2-18p 300V PHILIPS 2222-809-05003 C14 1005195D PTFE film 1p8-10p 500V PHILIPS 2222-809-05002 C18 1028813A trimmer 0p6-4p5 JOHANSON GIGATRIM 7273 INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1 57973V284 57973V284 L2 57973V285 57973V285 L3 72516-4-27 72516-4-27 L4 72516-4-28 72516-4-28 L6, 7 1025352N 0u39 0W17 MILLER 9230-10 RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 14 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R2, 12, 13
1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2
R3 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 R4, 19 1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2 R5, 9, 17, 26
1008734A metal film 332 1% 0W4 ROEDERSTEIN MK2
R6 1008742J metal film 681 1% 0W4 ROEDERSTEIN MK2 R7 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R8, 33, 34
1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2
R10, 29, 30
1008746N metal film 1k0 1% 0W4 ROEDERSTEIN MK2
R11 1008766K metal film 6k81 1% 0W4 ROEDERSTEIN MK2 R13 1008730W metal film 221 1% 0W4 ROEDERSTEIN MK2 R15, 24
1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2
R16, 18
1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2
R18, 22
1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2
R20 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2 R21 1008756Z metal film 2k74 1% 0W4 ROEDERSTEIN MK2 R23 1008784E metal film 39k2 1% 0W4 ROEDERSTEIN MK2
HA72500 APPENDIX F
F-19
R25, 27
1008706V metal film 22R1 1% 0W4 ROEDERSTEIN MK2
R31 1008726R metal film 150 1% 0W4 ROEDERSTEIN MK2 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1 1027485G slide SPST DIP CTS 206-006-LPST SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1-5 906654U NPN transistor MOTOROLA 2N2857 V6 1027618B HF amplifier NPN MOTOROLA MRF901 V7 1033538L transistor microwave AVANTEK AT-01635 V8 1026172E NPN transistor PHILIPS 2N2907A V9 1019399T hot carrier diode HP 5082-2817 or 5082-2811 V10 1026171D NPN transistor PHILIPS 2N2222A V11, 12
1006793Q switching diode FAIRCHILD 1N914A
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XS1-6 1028758Q jack CAMBION 450-3704-01-03-00 XT1-4 1036570G test terminal white WILLIAM HUGHES 101 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72552-4-06 coaxial 72552-4-06
F.5.20 1A72517 RF Filter CAPACITORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 2 1030213X trimmer 0P8-8p JOHANSON GIGATRIM 27293 INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1 72517-4-08 72517-4-08 L2 72517-4-09 72517-4-09 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XC1 1028851R coaxial SMA receptacle SUHNER 13SMA-50-0-52/199 XC2 1028908D stripline launcher SMA SUHNER 23SMA-50-0-52/199
F.5.21 1A72518 Modulator and Detector CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 3, 4, 7, 14, 25 1030188V ceramic 1n 10% 100V PHILIPS 2222-630-01802 C2, 9 1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K C5, 6, 10, 12, 13, 16, 18, 19, 23, 24 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C11 1026365P metal polyester 470n 10% 63V WIMA MKS2 C15, 20, 22
1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9
C17 1026339L metal polyester 3n3 10% 100V WIMA FKS2 C21 1030190X ceramic 100p 5% 100V VITRAMON VP12ABA101J C26-31
1036633A ceramic feedthru 100p 80% 100V SPECTRUM 5471300X5F101M
HA72500 APPENDIX F
F-20
DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1 1028749F quad 2-input NOR PHILIPS HEF4001BD D2 1028754L analogue mux/demux PHILIPS HEF4052BD ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1-4 1036584X dual operational amplifier RCA CA3240AE N5, 6 1028415T dual comparator NATIONAL LM219J RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1008710Z metal film 33R2 1% 0W4 ROEDERSTEIN MK2 R2 1008792N metal film 82k5 1% 0W4 ROEDERSTEIN MK2 R3 1008776W metal film 18k2 1% 0W4 ROEDERSTEIN MK2 R4 1008781B metal film 30k1 1% 0W4 ROEDERSTEIN MK2 R5 1008760D metal film 3k92 1% 0W4 ROEDERSTEIN MK2 R6 1008756Z metal film 2k74 1% 0W4 ROEDERSTEIN MK2 R7 1008742J metal film 681 1% 0W4 ROEDERSTEIN MK2 R8, 25, 28
1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2
R9 1008781B metal film 30k1 1% 0W4 ROEDERSTEIN MK2 R10, 23, 24, 38 1008762F metal film 475 1% 0W4 ROEDERSTEIN MK2 R11 1008767L metal film 7k5 1% 0W4 ROEDERSTEIN MK2 R12 1008743K metal film 750 1% 0W4 ROEDERSTEIN MK2 R14, 32, 51
1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2
R15 1008768M metal film 8k25 1% 0W4 ROEDERSTEIN MK2 R16, 21, 22, 31 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2 R17 1021545A metal film 2M21 1% 0W4 ROEDERSTEIN MK2 R18 1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2 R19 1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2 R26, 27
1008789K metal film 61k9 1% 0W4 ROEDERSTEIN MK2
R29 1008757A metal film 3K01 1% 0W4 ROEDERSTEIN MK2 R30 1008754X metal film 2K21 1% 0W4 ROEDERSTEIN MK2 R33 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R34, 39, 43, 47 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 R35 1008772R metal film 12k1 1% 0W4 ROEDERSTEIN MK2 R36, 52
1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2
R40, 42, 44, 45, 50 1008738E metal film 475 1% 0W4 ROEDERSTEIN MK2 R41 1008736C metal film 392 1% 0W4 ROEDERSTEIN MK2 R46, 48
1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2
R49 1008786G metal film 47k5 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R13, 37
1028756N cermet 1 -turn 2k 10% 0W5 BOURNS 3386F-1-202
R20 1028760T cermet 1 -turn 10k 10% 0W5 BOURNS 3386F-1-303 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1 1030651Y slide SPDT C&K 1101-M2-S3-CB-E
HA72500 APPENDIX F
F-21
SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1019399T hot carrier diode HP 5082-2817 or 5082-2811 V2 1026172E low power PNP transistor PHILIPS 2N2907A V3, 10-12
1026171D low power NPN transistor PHILIPS 2N2222A
V5, 9 1006793Q switching diode FAIRCHILD 1N914A CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XS1-14
1028758Q jack CAMBION 450-3704-01-03-00
XT1-4 1036570G test terminal white WILLIAM HUGHES 101 XT5, 6 1036569F test terminal black WILLIAM HUGHES 103 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 6 72518-4-15 7-way D-Type 72518-4-15 1 72518-3-29 20-way ribbon 72518-3-29
F.5.22 1A72519 Reply Detector CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 2, 11
1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805-Q220-JXA-AB
C3, 10 1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K C4 1026333E metal polyester 1n 10% 100v WIMA FKS2 C5, 7, 8, 12, 13 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C6 1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9 C9 1030188V ceramic 1n 10% 100v PHILIPS 2222-630-08102 C14, 15
1030190X ceramic 100p 5% 100V VITRAMON VP12BA101J
DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1 1030379C multiplexer PHILIPS HEF4053BD D2 1036596K quad XOR PHILIPS HEF4077BD D3 1028749F quad 2-input NOR PHILIPS HEF4001BD ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1-3 1036584X dual op amplifier RCA CA3240AE N4, 5 1028415T dual comparator NATIONAL LM219J RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 22 1035042W chip 110 1% 0W125 ROHM MCR18X 1100F EZH R2 1008776W metal film 18k2 1% 0W4 ROEDERSTEIN MK2 R3 1008748Q metal film 1k21 1% 0W4 ROEDERSTEIN MK2 R4 1008734A metal film 332 1% 0W4 ROEDERSTEIN MK2 R5 1008781B metal film 30k1 1% 0W4 ROEDERSTEIN MK2 R6 1008760D metal film 3k92 1% 0W4 ROEDERSTEIN MK2 R7-9, 18-21
1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2
R10 1021545A metal film 2M21 1% 0W4 ROEDERSTEIN MK2 R11, 14
1008747P metal film 1k1 1% 0W4 ROEDERSTEIN MK2
R12, 13
1008761E metal film 4k32 1% 0W4 ROEDERSTEIN MK2
R15-17
1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2
HA72500 APPENDIX F
F-22
R23, 25
1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2
R24 1008767L metal film 7k5 1% 0W4 ROEDERSTEIN MK2 R26 1036694R metal film 4M7 5% 0W5 PHILIPS 2322-186-13475 R27, 28
1008754X metal film 2K21 1% 0W4 ROEDERSTEIN MK2
R29 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 R30 1035090Y chip 82k5 1% 0W125 ROHM MCR18X 823F EZH R31 1008743K metal film 750 1% 0W4 ROEDERSTEIN MK2 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 2 1019399T hot carrier diode HP 5082-2817 or 5082-2811 V3 1026172E low power PNP transistor PHILIPS 2N2907A CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XC1 1028757P coaxial jack SMA SUHNER 21SMA-50-3-15
F.5.23 1A72520 Receiver Video SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72521 Main PWB Assembly, Receiver Video 1A72521 A2 1A72522 RF Source 1A72522 A3 1A72523 IF Amplifier 1A72523 A4 1A72524 RF Amplifier 1A72524 A5 1A72517 RF Filter 1A72517 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72520-4-14 coaxial BNC/SMA 72520-4-14 1 72520-4-15 coaxial BNC/SMA 72520-4-15 1 72520-4-16 coaxial SMA/SMA 72520-4-16 1 72520-4-21 coaxial SMA/SMA 72520-4-21 1 72520-4-18 ribbon 20-way 72520-4-18
F.5.24 1A72521 Receiver Video Main PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 3-12, 16-20, 23, 28-32, 34-37, 40-42, 44-47, 49-51, 53-55, 58-62, 66, 68-74, 76-78, 80-90, 92, 99, 100
1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C2, 15, 21, 33, 52, 79 1030190X ceramic 100p 5% 100V VITRAMON VP12BA101J C13, 14
1028347U ceramic 33p 5% 100V VITRAMON VP12BA330J
C22, 48, 57, 97, 98 1026345T metal polyester 10n 10% 63V WIMA MKS2 C24, 26, 27, 39, 43 1028882A ceramic monolyth 220p 10% 100V PHILIPS 2222-630-08221 C25 1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102 C38 1026365P metal polyester 470n 10% 63V WIMA MKS2 C63, 64, 67
1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9
C75, 91
1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9
C93, 95, 96
1026369U electrolytic tantalum 1u 10% 50V WIMA MKS2
HA72500 APPENDIX F
F-23
DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1 1028410M hex inverter PHILIPS HEF4049BD D2, 3, 14, 20, 35 1028375Z dual monostable PHILIPS HEF4528BD D4 1028382G tristate hex inverter PHILIPS HEF40098BD D5, 6, 18
1028376A 4-bit up/down binary counter PHILIPS HEF40193BD
D8 1028775J 14-stage fipple carry counter PHILIPS HEF4060BD D9, 28 1028749F quad 2-input NOR PHILIPS HEF4001BD D10 1030185R dual precision monostable PHILIPS HEF4538BD D11, 29, 30, 36, 39, 40, 43, 46 1028407J 4-bit binary down counter PHILIPS HEF4526BD D12 1028754L analogue mux/demux PHILIPS HEF4052BD D13, 21-25, 31-34, 42 1028747D 1-64 bit shift register PHILIPS HEF4557BD D15 1028887F 8-bit static shift register PHILIPS HEF4021BD D16 1028744A 5-stage Johnson counter PHILIPS HEF4017BD D17 1028475B quad 2-input NAND PHILIPS HEF4093BD D19 1030379C multiplexer PHILIPS HEF4053BD D26, 48
1028885D dual D flip-flop PHILIPS HEF4013BD
D27, 41, 52, 53 1028402D quad 2-input NAND PHILIPS HEF4011BD D37, 45, 47, 50 1028716V multiplexer PHILIPS HEF4051BD D38 57945V48 delay line 57945V48 D44 1030546J dual timer NATIONAL LM556J D49 1028886E 12-stage binary counter PHILIPS HEF4040BD D51 1028379D dual JK flip-flop PHILIPS HEF4027BD CRYSTALS REF CODE DESCRIPTION MFR/SUPPLIER REF G1 1028884C 5.5296 MHz HY-Q EE01C/QC18 INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1 1036587A yellow LED HP HLMP-3400-010 H2 1036588B red LED HP HLMP-3300-010 H3 1036586Z green LED HP HLMP-3502-010 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1 1036118Q voltage regulator +15V NATIONAL LM140AK-15 N2-4 1036504K quad comparator NATIONAL LM239N N5, 8 1028415T dual comparator NATIONAL LM219J N6, 7, 10
1036584X dual op amplifier RCA CA3240AE
RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 2, 9, 10, 26, 33, 41, 42, 47, 60, 70, 71, 79, 80 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R3, 5, 7, 53, 54, 59 1008794Q metal film 100k 1% 0W4 ROEDERSTEIN MK2 R4 1008799W metal film 162k 1% 0W4 ROEDERSTEIN MK2 R6 1008780A metal film 27k4 1% 0W4 ROEDERSTEIN MK2 R8, 11, 21
1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2
R12 1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2 R13, 62, 63
1008786G metal film 47k5 1% 0W4 ROEDERSTEIN MK2
R14, 17,29
1008798V metal film 150k 1% 0W4 ROEDERSTEIN MK2
R15, 18, 19, 32, 55, 72, 74, 81 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2
HA72500 APPENDIX F
F-24
R16, 75, 76, 82
1008810H metal film 475k 1% 0W4 ROEDERSTEIN MK2
R20, 23, 34, 51, 66-68 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R22, 69
1008788J metal film 56k2 1% 0W4 ROEDERSTEIN MK2
R24, 40, 43, 50 1008764H metal film 5k62 1% 0W4 ROEDERSTEIN MK2 R25 1008760D metal film 3k92 1% 0W4 ROEDERSTEIN MK2 R27 1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2 R28 1008735B metal film 365 1% 0W4 ROEDERSTEIN MK2 R31 1008782C metal film 33k2 1% 0W4 ROEDERSTEIN MK2 R35 1008748Q metal film 1k21 1% 0W4 ROEDERSTEIN MK2 R36 1008732Y metal film 274 1% 0W4 ROEDERSTEIN MK2 R38 1008803A metal film 243k 1% 0W4 ROEDERSTEIN MK2 R44 1008736C metal film 392 1% 0W4 ROEDERSTEIN MK2 R48 1008740G metal film 562 1% 0W4 ROEDERSTEIN MK2 R49 1008756Z metal film 2k74 1% 0W4 ROEDERSTEIN MK2 R52, 61
1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2
R56, 57, 64
1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2
R58 1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2 R65 1008768M metal film 8k25 1% 0W4 ROEDERSTEIN MK2 R73 1036576N wire wound 6R8 5% 6W5 IRH ASW-5 R77, 78
1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2
RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R37 1030146Z cermet 1-turn 100k 10% 0W5 BECKMAN 72PMR100K R39 1030542E cermet 1-turn 1M 10% 0W5 BOURNS 3386F-1-105 R45, 46
1028760T cermet 1-turn 10k 10% 0W5 BOURNS 3386F-1-103
RESISTOR NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN1-2, 6, 13-16 1028389P SIP 10-pin 15kx9 2% 1W25 BOURNS 4310R-101-153 RN3, 7-12
1036532Q SIP 8-pin 15kx4 2% 1W BOURN S 4608X-102-153
RN4 1036531P SIP 8-pin 1kx4 2% 1W BOURNS 4608X-102-102 RN5 1041467E SIP 8-pin 4k7x4 2% 1W BOURNS 4608X-104-104 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1-3 1036500F rotary hex coded ELMA 07-4153 S4, 5, 8, 9
1030651Y slide SPDT C&K 110 -M2-S3-CB-E
S6, 7 1036520C rotary hex coded SIEMENS C42315-A1353-A10 S11 1036501G toggle DPDT centre off C&K 7203-M-D9-A-B-E S12 1036499E toggle DPDT centre off C&K 7205-S-D9-A-B-E S13-16
1026437T DIL SPST 8-way CTS 206-8-LPST
SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1-10, 13,16-21 1006793Q switching diode FAIRCHILD 1N914A V11 1030394U zener diode 3V3 PHILIPS BZX79/B3V9 V14 1026171D low power NPN transistor PHILIPS 2N2222A V15 1026172E low power PNP transistor PHILIPS 2N2907A V22 1006326H zener diode 5V6 PHILIPS BZX79/C5V6
HA72500 APPENDIX F
F-25
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XA1-13
1030153G test jack SCOTT 4879-125-0
XN1 1036519B plug 96-way SIEMENS V42254-B1400-C910 XN2 1036522E header 20-way SIEMENS V23535-A2200-A200 XT1-14, 16, 18-20, 22-26 1036570G test terminal white WILLIAM HUGHES 101 XT15, 17, 21
1036569F test terminal black WILLIAM HUGHES 103
F.5.25 1A72522 RF Source CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 6 1028736R ceramic monolyth 470p 10% 100V PHILIPS 2222-630-08471 C2 1030189W ceramic 10p 5% 100V PHILIPS 2222-678-10109 C3 1004836T ceramic monolyth 10n 10% 100V VITRAMON CK05BX103K C5, 28, 29
1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K
C7 1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102 C9 1028736R ceramic monolyth 470p 10% 100V PHILIPS 2222-630-08471 C10 1028347U ceramic 33p 5% 100V VITRAMON VP12BA330J C11 1028928A ceramic 15p 5% 100V VITRAMON VP12BA150JB C13, 14, 17, 19, 22 1030190X ceramic 100p 5% 100V VITRAMON VP12BA101J C15, 20
1030211V ceramic 2p2 0p25 100V PHILIPS 2222-680-09228
C22, 24, 25
1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805Q220JXA-AB
C23 1028930C ceramic 3p3 0p25 100V PHILIPS 2222-678-09338 C27 1036651V ceramic 1p 0p25 100V PHILIPS 2222-678-03108 C31 1033436A ceramic chip 100p 5% 50V MURATA GR40-C06-101J-50V-M6 C32 1032940L ceramic chip 10p 5% 50V VITRAMON VJ0805-A100-JXAMT CAPACITORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C8 1005194C PTFE film 2-18p 300V PHILIPS 2222-809-05003 C12 1005195D PTFE film 1p8-10p 500V PHILIPS 2222-809-05002 C18, 26
1030213X trimmer 0p8-8p0
JOHANSON GIGATRIM 27293
CRYSTALS REF CODE DESCRIPTION MFR/SUPPLIER REF G1 Frequency is determined by DME operating
channel. Refer to crystal specification in Appendix N.
INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1 57973V284 57973V284 L2 57973V285 57973V285 L3 72522-4-32 72522-4-32 L4 69734-4-17 69734-4-17 L5 69734-4-18 69734-4-18 L6 405355D 0u82 0W25 MILLER 9310-10
HA72500 APPENDIX F
F-26
RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2 R2 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R3, 9 1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2 R4 1008742J metal film 681 1% 0W4 ROEDERSTEIN MK2 R5, 12, 13, 17, 20, 22 1008734A metal film 332 1% 0W4 ROEDERSTEIN MK2 R6 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R7, 16 1008730W metal film 221 1% 0W4 ROEDERSTEIN MK2 R8 1008766K metal film 6k81 1% 0W4 ROEDERSTEIN MK2 R10 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R11 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 R14, 18, 24
1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2
R15 1008756Z metal film 2k74 1% 0W4 ROEDERSTEIN MK2 R19 1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2 R21 1008726R metal film 150 1% 0W4 ROEDERSTEIN MK2 R23 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1-4 906654U low power NPN transistor MOTOROLA 2N2857 V5 1027618B HF amplifier NPN MOTOROLA MRF901 CONNECTORS REF/QTY
CODE DESCRIPTION MFR/SUPPLIER REF
XS1, 2
1028758Q jack CAMBION 450-3704-01-03-00
XT1-4 1036570G test terminal white WILLIAM HUGHES 101 1 72522-4-06 connector assembly 72522-4-06
F.5.26 1A72523 IF Amplifier CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C2 1028347U ceramic 33p 5% 100V VITRAMON VP12BA330J C3, 7, 13, 14, 16, 26 1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102 C4, 8, 9, 12, 24, 25, 34 1004863T ceramic monolyth 10n 10% 100V VITRAMON CK05BX103K C5, 36 1028736R ceramic monolyth 470p 10% 100V PHILIPS 2222-630-08471 C6 1016718D ceramic 12p 2% 100V PHILIPS 2222-632-10129 C10 1033436A ceramic chip 100p 5% 50V VITRAMON VJ0805-A101-JXAMT C11 1028882A ceramic monolyth 220p 10% 100V PHILIPS 2222-630-08221 C15 1029308N ceramic chip 470p 10% 50V VITRAMON VJ0805-A471-KXAMT C17, 21, 22, 27, 35 1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K C18 1036508P electrolytic tantalum 33u 20% 25V SIEMENS B45170-A1336-M9 C19 1028893M ceramic 150p 5% 100V PHILIPS 2222-678-34151 C20 1026358G metal polyester 100n 10% 63V WIMA MKS2 C23, 28, 30, 32, 33 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C29 1017579P ceramic 47p 2% 100V PHILIPS 2222-632-10479 C31 1036507N electrolytic tantalum 6u8 20% 35V SIEMENS 1345170-E4685-M9 CAPACITORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1005194C PTFE film 2-18p 300V PHILIPS 2222-809-05003
HA72500 APPENDIX F
F-27
DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1 57945V48 delay line 57945V48 CRYSTALS REF CODE DESCRIPTION MFR/SUPPLIER REF G1 1028897R 53.75 MHz third overtone HY-Q EE04S HC-18/U INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1, 8 1030131H 6u8H 10% MILLER 9310-32 L2 1036668N 0u1H 10% CAMBION 550-3399-01 L3 72523-3-37 72523-3-37 L4 72523-3-28 72523-3-28 L5 57998V481 57998V481 L6 57998V486 57998V486 L7 72523-3-38 72523-3-38 L9 1036710J 2u2H 10% CAMBION 550-3399-17 L10 1036711K 0u47H 10% CAMBION 550-3399-09 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1-8 1028894N log amplifier PLESSEY SL521CCM N9 1036584X dual op amplifier RCA CA3240AE N10 1028415T dual comparator NATIONAL LM219J N11 1036593G voltage regulator 1.2 to 37V SGS-THOMSON LM217T RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 4 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 R2 1008708X metal film 27R4 1% 0W4 ROEDERSTEIN MK2 R3 1008736C metal film 392 1% 0W4 ROEDERSTEIN MK2 R5, 47 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R7, 8, 31, 34, 44, 48, 51 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R6, 19, 35, 45 1008738E metal film 475 1% 0W4 ROEDERSTEIN MK2 R9 1008766K metal film 6k81 1% 0W4 ROEDERSTEIN MK2 R10, 14
1008732Y metal film 274 1% 0W4 ROEDERSTEIN MK2
R11 1008756Z metal film 2k74 1% 0W4 ROEDERSTEIN MK2 R12. 17, 20, 23, 28, 38, 41, 46, 49 1008794Q metal film 100k 1% 0W4 ROEDERSTEIN MK2 R13, 18, 36, 54 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2 R16 1008810H metal film 475k 1% 0W4 ROEDERSTEIN MK2 R21, 40
1008776W metal film 18k2 1% 0W4 ROEDERSTEIN MK2
R22 1008801Y metal film 200k 1% 0W4 ROEDERSTEIN MK2 R24 1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2 R25 1008763G metal film 5k11 1% 0W4 ROEDERSTEIN MK2 R26 1008730W metal film 221 1% 0W4 ROEDERSTEIN MK2 R27 1008743K metal film 750 1% 0W4 ROEDERSTEIN MK2 R30, 42
1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2
R32 1008753W metal film 2k 1% 0W4 ROEDERSTEIN MK2 R33 1036715P temp dependent NTC 5k 5% 0W1 PHILIPS 2322-645-03502 R37 1008804B metal film 274k 1% 0W4 ROEDERSTEIN MK2 R39 1008790L metal film 68k1 1% 0W4 ROEDERSTEIN MK2 R43 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R52 1008726R metal film 150 1% 0W4 ROEDERSTEIN MK2 R53 1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2 R55 1008773T metal film 13k0 1% W60 ROEDERSTEIN MK2 R56 1008727T metal film 162 1% 0W4 ROEDERSTEIN MK2 R57 1008741H metal film 619 1% 0W4 ROEDERSTEIN MK2 R58 1033316V chip 0R0 ALLEN-BRADLEY BCX0000JT
HA72500 APPENDIX F
F-28
R59, 60
1032675Y chip 221 1% 0W125 ROHM MCR 18X-221F-EZH
R61 1008802Z metal film 221k 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R15, 50
1018646Z cermet 1-turn 5k 10% 0W5 BOURNS 3386F-1-502
R29 1028877V cermet 1-turn 1k 10% 0W5 BOURNS 3386F-1-102 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 2 1043550U transistor dual gate MOSFET TEMIC BF964S V3, 6 1006678Q hot carrier diode HP 5082-2800 V4 906441M low power NPN transistor NATIONAL 2N918 V5 1026171D low power NPN transistor PHILIPS 2N2222A CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XC1 10288989T coaxial SMA receptacle SUHNER 82SMA-50-0-1/111 XN1 1036629W header 10-way VARELCO 00-8289-010-006-1-1-3 XN2 72523-4-29 header 72523-4-29 XT1, 3-13
1036570G test terminal white WILLIAM HUGHES 101
XT2 1036569F test terminal black WILLIAM HUGHES 103
F.5.27 1A72524 RF Amplifier CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 8, 13, 19
1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805-Q220-JXAAB
C2 1038980B ceramic chip 2p7 0p25 50V VITRAMON VP0805Q-2R7-CXA C3-5, 10,11, 17,18, 20, 21 1029308N ceramic chip 470p 10%. 50V VITRAMON VJ0805-A471-KXAMT C6 1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9 C7 227739T electrolytic tantalum 1u 10% 50V KEMET T110A105K35AS C9 1032956D ceramic chip 1p 0p25 50V MURATA GRM40COG1ROC50V C12 1032937H ceramic chip 2p2 0p25 50V VITRAMON VJ0805-A2R2-CXAMT C14 1018878B ceramic monolyth 100n 10% 100V KEMET CKO6BX104K C15 1029310Q ceramic chip 3p 0p25 100V VITRAMON VJ0805-A3RO-CXB C17 1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805-Q220JXAT C22-24
1036632Z ceramic feedthru 1n 100% 100V SPECTRUM 54713001X5U102P
RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1008728U metal film 182 1% 0W4 ROEDERSTEIN MK2 R2, 5 1008734A metal film 332 1% 0W4 ROEDERSTEIN MK2 R3 1008735B metal film 365 1% 0W4 ROEDERSTEIN MK2 R4, 6 1008727T metal film 162 1% 0W4 ROEDERSTEIN MK2162RF.E R7, 8 1032671U chip 100 1% 0W125 ROHM MCR18X-101F R9-12 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R13 1032960H chip 121 1% 0W125 ROHM MCR18X-121F R14 2000267D chip 15 2% 0W125 PHILIPS 2322-712-20159 MODULATORS REF CODE DESCRIPTION MFR/SUPPLIER REF U1 1029313U double balanced mixer MINI-CIRCUITS TFM-12
HA72500 APPENDIX F
F-29
SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1033634Q low noise NPN transistor VSI AT-41435 V2 1036581U zener diode 7V5 PHILIPS BZX79/C7V5 V3, 6 1006793Q switching diode FAIRCHILD 1N914A V4 1033634Q transistor microwave AVANTEK AT-41435-3 V5 1036581U zener diode 7V5 5% PHILIPS BZX79/C7V5/143 V7, 8 1019399T hot carrier diode HP 5082-2817 or 5082-2811 V9 1005279V zener diode 10V0 PHILIPS BZX79/C10 RF DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF W1 1030238Z wireline coupler 69742-4-20 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XC2-4 1028898T coaxial SMA receptacle SUHNER 82SMA-50-0-1/111 XS1-4 1028758Q jack CAMBION 450-3704-01-03-00 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72524-4-06 coaxial connector assembly 72524-4-06
F.5.28 1A72525 Transponder Power Supply SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72526 Main PWB Assembly, Transponder Power
Supply 1A72526
F.5.29 1A72526 Transponder Power Supply Main PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 2 1036539Y electrolytic aluminium 3m3 50% 100V PHILIPS 2222-114-19332 C3, 11, 13, 21 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C4, 6, 12
1036490V electrolytic tantalum 15u 20% 63V SIEMENS B45170-A65156-M9
C5, 7, 9, 16, 18, 25 1026358G metal polyester 100n 10% 63V WIMA MKS2 C8, 17 1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9 C10, 20
1036537W electrolytic aluminium 220u 50% 100V SIEMENS B41588-D9227-T
C15 1026337J metal polyester 2n2 10% 100V WIMA FKS2 C19 1036536V electrolytic aluminium 100u 50% 100V SIEMENS B41588-E9107-T C22, 23
1036508P electrolytic tantalum 33u 20% 10V SIEMENS B45170-A1336-M9
C24 1042217V metal polyester 10n 10% 63V ROEDERSTEIN MKT-2 C26 1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9 C27 1026347V metal polyester 15n 10% 63V WIMA MKS2 C28 1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102 INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1 1036586Z green LED HP HLMP-3502-010 H2 1036588B red LED HP HLMP-3300-010 RELAYS REF CODE DESCRIPTION MFR/SUPPLIER REF K1 1028795F flatpack 2 C/O contacts NATIONAL NCED-JP-DC24V
HA72500 APPENDIX F
F-30
INDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF L1, 3, 4
57973V286 80uH 57973V286
L2 2LE65378 11uH 2LE65378 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1 1028204N regulator NATIONAL LM3524N RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1036493Y metal film 110k 0.1% 0W1 PHILIPS 2322-160-41104 R2 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R3 1036575M wire wound 1R5 5% 3W DALE RS-2C1R5 R4 1036580T wire wound 4k7 5% 3W DALE RS-2C4K7 R5, 31 1036574L wire wound 0R1 5% 3W DALE RS-2C0R1 R6, 24 1008757A metal film 3k01 1% 0W4 ROEDERSTEIN MK2 R7 1008756Z metal film 2k74 1% 0W4 ROEDERSTEIN MK2 R8, 9 1036495A metal film 30k1 0.1% 0W1 PHILIPS 2322-160-43013 R10, 11
1008772R metal film 12k1 1% 0W4 ROEDERSTEIN MK2
R12 1008732Y metal film 274 1% 0W4 ROEDERSTEIN MK2 R13-15
1036496B metal film 10k 0.1% 0W1 PHILIPS 2322-160-41003
R16, 29
1008764H metal film 5k62 1% 0W4 ROEDERSTEIN MK2
R17 1008742J metal film 681 1% 0W4 ROEDERSTEIN MK2 R18, 38, 42, 43 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R19 1008796T metal film 121k 1% 0W4 ROEDERSTEIN MK2 R20, 21
1021549E metal film 3R32 1% 0W4 ROEDERSTEIN MK2
R23 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2 R25, 36
1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2
R27 1008771Q metal film 11k 1% 0W4 ROEDERSTEIN MK2 R28 1004228C metal oxide 2k2 10% 2W ROEDERSTEIN MK5 R30, 34, 35, 39 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R32 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 R33 1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2 R37 1008748Q metal film 1k21 1% 0W4 ROEDERSTEIN MK2 R40 select on test 0W4 ROEDERSTEIN MK2 R41, 45
1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2
R44 1008798V metal film 150k 1% 0W4 ROEDERSTEIN MK2 R46 1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2 R47 1008732Y metal film 274 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R26 1018646Z cermet 1 -turn 5k 10% 0W5 BOURNS 3386F-1-502 RESISTORS, NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN1, 2
1036531P SIP 8-pin 1kx4 2% 1W BOURNS 4608X-102-102
SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1 1036501G toggle DPDT centre off C&K 7203-M-D9-A-B-E
HA72500 APPENDIX F
F-31
TRANSFORMERS REF CODE DESCRIPTION MFR/SUPPLIER REF T1 57997V741 57997V741 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1036118Q voltage regulator +15V NATIONAL LM140AK-15 V2-4, 11, 20, 21, 26 1026171D low power NPN transistor PHILIPS 2N2222A V5, 7, 8, 18, 25 1026172E low power PNP transistor PHILIPS 2N2907A V6 1005272M zener diode 5V1 PHILIPS BZX79/C5V1 V9 1004812M rectifier diode IRC 1N4004 V10, 12, 15, 19 1032804N zener diode 36V PHILIPS BZT03-C36 V13, 14
1028794E rectifier diode PHILIPS BYV27-200
V16 1030119V rectifier diode PHILIPS BYW29-150 V17 906667H high power NPN transistor SGS-THOMSON 2N3055 V22 1028910F FET hex amplifier IRC IRF130 V23, 24
1006793Q switching diode FAIRCHILD 1N914A
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XA1-8 1030153G test jack SCOTT 4879-125-0 XN1 1036519B plug 96-way D SIEMENS V42554-B1400-C910 XT1, 2, 7, 10, 11 1036569F test terminal black WILLIAM HUGHES 103 XT3-6, 8, 9 1036570G test terminal white WILLIAM HUGHES 101
F.5.30 1A72530 Transmitter Driver SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF W1 1A72531 Pulse Shaper PWB Assembly 1A72531 W2 1A72532 Exciter 1A72532 W3 1A72533 Medium Power Driver 1A72533 W4 1A72534 Power Modulation Amplifier 1A72534 TERMINATIONS REF CODE DESCRIPTION VALUE RATING MFR/SUPPLIER REF E1 1030562B termination 50R 1W SUHNER 65SMA-50-0-1/111 E2 1038981C termination 50R 2W KDI T150M WAVEGUIDES REF CODE DESCRIPTION VALUE RATING MFR/SUPPLIER REF W1, 2 1028868K microwave circulator TELEDYNE C-0S23T-2
AEROTEK Do3A-IFFF/OPT1 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72530-4-14 coaxial BNC/SMA 72530-4-14 72530-4-15 coaxial SMA/SMA 72530-4-15 72530-4-16 coaxial SMA/SMA 72530-4-16 72530-4-17 coaxial BNC/SMA 72530-4-17 72530-3-18 ribbon 20-way 72530-3-18 72530-4-21 coaxial SMA/SMA 72530-4-21 72530-4-22 coaxial SMA/SMA 72530-4-22
HA72500 APPENDIX F
F-32
F.5.31 1A72531 Pulse Shaper PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 4-6, 15-17, 19, 20, 22, 29, 31, 32, 34-37, 45-47 1018878B ceramic monolyth 100n 10% 100V KEMET CKO6BX104K C2 224214L metal mica 470p 5% 500V ARCO DM15ED471J04CR C3, 40, 41
1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9
C7, 21, 25
1026365P metal polyester 470n 10% 63V WIMA MKS2
C8, 9, 11
1030190X ceramic 100p 5% 100V VITRAMON VP12BA101J
C10 1028735Q ceramic monolyth 330p 10% 100V PHILIPS 2222-630-08331 C12-14, 39, 44 1026369U metal polyester 1u 10% 50V WIMA MKS2 C18, 27, 28
1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102
C23, 24
1028928A ceramic 15p 5% 100V VITRAMON VP12BA150JB
C26 1028930C ceramic 3p3 0p25 100V VITRAMON VP12BA3R3C C30, 42
1036536V electrolytic aluminium 100u 50% 100V SIEMENS B41588-E9107-T
C33, 38, 43
1026362L metal polyester 220n 10% 63V WIMA MKS2
DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1 1028716V multiplex PHILIPS HEF4051BD D2 1028378C BCD up/down counter PHILIPS HEF4510BD D3 1028934G quad 2-input AND PHILIPS HEF4082BD D4 1028935H quad bilateral switch PHILIPS HEF4066BD D5, 7 1028379D dual JK flip-flop PHILIPS HEF4027BD D6 1028375Z dual monostable PHILIPS HEF4528BD D8 1030185R dual precision monostable PHILIPS HEF4538BD INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1 1036586Z green LED HP HLMP-3502-010 H2 1036588B red LED HP HLMP-3300-010 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1-6 1036584X dual op amplifier RCA CA3240AE N7, 8 1028415T dual comparator NATIONAL LM219J RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 14,15, 21, 30, 33, 41, 49, 72, 75, 78, 83, 93, 96, 117,133, 134, 135
1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R2, 4, 13, 38, 47, 48, 56, 64, 81, 103, 104, 112, 128, 129
1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R6, 8 1008760D metal film 3k92 1% 0W4 ROEDERSTEIN MK2 R10, 12, 37, 46,124, 125 1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2 R16, 32
1008773T metal film 13k 1% 0W4 ROEDERSTEIN MK2
R18, 40
1008738E metal film 475 1% 0W4 ROEDERSTEIN MK2
R19, 42, 67, 79, 106 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R20 1008776W metal film 18k2 1% 0W4 ROEDERSTEIN MK2 R22, 24, 26. 43, 45, 63, 71, 87 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2
HA72500 APPENDIX F
F-33
R23 1008782C metal film 33k2 1% 0W4 ROEDERSTEIN MK2 R25, 39
1008794Q metal film 100k 1% 0W4 ROEDERSTEIN MK2
R27 1008800X metal film 182k 1% 0W4 ROEDERSTEIN MK2 R28, 101, 102 1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2 R29 1008752W metal film 2k 1% 0W4 ROEDERSTEIN MK2 R31, 34, 50, 65, 86, 110 1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2 R35, 60
1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2
R44, 70, 73, 77, 82, 95, 111, 113, 116, 120, 130 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 R51, 59
1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2
R52, 80
1008766K metal film 6k81 1% 0W4 ROEDERSTEIN MK2
R55, 57, 98, 114 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R61 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 R66 1008744L metal film 825 1% 0W4 ROEDERSTEIN MK2 R68 1008742J metal film 681 1% 0W4 ROEDERSTEIN MK2 R74, 76, 90-92 1008730W metal film 221 1% 0W4 ROEDERSTEIN MK2 R84, 108, 118, 119 1008734A metal film 332 1% 0W4 ROEDERSTEIN MK2 R88, 89, 99 1008768M metal film 8k25 1% 0W4 ROEDERSTEIN MK2 R94 1008757A metal film 3k01 1% 0W4 ROEDERSTEIN MK2 R100 1008802Z metal film 221k 1% 0W4 ROEDERSTEIN MK2 R105 1008764H metal film 5k62 1% 0W4 ROEDERSTEIN MK2 R107, 123
1008718H metal film 68R1 1% 0W4 ROEDERSTEIN MK2
R109 1008763G metal film 5k11 1% 0W4 ROEDERSTEIN MK2 R121, 122
1008743K metal film 750 1% 0W4 ROEDERSTEIN MK2
R126, 127
1008767L metal film 7k5 1% 0W4 ROEDERSTEIN MK2
R131,132
1008786G metal film 47k5 1% 0W4 ROEDERSTEIN MK2
RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R3, 5 1028799K cermet 1-turn 50k 10% 0W5 BOURNS 3386F-1-503 R7, 9, 36
1018644X cermet 1-turn 20k 10% 0W5 BECKMAN 72PMR20K
R11, 13, 53, 69, 97, 115 1028760T cermet 1-turn 10k 10% 0W5 BOURNS 3386F-1-103 R17, 54
1018646Z cermet 1-turn 5k 10% 0W5 BOURNS 3386F-1-502
R58 1028756N cermet 1-turn 2k 10% 0W5 BOURNS 3386F-1-202 R62, 63
1031087X cermet 1-turn 10k 10% 0W5 BOURNS 3386X-1-103
R85 1028877V cermet 1-turn 1k 10% 0W5 BOURNS 3386F-1-102 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1 1036573K toggle DPDT C&K 7201 -M-D9-A-B-E S2-3 1032839B slide SPDT C&K 1201-M2-S3-CB-E S4 1030651Y slide SPDT C&K 1101-M2-S3-CB-E
HA72500 APPENDIX F
F-34
SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 2, 4, 7, 12, 24, 26 1006793Q switching diode FAIRCHILD 1N914A V3, 28 1026172E low power PNP transistor PHILIPS 2N2907A V5, 18 1006883N high power NPN transistor MOTOROLA 2N5320 V8, 10, 19, 25 1025349K high voltage PNP transistor MOTOROLA 2N5401 V9, 16, 20-22 1028933F high power NPN transistor MOTOROLA 2N5551 V11, 17, 29 1006485F high power PNP transistor RCA 2N5322 V13 1004812M rectifier diode IRC 1N4004 V14, 15
1005272M zener diode 5V1 PHILIPS BZX79/C5V1
V23, 30
1028910F FET hex amplifier IRC IRF130
V27 1026171D low power NPN transistor PHILIPS 2N2222A CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XA1-7 1030153G test jack SCOTT 4879-125-0 XN1 1036519B plug 96-way C SIEMENS V42254-B1400-C910 XN2 1036522E header 20-way SIEMENS V23535-A2200-A200 XT1, 2, 6, 8
1036569F test terminal black WILLIAM HUGHES 103
XT3-5, 7, 9-13 1036570G test terminal white WILLIAM HUGHES 101
F.5.32 1A72532 Exciter CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1030214Y ceramic chip 5p6 0.25pF 50V Philips 2222-861-14568 C2, 4, 8, 14, 16, 19, 20, 22, 23, 25, 27. 29, 31, 32 1036605V ceramic chip 22p 5% 50V VITRAMON Q220JXA-AB-07760K C3, 7, 24
1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102
C6, 9, 28
1018751N monolyth 1u 10% 50V VITRAMON CK06BX105K
CAPACITORS, VARIABLE REF CODE DESCRIPTION VALUE MFR/SUPPLIER REF C5, 15, 17, 21 1030213X trimmer 0p8-8p JOHANSON GIGATRIM 27293 C26, 30, 33, 34 1028813A trimmer 0p6-4p5 JOHANSON GIGATRIM 7273 INDUCTORS REF CODE DESCRIPTION VALUE MFR/SUPPLIER REF L1, 2 57969V28 57969V28 L5-12 57969V30 57969V30 RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 2 1035025C chip 10 1% 0W125 ROHM MCR18X-100F-EZH R6, 12, 13
1032676Z chip 51R1 1% 0W125 ROHM MCR18X-510F-EZH
R7, 9 1008738E metal film 475 1% 0W6 ROEDERSTEIN MK2 R8, 10 1008708X metal film 27R4 1% 0W4 ROEDERSTEIN MK2
HA72500 APPENDIX F
F-35
SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 3, 4
1030670U microwave NPN transistor MOTOROLA MRF1000MA
V5, 6 1030671V microwave NPN transistor MOTOROLA MRF1004MA
WARNING V1, 3, 4, 5, 6 may contain beryllium oxide RF DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF W1-4 1031473R wireline coupler 69826-4-45 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1 1036629W header 10-way VARELCO 00-8289-010-006-113
F.5.33 1A72533 Medium Power Driver SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72538 RF Amplifier Driver PWB Assembly 1A72538 CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C3, 5 1036606W ceramic chip 47p 5% 100V VITRAMON VJ0808-Q470-JXB-AB C4 1036658C ceramic chip 1n 10% 100V VITRAMON VJ0805-Y102-KXB-AB CAPACITORS, VARIABLE REF CODE DESCRIPTION VALUE MFR/SUPPLIER REF C1, 2 1028813A trimmer 0p6-4p5 JOHANSON GIGATRIM 7273 INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1 57969V30 inductor 57969V30 L2 69752-4-48 inductor 69752-4-48 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1028921T RF transistor GHZ 0912-45
WARNING V1 may contain beryllium oxide V3 1028910F FET hex amplifier IRC IRF130 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XC1 72533-4-08 termination assembly input 72533-4-08 XC2 72533-4-09 termination assembly output 72533-4-09 CABLE ASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF XN1 72533-4-07 connector and lead 4-way 72533-4-07
HA72500 APPENDIX F
F-36
F.5.34 1A72534 Power Modulation Amplifier SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72538 RF Amplifier Driver PWB Assembly 1A72538 CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1028810X ceramic chip 2p 0p1 500V ATC 100B-2R0-BCA-500X C2 1028811Y ceramic chip 4p7 0p1 500V ATC 100B-4R7-BCA-500X C3 1028812Z ceramic chip 3p3 0p1 500V ATC 100B-3R3-BCA-500X C5-8 1036606W ceramic chip 47p 5% 150 VITRAMON VJ0805-Q470-JXB-AB C9 1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805-Q220-JXA-AB C10, 11
1033436A ceramic chip 100p 5% 50V VITRAMON VJ0805-A101-JXAMT
CAPACITORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C4 1028813A trimmer 0p6-4p5 JOHANSON GIGATRIM 7273 INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1-3 30V57969 30V57969 RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R9 1021551G metal film 6R8 1% 0W4 ROEDERSTEIN MK2 R10, 11
1032676Z chip 51R1 1% 0W125 ROHM MCR18X-510F-EZH
R12 1035073E chip 15k 1% 0W125 ROHM MCR18X-153F-EZH SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1028916M microwave transistor GHZ 64042
WARNING V1 may contain beryllium oxide V2 1019399T hot carrier diode HP 5082-2817 or 5082-2811 V3 1028910F FET hex amplifier IRC IRF130 RF DEVICES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72534-4-30 balun 72534-4-30 1 72534-4-17 balun assembly 72534-4-17 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72534-3-18 connector and lead assembly 72534-3-18 1 72534-4-31 connector assembly RF output 72534-4-31
F.5.35 1A72535 1kW RF Power Amplifier SUBASSEMBLIES REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF A1-10 1A69873 250W RF Amplifier 1A69873 A11 1A72536 Power Divider Assembly 1A72536 A12 1A72537 Power Combiner Assembly 1A72537 A13 1A72534 Power Modulation Amplifier 1A72534 A14 1A72544 1kW PA Connector PWB Assembly 1A72544 A15 2A69757 50 Ohm Termination 2A69757
HA72500 APPENDIX F
F-37
RF DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF W1 1031469M circulator microwave TELEDYNE 23T-6
AEROTEK D03A-10FFF/OPT2 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72535-3-21 coaxial input 72535-3-21 1 72545-3-22 coaxial output 72545-3-22 20 72535-4-23 coaxial SMA/SMA 72535-4-23 1 72535-4-24 coaxial N/SMA 72535-4-24 1 72535-4-25 coaxial SMA/SMA 72535-4-25
F.5.36 1A72536 Power Divider CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1036605V ceramic chip 22p 5% 50V VITRAMON Q220JXA-AB-07760K RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1-3 1030123Z metal film microstrip 100 RF TECHNIQUES 1A100100
WARNING R1-3 may contain beryllium oxide R4-8 1028923V chip termination 50 KDI PPC100-200A-G50-2 R9-11 1032671U chip 100 1% 0W125 ROHM MCR18X-101F-EZH R12 1035039T chip 68R1 1% 0W125 ROHM MCR1BX-680F-EZH R13 1035033L chip 33R2 1% 0W125 ROHM MCR18X-330F-EZH R14 1035073E chip 15k 1% 0W125 ROHM MCR18X-153F-EZH SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1019399T hot carrier diode HP 5082-2817 or 5082-2811 RF DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF W1-5 1031473R wireline coupler 69826-4-45 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XF1-11
1028908D coaxial SMA SUHNER 22SMA-50-0-52/199
F.5.37 1A72537 Power Combiner CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1-20 1030632C electrolytic aluminium 100u 50% 100V SIEMENS B41588-E9107-T C21 1028393U ceramic monolyth 330p 10% 100V VITRAMON VP31BA331KB C101 1036605V ceramic chip 22p 5% 50V VITRAMON Q220JXA-AB-07760K INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1 405355D 0u82 MILLER 9310-10
HA72500 APPENDIX F
F-38
RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1-3 1030123Z metal film microstrip 100 RF TECHNIQUES 1A100100
WARNING R1-3 may contain beryllium oxide R4-8 1028923V chip termination 50 KDI PPC100-200A-G50-2 R9-11 1032671U chip 100 1% 0W125 ROHM MCR18X-101F-EZH R12 1036726B chip 47 1% 0W125 PHILIPS 2322-712-20479 R13 1036727C chip 56 1% 0W125 PHILIPS 2322-712-20569 R14 1035073E chip 15k 1% 0W125 ROHM MCR18X-153F-EZH SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1019399T hot carrier diode HP 5082-2817 or 5082-2811 RF DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF W1-5 1031473R wireline coupler 69826-4-45 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF X1-16 234894V terminal quick connect UTILUX H2880 XF1-13
1028908D coaxial SMA SUHNER 22SMA-50-0-52/199
F.5.38 1A72538 RF Amplifier Driver PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C15, 16
1036536V electrolytic aluminium 100u 50% 100V SIEMENS B41588-E9107-F
RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1008734A metal film 332 1% 0W4 ROEDERSTEIN MK2 R2 1008710Z metal film 33R2 1% 0W4 ROEDERSTEIN MK2 R3 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R4 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R6-8 1021546B metal film 1 1% 0W4 ROEDERSTEIN MK2 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V4 1006883N high power NPN transistor RCA 2N5320 V5 1006485F high power PNP transistor RCA 2N5322 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF X1-5 234894V terminal quick connect UTILUX H2880
F.5.39 1A72540 1kW Power Amplifier Power Supply SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72541 Control and Status PWB 1A72541 A2 1A72542 DC-DC Converter PWB Assembly 1A72542 CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 2 1031019Y electrolytic aluminium 6m8 50% 100V PHILIPS 2222-114-19682
HA72500 APPENDIX F
F-39
RELAYS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF K1 Opt 1
1030295L DPDT 20A contacts MATSUSHITA HG2DC24V
K1 Opt 2
1036646P power 2 form C V24 STRUTHERS-DUNN 298XBX-CSIU24D
INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L1 1TX80382 5mH 1TX80382 RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1021548D metal film 2R21 1% 0W4 ROEDERSTEIN MK2 R2 609894D metal oxide 2k7 5% 3W25 ROEDERSTEIN WK8 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XB1 1018227U terminal block 6-way KLIPPON 6252.2 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72540-3-27 lead group 72540-3-27
F.5.40 1A72541 Control and Status PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1-3, 11, 13-15 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C4 1036536V electrolytic aluminium 100u 50% 100V SIEMENS B41588-E9107-T C5, 7, 9
1026365P metal polyester 470n 10% 63V WIMA MKS2
C6, 8, 10, 16
1026369U metal polyester 1u 10% 50V WIMA MKS2
C12 1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9 INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1, 3 1036586Z green LED HP HLMP-3502-010 H2 1036588B red LED HP HLMP-3300-010 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1-3, 7
1028415T dual comparator NATIONAL LM219J
N4-6, 8
1036584X dual op amplifier RCA CA3240AE
N9 1036593G voltage regulator 1.2 to 37V SGS-THOMSON LM217T
HA72500 APPENDIX F
F-40
RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 6, 11
1008802Z metal film 221k 1% 0W4 ROEDERSTEIN MK2
R2, 7, 12, 21, 27, 33, 56 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R3, 8, 13
1008767L metal film 7k5 1% 0W4 ROEDERSTEIN MK2
R4, 9, 14
1008743K metal film 750 1% 0W4 ROEDERSTEIN MK2
R5, 10, 15
1008710Z metal film 33R2 1% 0W4 ROEDERSTEIN MK2
R16 1036496B metal film 10k 0.1% 0W1 PHILIPS 2322-160-41003 R17 1036493Y metal film 110k 0.1% 0W1 PHILIPS 2322-160-41104 R18, 22, 24, 28, 30, 34 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 R19, 25, 31, 40, 50 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R20, 38, 47
1008764H metal film 5k62 1% 0W4 ROEDERSTEIN MK2
R32 1008768M metal film 8k25 1% 0W4 ROEDERSTEIN MK2 R23, 29, 35
1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2
R26, 55
1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2
R36, 37, 48
1008757A metal film 3k01 1% 0W4 ROEDERSTEIN MK2
R39, 43
1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2
R41 1008755Y metal film 2k43 1% 0W4 ROEDERSTEIN MK2 R42 1008730W metal film 221 1% 0W4 ROEDERSTEIN MK2 R44 1008785F metal film 43k2 1% 0W4 ROEDERSTEIN MK2 R46 1008736C metal film 392 1% 0W4 ROEDERSTEIN MK2 R49, 57-59
1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2
R51 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 R52-54
1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2
RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R45 1028760T cermet 1-turn 10k 10% 0W5 BOURNS 3386F-1-103 RESISTORS, NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN1 1036531P SIP 8-pin 1kx4 2% 1W BOURNS 4608X-102-102 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1 1036501G toggle DPDT centre off C&K 7203-M-D9-A-B-E SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 2, 6
1026172E low power PNP transistor PHILIPS 2N2907A
V3-5 1006793Q switching diode FAIRCHILD 1N914A V7, 13, 10
1004812M rectifier diode IRC 1N4004
V9, 13 1026171D low power NPN transistor PHILIPS 2N2222A V12 1006326H zener diode 5V6 PHILIPS BZX79/C5V6 V14 1032804H zener diode 36V PHILIPS BZT03/C36
HA72500 APPENDIX F
F-41
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XA1-10
1030153G test jack SCOTT 4879-125-0
XN1 1036518A socket 9-way D AMP 747844-6 XN2 1036517Z plug 25-way D AMP 747842-6 XT1-3 1036570G test terminal white WILLIAM HUGHES 101 XT4 1036569F test terminal black WILLIAM HUGHES 103
F.5.41 1A72542 DC-DC Converter PWB SUBASSEMBLIES REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF A1 1A72543 Regulator PWB Assembly 1A72543 CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1026369U metal polyester 1u 10% 50V WIMA MKS2 C2, 4 1036538X electrolytic aluminium 2m2 30% 63V SIEMENS B41554-B8228-Q C3, 5 1026358G metal polyester 100n 10% 63V WIMA MKS2 C6, 7 226633Q metal polyester 22n 10% 400V PHILIPS 2222-368-55223 C8 1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9 C9, 10, 13
1036537W electrolytic aluminium 220u 50% 100V SIEMENS B41588-D9227-T
C11, 14
1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K
C12 1036539Y electrolytic aluminium 3m3 50% 100V PHILIPS 2222-114-19332 INDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF L1 57937V287 57937V287 L2 1LP80376 1LP80376 L3 57973V288 57973V288 RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1-4 1088T70P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R5-8, 11
1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2
R9, 10 1036549J wire wound 47 2% 4W DALE RS-2 R12 72542-4-34 resistance wire 0R06 1% 0W4 72542-4-34 R13, 17
1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2
R14, 15
1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2
RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R16 1031065Y cermet 1 turn 100 1% 0W4 BECKMAN 72PMR100R TRANSFORMERS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF T1-5 1LH80375 1LH80375 T6 1LP80377 1LP80377 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1-4 1028910F FET hex amplifier IRC IRF130 V5-12 596894Y zener diode 9V1 PHILIPS BZX79/C9V1 V13-16
1036638F transient supp diode 36V GSI 1.5KE36A
V17-21
1030119V rectifier diode PHILIPS BYW29/150
HA72500 APPENDIX F
F-42
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XP3-4 234894V terminal quick connect UTILUX H2880 XP5-6 1030740V terminal quick connect UTILUX H954 XS7 1036571H terminal printed board HARWIN H2103A-01 XS8-16
1028758Q connector jack CAMBION 450-3704-01-03-00
XT1, 14
1036569F test terminal black WILLIAM HUGHES 103
XT13 1036570G test terminal white WILLIAM HUGHES 101
F.5.42 1A72543 Regulator PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C101 1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9 C102, 105, 109, 110, 111 1026358G metal polyester 100n 10% 63V WIMA MKS2 C103 1004863T ceramic monolyth 10n 10% 100V VITRAMON CK05BX103K C104 1026362L metal polyester 220n 10% 63V WIMA MKS2 C106, 107
1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K
C108 1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9 C113 1030188V ceramic 1n 10% 100V PHILIPS 2222-630-08102 RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R101, 102
1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2
R103 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R104 1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2 R105 1008753W metal film 2k 1% 0W4 ROEDERSTEIN MK2 R106 1008786G metal film 47k5 1% 0W4 ROEDERSTEIN MK2 R107 1021512P metal film 1M0 1% 0W4 ROEDERSTEIN MK2 R108, 131-134 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 R109, 110, 116, 119 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R111 1008789K metal film 61k9 1% 0W4 ROEDERSTEIN MK2 R113 1008755Y metal film 2k43 1% 0W4 ROEDERSTEIN MK2 R114, 122, 123, 128 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R115 1008730W metal film 221 1% 0W4 ROEDERSTEIN MK2 R117, 120
1008732Y metal film 274 1% 0W4 ROEDERSTEIN MK2
R118, 121
1008748Q metal film 1k21 1% 0W4 ROEDERSTEIN MK2
R124 1008766K metal film 6k81 1% 0W4 ROEDERSTEIN MK2 R125 1008790L metal film 68k1 1% 0W4 ROEDERSTEIN MK2 R126 1008780A metal film 27k4 1% 0W4 ROEDERSTEIN MK2 R127 1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2 R129, 130
1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2
R135 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R112 1028877V cermet 1 -turn 1k 10% 0W5 BOURNS 3386F-1-102
HA72500 APPENDIX F
F-43
SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V101 1028204N regulator NATIONAL LM3524N V102 ,106, 107, 109, 110 1026171D low power NPN transistor PHILIPS 2N2222A V103-105.108, 111 1006793Q switching diode FAIRCHILD 1N914A V112, 116
1026172E low power PNP transistor
PHILIPS 2N2907A
V113 1005272M zener diode 5V1 PHILIPS BZX79/C5V1 V114 1005279V zener diode 10V PHILIPS BZX79/C10 V115 596890U zener diode 6V2 PHILIPS BZX79/C6V2 V117 1028876U thyristor MOTOROLA C106D V118, 119
1028382G tristate hex inverter PHILIPS HEF40098BD
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XT2-4, 6-12 1036570G test terminal white WILLIAM HUGHES 101 XT5 1036569F test terminal black WILLIAM HUGHES 103
F.5.43 1A72544 1kW PA Connector PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1-12 1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805-Q220-JXA-AB C13 1029308N ceramic chip 470p 10% 50V VITRAMON VJ0805-A471-KXAMT INDUCTORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF L3 405355D 0u82H MILLER 9310-10 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1 1036561X plug 15-way D AMP 745072-2 XN2 1036599N header 4-way KLIPPON 12363.6 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72544-4-16 coaxial SMA 72544-4-16 1 72544-4-20 coaxial SMA 72544-4-20 1 72544-3-21 4-way 72544-3-21 1 72544-3-22 lead group 72544-3-22
F.5.44 1A72545 RF Panel - Single DME SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72547 RF Panel PWB Assembly - Single DME 1A72547 RF DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF W1 1031469M Circulator microwave Teledyne C-ON23T-6 W3 69755-2-19 directional coupler 69755-2-19 FILTERS REF CODE DESCRIPTION MFR/SUPPLIER REF Z1 72546-3-01 preselector filter 72546-3-01
HA72500 APPENDIX F
F-44
CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72545-4-20 coaxial N/SMA 72545-4-20 1 72545-4-21 coaxial SMA 72545-4-21 2 72545-4-22 coaxial SMA 72545-4-22 1 72545-4-23 coaxial N/SMA 72545-4-23
F.5.45 2A72545 RF Panel - Dual DME SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 2A72547 RF Panel PWB Assembly - Dual DME 2A72547 A2 1A69757 50 Ohm Termination 1A69757 RELAYS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF K1 1036597L transfer N connectors 26R 26V K&L MICROWAVE LTS-28-F-N CIRCULATORS REF CODE DESCRIPTION MFR/SUPPLIER REF W1, 2 1031469M Circulator microwave Teledyne C-ON23T-6 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 2 72545-4-20 coaxial N/SMA 72545-4-20 1 72545-4-21 coaxial SMA 72545-4-21 4 72545-4-22 coaxial SMA 72545-4-22 1 72545-4-28 coaxial N 72545-4-28 1 72545-4-29 coaxial N 72545-4-29 1 72545-4-30 coaxial N/SMA 72545-4-30 1 72545-4-31 coaxial N/SMA 72545-4-31 1 72545-4-32 coaxial SMA 72545-4-32
F.5.46 1A72547 RF Panel PWB - Single DME CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2 R2 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V2 1026498J transient suppressor 10V PHILIPS BZW03-C12 V3 1030371U surge arrestor 90V SIEMENS B1-C90/20 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1 1036611B plug 9-way D AMP 745071-2 XN2 1036641J socket 9-way D AMP 745076-4
HA72500 APPENDIX F
F-45
F.5.47 2A72547 RF Panel PWB - Dual DME CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1018878B ceramic monolyth 100n 10% 100v KEMET CK06BX104K RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2 R2 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1 1036501G toggle DPDT centre off C&K 7203-M-D9-A-B-E SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1004812M rectifier diode IRC 1N4004 V2 1026498J transient suppressor 10V PHILIPS BZW03-C12 V3 1030371U surge arrestor 90V SIEMENS B1-C90/20 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF X1, 2 234894V terminal quick-connect UTILUX H2880 XN1 1036611B plug 9-way D AMP 745071-2 XN2 1036641J socket 9-way D AMP 745076-4
F.5.48 A72549 Power Distribution Panel - Single DME CIRCUIT BREAKERS REF CODE DESCRIPTION VALUE RATING MFR/SUPPLIER REF Q1, 2 1036656A no delay aux switch 20A 50V AIRPAX APG-1-1REC4-50-203 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1 1036666L plug 15-way style H15 ERNI 413-168 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72549-3-19 lead group 72549-3-19
F.5.49 2A72549 Power Distribution Panel - Dual DME CIRCUIT BREAKERS REF CODE DESCRIPTION VALUE RATING MFR/SUPPLIER REF Q1, 2 1036656A no delay aux switch 20A 50V AIRPAX APG-1-1REC4-50-203-A-01 Q3-5 1036655Z no delay aux switch 5A 50V AIRPAX APG-1-1REC4-50-502-A-1 CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1 1036666L plug 15-way style H15 ERNI 413-168 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72549-3-20 lead group 72549-3-20
HA72500 APPENDIX F
F-46
F.5.50 1A72550 Control and Test Unit SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A2 1A72552 CTU Processor PWB Assembly 1A72552 A3 1A72553 CTU Front Panel PWB Assembly 1A72553 A4 1A72555 RCMS Interface PWB Assembly 1A72555 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72550-3-16 ribbon 50-way 72550-3-16 1 72550-3-17 ribbon 64-way 72550-3-17 CAPACITORS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 electro alum 470u 50% 40V PHILIPS 2222-032-17471
F.5.51 1A72552 CTU Processor PWB TRANSDUCERS REF CODE DESCRIPTION MFR/SUPPLIER REF B1 1036622N speaker STAR QMX-05 CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 7-11, 14-17, 23, 24, 26-29, 31, 33-40, 42, 44-48, 50-53, 54-63, 65, 68, 69
1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C2-6, 41
1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K
C12, 13, 20
1028394V ceramic 22p 5% 100V VITRAMON VP12BA220J
C18, 22
1004863T ceramic monolyth 10n 10% 100V VITRAMON CK05BX103K
C19, 25, 30, 32, 43, 49, 64, 66, 67 1036508P electrolytic tantalum 33u 20% 10V SIEMENS B45170-A1336-M9 C21 1028347U ceramic 33p 5% 100V VITRAMON VP12BA330J DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1, D38
1032799H hex inverting Schmitt trigger NATIONAL MM74HC14N
D2 24A72502 PLD ident tone and keying 24A72502 D3, 11 1035335P quad 2-input OR RCA CD74HC32E D6 1036583W UART SIGNETICS SCC2691AE1N24 D7, 8, 10
1036477F octal D-type latch NATIONAL MM74HC573N
D9 1036469X 16-bit microprocessor INTEL TN80C186-12 D12 1035310M 14-stage binary counter TI SN74HC4020N D13 23A72502 PLD wait state generator 23A72502 D14, 15
1036623P 32kx8 CMOS static RAM AKM AKM62256LPI-10
D16 1036558U 8kx8 CMOS EEPROM CATALYST CAT28C65API-20 D17 1A72551 CTU software 2A72551 D18, 23, 26
1036604U octal latch ALLEGRO UCN5801A
D19, 20, 24, 25, 30, 31, 33, 34, 36, 37 1033775U octal buffer RCA CD74HC541E D21, 22
1032927X hex inverter NATIONAL MM74HC04N
D27, 39
1032802L quad 2-input NAND NATIONAL MM74HC00N
D28 1038948R hex inverter NATIONAL MM74AC04N D29, 32, 35
1034410J bi-directional buffer and latch NATIONAL MM74HC646N
HA72500 APPENDIX F
F-47
FUSES REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF F1, 2 1036602R voltage dep resistor 65VDC 10% 0W1 SIEMENS SIOV-SO5K50 F3 1036692P voltage dep resistor 38V 0W2 SIEMENS SIOV-S14K30 CRYSTALS REF CODE DESCRIPTION MFR/SUPPLIER REF G1 1036530N 20MHz 100 ppm HY-Q G2 1036529M 3M6864Hz 100 ppm HY-Q INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1-2, 4, 6-8 1036589C green LED HP HLMP-3507 INDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF L1 1033446L 2.5 turns PHILIPS 4312-020-36640 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1 1036585Y photomos relay NATIONAL AQV214 N2 1036505L microprocessor supervisory circuit MAXIM MAX691EPE N3 1038949T voltage regulator adjustable NATIONAL LM2931C N4, 5 1036671R RS422/RS485 transceiver NATIONAL DS75176BTN RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 2, 4, 5, 10 1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2 R3, 15, 31, 34, 40, 44 1029244U metal film 0R0 1% 0W4 ROEDERSTEIN MK2 R6, 11-14, 17, 22, 28, 29, 39, 43, 48, 49 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R7-9, 45
1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2
R16 1008753W metal film 2k 1% 0W4 ROEDERSTEIN MK2 R18, 19, 26, 27, 52, 53 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R21, 23
1008774U metal film 15k 1% 0W4 ROEDERSTEIN MK2
R25 1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2 R35, 46, 47
1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2
R36 1008755Y metal film 2k43 1% 0W4 ROEDERSTEIN MK2 R37 1008796T metal film 121k 1% 0W4 ROEDERSTEIN MK2 R38 1008786G metal film 47k5 1% 0W4 ROEDERSTEIN MK2 R50 1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2 R51 1008791M metal film 75k 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R32, 33
1028756N cermet -turn 2k 1% 0W4 BOURNS 3386F-1-202
HA72500 APPENDIX F
F-48
RESISTOR NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN1, 4, 7, 8
1036330W SIP 8-pin 10kx4 2% 1W ALLEN-BRADLEY 708B103
RN2, 3, 6, 10, 14, 16, 22-24 1027365B SIP 10-pin 10kx9 2% 1W25 BOURNS 4310R-101-103 RN5, 12
1030609C SIP 6-pin 4k7x5 2% 0W75 BOURNS 4306R-101-472
RN9, 11, 17, 18 1025401R SIP 10-pin 4k7x9 2% 1W25 BOURNS 4310R-101-472 RN13, 15
1036660E SIP 8-pin 22kx4 2% 1W BOURNS 4608X-102-223
RN19 1036673U SIP 10-pin 10kx5 2% 1W25 BOURNS 4610X-102-103 RN20, 21, 25, 26, 30, 31 1036555Q SIP 8-pin 100x4 2% 1W BOURNS 4608X-102-101 RN27-29. 32-34 1032352X SIP 10-pin 47kx9 2% 1W25 BOURNS 4610X-101-473 RN35 1028388N SIP 8-pin 15kx7 2% 1W BOURNS 4308R-101-153 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1, 2 1026437T DIL SPST 8-way CTS 206-8-LPST SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1, 4 1004812M rectifier diode IRC 1N4004 V2, 3 1006883N high power NPN transistor RCA 2N5320 V5, 6, 8-11
1006793Q switching diode FAIRCHILD 1N914A
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1, 2
1036519B plug 96-way SIEMENS V42254-B1400-C910
XN3 1036616G header 50-way VARELCO 00-8289-050-007-213 XN4 1036614E header 60-way VARELCO 00-8289-060-007-213 XN5-10
72552-4-19 header 2-way 72552-4-19
XN11 1036599N header 4-way KLIPPON 12363.6
F.5.52 1A72553 CTU Front Panel PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 14, 19, 22 1036508P electrolytic tantalum 33u 20% 10V SIEMENS B45170-A1336-M9 C3, 5, 11-13, 15-18, 20, 21, 23-25 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C8-10 1018751N ceramic monolyth 1u 10% 50V VITRAMON CK06BX105K DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D3 1033775U octal buffer non-inverting RCA CD74HC541E D4 1032799H hex inverting Schmitt trigger NATIONAL MM74HC14N D5 26A72502 front panel key switch PLD 26A72502 D6, 8, 9-12
1036604U octal latch ALLEGRO UCN5801A
D7 1035245R octal bus transceiver TI SN74HC245N INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H5, 8, 11, 38
1036590D yellow LED HP HLMP-3401
HA72500 APPENDIX F
F-49
H6, 7, 12, 13, 17-19, 35-37 1036589C green LED HP HLMP-3507 H9, 10, 15, 16, 20-28, 30-33, 39, 40 1036591E red LED HP HLMP-3301 H14 1036586Z green LED HP HLMP-3502-010 Display 1036607X 2 line 40 char LCD OPTREX DMC40218H INDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF L1, 2 1033446L 2.5 turns PHILIPS 4312-020-36640 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1 1041482W dual op amplifier TEXAS INSTRUMENTS RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R8, 13 100869BL metal film 10 1% 0W4 ROEDERSTEIN MK2 R3 1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2 R4 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R5 1008749R metal film 1k3 1% 0W4 ROEDERSTEIN MK2 R6 1021512P metal film 1M 1% 0W4 ROEDERSTEIN MK2 R7 1008740G metal film 562 1% 0W4 ROEDERSTEIN MK2 R10-12 1008777X metal film 20k 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1030147A cermet 1-turn 10k 10% 0W5 BECKMAN 72XR10K RESISTOR NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN 1, 2, 4, 5. 12, 13 1036555Q sip 8-pin 100x4 2% 1W BOURNS 4608X-102-101 RN3, 6-11, 14-20, 22, 23 1027365B sip 10-pin 10kx9 2% 1W25 BOURNS 4310R-101-103 RN21 1036330W sip 8-pin 10kx4 2% 1W ALLEN-BRADLEY 708B103 SWITCHES REF CODE DESCRIPTION MFR/SUPPLIER REF S1-7, 10, 13-20 1036608Y pushbutton black ITT-STC SE-T-BK-AU-OA S11 1036610A rotary BCD coded ELMA 07-4133 S12 1036609Z rotary BCD coded SIEMENS C42315-A1353-A1 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1-6 1006793Q switching diode FAIRCHILD 1N914A V7, 8 1026171D low power NPN transistor PHILIPS 2N2222A CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1 1036615F header 50-way VARELCO 00-8289-050-006-2-1-3 XN2 72553-4-26 header 2-row 14-way 72553-4-26
F.5.53 1A72555 RCMS Interface PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1, 6, 10, 12, 14-21, 24, 25, 27 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C2, 22 1036506M electrolytic tantalum 33u 20% 35V SIEMENS B45170-E4336-M9 C3-5, 7-9
1028369U metal polyester 1u 10% 50V WIMA MKS2
HA72500 APPENDIX F
F-50
C11, 13, 23, 26 1036508P electrolytic tantalum 33u 20% 10V SIEMENS B45170-A1336-M9 DIGITAL DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF D1 27A72502 PLD RCMS interface 27A72502 D2 1035245R octal bus transceiver TI SN74HC245N D3, 4 1036604U octal latch ALLEGRO UCN5801A D5 1036477F octal D-type latch NATIONAL MM74HC573N D6, 7 1033775U octal buffer RCA CD74HC541E FUSES REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF F2-31 1036602R voltage dep resistor 65VDC 10% 0W1 SIEMENS SIOV-SO5K50 INDICATORS REF CODE DESCRIPTION MFR/SUPPLIER REF H1 1036586Z green LED HP HLMP-5050 RELAYS REF CODE DESCRIPTION MFR/SUPPLIER REF K1-15 1036204J monostable 2 changeover contacts SIEMENS V23042-A2005-B101 INDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF L1, 2 1033446L 2.5 turns PHILIPS 4312-020-36640 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1-6 1032286A opto-isolator SIEMENS CNY 17-II N7 1038949T voltage regulator NATIONAL LM2931CT RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R2-7 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R8 1008770P metal film 10k 1% 0W4 ROEDERSTEIN MK2 R10 1008794Q metal film 100k 1% 0W4 ROEDERSTEIN MK2 R12 1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2 R15 1008778Y metal film 22k1 1% 0W4 ROEDERSTEIN MK2 R16 1008791M metal film 75k 1% 0W4 ROEDERSTEIN MK2 RESISTORS, VARIABLE REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1 1030141U cermet 1 -turn 2k 10% 0W5 BECKMAN 72XR2K RESISTOR NETWORKS REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF RN1, 6, 7, 10, 11 1027365B SIP 10-pin 10kx9 2% 1W25 BOURNS 4310R-101-103 RN2-5, 8, 9
1036555Q SIP 8-pin 100x4 2% 1W BOURNS 4608X-102-101
TRANSFORMERS REF CODE DESCRIPTION MFR/SUPPLIER REF T1 1036236U line 600/600/150 ohms ERICSSON REKP173511 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1-3, 7-9
1030394U zener diode 3V3 PHILIPS BZX79B3V9
V4-6, 10-12
1006793Q switching diode FAIRCHILD 1N914A
HA72500 APPENDIX F
F-51
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1, 2
1036519B plug 96-way SIEMENS V42254-B1400-C910
XN3 1036616G header 50-way VARELCO 00-8289-050-007-213 XN4 1036614E header 60-way VARELCO 00-8289-060-007-213
F.5.54 1A72556 Transponder Subrack Motherboard CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XN1-5 1036528L socket 96-way C SIEMENS V42254-B2470-C960 XN6 1036525H plug 64-way R SIEMENS V42254-B1463-R963 XN7 1036516Y socket 25-way D AMP 745978-4 XN8, 9
1036599N header 4-way KLIPPON 12363.6
F.5.55 1A72557 External I/O PWB CAPACITORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF C1 1018878B ceramic monolyth 100n 10% 100V KEMET CK06BX104K C2 1036507N electrolytic tantalum 6u8 20% 35V SIEMENS B45170-E4685-M9 ANALOGUE DEVICES REF CODE DESCRIPTION MFR/SUPPLIER REF N1 1036593G voltage regulator 1.2 to 37V SGS-THOMSON LM217T N2 1035632M op amplifier TI TL081BCP RESISTORS, FIXED REF CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF R1, 2 1008757A metal film 3k01 1% 0W4 ROEDERSTEIN MK2 R3 1008742J metal film 681 1% 0W4 ROEDERSTEIN MK2 R4 1008696L metal film 10 1% 0W4 ROEDERSTEIN MK2 R5 1021549E metal film 3R32 1% 0W4 ROEDERSTEIN MK2 R6 1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2 R7 1008805C metal film 301k 1% 0W4 ROEDERSTEIN MK2 R8 1008797U metal film 130k 1% 0W4 ROEDERSTEIN MK2 R9 1008793P metal film 90k9 1% 0W4 ROEDERSTEIN MK2 R14 1029244U metal film 0R0 1% 0W4 ROEDERSTEIN MK2 R15 1008731X metal film 243 1% 0W4 ROEDERSTEIN MK2 R16 1021313Y metal film 2k15 1% 0W4 ROEDERSTEIN MK2 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 906806J low power PNP transistor PHILIPS 2N2905A
HA72500 APPENDIX F
F-52
CONNECTORS REF CODE DESCRIPTION MFR/SUPPLIER REF XB1-11
1036644M terminal block 6-way PHOENIX 17-25-04-1
XN1 1036518A socket 9-way D AMP 747844-6 XN2, 4
1036640H plug 9-way D AMP 747840-6
XN3 1036517Z plug 25-way D AMP 747842-6 XN5 1036599N header 4-way KLIPPON 12363.6 XN6, 8
1036525H plug 64-way R SIEMENS V42254-B1463-R963
XN7 1036518A socket 9-way D AMP 747844-6
F.5.56 1A72558 Rack Frame Wired - Single 1kWDME SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72506 CTU Subrack 1A72506 A2 1A72513 Transponder Subrack 1A72513 A3 1A72557 External I/O PWB Assembly 1A72557 A4 1A72503 1kW PA Power Supply Frame 1A72503 A7 1A72545 RF Panel - Single DME 1A72545 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1036684F dual diode rectifier 60V MOTOROLA MBR20060CT CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF W20 72558-2-29 coaxial 72558-2-29 W21 72558-3-31 coaxial 72558-3-31 W22 72558-3-32 coaxial 72558-3-32 W23 72558-2-35 coaxial 72558-2-35 W24 72558-2-37 coaxial 72558-2-37 1 72558-3-39 ribbon, 64-way 72558-3-39 1 72558-3-41 ribbon, 64-way 72558-3-41 1 72558-3-42 ribbon, 64-way 72558-3-42 1 72558-3-40 ribbon, 64-way 72558-3-40 1 72558-1-43 loom, main power 72558-1-43 1 72558-1-44 loom, 1kW PA, power 72558-1-44 1 72558-1-45 loom, 1kW PA, signal 72558-1-45 1 72558-4-46 power 72558-4-46 3 72558-4-47 earth 72558-4-47 1 72558-4-48 door earth 72558-4-48 1 72558-3-54 DC power 72558-3-54 1 72558-2-55 signal 72558-2-55 1 72558-1-86 mains cable and filter assembly 72558-1-86 CONNECTORS QTY CODE DESCRIPTION MFR/SUPPLIER REF XB12 103173BE terminal strip 6-way KLIPPON KS6/014062
HA72500 APPENDIX F
F-53
F.5.57 2A72558 Rack Frame Wired - Dual 1kW DME SUBASSEMBLIES REF CODE DESCRIPTION MFR/SUPPLIER REF A1 1A72506 CTU Subrack 1A72506 A2 1A72513 Transponder Subrack 1A72513 A3 1A72557 External I/O PWB Assembly 1A72557 A4 1A72503 1kW PA Power Supply Frame 1A72503 A5 1A72513 Transponder Subrack 1A72513 A6 1A72503 1kW PA Power Supply Frame 1A72503 A7 2A72545 RF Panel - Dual DME 2A72545 SEMICONDUCTORS REF CODE DESCRIPTION MFR/SUPPLIER REF V1 1036684F dual diode rectifier 60V MOTOROLA MBR20060CT CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF W20 72558-2-29 coaxial 72558-2-29 W21 72558-3-31 coaxial 72558-3-31 W22 72558-3-32 coaxial 72558-3-32 W23 72558-2-35 coaxial 72558-2-35 W24 72558-2-37 coaxial 72558-2-37 W28 72558-2-30 coaxial 72558-2-30 W29 72558-3-33 coaxial 72558-3-33 W30 72558-2-34 coaxial 72558-2-34 W31 72558-2-36 coaxial 72558-2-36 W32 72558-2-38 coaxial 72558-2-38 1 72558-3-39 ribbon, 64-way 72558-3-39 1 72558-3-41 ribbon, 64-way 72558-3-41 1 72558-3-42 ribbon, 64-way 72558-3-42 1 72558-3-40 ribbon, 64-way 72558-3-40 1 72558-1-43 loom, main power 72558-1-43 2 72558-1-44 loom, 1kW PA, power 72558-1-44 2 72558-1-45 loom, 1kW PA, signal 72558-1-45 2 72558-4-46 power 72558-4-46 3 72558-4-47 earth 72558-4-47 1 72558-4-48 door earth 72558-4-48
F.5.58 1A72560 Antenna Cable Set for Single Installation CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 1031588R 20m LDF4-50 cable, with L44AW
connector one end ANDREW LDF4-50
1 72560-4-01 coaxial, monitor 72560-4-01 1 72560-4-02 coaxial, antenna feeder tail 72560-4-02 CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72560-4-03 cable accessories kit, single 72560-4-03
F.5.59 2A72560 Antenna Cable Set for Dual Installation CABLE ASSEMBLIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 1031588R 20m LDF4-50 cable, with L44W
connector one end ANDREW LDF4-50
2 72560-4-01 coaxial, monitor 72560-4-01 1 72560-4-02 coaxial, antenna feeder tail 72560-4-02
HA72500 APPENDIX F
F-54
ACCESSORIES QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72560-4-04 cable accessories kit, dual 72560-4-04
F.5.60 1A72561 Accessory Kit, DME Test QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 1A72562 Transponder extender frame 1A72562 2 1036676X Eurocard 6U extenders VERO 09-0108E 1 1A72563 Special tools and fittings 1A72563 1 1A72564 Coaxial cables and accessories 1A72564 1 1036132F power supply extender card ERICSSON ROF 131391/1
F.5.61 1A72562 Transponder Extender Frame QTY CODE DESCRIPTION MFR/SUPPLIER REF 2 72562-4-11 coaxial jack/SMA 72562-4-11 2 72562-4-07 coaxial BNC/SMA 72562-4-07
F.5.62 1A72563 Special Tools and Fittings QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 1021120N screwdriver Posidrive No. 1 STANLEY 65-532 1 1021121P screwdriver Posidrive No. 2 STANLEY 533 1 6A70756 Extension cable assembly, mains
cable 6A70756
1 1036731G spanner open ended metric A/F 8x9 mm SIDCHROME 0397-7415 1 1036732H alignment tool JOHANSON 8777
F.5.63 1A72564 Coaxial Cables and Accessories QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 72564-3-01 Cable assembly CRO trigger 72564-3-01 1 72564-3-02 Cable assembly RF test 72564-3-02 1 72564-3-03 Cable assembly test 72564-3-03 1 1030262A attenuator fixed 50 ohms 3 dB SMA KDI A303M 1 1030560Z attenuator fixed 50 ohms 6 dB SMA KDI A306M 1 1031583L adapter coax N(M)-SMA(F) SUHNER 33N-SMA-50-1/133
HA72500 APPENDIX G
APPENDIX G
COMPONENT SUPPLIERS
G-i
HA72500 APPENDIX G
TABLE of CONTENTS
G. COMPONENT SUPPLIERS................................................................... G-1 G.1 COMPONENT MANUFACTURERS AND AGENTS G-1
G-ii
HA72500 APPENDIX G
G. COMPONENT SUPPLIERS G.1 COMPONENT MANUFACTURERS AND AGENTS The component schedules contained in Appendix F identify manufacturers and/or suppliers of items by an abbreviated name form. The abbreviations used, and the manufacturer and/or supplier identities which they represent, are listed below in alphabetical order.
In instances where organisations based outside Australia are included the Australian representative or agent, if any, is shown in the right-hand column.
AIRPAX Airpax Corporation Philips Components Pty Ltd PO Box 373 NORTH RYDE NSW 2113 AUST
AKM AKM Braemac Pty Ltd 6/111 Moore Street LEICHHARDT NSW 2040 AUST
ALLEGRO Allegro VSI Electronics (Australia) Pty LtdPO Box 578 CROWS NEST NSW 2065 AUST
ALLEN-BRADLEY Allen-Bradley Pty Ltd Daktron Electronics Pty Ltd PO Box 6166 BAULKHAM HILLS NSW 2153 AUST
AMP Australian AMP Pty Ltd PO Box 557 CASTLE HILL NSW 2154 AUST
ANDREW Andrew Australia 153 Barry Road CAMPBELLFIELD VIC 3061 AUST
ARCO ARCO Tri-Components Pty Ltd 5 Hampshire Road GLEN WAVERLEY VIC 3150 AUST
ATC American Transistor Corporation
A. J. Distributors PO Box 71 PROSPECT SA 5082 AUST
BECKMAN Beckman Industrial Corporation
VSI Electronics (Australia) Pty LtdPO Box 578 CROWS NEST NSW 2065 AUST
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HA72500 APPENDIX G
BOURNS Bourns Incorporated VSI Electronics (Australia) Pty LtdPO Box 578 CROWS NEST NSW 2065 AUST
BRAEMAC Braemac Pty Ltd 6/111 Moore Street LEICHHARDT NSW 2040 AUST
C&K C&K Electronics Pty Ltd PO Box 229 PARRAMATTA NSW 2124 AUST
CAMBION Cambion Electronic Development Sales Pty Ltd PO Box 822 LANE COVE NSW 2066 AUST
CATALYST Catalyst Veltek Pty Ltd 10 Harker Street BURWOOD VIC 3125 AUST
CTS CTS Corporation Moncrief Pty Ltd 8th Floor, 275 Alfred Street NORTH SYDNEY NSW 2060 AUST
DALE Dale Electronics Inc. EC Capacitors Pty Ltd PO Box 224 RESERVOIR VIC 3073 AUST
ELMA Elma Electronics Ag Associated Controls Pty Ltd 29 Smith Street HILLSDALE NSW 2036 AUST
ERICSSON L. M. Ericsson Pty Ltd PO Box 41 BROADMEADOWS VIC 3047 AUST
ERNI Erni Australia Pty Ltd PO Box 62 MITCHAM VIC 3132 AUST
FAIRCHILD Fairchild NSD Australia Pty Ltd Locked Bag 9 BOX HILL VIC 3128 AUST
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GHZ GHZ Technologies Inc.
3800 Oakmead Village Drive SANTA CLARA CA 95051 USA
GSI General Semiconductor Industries
Clarke and Severn Electronics 2/107 Hunter Street HORNSBY NSW 2077 AUST
HARWIN Harwin Clarke and Severn Electronics 2/107 Hunter Street HORNSBY NSW 2077 AUST
HEWLETT PACKARD
Hewlett Packard VSI Electronics (Australia) Pty LtdPO Box 578 CROWS NEST NSW 2065 AUST
HY-Q HY-Q International (Australia) Pty Ltd PO Box 210 CLAYTON VIC 3168 AUST
INTEL Intel Corporation Email Electronics 15-17 Hume Street HUNTINGDALE VIC 3166 AUST
IRC International Rectifier Corporation
NSD Australia Pty Ltd Locked Bag 9 BOX HILL VIC 3128 AUST
IRH IRH Components Locked Bag 33 LIDCOMBE NSW 2141 AUST
ITT ITT-STC Alcatel Components Ltd PO Box 317 ROSEBERY NSW 2018 AUST
JOHANSON Johanson Manufacturing Corporation
Captron Pty Ltd PO Box 1005 BROOKVALE NSW 2100 AUST
K&L MICROWAVE
K&L Microwave Hawker de Havilland Victoria Ltd GPO Box 779H MELBOURNE VIC 3001 AUST
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KDI KDI/Triangle Electronics Inc Electronic Development Sales Pty Ltd PO Box 822 LANE COVE NSW 2066 AUST
KEMET Kemet IRH Components Locked Bag 33 LIDCOMBE NSW 2141 AUST
KLIPPON Klippon Electricals Pty Ltd Weidmuller (Klippon Products) PO Box 323 PENRITH NSW 2751 AUST
MATSUSHITA Matsushita RVB Products Pty Ltd 23 DeHavilland Road BRAESIDE VIC 3195 AUST
MAXIM Maxim Veltek Pty Ltd 10 Harker Street BURWOOD VIC 3125 AUST
McMURDO McMurdo Swann Electronics Group Limited5 Dunlop Grove MULGRAVE VIC 3170 AUST
MILLER MGI Incorporated 114 Pleasant Avenue UPPER SADDLE RIVER NJ 07458 USA
MICROLAB/FXR Microlab/FXR AWA Distribution Tower A, 112-118 Talavera RoadNORTH RYDE NSW 2113 AUST
MINI-CIRCUITS Sigra Electronics Incorporated 7397 Davie Road Extension HOLLYWOOD FLA 33024 USA
MOTOROLA Motorola Semiconductor Products
VSI Electronics (Australia) Pty LtdPO Box 578 CROWS NEST NSW 2065 AUST
NATIONAL National Semiconductor NSD Australia Pty Ltd Locked Bag 9 BOX HILL VIC 3128 AUST
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OMNISPECTRA Sigra Electronics Incorporated
7397 Davie Road Extension HOLLYWOOD FLA 33024 USA
PHILIPS Philips Components Pty Ltd PO Box 373 NORTH RYDE NSW 2113 AUST
PHOENIX Phoenix Contact IRH Components Locked Bag 33 LIDCOMBE NSW 2141 AUST
PLESSEY Plessey Semiconductors GEC Electronics Division Locked Bag 29 RYDALMERE NSW 2116 AUST
RCA RCA Solid State Division VSI Electronics (Australia) Pty LtdPO Box 578 CROWS NEST NSW 2065 AUST
RF TECHNIQUES R. F. Techniques 140 San Lazaro Avenue SUNNYVALE CA 94086 USA
ROEDERSTEIN Firmengruppe Roederstein Meyer Kreig and Co. PO Box 686 UNLEY SA 5061 AUST
ROHM ROHM Company Fairmont Marketing 57 St Heftier Street HEIDELBERG HEIGHTS VIC 3081 AUST
SCOTT Scott (EMC) Ampec Technologies Pty Ltd 13 Smail Street ULTIMO NSW 2007 AUST
SGS-THOMSON SGS-Thomson GEC Electronics Division Locked Bag 29 RYDALMERE NSW 2116 AUST
SIDCHROME J. Blackwood and Son Ltd 13 Cooper Street SMITHFIELD NSW 2164 AUST
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SIEMENS Siemens Ltd
383 Pacific Highway ARTARMON NSW 2064 AUST
SIGNETICS Signetics Philips Components Pty Ltd PO Box 373 NORTH RYDE NSW 2113 AUST
SPECTRUM Spectrum Control ASEA Brown Boveri Distribution 376 Newbridge Road LIVERPOOL NSW 2170 AUST
STANLEY Stanley Tools David Piper Pty Ltd PO Box 161 CONCORD NSW 2137 AUST
STAR Star Koloona Industries Pty Ltd PO Box 177 MOOREBANK NSW 2170 NSW
STRUTHERS-DUNN
Struthers-Dunn Inc. Aerospace and Defence Products4/53 Kalang Road ELANORA HEIGHTS NSW 2101 AUST
SUHNER Huber and Suhner (Australia) Pty Ltd PO Box 372 NARABEEN NSW 2101 AUST
TELEDYNE Teledyne Microwave 1290 Terra Bella Avenue MOUNT VIEW CA 94043 USA
TEXAS INSTRUMENTS
Texas Instruments VSI Electronics (Australia) Pty LtdPO Box 578 CROWS NEST NSW 2065 AUST
UTILUX Utilux Pty Ltd PO Box 68 KINGSGROVE NSW 2208 AUST
VARELCO Varelco M. Rutty and Company Pty Ltd 1/38 Leighton Place HORNSBY NSW 2077 AUST
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VERO Vero Systems IRH Components Locked Bag 33 LIDCOMBE NSW 2141 AUST
VITRAMON Vitramon Pty Ltd PO Box 94 AUBURN NSW 2144 AUST
WILLIAM HUGHES
William Hughes Inc. Kingfisher International 4/19 Viewtech Place ROWVILLE VIC 3178 AUST
WIMA Wilhelm Westerman Techncial Imports Australia Pty Ltd PO Box 1120 CASTLE HILL NSW 2154 AUST
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HA72500 APPENDIX H
APPENDIX H
CTU SOFTWARE
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TABLE of CONTENTS
H. CTU SOFTWARE ...................................................................................H-1 H.1 OVERVIEW H-1 H.2 BEACON MODULE H-5
H.2.1 The Beacon Control Task............................................................................H-5 H.2.2 Power Up Sequence....................................................................................H-6 H.2.3 Power Down Sequence ...............................................................................H-6
H.3 ZMODEM MODULE H-6 H.4 NMP MODULE H-7 H.5 MEASUREMENT MODULE H-9
H.5.1 Introduction..................................................................................................H-9 H.5.2 Interface to Other Software Modules...........................................................H-9 H.5.3 Measurement Types..................................................................................H-10 H.5.4 Higher Level Measurement Functions in Other Modules ..........................H-12
H.6 TEST MODULE H-13 H.6.1 Introduction................................................................................................H-13 H.6.2 Test Module Tasks ....................................................................................H-13 H.6.3 Interface to Other Software Modules.........................................................H-14
H.7 LOCAL MODULE H-15 H.7.1 Introduction................................................................................................H-15 H.7.2 Local Module Tasks...................................................................................H-15 H.7.3 Interface to Other Software Modules.........................................................H-15
H.8 RCMS MODULE H-16 H.8.1 Introduction................................................................................................H-16 H.8.2 CMS Module Task .....................................................................................H-16 H.8.3 Interface to Other Software Modules.........................................................H-16
H.9 STARTUP SOFTWARE H-17 H.9.1 Hardware Initialise .....................................................................................H-17 H.9.2 Software Initialise ......................................................................................H-17 H.9.3 Production Test Software ..........................................................................H-17
H.10 TASK SCHEDULER H-17 H.11 INTERRUPT SERVICE ROUTINES H-17
H.11.1 Serial Interrupt Service Routine.................................................................H-17 H.11.2 Timer Interrupt Service Routine.................................................................H-17
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LIST of FIGURES
Figure H-1 CTU Software Data Flow Diagram ........................................................ H-2 Figure H-2 CTU Software Structure Diagram.......................................................... H-4
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HA72500 APPENDIX H
H. CTU SOFTWARE H.1 OVERVIEW This appendix presents an overview of the operation of the Control and Test Unit (CTU) software. For more detailed information about the operation of the CTU and the parent DME LDB-102 system itself, see Appendix A.
The main functions of the software are:
a. To control the operation of an LDB-102 DME navaid with either single or dual transponder configuration. This control may be exercised either locally or remotely.
b. To collect and display (either locally or remotely) the operational status of the various modules of the LDB-102 and of the overall beacon.
c. To measure a number of operational parameters from the various modules of the LDB-102 for use by the Remote Maintenance and Monitoring (RMM) system, if this option is installed.
d. To control the test functions of the LDB-102.
In order to accomplish these objectives, the CTU software is divided into a number of self-contained modules which are linked with various data flows. This is shown diagrammatically in Figure H-1. These modules are:
• Zmodem Module.
• NMP (Navaid Maintenance Processor) Interface Module.
• RCMS (Remote Control and Monitoring System) Module.
• Local Module.
• Test Module.
• Measurement Module.
• Beacon Module.
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HA72500 APPENDIX H
Figure H-1 CTU Software Data Flow Diagram
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HA72500 APPENDIX H
There are four hardware blocks to which the CTU software must interface, each aspect of which is taken care of by a separate software module:
• The CTU serial port hardware.
The CTU serial port data is handled by the Zmodem Module, which uses RMM messages to communicate with the NMP Interface Module.
• The RCMS hardware interface.
The RCMS interface hardware is handled by the RCMS Module, which reads the RCMS inputs and controls the RCMS outputs.
• The CTU front panel.
The control switches and status indicators on the CTU front panel are handled by the Local Module, while the test switches and indicators on the CTU front panel are handled by the Test Module.
• The CTU transponder hardware.
The Beacon Module handles the control and status of the transponder hardware, while the Measurement Module handles the transponder hardware measurement registers.
The NMP Interface, RCMS and Local Modules are all used to convey control and status information to the Beacon Module using the data paths shown in Figure H-1. The Test Module and Measurement Module convey measurement requests and results to the Beacon Module.
The software structure diagram, shown in Figure H-2, broadly describes the control flow of the CTU software. The diagram is read from top to bottom, and left to right. Each rectangle represents a logical block or module of software. If there is a choice between modules, each rectangle at that particular level will have a small circle in the top right hand corner of that rectangle. If there is a loop in a module, or group of modules, a small circular arrow symbol is shown on the input to those modules.
There are two infinite loops in the CTU software; one is formed in the Task Scheduler, and the other is in the Production Test software module. Additional software modules shown on the flow diagram are:
• Hardware Initialise Module.
• Software Initialise Module.
• Interrupt Service Routines.
• Task Scheduler.
• Production Test Module.
Descriptions of each of the functions shown in Figure H-2 are given in the following sections.
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HA72500 APPENDIX H
Figure H-2 CTU Software Structure Diagram
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HA72500 APPENDIX H
H.2 BEACON MODULE
H.2.1 The Beacon Control Task The predominant function of the CTU software is that of beacon control. To this end, the Beacon Control Task can be said to have four distinct states:
a. OFF;
b. BEACON_NO1;
c. BEACON_NO2; and
d. SHUTDOWN.
The beacon starts in the OFF state. If either transponder is currently on, but not selected as main by the front panel switches (initially OFF is selected), it is powered down. The task then continually waits for either the Local control task functions or the NMP/RCMS tasks (in the case of remote access) to signal that the user has turned on one of the transponders using the SELECT MAIN switches. The internal beacon variables are then reset and either the BEACON_NO1 or BEACON_NO2 states are entered, depending upon which transponder was selected as main.
In the BEACON_NO1 or BEACON_NO2 states, the Beacon Control Task cycles through the following actions:
a. If the battery is not OK or if any front panel switch changes have occurred, return to the OFF state to properly set the internal variables to reflect the new conditions.
b. If in BEACON_NO1 state and Transponder 2 is currently powered, then power it down. If in BEACON_NO2 state and Transponder 1 is currently powered, then power it down.
c. If in BEACON_NO1 state and Transponder 1 is currently powered down, then power it up. If in BEACON_NO2 state and Transponder 2 is currently powered down, then power it up.
d. Determine whether any faults are present. This includes performing a monitor module self-test every 15 seconds.
e. If the DME is a dual configuration, and the currently operating transponder's faults are 'worse' than the current standby transponder's (that is, if the operating transponder has any fault while the current standby has none, or the operating transponder has a primary fault while the current standby has a secondary fault) then the current transponder is powered down, the transfer flag is set, and the task enters either the BEACON_NO1 or BEACON_NO2 state, depending upon which transponder is currently in standby. Otherwise, if there are primary faults, power down the currently operating transponder, then enter the SHUTDOWN state.
In the SHUTDOWN state, the Beacon Control Task firstly increments the shutdown count, then proceeds to power down any transponder that is still operating. All test interrogator and monitor modules are powered down and the recycle timer is reset. The task then waits either for the user to SELECT MAIN OFF or, if retries are permitted, for the retry counter to expire before entering the OFF state.
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HA72500 APPENDIX H
H.2.2 Power Up Sequence When a transponder is powered up, the following sequence of events takes place:
a. Switch the antenna to the desired transponder.
b. Switch the associated ident in/out controls to the desired transponder.
c. Switch on the available test interrogator/monitor modules.
d. 20 milliseconds delay for power stabilisation.
e. Switch on the transponder supply.
f. 20 milliseconds delay for power stabilisation.
g. Switch on the power amplifier supply.
h. 20 milliseconds delay for power stabilisation.
i. Enable RF and the replies.
j. Wait for the selected cold start delay, or wait for the 2-second warm start delay.
k. Enable ident transmission if monitor alarms are normal.
H.2.3 Power Down Sequence When a transponder is powered down, the following sequence of events takes place:
a. Inhibit replies.
b. Disable RF output.
c. If cold standby or faults, turn off the power amplifier and transponder hardware power supplies, otherwise turn on the power amplifier and transponder hardware supplies.
H.3 ZMODEM MODULE The CTU communicates with the RMM System using Zmodem data packets. In order to achieve reliable transmission and reception of such packets, the Zmodem file transfer protocol is used as the transport mechanism for the Zmodem data packets.
When the Zmodem Task is passed an RMM message from the NMP Task, it initiates a Zmodem session (using Zmodem packets) with the RMM system via the CTU serial port. Once the session has been established, the RMM message is encapsulated within a Zmodem data packet and sent to the serial port. Upon completion, the session is terminated and the success or failure of the transmission is conveyed to the NMP Task. A success indication is a guarantee that the message was received by the RMM system.
When the CTU serial port indicates that there are incoming characters, the Zmodem Task scans the incoming data stream for Zmodem packets in order to establish a Zmodem session. Once this is done, the incoming Zmodem data packets have their contents (an RMM message) extracted and buffered. When the Zmodem session is terminated successfully, the Zmodem Task signals the NMP Task that an RMM message was received and waits for the NMP Task to remove the message from its buffer.
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HA72500 APPENDIX H
H.4 NMP MODULE The NMP Task accepts RMM messages from the Zmodem Task, performs the appropriate actions, and returns any relevant data to the RMIM system in the form of RMM messages.
The following table lists the events that may be received from the RMM System and indicates the NMP Task's responses to them.
EVENT RECEIVED FROM RMM SYSTEM SERVICE PROVIDED BY NMP TASK Received Initiate Message from RMM System Send Acknowledge Message to the RMM
System Received Terminate Message from RMM System
Send Terminate Message to the RMM System
Received Check Message from RMM System Send Acknowledge Message to the RMM System
Received Control Message from RMM System with a SET_OFF argument
If SOURCE switch is set to REMOTE, signal Beacon Task to turn off the DME, otherwise send an Error Message with an ERR_SOURCE argument
Received Control Message from RMM System with a SET_NO1 argument
If SOURCE switch is set to REMOTE and Transponder 2 is not selected as main, select Transponder 1 as main and turn it on. If the SOURCE switch is set to LOCAL, send an Error Message with an ERR_SOURCE argument. If the SOURCE switch is set to REMOTE but SELECT MAIN is set to NO2, send an Error Message with an ERR-MODE argument.
Received Control Message from RMM System with a SET_NO2 argument
If SOURCE switch is set to REMOTE and Transponder 1 is not selected as main, select Transponder 2 as main and turn it on. If the SOURCE switch is set to LOCAL, send an Error Message with an ERR_SOURCE argument. If the SOURCE switch is set to REMOTE but SELECT MAIN is set to NO1, send an Error Message with an ERR_MODE argument.
Received an Info Request Message from RMM System with a GET_STATUS argument
Send Status Message to RMM System
Received an Info Request Message from RMM System with a GET_MEASUREMENTS argument
If the MAINTENANCE switch is OFF, request measurement results from the Measurement Task then send a Measurement Message to the RMM System, otherwise send an Error Message with an ERR_MODE argument.
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HA72500 APPENDIX H
The NMP Task may also receive requests from the Beacon Control Task or the Local Task to send performance characteristics and navaid status information to the RMM system. The following table lists the events in Beacon Control Task or Local Task that cause service requests to the NMP Task, as well as the NMP Task's response to them.
EVENT RECEIVED FROM RMM SYSTEM SERVICE PROVIDED BY NMP TASK Local Task detects a CTU Front Panel control switch was pressed
Send a Switch Change Message to the RMM System. The argument can be one of the following:
OFF_SELECTED, NO1_SELECTED, NO2_SELECTED, MON_ACTION_INHIBITED, MON_ACTION_ENABLED, MAINTENANCE_SELECTED, MAINTENANCE_DESELECTED, LOCAL_SELECTED, REMOTE_SELECTED, RECYCLE_SELECTED or RECYCLE_DESELECTED.
Beacon Task detects a Primary or Secondary Fault
Send an Alarm Message (with either a P_ALARMS or S_ALARMS argument) and a Postfault Measurement Message to the RMM System
Beacon Task took some form of action due to faults or low battery power
Send an Action Message to the RMM System. The argument can be one of the following:
POWERDOWN_NO1, POWERDOWN_NO2, POWERUP_NO1, POWERUP_NO2, TRANSFER_TO_NO1, TRANSFER_TO_NO2, SHUTDOWN_FAULTS, SHUTDOWN_BATTERY, STOP_RECYCLE, WAIT_RECYCLE, RESTART_FAULTS or RESTART_BATTERY.
Beacon Task detects low battery voltage Send a Power Message to the RMM System
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HA72500 APPENDIX H
H.5 MEASUREMENT MODULE
H.5.1 Introduction The Measurement Module is a collection of functions used by the other tasks to operate the measurement hardware in the LDB-102 DME. The other tasks communicate with the Measurement Module by initialising the input fields of the control buffer, calling the relevant modules, and reading the results from the output fields of this buffer.
To prevent tasks from interfering with each other, a priority system is set up for each basic class of measurement that can be performed. A task whose priority is higher than the current task using the measurement functions can interrupt that measurement. The lower priority task will then receive an error message to indicate that its measurement did not complete successfully.
When the entry functions are called, they in turn call more specific functions, depending on the requested measurement class and type. For example when 'MeasureRead' is called requesting a 24 volts measurement, this function calls 'MeasureReadVolts' to perform the measurement. As each of the monitor fault limit measurements is significantly different from the others, the 'MeasureReadLimit' function calls individual functions for each of the monitor fault limits.
H.5.2 Interface to Other Software Modules Other software modules interface to the measurement functions by:
a. Setting up the test interrogation level and rate, using the 'MeasureSet' function.
b. Setting up the interface buffer area, an area unique to each module that requires measurement functions to be performed.
c. Calling the 'MeasureStart' function, passing it a pointer to the initialised buffer area. If there are problems with the data fields or another higher priority function is currently using the measurement facilities, an error message will be returned and the measurements not started. If the measurements were successfully started, a NO_ERROR message will be returned and the selected measurement started.
d. The calling module can check on the progress of the selected measurement by calling the 'MeasureRead', with the pointer to the buffer area, and checking for the error messages from this routine. When NO_ERROR has been returned, the selected measurement has been done and the results stored in the buffer area, and the measurement hardware has been stopped using a call to the 'MeasureStop' function.
e. The calling module needs to check that the measurement has not been interrupted by a module with higher priority; if this has happened the measurement shall be restarted by the calling module if required.
f. Resetting the test interrogation level and rate, using the 'MeasureSet' function.
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HA72500 APPENDIX H
The structure of the interface buffer is:
monitor input calling routine shall state which test interrogator/monitor module is to used for the requested measurement.
tpndr input specify the transponder that is on. class input specify the generic type of measurement to be done
(e.g.: RATES, TIMES, etc). type input specify the type of measurement to be done
(e.g.: DELAY, SPACING, etc). ti_rate input current test interrogation rate set on the hardware. ti_level input current test interrogation level set on the hardware. info output pointer to a lookup information table for the display strings, scaling
factor, and units associated with a particular measurement, set up by 'MeasureStart' routines.
value1 output result of a measurement. value2 output result of a measurement; for example, from second channel or the
upper limit.
The structure of the information table used for information on display and scaling is:
name pointer to an ASCII string, up to 15 characters, used to describe the quantity being measured.
format pointer to a string, up to five characters, used to specify the format to be used by the display functions.
units pointer to a string, up to four characters, to be displayed after the measurement, for the units of the display.
offset added to the result before the result is displayed. scale multiplied with the result before it is displayed.
H.5.3 Measurement Types The CTU hardware is designed to measure 'time', 'rate', 'voltage', 'Boolean', and 'monitor fault limits'. The first four classes of measurements may be run in parallel, and each channel may be running at the same time. If any monitor fault limit is started, no other class of measurement can be started.
a. The test interrogator module can provide the following time measurements, in 0.1 microseconds steps:
• 0 microseconds calibration • Delay • Spacing • Transmit pulse width • Transmit pulse rise time • Transmit pulse fall time • 100 microseconds calibration pulse width - from the internal test
interrogator timebase.
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b. The test interrogator module can provide the following rate measurements, with a 1 MHz timebase:
• 0 Hz calibration • Decoded pulse rate • Transmit pulse rate • Transponder efficiency • 5 kHz calibration rate - from the internal test interrogator timebase.
c. The monitor module can provide the following voltage measurements, in 256 steps from 0 to 5 volts:
• 0 volts level • Receiver video oscillator level • Receiver video driver level • Transmitter drive level • Transmitter driver modulation level • Power amplifier drive level • Power amplifier modulation level • Power amplifier output level • Power amplifier supply level • Test interrogator RF level • Transponder power output level • Transponder 15 volts supply level • Transponder 18 volts supply level • Transmitter driver power supply level • Battery 24 volts supply level • A DC voltage calibration signal.
d. The monitor module can sample the following flags:
• Monitor module power supply status • Receiver video module power supply status • Test interrogator module power supply status • Receiver video RF triggers normal.
e. The test interrogator and monitor modules can provide the following monitor fault limit measurements:
• Lower reply delay limit • Upper reply delay limit • Lower spacing limit • Upper spacing limit • Lower transmit rate limit • Upper transmit rate limit • Lower efficiency limit • Lower output power limit.
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H.5.4 Higher Level Measurement Functions in Other Modules The NMP interface module has the following measurement functions, to measure all the indicated parameters sequentially, except the calibration signals, and using only one test interrogator/monitor module at a time. The following functions also format and write to the output RMM message buffer:
• 'NmpMeasureAllTimes' measures all the times.
• 'NmpMeasureAllRates' measures all the rates.
• ‘NmpMeasureAllVolts' measures all the voltages, also used in the beacon postfault measurements.
• 'NmpMeasureAllBooleans' measures all Booleans, also used in the beacon postfault measurements.
• 'NmpMeasureAllLimits' measures all the limits, also used in the beacon postfault measurements.
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HA72500 APPENDIX H
H.6 TEST MODULE
H.6.1 Introduction The test module is a group of tasks that handle the operation of the test section of the Control and Test Unit (CTU) user interface. This module also provides a collection of functions used by the other software modules to access the functions of the test section needed by the other modules. and to communicate with the test module.
H.6.2 Test Module Tasks There are three test module tasks - Test Measure Task, Test TI Task, and Test Flash Task.
Test Measure Task performs the following functions:
a. Start a new parameter measurement when a new parameter is selected, and stop the measurements when the parameter is deselected, or the menu is changed.
b. Run the measurement process:
1. Call the required measurement functions, including the initialising and running the buffer areas.
2. Process and display the results, together with the required text strings.
3. Detect and display any exceptions that may occur ('overflow').
4. Detect hardware problems, and display 'wait’ if a valid reading is not available after 6 seconds.
c. Trigger the flashing of the softkeys when a measurement is started, and stop the flashing when the measurement is stopped.
Test TI Task handles the following functions:
a. Monitor the status of the TI RATE 1 kHz pushbutton. If the maintenance function has been selected, toggle the test interrogation pulse repetition frequency (TIPRF) between the normal rate (50 Hz or 100 Hz) and the 1 kHz rate, otherwise generate <<< Select MAINTENANCE first >>> error message.
b. Monitor the status of the TI RATE 10 kHz pushbutton. If the maintenance function has been selected, then while this button is pressed select the test interrogation pulse repetition frequency (TIPRF) of 10 kHz; when this button is released, return the TIPFIF to the previously selected rate (50 Hz or 100 Hz or 1 kHz rates). If the maintenance function has not been selected, generate <<< Select MAINTENANCE first >>> error message.
Test Flash Task handles the following functions:
a. Flash five time any error messages that are required by other functions and tasks.
b. Flash the softkey labels while there is a parameter measurement is in progress.
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H.6.3 Interface to Other Software Modules a. Test Menu Processor.
This function is called by the Local Task, when a test section activated pushbutton is detected. This function then takes the necessary action to change the current menu or action the selected menu item.
b. Miscellaneous Display Drivers.
These functions are called when other software modules need to access the LCD display in the test section.
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H.7 LOCAL MODULE
H.7.1 Introduction The test module is a group of tasks that handle the operation of the control section of the Control and Test Unit (CTU) user interface. This module provides the necessary user feedback, including any error messages, to guide the user in the operation of the LDB-102. This module also provides a collection of functions used by the other software modules to access the functions of the control section needed by the other modules, and to communicate with the local module.
H.7.2 Local Module Tasks There are two local module tasks, Local Task and Local Options Task.
Local Task operates the keyboard hardware and, if there is any activity, calls the relevant processor module. If a pushbutton from the control section is pressed, it calls the 'Local Switch Processor' routine. If a pushbutton from the test section of the front panel is pressed, it calls the 'Test Menu Processor' routine. The task waits for the pushbutton to be released before the pushbutton processor routines are called again. The two TI RATE pushbuttons (1 kHz and 10 kHz) are handled by the Test Module.
Local Options Task handles the following functions:
a. Collect the power status of the LDB-102, and update this status to the CTU front panel and to the CTU RCMS system.
b. Collect the options set on the CTU switches (internal and external), and update and initialise the internal 'Controls' database.
c. Detect the test interrogator/monitor modules being placed in 'normal' mode, and rewrite the control latches in these modules.
d. Update the 'test' status indicators from the transponder hardware. The TEST indicators will be on if the important transponder module switches or the antenna relay are not if the correct position for normal operation.
e. Toggle the watchdog timer hardware, to prevent a hardware reset.
H.7.3 Interface to Other Software Modules a. Local Put Controls.
This function is called when another module needs to write to the indicators in the control section of the CTU front panel.
b. Local Put Status.
This function is called when a module needs to write to the indicators in the status section of the CTU front panel.
c. Local Put Alarms.
This function, and ‘Local Show Alarms', are called when a module needs to write to the indicators in the alarm section of the CTU front panel. These routines also select which transponder's alarms are displayed, depending on the input from the menu system.
d. Local Put Power.
This function is called when a module needs to write to the indicators in the status section of the CTU front panel. This function also operates the heartbeat indicators on the CTU processor and front panel boards.
H-15
HA72500 APPENDIX H
H.8 RCMS MODULE
H.8.1 Introduction The RCMS module is a task that handle the operation of the Remote Control and Maintenance System (RCMS) of the Control and Test Unit (CTU) RCMS interface. This module also provides a collection of functions used by the other software modules to access the functions of the RCMS interface hardware needed by the other modules, and to communicate with the RCMS module.
H.8.2 CMS Module Task This task monitors the RCMS control inputs if the transponder is set to remote control via the RCMS system. There is an active input the ‘Beacon Set Controls' routine is called to select ‘OFF', ‘NO1 ON', or 'NO2 ON’, via the relevant control routines.
H.8.3 Interface to Other Software Modules a. RCMS Put Controls.
This function is called when another software module needs to write the control status to the outputs of the RCMS interface.
b. RCMS Put Status.
This function is called when another software module needs to write the beacon status to the status outputs of the RCMS interface.
c. RCMS Put Alarms.
This function is called when another software module needs to write to the alarm status to the status outputs of the RCMS interface.
d. RCMS Put Power.
This function is called when another software module needs to write to the power status to the status outputs of the RCMS interface. This routine also operates the heartbeat indicator on the RCMS interface board.
H-16
HA72500 APPENDIX H
H.9 STARTUP SOFTWARE
H.9.1 Hardware Initialise The startup code will perform the following hardware tests and initialisations:
• ROM test; the 'ROM TEST OK’ indicator on the CTU processor board will be lit if the test passes.
• RAM test; the 'RAM TEST OK’ indicator on the CTU processor board will be lit if the test passes.
• Initialise the 80186 hardware, including interrupt controller, address decoder and timer hardware.
• Initialise the interrupt vector tables.
• Initialise the initialised 'C' variables.
• Initialise the library routines, and their variables.
H.9.2 Software Initialise The software initialise section of the main routine will execute the 'Init' function from each of the software modules.
H.9.3 Production Test Software If the production tests are selected, they will loop, waiting for a control input, until the processor is turned off or reset. If the production software is not enabled, the normal operational software will be started by initialising and then starting the Task Scheduler.
H.10 TASK SCHEDULER The Task Scheduler is a co-operative round robin task scheduler. This means that each task is run in turn (or restarted), and each task has full control of the processor, and resources, until it decides to release control. When all the tasks have been run, the first one is restarted, then the next one, etc.
H.11 INTERRUPT SERVICE ROUTINES
H.11.1 Serial Interrupt Service Routine This routine is called by the hardware when a character is received on the serial port. The character is then saved in a circular buffer for the 'Zmodem' routines. There is no transmit interrupt service routine set up, as the characters are transmitted directly by the 'Zmodem' routines. When the production tests are running the 'Zmodem' protocol in not used.
H.11.2 Timer Interrupt Service Routine The third internal 80186 timer is set up to produce a regular 10 milliseconds interrupt. The timer interrupt service routine decrements 16 software timers once every timer tick, until they are zero. Fifteen of these timers are 16-bit numbers, giving a maximum time of 655 seconds (approximately 10 minutes). These software timers are used by various software modules to time various actions in real-time, such as flashing displays and timing the hardware actions and responses. The 16th software timer is a 32-bit number, giving the range necessary to detect and process the recycle rate.
H-17
HA72500 APPENDIX I
APPENDIX I
COMPONENT LAYOUT DIAGRAMS
I-i
HA72500 APPENDIX I
I-ii
TABLE of CONTENTS
I. COMPONENT LAYOUT DRAWINGS .......................................................... I-1
HA72500 APPENDIX I
I-iii
LIST of FIGURES
Figure I-1 Component Layout Diagram : 1A72511 Main PWB Assembly, Monitor Module ..... I-1 Figure I-2 Component Layout Diagram : 1A72512 Peak Power Monitor ................................. I-2 Figure I-3 Component Layout Diagram : 1A72515 Main PWB Assembly, Test Interrogator ... I-3 Figure I-4 Component Layout Diagram : 1A72516 RF Generator ........................................... I-4 Figure I-5 Component Layout Diagram : 1A72518 Modulator and Detector ........................... I-5 Figure I-6 Component Layout Diagram : 1A72519 Reply Detector ......................................... I-6 Figure I-7 Component Layout Diagram : 1A72521 Main PWB Assembly, Receiver Video ..... I-7 Figure I-8 Component Layout Diagram : 1A72522 RF Source ................................................ I-8 Figure I-9 Component Layout Diagram : 1A72523 IF Amplifier ............................................... I-9 Figure I-10 Component Layout Diagram : 1A72524 RF Amplifier ....................................... I-10 Figure I-11 Component Layout Diagram : 1A72526 Main PWB Assembly,
Transponder Power Supply ............................................................................... I-11 Figure I-12 Component Layout Diagram : 1A72531 Pulse Shaper PWB Assembly ............ I-12 Figure I-13 Component Layout Diagram : 1A72532 Exciter ................................................ I-13 Figure I-14 Component Layout Diagram : 1A72538 RF Amplifier Driver PWB Assembly ... I-14 Figure I-15 Component Layout Diagram : 1A72541 Control and Status PWB Assembly .... I-15 Figure I-16 Component Layout Diagram : 1A72542 DC-DC Converter PWB Assembly ..... I-16 Figure I-17 Component Layout Diagram : 1A72543 Regulator PWB Assembly .................. I-17 Figure I-18 Component Layout Diagram : 1A72544 1kW Power Amplifier
Connector PWB Assembly ................................................................................ I-18 Figure I-19 Component Layout Diagram : 1A72547 RF Panel PWB Assembly
- Single DME ..................................................................................................... I-19 Figure I-20 Component Layout Diagram : 2A72547 RF Panel PWB Assembly
- Dual DME ........................................................................................................ I-20 Figure I-21 Component Layout Diagram : 1A72552 CTU Processor PWB Assembly ........ I-21 Figure I-22 Component Layout Diagram : 1A72553 CTU Front Panel PWB Assembly ...... I-22 Figure I-23 Component Layout Diagram : 1A72555 RCMS Interface PWB Assembly ........ I-23 Figure I-24 Component Layout Diagram : 1A72556 Transponder Subrack Motherboard ... I-24 Figure I-25 Component Layout Diagram : 1A72557 External I/O PWB Assembly .............. I-25
HA72500 APPENDIX I
I-1
I. COMPONENT LAYOUT DRAWINGS Figure I-1 Component Layout Diagram : 1A72511 Main PWB Assembly,
Monitor Module
HA72500 APPENDIX I
I-2
Figure I-2 Component Layout Diagram : 1A72512 Peak Power Monitor
HA72500 APPENDIX I
I-3
Figure I-3 Component Layout Diagram : 1A72515 Main PWB Assembly, Test Interrogator
HA72500 APPENDIX I
I-4
Figure I-4 Component Layout Diagram : 1A72516 RF Generator
HA72500 APPENDIX I
I-5
Figure I-5 Component Layout Diagram : 1A72518 Modulator and Detector
HA72500 APPENDIX I
I-6
Figure I-6 Component Layout Diagram : 1A72519 Reply Detector
HA72500 APPENDIX I
I-7
Figure I-7 Component Layout Diagram : 1A72521 Main PWB Assembly, Receiver Video
HA72500 APPENDIX I
I-8
Figure I-8 Component Layout Diagram : 1A72522 RF Source
HA72500 APPENDIX I
I-9
Figure I-9 Component Layout Diagram : 1A72523 IF Amplifier
HA72500 APPENDIX I
I-10
Figure I-10 Component Layout Diagram : 1A72524 RF Amplifier
HA72500 APPENDIX I
I-11
Figure I-11 Component Layout Diagram : 1A72526 Main PWB Assembly, Transponder Power Supply
HA72500 APPENDIX I
I-12
Figure I-12 Component Layout Diagram : 1A72531 Pulse Shaper PWB Assembly
HA72500 APPENDIX I
I-13
Figure I-13 Component Layout Diagram : 1A72532 Exciter
HA72500 APPENDIX I
I-14
Figure I-14 Component Layout Diagram : 1A72538 RF Amplifier Driver PWB Assembly
HA72500 APPENDIX I
I-15
Figure I-15 Component Layout Diagram : 1A72541 Control and Status PWB Assembly
HA72500 APPENDIX I
I-16
Figure I-16 Component Layout Diagram : 1A72542 DC-DC Converter PWB Assembly
HA72500 APPENDIX I
I-17
Figure I-17 Component Layout Diagram : 1A72543 Regulator PWB Assembly
HA72500 APPENDIX I
I-18
Figure I-18 Component Layout Diagram : 1A72544 1kW Power Amplifier Connector PWB Assembly
HA72500 APPENDIX I
I-19
Figure I-19 Component Layout Diagram : 1A72547 RF Panel PWB Assembly - Single DME
HA72500 APPENDIX I
I-20
Figure I-20 Component Layout Diagram : 2A72547 RF Panel PWB Assembly - Dual DME
HA72500 APPENDIX I
I-21
Figure I-21 Component Layout Diagram : 1A72552 CTU Processor PWB Assembly
HA72500 APPENDIX I
I-22
Figure I-22 Component Layout Diagram : 1A72553 CTU Front Panel PWB Assembly
HA72500 APPENDIX I
I-23
Figure I-23 Component Layout Diagram : 1A72555 RCMS Interface PWB Assembly
HA72500 APPENDIX I
I-24
Figure I-24 Component Layout Diagram : 1A72556 Transponder Subrack Motherboard
HA72500 APPENDIX I
I-25
Figure I-25 Component Layout Diagram : 1A72557 External I/O PWB Assembly
HA72500 APPENDIX J
APPENDIX J
AC POWER SUPPLY 3A71130
J-i
HA72500 APPENDIX J
TABLE of CONTENTS
J. AC POWER SUPPLY 3A71130.................................................................. J-1 J.1 DOCUMENTATION J-1
J-ii
HA72500 APPENDIX J
J. AC POWER SUPPLY 3A71130 J.1 DOCUMENTATION This power supply replaces the earlier version type 2A71130, which was manufactured by Ericsson as the BMTP 344002 Rectifier.
All technical, operation and maintenance information for the 3A71130 AC Power Supply is contained in a separate handbook, HA71130.
J-1
HA72500 APPENDIX K
APPENDIX K
DEPOT TEST FACILITY 3A72500
K-i
HA72500 APPENDIX K
TABLE of CONTENTS
K. DEPOT TEST FACILITY 3A72500 .............................................................K-1 K.1 BRIEF DESCRIPTION AND SPECIFICATION K-1
K.1.1 Introduction.................................................................................................. K-1 K.1.2 Functional Description ................................................................................. K-1 K.1.3 Major Items.................................................................................................. K-1
K.2 OPERATING INSTRUCTIONS K-2 K.2.1 Introduction.................................................................................................. K-2 K.2.2 Initial Settings .............................................................................................. K-2 K.2.3 Application of Power.................................................................................... K-3 K.2.4 Local Maintenance Operation...................................................................... K-4 K.2.5 Signal Generator Adjustments..................................................................... K-5 K.2.6 Operating Notes .......................................................................................... K-6
K.3 TECHNICAL DESCRIPTION K-7 K.3.1 System......................................................................................................... K-7 K.3.2 Module Descriptions .................................................................................... K-7
K.4 UNIT PERFORMANCE CHECKS AND ALIGNMENT K-11 K.4.1 RF Generator (Modified) 2A72516 ............................................................ K-11
K.5 DRAWINGS K-14 K.6 COMPONENTS SCHEDULE K-15
K.6.1 3A72500 DME LDB-102 Depot Test Facility ............................................. K-15 K.6.2 3A72505 Rack Assembly (Depot Test Facility) ......................................... K-15 K.6.3 2A72514 Test Interrogator......................................................................... K-15 K.6.4 A72516 RF Generator (Modified) .............................................................. K-16 K.6.5 2A72520 Receiver Video........................................................................... K-17 K.6.6 3A72558 Rack Frame Wired (Depot Test Facility) .................................... K-17
K-ii
HA72500 APPENDIX K
LIST of FIGURES
Figure K-1 Depot Test Facility Rack Layout............................................................ K-9 Figure K-2 Depot Test Facility Signal Flow Diagram............................................. K-10
K-iii
HA72500 APPENDIX K
K. DEPOT TEST FACILITY 3A72500 K.1 BRIEF DESCRIPTION AND SPECIFICATION
K.1.1 Introduction The DME Depot Test Facility type 3A72500 is basically a single LDB-102 DME rack type 1A72505 which has been modified to provide for more flexible operation, thus enabling easier testing of DME subunits. This appendix contains information which includes a description of the variations and additions within the rack, both technical and operational, with component parts lists and circuit diagrams.
K.1.2 Functional Description The Depot Test Facility is intended for a central maintenance depot where LDB-102 DME line-replaceable units (LRUs) can be fully serviced - fault location, component replacement or repair, and unit testing.
Whilst DME rack faults can only be diagnosed and repaired on site, LRUs can more efficiently be restored to operational condition at a fully equipped maintenance depot.
This depot test bench is based on an LDB-102 DME Single 1kW rack to allow for substitution of LRUs on test into a working transponder. A recommended set of test equipment is used, in conjunction with the rack, to fully exercise any LRU under its normal working conditions. Diagnosis, repair, re-alignment and re-test may be performed on the frequency at which the LRU is to be used.
The principal difference between the Depot Test Rack and a standard DME rack is the inclusion of two synthesiser signal generators, to act as reply (and local oscillator) frequency source and test interrogation frequency source.
K.1.3 Major Items The following list details the major components in the Depot Test Facility rack, many of them being LDB-102 standard parts:
Control and Test Unit 1A72550 Power Distribution Panel (Single) 1A72549 Monitor Module 1A72510 Test Interrogator, Modified 2A72514 Transponder Power Supply 1A72525 Transmitter Driver 1A72530 Receiver Video, Modified 2A72520 Signal Generator, UHF LEADER 3220 (Qty 2) 1kW RF Power Amplifier 1A72535 1kW PA Power Supply 1A72540 AC Power Supply 3A71130 RF Panel 1A72545 Including Preselector Filter 1A72516 Directional Coupler 1A69755 Circulator
These items are housed in the equipment rack as shown in Figure K-1.
K-1
HA72500 APPENDIX K
K.2 OPERATING INSTRUCTIONS
K.2.1 Introduction a. The procedures in this section detail the steps required to place a DME Depot
Test Rack into operation. Each mode of operation is described separately and some guidance is given concerning action required when abnormal performance occurs.
b. For in-depth explanation of the various controls, indicators, and facilities, refer to the following sections:
• CTU Facilities and Operating Procedure: see Section A.3;
• Module Controls and Indicators: see Section A.4;
• Module Preset Switches and Links: see Section A5.
Note that an ANTENNA INTEGRITY test fixture, as described in Section 3.3.3.9.3, is to be fitted to XN2 on the RF Panel PWB Assembly, as no antenna is used. Check that the coaxial cables from the signal generators for reply signal and interrogation signal inputs are connected to receiver video and test interrogator modules respectively (refer to Drawing 72505-2-21).
K.2.2 Initial Settings The following table lists the settings of the front panel switches prior to placing the test rack in operation. These settings are independent of the final mode of operation of the rack.
UNIT SWITCH SETTING AC Power Supply POWER OFF Power Distribution Panel Both circuit breakers OFF Monitor MONITOR OUTPUTS NORMAL Test Interrogator MONITOR AND
INTERROGATOR DC POWER NORMAL
Transponder Power Supply TRANSPONDER DC POWER NORMAL Transmitter Driver DRIVER DC POWER NORMAL Receiver Video IDENT NORMAL 1kW PA Power Supply AMPLIFIER DC POWER NORMAL Control and Test Unit (CTU) ALARM DELAY As required
K-2
HA72500 APPENDIX K
K.2.3 Application of Power a. On the AC power supply, set the POWER switch on. Check that the front panel
voltmeter indicates a voltage of 27.0 ± 0.5 volts.
b. On both signal generators, set the POWER switch on
c. On the power distribution panel, set both circuit breakers on. After a short delay (about 10 seconds), check that the following CTU front panel indicators are on:
AC PWR NORM BATT CH1 LOCAL (press LOCAL pushbutton if the indicator is off) OFF/RESET (press OFF/RESET pushbutton if the indicator is off) MAINTENANCE (press MAINTENANCE pushbutton if the indicator is off)
d. Check that the following CTU front panel indicators are off:
TEST section:
MODULES ANT RELAY
POWER section:
BATT CH2 BATT LOW
DME CONTROL section:
RECYCLE (press RECYCLE pushbutton if the RECYCLE indicator is on) LOCAL (press LOCAL pushbutton if the REMOTE indicator is on) MONITOR ALARM (press MONITOR ALARM INHIBIT pushbutton if the indicator is on)
STATUS section:
NO1 ON NO2 ON NORMAL TRANSFER SHUTDOWN
If the indications are contrary to the above, refer to Section K.2.6 below.
K-3
HA72500 APPENDIX K
K.2.4 Local Maintenance Operation The 'maintenance' mode is normally used during servicing or alignment in the test rack. The 'maintenance' mode is essentially the same as the 'normal' mode, except that more extensive tests are available from the CTU, and the 1 kHz and 10 kHz TI RATE switches are enabled.
K.2.4.1 Switch-on Procedure a. Set the front panel switches initially as in Section K.2.2.
b. Apply mains power to the rack as in Section K.2.3.
c. Check that the LOCAL and MAINTENANCE indicators are on.
d. On the CTU, press the SELECT MAIN, NO1 pushbutton. This activates the rack in its maintenance operating mode. The following indications should result:
1. SELECT MAIN, NO1 indicator on.
2. NO1 ON status indicator on, after the selected ALARM DELAY time.
3. MAINTENANCE status indicator on.
4. All the ALARM REGISTER indicators off immediately, and stay off unless a fault is present.
K.2.4.2 Switch-off Procedure On the CTU, press the SELECT MAIN, OFF/RESET pushbutton. The indicators in the STATUS section should go off, after a short delay. The OFF/RESET indicator should be on, and the SELECT MAIN, NO1 and NO2 indicators should be off.
K.2.4.3 Reset Procedure To reset the rack following a shutdown due to an alarm, press the SELECT MAIN, OFF/RESET pushbutton, and then press the SELECT MAIN, NO1 pushbutton.
K-4
HA72500 APPENDIX K
K.2.5 Signal Generator Adjustments The two RF signal generators must be set up for both frequency and output level, to provide the correct drive to the associated units in the rack, before the Depot Test Rack can become operational.
a. Set the frequencies of both generators to the appropriate frequencies for the DME channel required; see Appendix L for the channel frequency tables.
The upper signal generator shall be set to the AIRBORNE INTERROGATION FREQUENCY and the lower one to the GROUND REPLY FREQUENCY.
Depress the signal generator keys in the order:
FUNCTION FREQ DATA (enter frequency digits) UNIT MHz/dBm
Check the display for correct entry in each case.
b. Check that the MODULATION function is disabled by pressing MOD ON repeatedly until no characters are visible in the MODULATION display.
c. Set the output level of the lower signal generator to +4 dBm.
Depress the signal generator keys in order:
FUNCTION LEVEL DATA 4 . 0 UNIT MHz/dBm
Check the OUTPUT LEVEL display for correct entry.
d. Set the output level of the upper signal generator as follows:
1. Connect a calibrated oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH on the front panel of the test interrogator. Measure the peak amplitude of the displayed pulses:
2. Adjust the signal generator level, starting at -10 dBm, to achieve a peak amplitude of 3.0 ± 0.1 volts. (The signal generator level must remain in the range -3 dBm to -7 dBm).
K-5
HA72500 APPENDIX K
K.2.6 Operating Notes For a full definition of the CTU controls and indicators, refer to Section A.3 - CTU Controls and Indicators.
The following notes are given to assist the operator when an abnormal indication occurs on the CTU:
a. If the AC PWR NORM, and BATT CHG1 indicators are not on after the power distribution panel circuit breakers are closed, then the operation of the AC power supply should be checked for the presence of AC mains and correct DC output voltage.
b. If the BATT LOW indicator turns on after the power distribution panel circuit breakers are closed, then the rack DC supply is too low for proper operation, and the transponder will not switch on. The DC output from the AC power supply and the battery voltage should be checked.
c. If the CTU fault indicator, in the ALARM REGISTER, turns on after the power distribution panel circuit breakers are closed, then the controller circuits are not operating correctly. Reset the system by switching the circuit breakers off then on again. If the CTU fault indicator is still on, or flashing, then the CTU module should be replaced.
d. If any of the ALARM REGISTER, PRIMARY or SECONDARY indicators turn on following switch-on, then one of the transponder operating parameters is out of tolerance; if this parameter is a primary fault, the transponder should shut down after the ALARM DELAY period. The indicators in the ALARM REGISTER can be used as a guide to locating the cause of the fault condition, after the transponder has shut down. (See also Section 4.1.2 for LRU fault location).
K-6
HA72500 APPENDIX K
K.3 TECHNICAL DESCRIPTION
K.3.1 System REFER Figure K-2.
The Depot Test Rack acts as a conventional DME transponder, but working into a dummy load instead of a radiating antenna. Interrogation signals are solely generated by the test interrogator which operates at the desired air-ground frequency, with selectable pulse separation to simulate X or Y channel interrogations: they are injected into the antenna feeder by the directional coupler, then to the receiver via the preselector. The reply signals, generated in response to the successfully decoded interrogations, at the required ground-air frequency, are fed to the antenna output, then to a 50 ohm power load. A small proportion of the reply signal is fed, via the directional coupler, to a detector in the test interrogator, which verifies that replies are correctly being transmitted as a result of the interrogation pulses.
In a normal DME rack both the reply and the test interrogation frequencies are generated by crystal controlled oscillators, as each station is at a fixed frequency. The Depot Test Rack is required to test line-replaceable units (LRU) from many stations at different frequencies. For this reason, the two crystals controlled oscillators are replaced by two synthesised RF signal generators, so that required station frequencies can be easily selected by pushbuttons.
These signal generators are commercial units and the reader is referred to the manufacturer's handbook for further detail.
K.3.2 Module Descriptions
K.3.2.1 Receiver Video Module 2A72520 REFER Interwiring Diagram 72520-3-24
In this module the RF source and RF filter are present, but not used for normal Test Rack operation. For this mode of operation, the RF input to the RF amplifier comes directly from the lower UHF signal generator, connected to the REPLY SIGNAL GENERATOR connector on the receiver video front panel.
The external connection between the signal generator and the Receiver Video module front panel receptacle is made in coaxial cable, terminated in the appropriate coaxial connectors.
There are no other changes within the module and consequently no changes to circuit functioning.
K.3.2.2 Test Interrogator Module 2A72514 REFER Interwiring Diagram 72514-3-23
In this module the only change is to the RF generator unit which has been designed to operate from an external, variable frequency, signal source rather than the internal crystal controlled fixed frequency source of the standard version.
The RF generator now has a TNC coaxial connector which protrudes through the module front panel and is labelled INTERROGATION SIGNAL GENERATOR: it is connected to the upper UHF signal generator.
The external connection to the signal generator is made in coaxial cable terminated in the appropriate connectors. There are no other changes within the test interrogator module.
K-7
HA72500 APPENDIX K
K.3.2.3 RF Generator 2A72516 REFER Circuit Diagram 72516-2-41
The circuit of this unit has been designed to accept signal from the external generator over a frequency range of 1025 MHz to 1150 MHz. This circuit is pre-tuned and needs no adjustment, apart from input level setting, to cover the band.
The circuit is a modified version of the RF Generator 1A72516 used in the standard DME rack. It consists of a three-stage voltage-controlled PIN diode attenuator and three stages of transistor amplifiers to boost the RF signal level to around +12 dBm.
Both the attenuator section V1, V2 and V3 and the amplifiers V5, V6 and V7 are pulse modulated to create the required RF pulse envelope at the output as well as obtaining the required on/off output signal ratios. There are two types of modulation inputs to the unit both supplied from the pulse shape circuitry on the modulator and detector. One is DRIVE IN, a square wave pulse input at XS4 that activates V4, V6 and V7 by an on/off action; the other is a shaped pulse MOD IN at input XS2 which shapes, in V5, the RF envelope.
The DRIVE IN pulse turns the switch V4 and bias amplifier V8 on and supplies bias drive to V6. V4 turns the attenuator off, thus allowing the RF signal to pass and V8 switches on V7, so that V6 and V7 are operating normally, ready for the shaped modulation to develop.
The MOD IN input pulse has a constant DC pedestal voltage of approximately 1 volt and, on top of this, the trapezoidal modulation pulse will be positioned and aligned in the centre of the DRIVE IN pulse.
K-8
HA72500 APPENDIX K
Figure K-1 Depot Test Facility Rack Layout
K-9
HA72500 APPENDIX K
Figure K-2 Depot Test Facility Signal Flow Diagram
K-10
HA72500 APPENDIX K
K.4 UNIT PERFORMANCE CHECKS AND ALIGNMENT The modules fitted to the Depot Test Facility are generally standard modules, for which performance checks and alignment procedures are detailed in Section 3.
The only special module is the RF Generator (Modified) 2A72516, for which performance check and alignment procedures are given following.
K.4.1 RF Generator (Modified) 2A72516
K.4.1.1 Test Equipment Oscilloscope Spectrum Analyser Peak Power Meter
K.4.1.2 Test Setup and Initial Check 1. Switch the DME OFF. Remove the coaxial cable connected to the
INTERROGATION SIGNAL GENERATOR connector on the front panel of the test interrogator. Remove the test interrogator from the transponder subrack. Remove the lids and shims from the RF generator (modified) and the modulator and detector diecast boxes.
2. Replace the RF generator (modified) from the rack with the RF generator (modified) to be tested (after first removing the coaxial connected to the output connector, XC1, the main PWB assembly test interrogator, the four screws securing the RF generator (modified) to the chassis and the six leads from the modulator and detector).
3. Reconnect the six leads from the modulator and detector. Restore the main PWB assembly test interrogator to its chassis. Extend the test interrogator in the transponder subrack using the transponder extender frame.
4. Connect the spectrum analyser to the output connector, XC1, of the unit under test.
5. Switch the DME ON. On the test interrogator front panel, switch MONITOR AND INTERROGATOR DC POWER to ON.
6. On the modulator and detector PWB assembly, switch S1 to TEST.
7. On the CTU front panel, select Hi Eff (High Efficiency) test in MAINTENANCE mode and a TI RATE of 1 kHz.
8. Using Channel 1 of the oscilloscope (externally triggered from test jacks TRIGGER and EARTH on the test interrogator front panel) check the following voltages and waveforms on the unit under test (connect the oscilloscope EARTH lead to the unit under test diecast box):
K-11
HA72500 APPENDIX K
K.4.1.3 Alignment 1. Set the interrogation signal generator frequency to 1090 MHz and output level to
-10 dBm.
2. Disconnect the MOD_PULSE_INPUT lead to XS7 of the modulator and detector and connect + 15 volts DC to XS7.
3. Tune the capacitors C18 and C22 on the unit under test to peak the RF output as observed on spectrum analyser; it should peak at greater than +16 dBm.
4. Vary the frequency of the interrogation signal generator from 1025 MHz to 1150 MHz and check that the RF output does not vary more than 3 dB over the band. Adjust the capacitors C18 and C22, if necessary, to reduce the variation of the output over the band.
5. Check that all harmonics and spurious are below 60 dB with respect to the carrier at each of the above three frequencies.
6. Disconnect +15 volts DC from XS7 on the modulator and detector.
7. Tune capacitors C2, C4 and C7 to minimise the RF output level over the band 1025 MHz to 1150 MHz (at least 70 dB down with respect to the level recorded in step 4 above). Record the highest level and the frequency at which it occurs.
8. Reconnect the MOD_PULSE_INPUT lead from the main PWB to XS7 on the modulator and detector. Set switch S1 on the modulator and detector board to NORMAL. Set the interrogation signal generator frequency to 1090 MHz.
9. Connect the probe on channel 1 of oscilloscope to test jacks DETECTED INTERROGATIONS and EARTH on the front panel of the test interrogator. The shape of the pulse displayed on the oscilloscope should be as shown below:
K-12
HA72500 APPENDIX K
Adjust the following controls on the modulator and detector, as required, to achieve:
• PULSE SHAPE for a FLAT TOP DURATION of 1.0 ±0.2 microseconds,
• PULSE AMPLITUDE for a PEAK AMPLITUDE of 3.0 ±0.1 volts, and
• PULSE PEDESTAL for a PEDESTAL HEIGHT of 0.2 ±0.1 volts.
If the controls interact, repeat the adjustments until the required shape is achieved.
The baseline DC Level should be 3.6 ± 0.3 volts.
10. Vary the interrogation signal generator frequency from 1025 MHz to 1150 MHz and record the pulse peak amplitude and the frequencies at which they occur. The difference between the maximum and minimum amplitudes should be < 0.4 volts.
11. Set the interrogation signal generator to the frequency where the pulse amplitude was minimum and increase the signal level (3 dB maximum) to get the pulse shape back as close as possible to that in Step 9 above.
12. Restore the interrogation signal generator level to -10 dBm. Set the interrogation signal generator to the frequency where the pulse amplitude was maximum and reduce the signal level (3 dB maximum) to get the pulse shape back as close as possible to that in Step 9 above.
K.4.1.4 Tidy Up 1. After having performed the above tests, switch the DME OFF, remove the unit
under test from the test interrogator, and restore the rack RF generator (modified) back to the 'test interrogator, ensuring that all screws and electrical connections are correctly replaced and securely tightened.
2. Replace the shims and lids of the diecast boxes. Note that the lids are deliberately warped to ensure good RF sealing. Tighten the screws firmly.
3. Remove the transponder extender frame and install the test interrogator back in the DME rack.
K-13
HA72500 APPENDIX K
K.5 DRAWINGS The drawings listed following, which are specific to the Depot Test Rack 3A72500 and the specialised assemblies it contains, are included at the rear of this appendix.
DRAWING TITLE DRAWING NUMBER
3A72505 Rack Assembly (Depot Test Facility) INTERWIRING (3 sheets) 72505-2-21 2A72514 Test Interrogator (Modified) INTERWIRING 72514-3-23 2A72516 RF Generator (Modified) CIRCUIT 72516-3-41 2A72520 Receiver Video (Modified) INTERWIRING 72520-3-24
K-14
HA72500 APPENDIX K
K.6 COMPONENTS SCHEDULE Many of the subassemblies and components of the Depot Test Facility rack are common to the operational configurations. The components schedules for those items are contained in Appendix F, and only those for items specific to the Depot Test Facility rack are contained here. If a components schedule is not listed following, refer to Appendix F for details.
K.6.1 3A72500 DME LDB-102 Depot Test Facility SUBASSEMBLIES COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
A1 Rack Assembly (Depot Test Facility) 3A72505 A3 Accessory Kit, DME Test 1A72561
K.6.2 3A72505 Rack Assembly (Depot Test Facility) SUBASSEMBLIES
REF/ QTY
CODE DESCRIPTION MFR/SUPPLIER REF
A1 Receiver Video, Modified 2A72520 A2 Transmitter Driver 1A72530 A3 Transponder Power Supply 1A72525 A4 Monitor Module 1A72510 A5 Test Interrogator, Modified 2A72514 A6 1kW RF Power Amplifier 1A72535 A7 1kW PA Power Supply 1A72540 A8 Rack Frame Wired - Depot Test Facility 3A72558 A9 Power Supply 24V DC 3A71130 A11 Control and Test Unit 1A72550 A12 Power Distribution Panel - Single DME 1A72549 2 1036672T UHF signal generator LEADER 3220
K.6.3 2A72514 Test Interrogator SUBASSEMBLIES COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
A1 Main PWB Assembly, Test Interrogator 1A72515 A2 RF Generator (Modified) 2A72516 A3 Attenuator 1A69737 A4 Modulator and Detector 1A72518 A5 Reply Detector 1A72519 ATTENUATORS
QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 1030202K fixed coaxial 50 ohms SMA 20dB MICROLAB/FXR AG-20F 1 1030203L fixed coaxial 50 ohms SMA 30dB MICROLAB/FXR AG-30F CABLE ASSEMBLIES
QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 coaxial BNC/SMA 72514-4-12 1 coaxial BNC/SMA 72514-4-13 1 coaxial SMA/SMA 72514-4-14 1 single 72514-4-16
K-15
HA72500 APPENDIX K
K.6.4 A72516 RF Generator (Modified) CAPACITORS, FIXED COMP REF
CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF
C1, 3, 5, 6. 9-17, 19-21, 24-28, 34, 35 1036605V ceramic chip 22p 5% 50V VITRAMON VJ0805 C14 1036651V ceramic 1p 0P25 100V PHILIPS 2222-678-03108 C29 1033084T ceramic chip 10n 10% 50V VITRAMON
VJ0805Y103KXAMT C30 1030214Y ceramic chip 5p6 nom 50V VITRAMON 7800P7G02F C36 1030211V ceramic 2p2 0p25 100V PHILIPS 2222-680-09228 C37 1018878B ceramic monolyth 100n 10% 100V VITRAMON CK06BX104K CAPACITORS, VARIABLE COMP REF
CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF
C2, 4, 7 1028813A trimmer 0p6-4p5 JOHANSON GIGATRIM 7273 C18, 22 1030213X trimmer 0P8-8p JOHANSON GIGATRIM 27293 INDUCTORS COMP REF
CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF
L3, 8 72516-4-55 L4, 7 72516-4-53 L5 72516-4-54 L6, 10-13
1025352N 0u39 OW17 MILLER 9230-10
RESISTORS, FIXED
COMP REF
CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF
R1, 2, 5, 29, 30
1008746N metal film 1k 1% 0W4 ROEDERSTEIN MK2
R4 1008762F metal film 4k75 1% 0W4 ROEDERSTEIN MK2 R8, 33 1008698L metal film 10 1% 0W4 ROEDERSTEIN MK2 R18 1008722M metal film 100 1% 0W4 ROEDERSTEIN MK2 R19, 24 1008752V metal film 1k82 1% 0W4 ROEDERSTEIN MK2 R20 1008753W metal film 2k 1% 0W4 ROEDERSTEIN MK2 R21 1008750T metal film 1k5 1% 0W4 ROEDERSTEIN MK2 R22, 25 1008706V metal film 22R1 1% 0W4 ROEDERSTEIN MK2 R23 1008777X metal film 20k 1% 0W4 ROEDERSTEIN MK2 R27 1008714D metal film 47R5 1% 0W4 ROEDERSTEIN MK2 R28 1008758B metal film 3k32 1% 0W4 ROEDERSTEIN MK2 R31 1008726R metal film 150 1% 0W4 ROEDERSTEIN MK2 R32 1008754X metal film 2k21 1% 0W4 ROEDERSTEIN MK2 SWITCHES COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
S1 11030651Y slide SPDT C&K 1101-M2-S3-C-B-E SEMICONDUCTORS COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
V1-3 1037858G diode switching PIN HP 5082-3043 V4 906654U low power NPN transistor MOTOROLA 2N2857 V5, 6 1027618B HF amplifier NPN MOTOROLA, MRF901 V7 1030216A transistor MOTOROLA 2N6604 V8 1026172E low power NPN transistor MOTOROLA 2N2907A V9 1019399T hot carrier diode HP 5082-2817 or 5082-2811 V10 1026171D low power NPN transistor SGS-THOMSON 2N2222A V12 1006793Q switching diode FAIRCHILD 1N914A
K-16
HA72500 APPENDIX K
CONNECTORS COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
XtC2 1037859H coaxial receptacle TNC SUHNER 23TNC-50-0-2/133 XS1-6 1028758Q jack CAMBION 450-3704-01-03-00 Xt1, 2 1036570G test terminal white WILLIAM HUGHES 101 CABLE ASSEMBLIES COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
1 coaxial 72522-4-06
K.6.5 2A72520 Receiver Video SUBASSEMBLIES COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
A1 Main PWB Assembly, Receiver Video 1A72521 A2 RF Source 1A72522 A3 IF Amplifier 1A72523 A4 RF Amplifier 1A72524 CABLE ASSEMBLIES
QTY CODE DESCRIPTION MFR/SUPPLIER REF 1 coaxial BNC/SMA 72520-4-14 1 coaxial BNC/SMA 72520-4-15 1 coaxial SMA/SMA 72520-4-16 1 coaxial SMA/SMA 72520-4-17 1 ribbon 20-way 72520-4-18 1 coaxial SMA/TNC 72520-4-28
K.6.6 3A72558 Rack Frame Wired (Depot Test Facility) SUBASSEMBLIES COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
A1 CTU Subrack 1A72506 A2 Transponder Subrack 1A72513 A3 External I/O PWB Assembly 1A72557 A4 1kW PA Power Supply Frame 1A72503 A7 RF Panel - Single DME 1A72545 SEMICONDUCTORS COMP REF
CODE DESCRIPTION VALUE TOL RATING MFR/SUPPLIER REF
V1 1036684F dual diode rectifier 60V 100A MOTOROLA MBR20060CT
K-17
HA72500 APPENDIX K
CABLE ASSEMBLIES
REF/ QTY
CODE DESCRIPTION MFR/SUPPLIER REF
W20 coaxial 72558-2-29 W21 coaxial 72558-3-31 W22 coaxial 72558-3-32 W23 coaxial 72558-2-71 W24 coaxial 72558-2-37
1 ribbon, 64-way 72558-3-39 1 ribbon, 64-way 72558-3-41 1 ribbon, 64-way 72558-3-42 1 ribbon, 64-way 72558-3-40 1 loom, main power 72558-1-43 1 loom, 1kW PA, power 72558-1-44 1 loom, 1kW PA, signal 72558-1-45 1 power 72558-4-46 3 earth 72558-4-47 1 door earth 72558-4-48 1 DC power 72558-3-54 1 signal 72558-2-55
CONNECTORS COMP REF
CODE DESCRIPTION MFR/SUPPLIER REF
XB12 1031738E terminal strip 6-way KLIPPON KS6/014062
K-18
HA72500 APPENDIX L
APPENDIX L
CHANNEL FREQUENCY AND SPACING SPECIFICATION
L-i
HA72500 APPENDIX L
TABLE of CONTENTS
L. CHANNEL FREQUENCY AND SPACING SPECIFICATION ..................... L-1
L-ii
HA72500 APPENDIX L
L. CHANNEL FREQUENCY AND SPACING SPECIFICATION
AIRBORNE INTERROGATION GROUND REPLY CHANNEL FREQUENCY
(MHz) PULSE CODE
(microseconds) FREQUENCY
(MHz) PULSE CODE
(microseconds) 1X 1025 12 962 12
1Y 1025 36 1088 30 2X 1026 12 963 12
2Y 1026 36 1089 30 3X 1027 12 964 12
3Y 1027 36 1090 30 4X 1028 12 965 12
4Y 1028 36 1091 30 5X 1029 12 966 12
5Y 1029 36 1092 30 6X 1030 12 967 12
6Y 1030 36 1093 30 7X 1031 12 968 12
7Y 1031 36 1094 30 8X 1032 12 969 12
8Y 1032 36 1095 30 9X 1033 12 970 12
9Y 1033 36 1096 30 10X 1034 12 971 12
10Y 1034 36 1097 30 11X 1035 12 972 12
11Y 1035 36 1098 30 12X 1036 12 973 12
12Y 1036 36 1099 30 13X 1037 12 974 12
13Y 1037 36 1100 30 14X 1038 12 975 12
14Y 1038 36 1101 30 15X 1039 12 976 12
15Y 1039 36 1102 30 16X 1040 12 977 12
16Y 1040 36 1103 30 17X 1041 12 978 12
17Y 1041 36 1104 30 18X 1042 12 979 12
18Y 1042 36 1105 30 19X 1043 12 980 12
19Y 1043 36 1106 30 20X 1044 12 981 12
20Y 1044 36 1107 30
L-1
HA72500 APPENDIX L
AIRBORNE INTERROGATION GROUND REPLY CHANNEL FREQUENCY
(MHz) PULSE CODE
(microseconds) FREQUENCY
(MHz) PULSE CODE
(microseconds) 21X 1045 12 982 12
21Y 1045 36 1108 30 22X 1046 12 983 12
22Y 1046 36 1109 30 23X 1047 12 984 12
23Y 1047 36 1110 30 24X 1048 12 985 12
24Y 1048 36 1111 30 25X 1049 12 986 12
25Y 1049 36 1112 30 26X 1050 12 987 12
26Y 1050 36 1113 30 27X 1051 12 988 12
27Y 1051 36 1114 30 28X 1052 12 989 12
2BY 1052 36 1115 30 29X 1053 12 990 12
29Y 1053 36 1116 30 30X 1054 12 991 12
30Y 1054 36 1117 30 31X 1055 '12 992 12
31Y 1055 36 1118 30 32X 1056 12 993 12
32Y 1056 36 1119 30 33X 1057 12 994 12
33Y 1057 36 1120 30 34X 1058 12 995 12
34Y 1058 36 1121 30 35X 1059 12 996 12
35Y 1059 36 1122 30 36X 1060 12 997 12
36Y 1060 36 1123 30 37X 1061 12 998 12
37Y 1061 36 1124 30 38X 1062 12 999 12
38Y 1062 36 1125 30 39X 1063 12 1000 12
39Y 1063 36 1126 30 40X 1064 12 1001 12
40Y 1064 36 1127 30 41X 1065 12 1002 12
41Y 1065 36 1128 30 42X 1066 12 1003 12
42Y 1066 36 1129 30 43X 1067 12 1004 12
L-2
HA72500 APPENDIX L
AIRBORNE INTERROGATION GROUND REPLY CHANNEL FREQUENCY
(MHz) PULSE CODE
(microseconds) FREQUENCY
(MHz) PULSE CODE
(microseconds) 43Y 1067 36 1130 30
44X 1068 12 1005 12 44Y 1068 36 1131 30
45X 1069 12 1006 12 45Y 1069 36 1132 30
46X 1070 12 1007 12 46Y 1070 36 1133 30
47X 1071 12 1008 12 47Y 1071 36 1134 30
48X 1072 12 1009 12 48Y 1072 36 1135 30
49X 1073 12 1010 12 49Y 1073 36 1136 30
50X 1074 12 1011 12 50Y 1074 36 1137 30
51X 1075 12 1012 12 51Y 1075 36 1138 30
52X 1076 12 1013 12 52Y 1076 36 1139 30
53X 1077 12 1014 12 53Y 1077 36 1140 30
54X 1078 12 1015 12 54Y 1078 36 1141 30
55X 1079 12 1016 12 55Y 1079 36 1142 30
56X 1080 12 1017 12 56Y 1080 36 1143 30
57X 1081 12 1018 12 57Y 1081 36 1144 30
58X 1082 12 1019 12 58Y 1082 36 1145 30
59X 1083 12 1020 12 59Y 1083 36 1146 30
60X 1084 12 1021 12 60Y 1084 36 1147 30
61X 1085 12 1022 12 61 Y 1085 36 1148 30
62X 1086 12 1023 12 62Y 1086 36 1149 30
63X 1087 12 1024 12 63Y 1087 36 1150 30
64X 1088 12 1151 12 64Y 1088 36 1025 30
65X 1089 12 1152 12 65Y 1089 36 1026 30
L-3
HA72500 APPENDIX L
AIRBORNE INTERROGATION GROUND REPLY CHANNEL FREQUENCY
(MHz) PULSE CODE
(microseconds) FREQUENCY
(MHz) PULSE CODE
(microseconds) 66X 1090 12 1153 12
66Y 1090 36 1027 30 67X 1091 12 1154 12
67Y 1091 36 1028 30 68X 1092 12 1155 12
68Y 1092 36 1029 30 69X 1093 12 1156 12
69Y 1093 36 1030 30 70X 1094 12 1157 12
70Y 1094 36 1031 30 71X 1095 12 1158 12
71Y 1095 36 1032 30 72X 1096 12 1159 12
72Y 1096 36 1033 30 73X 1097 12 1160 12
73Y 1097 36 1034 30 74X 1098 12 1161 12
74Y 1098 36 1035 30 75X 1099 12 1162 12
75Y 1099 36 1036 30 76X 1100 12 1163 12
76Y 1100 36 1037 30 77X 1101 12 1164 12
77Y 1101 36 1038 30 78X 1102 12 1165 12
78Y 1102 36 1039 30 79X 1103 12 1166 12
79Y 1103 36 1040 30 80X 1104 12 1167 12
80Y 1104 36 1041 30 81X 1105 12 1168 12
81Y 1105 36 1042 30 82X 1106 12 1169 12
82Y 1106 36 1043 30 83X 1107 12 1170 12
83Y 1107 36 1044 30 84X 1108 12 1171 12
84Y 1108 36 1045 30 85X 1109 12 1172 12
85Y 1109 36 1046 30 86X 1110 12 1173 12
86Y 1110 36 1047 30 87X 1111 12 1174 12
87Y 1111 36 1048 30 88X 1112 12 1175 12
L-4
HA72500 APPENDIX L
AIRBORNE INTERROGATION GROUND REPLY CHANNEL FREQUENCY
(MHz) PULSE CODE
(microseconds) FREQUENCY
(MHz) PULSE CODE
(microseconds) 88Y 1112 36 1049 30
89X 1113 12 1176 12 89Y 1113 36 1050 30
90X 1114 12 1177 12 90Y 1114 36 1051 30
91X 1115 12 1178 12 91Y 1115 36 1052 30
92X 1116 12 1179 12 92Y 1116 36 1053 30
93X 1117 12 1180 12 93Y 1117 36 1054 30
94X 1118 12 1181 12 94Y 1118 36 1055 30
95X 1119 12 1182 12 95Y 1119 36 1056 30
96X 1120 12 1183 12 96Y 1120 36 1057 30
97X 1121 12 1184 12 97Y 1121 36 1058 30
98X 1122 12 1185 12 98Y 1122 36 1059 30
99X 1123 12 1186 12 99Y 1123 36 1060 30
100X 1124 12 1187 12 100Y 1124 36 1061 30
101X 1125 12 1188 12 101Y 1125 36 1062 30
102X 1126 12 1189 12 102Y 1126 36 1063 30
103X 1127 12 1190 12 103Y 1127 36 1064 30
104X 1128 12 1191 12 104Y 1128 36 1065 30
105X 1129 12 1192 12 105Y 1129 36 1066 30
106X 1130 12 1193 12 106Y 1130 36 1067 30
107X 1131 12 1194 12 107Y 1131 36 1068 30
108X 1132 12 1195 12 108X 1132 36 1069 30
109X 1133 12 1196 12 109Y 1133 36 1070 30
110X 1134 12 1197 12 110Y 1134 36 1071 30
L-5
HA72500 APPENDIX L
AIRBORNE INTERROGATION GROUND REPLY CHANNEL FREQUENCY
(MHz) PULSE CODE
(microseconds) FREQUENCY
(MHz) PULSE CODE
(microseconds) 111X 1135 12 1198 12
111Y 1135 36 1072 30 112X 1136 12 1199 12
112Y 1136 36 1073 30 113X 1137 12 1200 12
113Y 1137 36 1074 30 114X 1138 12 1201 12
114Y 1138 36 1075 30 115X 1139 12 1202 12
115Y 1139 36 1076 30 116X 1140 12 1203 12
116Y 1140 36 1077 30 117X 1141 12 1204 12
117Y 1141 36 1078 30 118X 1142 12 1205 12
118Y 1142 36 1079 30 119X 1143 12 1206 12
119Y 1143 36 1080 30 120X 1144 12 1207 12
120Y 1144 36 1081 30 121X 1145 12 1208 12
121 Y 1145 36 1082 30 122X 1146 12 1209 12
122Y 1146 36 1083 30 123X 1147 12 1210 12
123Y 1147 36 1084 30 124X 1148 12 1211 12
124Y 1148 36 1085 30 125X 1149 12 1212 12
125Y 1149 36 1086 30 126X 1150 12 1213 12
126Y 1150 36 1087 30
L-6
HA72500 APPENDIX M
M-i
APPENDIX M
PROGRAMMABLE LOGIC DEVICE DESCRIPTIONS
HA72500 APPENDIX M
M-ii
TABLE of CONTENTS
M. PROGRAMMABLE LOGIC DEVICE DESCRIPTIONS ......................... M-1 M.1 INTRODUCTION M-1 M.2 MONITOR BUS INTERFACE - PLD Type 3A72502 M-2 M.3 MONITOR WIDTH COUNTER - PLD Type 4A72502 M-4 M.4 MONITOR FALL COUNTER - PLD Type 5A72502 M-7 M.5 MONITOR RISE COUNTER - PLD Type 6A72502 M-10 M.6 MONITOR FAULT DRIVER - PLD Type 7A72502 M-10 M.7 MONITOR PULSE SHAPE ERROR COUNTER 1 - PLD Type 8A72502 M-12 M.8 MONITOR CLOCK 1 - PLD Type 9A72502 M-15 M.9 MONITOR PULSE SHAPE ERROR COUNTER 2 - PLD Type 10A72502 M-16 M.10 MONITOR CLOCK 2 - PLD Type 11A72502 M-17 M.11 MONITOR DELAY COUNTER - PLD Type 12A72502 M-18 M.12 MONITOR SPACING COUNTER - PLD Type 13A72502 M-19 M.13 MONITOR IDENT EXTRACTION - PLD Type 14A72502 M-22 M.14 MONITOR PRIMARY ERROR COUNTER - PLD Type 15A72502 M-26 M.15 MONITOR INHIBIT DEVICE DRIVER - PLD Type 16A72502 M-27 M.16 MONITOR IDENT COUNTER - PLD Type 17A72502 M-30 M.17 MONITOR RATE COUNTER - PLD Type 18A72502 M-35 M.18 MONITOR IDENT ERROR COUNTER - PLD Type 19A72502 M-37 M.19 MONITOR EFFICIENCY COUNTER - PLD Type 20A72502 M-41 M.20 TEST INTERROGATOR COUNTER TIMER - PLD Type 21A72502 M-43 M.21 TEST INTERROGATOR BUS INTERFACE - PLI) Type 22A72502 M-46 M.22 CTU PROCESSOR WAIT STATE GENERATOR - PLD Type 23A72502 M-48 M.23 CTU PROCESSOR IDENT TONE AND KEYING - PLD Type 24A72502 M-50 M.24 CTU FRONT PANEL ADDRESS DECODER - PLD Type 25A72502 M-52 M.25 CTU FRONT PANEL KEY SWITCH INTERFACE - PLD Type 26A72502 M-54 M.26 RCMS INTERFACE ADDRESS DECODER - PLD Type 27A72502 M-56
HA72500 APPENDIX M
M-iii
LIST of FIGURES
Figure M-1 Timing Diagram : Monitor Width Counter ..............................................M-6 Figure M-2 Timing Diagram : Monitor Fall Counter..................................................M-9 Figure M-3 Timing Diagram : Monitor Pulse Shape Error Counter 1 .....................M-14 Figure M-4 Timing Diagram : Monitor Spacing Counter ........................................M-21 Figure M-5 Timing Diagram : Monitor Ident Counter Ident Message Spacing ..............
Check ..................................................................................................M-24 Figure M-6 Timing Diagram : Monitor Ident Counter Ident Extraction ...................M-25 Figure M-7 Timing Diagram : Monitor Inhibit Device Driver ...................................M-29 Figure M-8 Timing Diagram : Monitor Ident Counter - Pulse Rate Within Ident ............
Range ..................................................................................................M-32 Figure M-9 Timing Diagram : Monitor Ident Counter - Pulse Rate Higher Than Ident
Rate .....................................................................................................M-33 Figure M-10 Timing Diagram : Monitor Ident Counter - Pulse Rate Lower Than Ident
Rate .....................................................................................................M-34 Figure M-11 Timing Diagram : Monitor Ident Error Counter - Ident Tone ExtractionM-39 Figure M-12 Timing Diagram : Monitor Ident Error Counter - Ident Error Detection and
Inhibit Control ......................................................................................M-40 Figure M-13 Timing Diagram : Test Interrogator Counter Timer..............................M-45
HA72500 APPENDIX M
M-1
M. PROGRAMMABLE LOGIC DEVICE DESCRIPTIONS M.1 INTRODUCTION Programmable logic devices (PLD) provide on a single 24-pin DIP chip a number of user-programmable AND and OR arrays and associated input (such as latches) and output (such as output controls, registers) blocks. They allow complex logic processing functions to be designed on microcomputer and implemented in the PLD.
The PLDs used in the LDB-102 equipment are equivalent to INTEL TD85C060-25 devices. They provide 16 macrocells of programmable I/O architecture, programmable clock systems and programmable output registers, which can be configured as D, T, SR or JK types.
This appendix identifies all the PLD used in the LDB-102, describes the function provided, and lists and specifies their associated input and output signals. Summary descriptions are given of the system functions provided by each PLD and, where applicable, detailed timing diagrams are included.
HA72500 APPENDIX M
M-2
M.2 MONITOR BUS INTERFACE - PLD Type 3A72502
NAME: Monitor Bus Interface TYPE No: 3A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D2 FUNCTION: To decode the address lines on the Extended CTU Bus to the Monitor
PWB Assembly and produce the required chip select lines. INPUTS: CLK1 Pin 1 Synchronous clock input - unused CLK2 Pin 13 Synchronous clock input - unused RD Pin 2 Read Signal from Extended CTU Bus. Active LOW WR Pin 3 Write Signal from Extended CTU Bus. Active LOW DT_R Pin 4 Data Transmit/Receive Signal from Extended CTU Bus.
When LOW, data is read out of the PWBA; when HIGH data is written to the PWBA.
DEN Pin 5 Data Enable Signal from Extended CTU Bus. Active LOW during memory and I/O accesses.
A0 Pin 6 Address Signal from Extended CTU Bus. Active HIGH A1 Pin 7 Address Signal from Extended CTU Bus. Active HIGH A2 Pin 8 Address Signal from Extended CTU Bus. Active HIGH A3 Pin 9 Address Signal from Extended CTU Bus. Active HIGH A5 Pin 10 Address Signal from Extended CTU Bus. Active HIGH BS Pin 11 Board Select Signal from Extended CTU Bus. Active LOW RES Pin 14 Reset Signal from Extended CTU Bus. Active HIGH GUNIT Pin 23 Locally Generated Bus Enable Signal. Active HIGH OUTPUTS: BUFEN Pin 22 Data Bus Transceiver Enable BEN_00 Pin 21 Monitor Status Read Select - Fault and Status Signals BEN_02 Pin 20 Monitor Status Read Select - Fault Signals BEN_04 Pin 19 Monitor Status Read Select - Feedback of outputs on
LEN_06 LEN_06 Pin 18 Monitor Control Outputs Select - Analogue Input Control LEN_08 Pin 17 Monitor Control Outputs Select - Monitor Testing BEN_0A Pin 16 Monitor Status Read Select - A to D Output BEN_12 Pin 15 Monitor Status Read Select - A to D & Miscellaneous Status
Data Bus Transceiver Enable BUFEN enables the transceiver for the data bus. Active LOW when inputs BS and DEN are active LOW and A5 is HIGH.
HA72500 APPENDIX M
M-3
Monitor Status Read Selects BEN_00 enables read access of fault and status signals from the Monitor circuitry. Is active LOW when inputs: BS and RD are active LOW and the address is 20H or 30H.
BEN_02 enables read access of fault signals from the Monitor circuitry. Is active LOW when inputs: BS and RD are active LOW and the address is 21H or 31H.
BEN_04 enables read access of the output signals written to at the address selected by LEN_06 (for self test capability). Is active LOW when inputs: BS and RD are active LOW and the address is 22H or 32H.
BEN_0A enables read access of the 8-bit output of the Analogue to Digital Converter. Is active LOW when inputs: BS and RD are active LOW and the address is 25H or 35H.
BEN_12 enables read access of status of the Analogue to Digital Converter and other signals from the Monitor circuitry. Is active LOW when inputs: BS and RD are active LOW and the address is 29H or 39H.
Monitor Control Outputs Selects LEN_06 enables write access to an octal latch driving control outputs to the Analogue to Digital Converter and Input Analogue Multiplexers. Is active HIGH when inputs: BS and WR are active LOW and the address is 23H or 33H.
LEN_08 enables write access to an octal latch driving control outputs to test the Monitor circuitry. Is active HIGH when inputs: BS and WR are active LOW and the address is 24H or 34H.
HA72500 APPENDIX M
M-4
M.3 MONITOR WIDTH COUNTER - PLD Type 4A72502
NAME: Monitor Width Counter TYPE No: 4A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D9 FUNCTION: To determine whether the Width pulses from the Test Interrogator are
within the limits set by inputs from the fault limit switches. INPUTS: CLOCK Pin 1 Synchronous clock input - 10 MHz CLOCK Pin 13 Synchronous clock input - 10 MHz TIPRF Pin 2 Timing pulse before arrival of pulse to be checked PULSE Pin 11 Pulse to be checked B0 Pin 23 Accept Window Input B1 Pin 22 Accept Window Input B2 Pin 21 Accept Window Input B3 Pin 20 Accept Window Input B4 Pin 14 Accept Window Input OUTPUTS: A0P Pin 16 Part of Binary Down Counter A0P to A9P A1P Pin 15 Part of Binary Down Counter A0P to A9P A2P Pin 10 Part of Binary Down Counter A0P to A9P A3P Pin 9 Part of Binary Down Counter A0P to A9P A4P Pin 8 Part of Binary Down Counter A0P to A9P A5P Pin 7 Part of Binary Down Counter A0P to A9P A6P Pin 6 Part of Binary Down Counter A0P to A9P A7P Pin 5 Part of Binary Down Counter A0P to A9P A8P Pin 4 Part of Binary Down Counter A0P to A9P A9P Pin 3 Part of Binary Down Counter A0P to A9P SCNTP Pin 17 Second Count Indicator: LOW when Counter is in Lower Limit
Stage; HIGH when Counter is in Accept Window Stage FLAG Pin 18 Pulse Output to indicate that the duration of PULSE is within
limits CNT1P Pin 19 Counter Active Indicator
Lower Limit Counter A0P to A9P form a 10-bit Presettable Binary Down Counter (A0P is the Least Significant Bit) clocked by the 10 MHz CLOCK. On reaching a count of zero, provided Flip Flop SCNTP is HIGH, counting ceases and the count remains at zero until a positive TIPRF pulse is received. While TIPRF pulse is HIGH, the counter outputs are placed in a high impedance state and the binary data fed to these outputs (through series resistors) is loaded into the counter. Also while TIPRF pulse is HIGH, Flip Flop SCNTP goes to LOW and stays LOW until the start of the second count (i.e. in the Accept Window Stage).
After TIPRF returns to LOW, the counter maintains its preset count until the arrival of a positive PULSE input. A HIGH on PULSE causes Flip Flop CNT1P to be set HIGH and the counter to commence the Lower Limit Stage. While CNT1P remains HIGH, the counter counts down towards zero. When a count of ONE is reached, the next CLOCK pulse causes Flip Flop CNT1P to be reset LOW and the counter counts to ZERO completing the Lower Limit Stage.
HA72500 APPENDIX M
M-5
Accept Window Counter Provided TIPRF is still LOW, the next CLOCK pulse causes Flip Flop SCNTP to go HIGH and stay HIGH until the next TIPRF pulse. This is the commencement of the Accept Window Stage. If PULSE is still HIGH, this next CLOCK pulse also causes the counter to be loaded with the binary data on inputs B0 to B4 (B0 is the Least Significant Bit) and Flip Flop CNT1P to be set HIGH. (However, if the binary data on inputs B0 to B4 is ZERO, Flip Flop CNT1P is not set HIGH and the counter will remain at count ZERO.)
Continuing from the next CLOCK pulse, the counter again counts down towards zero. When a count of ONE is reached, the next CLOCK pulse causes Flip Flop CNT1P to be reset LOW and the counter counts to ZERO. Since Flip Flop SCNTP is HIGH, counting ceases and the count remains at zero until a positive TIPRF pulse is received. This is the completion of the Accept Window Stage.
Provided PULSE goes LOW while Flip Flops SCNTP and CNT1P are HIGH (i.e. during the Accept Window Stage), Flip Flop FLAG will be set HIGH indicating that the duration of PULSE is within the preset limits. Flip Flop FLAG is reset following the count reaching ZERO while Flip Flop SCNTP is HIGH, i.e. at the completion of the Accept Window Stage.
If PULSE goes LOW during the Lower Limit Stage or is still HIGH at the completion of the Accept Window Stage, Flip Flop FLAG will not be set HIGH, indicating that the duration of PULSE is outside the preset limits.
Example and Timing Diagram Figure M-1 shows the timing relationships when the lower limit input data is set to 617 and the window input data is set to 11. The two waveforms at the bottom of the figure show the minimum width and maximum width PULSE signals which give 50% FLAG pulses. If AN and BN are the lower limit input data and window input data respectively, then it can be seen from the figure that the minimum and maximum width PULSE signals which give 50% FLAG pulses have duration AN + 1.5 and AN + BN + 1.5 CLOCK periods respectively. Thus PULSE signals with duration less than or equal to AN + 1 or greater than or equal to AN + BN + 2 CLOCK periods will be rejected.
HA72500 APPENDIX M
M-6
Figure M-1 Timing Diagram : Monitor Width Counter
HA72500 APPENDIX M
M-7
M.4 MONITOR FALL COUNTER - PLD Type 5A72502 NAME: Monitor Fall Counter TYPE No: 5A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D10 FUNCTION: To determine whether the Fall pulses from the Test Interrogator are
within the limits set by inputs from the fault limit switches. INPUTS: CLOCK Pin 1 Synchronous clock input - 10 MHz CLOCK Pin 13 Synchronous clock input - 10 MHz TIPRF Pin 2 Timing pulse before arrival of pulse to be checked PULSE Pin 11 Pulse to be checked OUTPUTS: A0P Pin 16 Part of Binary Down Counter A0P to A9P A1P Pin 15 Part of Binary Down Counter A0P to A9P A2P Pin 10 Part of Binary Down Counter A0P to A9P A3P Pin 9 Part of Binary Down Counter A0P to A9P A4P Pin 8 Part of Binary Down Counter A0P to A9P A5P Pin 7 Part of Binary Down Counter A0P to A9P A6P Pin 6 Part of Binary Down Counter A0P to A9P A7P Pin 5 Part of Binary Down Counter A0P to A9P A8P Pin 4 Part of Binary Down Counter A0P to A9P A9P Pin 3 Part of Binary Down Counter A0P to A9P FLAG Pin 18 Pulse Output to indicate that the duration of PULSE is within
limits CNT1P Pin 17 Counter Active Indicator
Limit Counter A0P to A9P form a 10-bit Presettable Binary Down Counter (A0P is the Least Significant Bit) clocked by the 10 MHz CLOCK. On reaching a count of zero, provided input TIPRF is not HIGH, counting ceases and the counter is held reset at ZERO until a 'positive TIPRF pulse is received. While TIPRF pulse is HIGH, the counter outputs are placed in a high impedance state and the binary data fed to these outputs (through series resistors) is loaded into the counter.
After TIPRF returns to LOW, the counter maintains its preset count until the arrival of a positive PULSE input. A HIGH on PULSE causes Flip Flop CNT1P to be set HIGH. While CNT1P remains HIGH, the counter counts down towards zero. When a count of ZERO is reached, the next CLOCK pulse causes Flip Flop CNT1P to be reset LOW and the counter remains at a count of ZERO.
Provided PULSE goes LOW while Flip Flop CNT1P is HIGH, Flip Flop FLAG will be set HIGH indicating that the duration of PULSE is less than the preset limit. Flip Flop FLAG is reset following the count reaching ZERO.
If PULSE is still HIGH after the count reaches ZERO, Flip Flop FLAG will not be set HIGH, indicating that the duration of PULSE is greater than the preset limit.
HA72500 APPENDIX M
M-8
Example and Timing Diagram Figure M-2 shows the timing relationships when the upper limit input data is set to 617. The waveform at the bottom of the figure shows the maximum width PULSE signals which give 50% FLAG pulses. If AN is the upper limit input data, then it can be seen from the figure that the maximum width PULSE signal which gives 50% FLAG pulses has a duration AN + 0.5. Thus PULSE signals with duration greater than or equal to AN + 1 CLOCK periods will be rejected.
HA72500 APPENDIX M
M-9
Figure M-2 Timing Diagram : Monitor Fall Counter
HA72500 APPENDIX M
M-10
M.5 MONITOR RISE COUNTER - PLD Type 6A72502 NAME: Monitor Rise Counter TYPE No: 6A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D11 FUNCTION: To determine whether the Rise pulses from the Test Interrogator are
within the limits set by inputs from the fault limit switches. INPUTS: CLOCK Pin 1 Synchronous clock input - 10 MHz CLOCK Pin 13 Synchronous clock input - 10 MHz TIPRF Pin 2 Timing pulse before arrival of pulse to be checked PULSE Pin 11 Pulse to be checked OUTPUTS: A0P Pin 16 Part of Binary Down Counter A0P to A9P A1P Pin 15 Part of Binary Down Counter A0P to A9P A2P Pin 10 Part of Binary Down Counter A0P to A9P A3P Pin 9 Part of Binary Down Counter A0P to A9P A4P Pin 8 Part of Binary Down Counter A0P to A9P A5P Pin 7 Part of Binary Down Counter A0P to A9P A6P Pin 6 Part of Binary Down Counter A0P to A9P A7P Pin 5 Part of Binary Down Counter A0P to A9P A8P Pin 4 Part of Binary Down Counter A0P to A9P A9P Pin 3 Part of Binary Down Counter A0P to A9P FLAG Pin 18 Pulse Output to indicate that the duration of PULSE is within
limits CNT1P Pin 17 Counter Active Indicator
The operation of the Monitor Rise Counter is identical to that of the Monitor Fall Counter, Type 5A72502.
M.6 MONITOR FAULT DRIVER - PLD Type 7A72502 NAME: Monitor Fault Driver TYPE No: 7A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D13 FUNCTION: Logic processing of the Fault signals from the Monitor Module Fault
Detectors to produce the Fault Signals to the CTU and the signals to drive the OK lamps on the Monitor Module.
INPUTS: IFLT Pin 2 Output from Ident Fault Detector. Active HIGH DELFLT Pin 3 Output from Delay Fault Detector. Active HIGH SEPFLT Pin 4 Output from Spacing Fault Detector. Active HIGH EFLT Pin 5 Output from Efficiency Fault Detector. Active HIGH RFLT Pin 6 Output from Rate Fault Detector. Active HIGH FALLFLT Pin 7 Output from Pulse Fall Time Fault Detector. Active HIGH RISEFLT Pin 8 Output from Pulse Rise Time Fault Detector. Active HIGH WIDTHFLT Pin 9 Output from Pulse Width Fault Detector. Active HIGH PFLT Pin 10 Output from Transmitted Power Fault Detector. Active HIGH AI1FLT Pin 11 Output from Antenna Fault Detector. Active LOW AI2FLT Pin 14 Output from Antenna Fault Detector. Active LOW FAIL Pin 23 From FAIL/NORMAL Front Panel switch. HIGH = FAIL
HA72500 APPENDIX M
M-11
OUTPUTS: PRIFLT Pin 22 Primary Fault Output SECFLT Pin 19 Secondary Fault Output DELRVFLT Pin 16 Delay Fault Signal to Receiver Video SPCRVFLT Pin 15 Spacing Fault Signal to Receiver Video PSFLT Pin 21 Pulse Shape Fault Output ANT Pin 20 Antenna Fault Output NFAIL Pin 18 Buffered FAIL input signal
Primary Fault Logic PRIFLT is Active HIGH if either input DELFLT or SEPFLT is Active HIGH.
Secondary Fault Logic SECFLT is Active HIGH if any of the inputs EFLT, RFLT, PFLT or IFLT or either of the outputs PSFLT or ANT is Active HIGH.
Fault Signals to Receiver Video DELRVFLT is buffered and inverted DELFLT input signal. This Active LOW signal is fed to the Receiver Video where it is used to inhibit replies should the CTU fail to shut down a transponder with Primary Faults.
SPCRVFLT is buffered and inverted SEPFLT input signal. This Active LOW signal is fed to the Receiver Video where it is used to inhibit replies should the CTU fail to shut down a transponder with Primary Faults.
Pulse Shape Fault Logic PSFLT is Active HIGH if any of the inputs FALLFLT, RISEFLT or WIDTHFLT is Active HIGH.
Antenna Fault Logic ANT is Active HIGH if either input AI1FLT or AI2FLT is Active LOW.
Test Signals NFAIL is buffered FAIL input signal.
HA72500 APPENDIX M
M-12
M.7 MONITOR PULSE SHAPE ERROR COUNTER 1 - PLD Type 8A72502
NAME: Monitor Pulse Shape Error Counter 1 TYPE No: 8A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D17 FUNCTION: To provide digital filtering of Parameter OK (FLAG) signals from the
Parameter Counters to produce Fault indication signals. Two counters are provided in the PLD (identified with "A" and “B” suffixes respectively in the I/O lists) plus some common circuitry.
INPUTS: PRF Pin 2 (TIPRF) Timing pulse at beginning of Parameter
Measurement INH Pin 23 Inhibit Measurement. Indicates a low level interrogation and
parameter measurements are not to be made. In most operating modes, toggles between HIGH and LOW before the PRF pulses.
FLTA Pin 11 Positive pulses (following PRF) indicating that the parameter was within limits. Absence of pulse indicates that the parameter was outside its preset limits.
FLTB Pin 14 (See FLTA) OUTPUTS: PRFCNT0 Pin 10 Part of divide by 3 counter used to select every third
(not INHibited) PRF pulse to the Error Counter PRFCNT1 Pin 15 (See PRFCNT0) ALLCLCKA Pin 9 Clock signal combining all (not INHibited) PRF and FLTA
pulses TIMCLKA Pin 7 Clock signal to Error Counter. Clocks on negative edge DECA Pin 6 Count UP/DOWN control for Error Counter. Counts DOWN
when LOW; counts UP when it and PRFCNT0 are HIGH A0P Pin 3 Part of Error Counter consisting of A0P to A2P A1P Pin 4 Part of Error Counter consisting of A0P to A2P A2P Pin 5 Part of Error Counter consisting of A0P to A2P FLAGA Pin 8 Fault output signal. HIGH indicates that the measured
parameter is consistently within limits; LOW indicates that the measured parameter is consistently outside limits
ALLCLCKB Pin 16 (See ALLCLCKA) TIMCLKB Pin 18 (See TIMCLKA) DECB Pin 19 (See DECA) B0P Pin 22 (See A0P) B1P Pin 21 (See A1P) B2P Pin 20 (See A2P) FLAGB Pin 17 (See FLAGA)
Divide by 3 Counter PRFCNT1 and PRKNT0 form a divide by 3 counter clocked by PRF. The count cycles through the values 1,2 and 3 (PRFCNT0 is the least significant bit). (See Figure M-3.)
HA72500 APPENDIX M
M-13
Clock Signals ALLCLCK(A/B) ORs the input signals PRF and FLT(A/B) when INH is inactive LOW. (See Figure M-3)
TIMCLK(A/B) is basically the same as ALLCLCK(A/B) but with the PRF pulses passed through a gate controlled by PRFCNT0 being LOW. (See Figure M-3)
Error Counter UP/DOWN Control DEC(A/B) is a synchronous S/R Flip Flop clocked by ALLCLCK(A/B). It is set by positive PRF pulses and reset by positive FLT(A/B) PULSES.
Error Counter (A/B)0P to (A/B)2P form a binary UP/DOWN counter which counts between 0 and 7. It cannot count UP past 7 nor DOWN past 0. The counter counts UP by 1 on the negative edges of TIMCLK(A/B) when both DEC(A/B) and PRFCNT0 are HIGH and counts DOWN by 1 on the negative edges of TIMCLK(A/B) when DEC(A/B) is LOW.
In effect, the counter counts DOWN on every input FLT(A/B) pulse which occurs while input INH is inactive LOW, and counts UP on every third PRF input pulse which occurs while input INH is inactive LOW.
OK Output Flag FLAG(A/B) is a synchronous S/R Flip Flop clocked by ALLCLK(A/B). It is set HIGH on the positive edge of ALLCLCK(A/B) when the Error Counter count reaches 0, and is reset LOW on the positive edge of ALLCLK(A/B) when the Error Counter count reaches 7.
Thus if the FLT(/B) input pulses consistently occur more often than one third of the PRF pulses, the Error Counter will count DOWN to 0 and FLAG(A/B) will be set HIGH. However if the FLT(/B) input pulses consistently occur less often than one third of the PRF pulses, the Error Counter will count UP to 7 and FLAG(A/B) will be reset LOW.
HA72500 APPENDIX M
M-14
Figure M-3 Timing Diagram : Monitor Pulse Shape Error Counter 1
HA72500 APPENDIX M
M-15
M.8 MONITOR CLOCK 1 - PLD Type 9A72502 NAME: Monitor Clock 1 TYPE No: 9A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D19 FUNCTION: To produce a range of clock frequencies from the 10 MHz reference
oscillator. INPUTS: CLK1 Pin 1 Clock to Decade Counter consisting of A0P to A2P and
OUT1 CLK2 Pin 2 Clock to Decade Counter consisting of B0P to B2P and
OUT2 CLK3 Pin 11 Clock to Decade Counter consisting of C0P to C2P and
OUT3 CLK4 Pin 14 Clock to Decade Counter consisting of D0P to D2P and
OUT4 OUTPUTS: A0P Pin 4 Part of Decade Counter consisting of A0P to A2P and OUT1 A1P Pin 5 Part of Decade Counter consisting of A0P to A2P and OUT1 A2P Pin 6 Part of Decade Counter consisting of A0P to A2P and OUT1 OUT1 Pin 3 Part of Decade Counter consisting of A0P to A2P and OUT1 B0P Pin 7 Part of Decade Counter consisting of B0P to B2P and OUT2 B1P Pin 8 Part of Decade Counter consisting of B0P to B2P and OUT2 B2P Pin 9 Part of Decade Counter consisting of B0P to B2P and OUT2 OUT2 Pin 10 Part of Decade Counter consisting of B0P to B2P and OUT2 C0P Pin 18 Part of Decade Counter consisting of C0P to C2P and OUT3 C1P Pin 17 Part of Decade Counter consisting of C0P to C2P and OUT3 C2P Pin 16 Part of Decade Counter consisting of C0P to C2P and OUT3 OUT3 Pin 15 Part of Decade Counter consisting of C0P to C2P and OUT3 D0P Pin 19 Part of Decade Counter consisting of D0P to D2P and OUT4 D1P Pin 20 Part of Decade Counter consisting of D0P to D2P and OUT4 D2P Pin 21 Part of Decade Counter consisting of D0P to D2P and OUT4 OUT4 Pin 22 Part of Decade Counter consisting of D0P to D2P and OUT4
Counter 1 A0P to A2P form a 3-bit divide-by-5 Binary Down Counter (A0P is the Least Significant Bit) clocked by CLK1. The counter cycles through the values 4 to 0.
On reaching a count of zero, the next pulse of CLK1 toggles OUT1. OUT1 is thus a square wave with a frequency one tenth of CLK1.
Counters 2 to 4 Counters 2 to 4 are identical to Counter 1.
HA72500 APPENDIX M
M-16
M.9 MONITOR PULSE SHAPE ERROR COUNTER 2 - PLD Type 10A72502
NAME: Monitor Pulse Shape Error Counter 2 TYPE No: 10A72502 WHERE USED: 1A72511, Monitor PWIB Assembly; D23 FUNCTION: To provide digital filtering of Parameter OK (FLAG) signals from the
Parameter Counters to produce Fault indication signals. Two counters are provided in the PLD (identified with "A" and "B" suffixes respectively in the I/O lists) plus some common circuitry.
INPUTS: PRF Pin 2 (TIPRF) Timing pulse at beginning of Parameter
Measurement 1 NH Pin 23 Inhibit Measurement. Indicates a low level interrogation and
parameter measurements are not to be made. In most operating modes, toggles between HIGH and LOW before the PRF pulses.
FLTA Pin 11 Positive pulses (following PRF) indicating that the parameter was within limits. Absence of pulse indicates that the parameter was outside its preset limits.
FLTB Pin 14 (See FLTA) OUTPUTS: PRFCNT0 Pin 10 Part of divide by 3 counter used to select every third
(not INHibited) PRF pulse to the Error Counter PRFCNT1 Pin 15 (See PRFCNT0) ALLCLCKA Pin 9 Clock signal combining all (not INHibited) PRF and FLTA
pulses TIMCLKA Pin 7 Clock signal to Error Counter. Clocks on negative edge DECA Pin 6 Count UP/DOWN control for Error Counter. Counts DOWN
when LOW; counts UP when it and PRFCNT0 are HIGH A0P Pin 3 Part of Error Counter consisting of A0P to A2P A1P Pin 4 Part of Error Counter consisting of A0P to A2P A2P Pin 5 Part of Error Counter consisting of A0P to A2P FLAGA Pin 8 Fault output signal. HIGH indicates that the measured
parameter is consistently within limits; LOW indicates that the measured parameter is consistently outside limits
ALLCLCKB Pin 16 (See ALLCLCKA) TIMCLKB Pin 18 (See TIMCLKA) DECB Pin 19 (See DECA) B0P Pin 22 (See A0P) B1P Pin 21 (See A1P) B2P Pin 20 (See A2P) FLAGB Pin 17 (See FLAGA)
The operation of the Monitor Pulse Shape Error Counter 2 is identical to that of the Monitor Pulse Shape Error Counter 1, Type 8A72502.
HA72500 APPENDIX M
M-17
M.10 MONITOR CLOCK 2 - PLD Type 11A72502 NAME: Monitor Clock 2 TYPE No: 11A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D24 FUNCTION: To produce a range of clock frequencies from the 10 MHz reference
oscillator. INPUTS: CLK1 Pin 1 Clock to Decade Counter consisting of A0P to A2P and
OUT1 CLK2 Pin 2 Clock to Decade Counter consisting of B0P to B2P and
OUT2 CLK3 Pin 11 Clock to Decade Counter consisting of C0P to C2P and
OUT3 CLK4 Pin 14 Clock to Decade Counter consisting of D0P to D2P and
OUT4 OUTPUTS: A0P Pin 4 Part of Decade Counter consisting of A0P to A2P and OUT1 A1P Pin 5 Part of Decade Counter consisting of A0P to A2P and OUT1 A2P Pin 6 Part of Decade Counter consisting of A0P to A2P and OUT1 OUT1 Pin 3 Part of Decade Counter consisting of A0P to A2P and OUT1 B0P Pin 7 Part of Decade Counter consisting of B0P to B2P and OUT2 B1P Pin 8 Part of Decade Counter consisting of B0P to B2P and OUT2 B2P Pin 9 Part of Decade Counter consisting of B0P to B2P and OUT2 OUT2 Pin 10 Part of Decade Counter consisting of B0P to B2P and OUT2 C0P Pin 18 Part of Decade Counter consisting of C0P to C2P and OUT3 C1P Pin 17 Part of Decade Counter consisting of C0P to C2P and OUT3 C2P Pin 16 Part of Decade Counter consisting of C0P to C2P and OUT3 OUT3 Pin 15 Part of Decade Counter consisting of C0P to C2P and OUT3 D0P Pin 19 Part of Decade Counter consisting of D0P to D2P and OUT4 D1P Pin 20 Part of Decade Counter consisting of D0P to D2P and OUT4 D2P Pin 21 Part of Decade Counter consisting of D0P to D2P and OUT4 OUT4 Pin 22 Part of Decade Counter consisting of D0P to D2P and OUT4
Counter 1 A0P to A2P form a 3-bit divide-by-5 Binary Down Counter (A0P is the Least Significant Bit) clocked by CLK1. The counter cycles through the values 4 to 0.
On reaching a count of zero, the next pulse of CLK1 toggles OUT1. OUT1 is thus a square wave with a frequency one tenth of CLK1.
Counters 2 to 4 Counters 2 to 4 are identical to Counter 1.
HA72500 APPENDIX M
M-18
M.11 MONITOR DELAY COUNTER - PLD Type 12A72502 NAME: Monitor Delay Counter TYPE No: 12A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D30 FUNCTION: To determine whether the Delay pulses from the Test Interrogator are
within the limits set by inputs from the fault limit switches. INPUTS: CLOCK Pin 1 Synchronous clock input - 10 MHz CLOCK Pin 13 Synchronous clock input - 10 MHz TIPRF Pin 2 Timing pulse before arrival of pulse to be checked PULSE Pin 11 Pulse to be checked B0 Pin 23 Accept Window Input B1 Pin 22 Accept Window Input B2 Pin 21 Accept Window Input B3 Pin 20 Accept Window Input B4 Pin 14 Accept Window Input OUTPUTS: A0P Pin 16 Part of Binary Down Counter A0P to A9P A1P Pin 15 Part of Binary Down Counter A0P to A9P A2P Pin 10 Part of Binary Down Counter A0P to A9P A3P Pin 9 Part of Binary Down Counter A0P to A9P A4P Pin 8 Part of Binary Down Counter A0P to A9P A5P Pin 7 Part of Binary Down Counter A0P to A9P A6P Pin 6 Part of Binary Down Counter A0P to A9P A7P Pin 5 Part of Binary Down Counter A0P to A9P A8P Pin 4 Part of Binary Down Counter A0P to A9P A9P Pin 3 Part of Binary Down Counter A0P to A9P SCNTP Pin 17 Second Count Indicator: LOW when Counter is in Lower Limit
Stage; HIGH when Counter is in Accept Window Stage FLAG Pin 18 Pulse Output to indicate that the duration of PULSE is within
limits CNT1P Pin 19 Counter Active Indicator
The operation of the Monitor Delay Counter is identical to that of the Monitor Width Counter, Type 4A72502.
HA72500 APPENDIX M
M-19
M.12 MONITOR SPACING COUNTER - PLD Type 13A72502 NAME: Monitor Spacing Counter TYPE No: 13A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D31 FUNCTION: To determine whether the Spacing pulses from the Test Interrogator
are within the limits set by inputs from the fault limit switches. INPUTS: CLOCK Pin 1 Synchronous clock input - 10 MHz CLOCK Pin 13 Synchronous clock input - 10 MHz TIPRF Pin 2 Timing pulse before arrival of pulse to be checked PULSE Pin 11 Pulse to be checked B0 Pin 23 Accept Window Input B1 Pin 22 Accept Window Input B2 Pin 21 Accept Window Input B3 Pin 20 Accept Window Input B4 Pin 14 Accept Window Input OUTPUTS: TI2P Pin 3 TIPRF retimed by CLOCK A0P Pin 16 Part of Binary Down Counter A0P to A8P A1P Pin 15 Part of Binary Down Counter A0P to A8P A2P Pin 10 Part of Binary Down Counter A0P to A8P A3P Pin 9 Part of Binary Down Counter A0P to A8P A4P Pin 8 Part of Binary Down Counter A0P to A8P A5P Pin 7 Part of Binary Down Counter A0P to A8P A6P Pin 6 Part of Binary Down Counter A0P to A8P A7P Pin 5 Part of Binary Down Counter A0P to A8P A8P Pin 4 Part of Binary Down Counter A0P to A8P SCNTP Pin 17 Second Count Indicator: LOW when Counter is in Lower Limit
Stage; HIGH when Counter is in Accept Window Stage FLAG Pin 18 Pulse Output to indicate that the duration of PULSE is within
limits CNT1P Pin 19 Counter Active Indicator
Retiming of TIPRF TI2P is the output of a D-Type Flip Flop clocked by CLOCK and with TIPRF as input.
Lower Limit Counter A0P to A8P form a 9-bit Presettable Binary Down Counter (A0P is the Least Significant Bit) clocked by the 10 MHz CLOCK. On reaching a count of zero, provided Flip Flop SCNTP is HIGH, counting ceases and the count remains at zero until a positive TI2P pulse is received. While TI2P pulse is HIGH, the counter outputs are placed in a high impedance state and the binary data fed to these outputs (through series resistors) is loaded into the counter. Also while TIPRF pulse is HIGH, Flip Flop SCNTP goes to LOW and stays LOW until the start of the second count (i.e. in the Accept Window Stage).
After TI2P returns to LOW, the counter maintains its preset count until the arrival of a positive PULSE input. A HIGH on PULSE causes Flip Flop CNT1P to be set HIGH and the counter to commence the Lower Limit Stage. While CNT1P remains HIGH, the counter counts down towards zero. When a count of ONE is reached, the next CLOCK pulse causes Flip Flop CNT1P to be reset LOW and the counter counts to ZERO completing the Lower Limit Stage.
HA72500 APPENDIX M
M-20
Accept Window Counter Provided TI2P is still LOW, the next CLOCK pulse causes Flip Flop SCNTP to go HIGH and stay HIGH until the next TIPRF pulse. This is the commencement of the Accept Window Stage. If PULSE is still HIGH, this next CLOCK pulse also causes the counter to be loaded with the binary data on inputs B0 to B4 (B0 is the Least Significant Bit) and Flip Flop CNT1P to be set HIGH. (However, if the binary data on inputs B0 to B4 is ZERO, Flip Flop CNT1P is not set HIGH and the counter will remain at count ZERO.)
Continuing from the next CLOCK pulse, the counter again counts down towards zero. When a count of ONE is reached, the next CLOCK pulse causes Flip Flop CNT1P to be reset LOW and the counter counts to ZERO. Since Flip Flop SCNTP is HIGH, counting ceases and the count remains at zero until a positive TIPRF pulse is received. This is the completion of the Accept Window Stage.
Provided PULSE goes LOW while Flip Flops SCNTP and CNT1P are HIGH (i.e. during the Accept Window Stage), Flip Flop FLAG will be set HIGH indicating that the duration of PULSE is within the preset limits. Flip Flop FLAG is reset following the count reaching ZERO while Flip Flop SCNTP is HIGH, i.e. at the completion of the Accept Window Stage.
If PULSE goes LOW during the Lower Limit Stage or is still HIGH at the completion of the Accept Window Stage, Flip Flop FLAG will not be set HIGH, indicating that the duration of PULSE is outside the preset limits.
Example and Timing Diagram Figure M-4 shows the timing relationships when the lower limit input data is set to 105 and the window input data is set to 11. The two waveforms at the bottom of the figure show the minimum width and maximum width PULSE signals which give 50% FLAG pulses. If AN and BN are the lower limit input data and window input data respectively, then it can be seen from the figure that the minimum and maximum width PULSE signals which give 50% FLAG pulses have duration AN + 1.5 and AN + BN + 1.5 CLOCK periods respectively. Thus PULSE signals with duration less than or equal to AN + 1 or greater than or equal to AN + BN + 2 CLOCK periods will be rejected.
HA72500 APPENDIX M
M-21
Figure M-4 Timing Diagram : Monitor Spacing Counter
HA72500 APPENDIX M
M-22
M.13 MONITOR IDENT EXTRACTION - PLD Type 14A72502 NAME: Monitor Ident Extraction TYPE No: 14A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D33 FUNCTION: To extract Ident Information from Detected Transmitter Pulses and
detect Ident failure (i.e. Ident absent for longer than the preset limit). INPUTS: CLOCK Pin 1 Synchronous clock input - 1 Hz CLOCK Pin 13 Synchronous clock input - 1 Hz CENABLE Pin 11 Ident Message Spacing (i.e. the time between transmissions
of the Ident Code) MHZ Pin 23 1 MHz Clock EN Pin 2 Detected Transmitter Pulses GATE Pin 14 40 microseconds pulses triggered by DEC output OUTPUTS: CENOUT Pin 17 CENABLE input retimed by CLOCK CLR75 Pin 16 Positive pulse, one CLOCK period wide, indicates positive
transition of CENABLE LOAD Pin 20 Load signal to counter consisting of C6P to C0P C0P Pin 9 Part of Counter consisting of C6P to C0P, clocked by CLOCK C1P Pin 8 Part of Counter consisting of C6P to C0P, clocked by CLOCK C2P Pin 7 Part of Counter consisting of C6P to C0P, clocked by CLOCK C3P Pin 6 Part of Counter consisting of C6P to C0P, clocked by CLOCK C4P Pin 5 Part of Counter consisting of C6P to C0P, clocked by CLOCK C5P Pin 4 Part of Counter consisting of C6P to C0P, clocked by CLOCK C6P Pin 3 Part of Counter consisting of C6P to C0P, clocked by CLOCK NOIDENT Pin 21 Ident Spacing Error D0P Pin 19 EN input retimed by MHZ DEC Pin 10 Ident Decide. Positive pulse, one MHZ period wide, indicates
positive transition of EN CLEAR Pin 22 Ident Clear. DEC pulse delayed by one period of MHZ ENOUT Pin 15 CLEAR pulse delayed by one period of MHZ GAP Pin 18 Ident Pulse. Negative pulse, three MHZ periods wide,
negative edge aligned with positive edge of CLEAR
Ident Message Spacing Check Input signal CENABLE is a positive pulse representing the time between transmissions of the Ident Code. This signal is retimed by the 1 Hz clock signal CLOCK as CENOUT. (See Figure M-5.)
D-Type Flip Flop CLR75 has as input the ANDing of CENABLE being HIGH and CENOUT being LOW. i.e. CLR75 produces positive pulses on positive transitions of CENABLE. The input signal to Flip Flop CLR75 is also used to reset the counter consisting of C6P to C0P to ZERO.
LOAD D-Type Flip Flop, also clocked by CLOCK, has as input the ORing of CLR75 and the counter being at a count of 0 or 1. Since the counter is reset to 0 on the rising edge of CENABLE, LOAD will go HIGH on the next CLOCK pulse. It will stay HIGH until one CLOCK pulse after CLR75 goes LOW.
While Load is HIGH, the counter outputs are placed in a high impedance state and the binary data fed to these outputs (through series resistors) is loaded into the counter on the positive edges of CLOCK.
HA72500 APPENDIX M
M-23
The counter consisting of C6P to C0P is a 7-bit binary down counter clocked by the positive edges of CLOCK. It is enabled to count provided LOAD is LOW, CLR75 is LOW, CENOUT is HIGH and the counter is not at a count of 0. Thus, from the CLOCK pulse following LOAD going LOW, the counter will count down from the preloaded value until either CENABLE (and thus CENOUT) goes LOW or the counter reaches a count of 0.
S/R Flip Flop NOI DENT is clocked by the negative edges of the 1 MHz clock signal MHZ. NOIDENT is synchronously set HIGH if the counter reaches a count of 1 and CENOUT is still HIGH. It is synchronously reset LOW when CENABLE goes LOW (provided the counter is at a count of 0). Output pulses at NOIDENT thus indicate that the input CENABLE pulses have a longer duration than the preset limit.
From Figure M-5 it can be seen that the longest duration of CENABLE for which no NOIDENT pulses are produced is AN + 1 CLOCK periods, where AN is the value preloaded into the counter. Thus CENABLE pulses AN + 2 or more CLOCK pulses in duration will cause NOIDENT output error pulses.
Ident Extraction Input signal EN is a pair of positive pulses representing the detected transmitted Reply pulses. This signal is gated by input GATE being LOW and retimed by the negative transitions of 1 MHz clock signal MHZ to produce D0P. (See Figure M-6)
Positive transitions of EN (detected by EN being HIGH and D0P being LOW) are clocked out at DEC by the negative transitions of MHZ. The positive edges of DEC are used to trigger an external One-shot with a nominal duration of 40 microseconds. This One-shot is the GATE input signal and has the effect of removing the second pulse of the EN pulse pair. (Since the maximum nominal pulse spacing of the pulse pairs is 30 microseconds and the pulse widths are not greater than 4 microseconds, the 40 microseconds GATE pulses is guaranteed to completely remove the second pulse of the pulse pair.)
DEC also forms the first stage of a 3-stage shift register with CLEAR and ENOUT. All three stages are clocked by the negative transitions of MHZ.
Output GAP is a D-Type Flip Flop also clocked by the negative transitions of MHZ. Its input is HIGH only when all three stages of the above shift register are LOW. The one MHZ clock period wide positive pulse propagating through the above shift register produces a GATE output (which is normally HIGH) going LOW for 3 MHZ clock periods each time a transmitted pulse pair is transmitted.
Other circuitry is used to detect if the GATE output waveform indicates the presence of the 1350 Hz Ident Tone.
HA72500 APPENDIX M
M-24
Figure M-5 Timing Diagram : Monitor Ident Counter Ident Message Spacing Check
HA72500 APPENDIX M
M-25
Figure M-6 Timing Diagram : Monitor Ident Counter Ident Extraction
HA72500 APPENDIX M
M-26
M.14 MONITOR PRIMARY ERROR COUNTER - PLD Type 15A72502 NAME: Monitor Primary Error Counter TYPE No: 15A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D37 FUNCTION: To provide digital filtering of Parameter OK (FLAG) signals from the
Parameter Counters to produce Fault indication signals. Two counters are provided in the PLD (identified with "A" and "B" suffixes respectively in the I/O lists) plus some common circuitry.
INPUTS: PRF Pin 2 (TIPRF) Timing pulse at beginning of Parameter
Measurement. INH Pin 23 Inhibit Measurement. Indicates a low level interrogation and
parameter measurements are not to be made. In most operating modes, toggles between HIGH and LOW before the PRF pulses.
FLTA Pin 11 Positive pulses (following PRF) indicating that the parameter was within limits. Absence of pulse indicates that the parameter was outside its preset limits.
FLTB Pin 14 (See FLTA) OUTPUTS: PRFCNT0 Pin 10 Part of divide by 3 counter used to select every third
(not INHibited) PRF pulse to the Error Counter PRFCNT1 Pin 15 (See PRFCNT0) ALLCLCKA Pin 9 Clock signal combining all (not INHibited) PRF and FLTA
pulses TIMCLKA Pin 7 Clock signal to Error Counter. Clocks on negative edge DECA Pin 6 Count UP/DOWN control for Error Counter. Counts DOWN
when LOW; counts UP when it and PRFCNTO are HIGH A0P Pin 3 Part of Error Counter consisting of A0P to A2P A1P Pin 4 Part of Error Counter consisting of A0P to A2P A2P Pin 5 Part of Error Counter consisting of A0P to A2P FLAGA Pin 8 Fault output signal. HIGH indicates that the measured
parameter is consistently within limits; LOW indicates that the measured parameter is consistently outside limits.
ALLCLCKB Pin 16 (See ALLCLCKA) TIMCLKB Pin 18 (See TIMCLKA) DECB Pin 19 (See DECA) B0P Pin 22 (See A0P) B1P Pin 21 (See A1P) B2P Pin 20 (See A2P) FLAGB Pin 17 (See FLAGA)
The operation of the Monitor Primary Error Counter is identical to that of the Monitor Pulse Shape Error Counter 1, Type 8A72502.
HA72500 APPENDIX M
M-27
M.15 MONITOR INHIBIT DEVICE DRIVER - PLD Type 16A72502 NAME: Monitor Inhibit Device Driver TYPE No: 16A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D51 FUNCTION: To generate a retimed TIPRF pulse to the Delay, Spacing and Pulse
Shape (Width, Fall and Rise) Counters; to produce Inhibit signals to the Efficiency and Delay Counters; and provide the input data switching for the Delay and Spacing Monitor Fault Testing
INPUTS: CLK Pin 1 Synchronous clock input - 10 MHz CLK Pin 13 Synchronous clock input - 10 MHz DELIN Pin 3 Bit A5 from the "Delay Lower Limit Set” switches SEPIN Pin 4 Bit A5 from the "Spacing Lower Limit Set" switches MON TEST Pin 5 Monitor Fault Test control from CTU INH Pin 6 Inhibit control from Ident Extraction. HIGH when Ident is
detected as being transmitted DEL_EN Pin 7 Delay Enable EFF_EN Pin 8 Efficiency Enable TIPRF Pin 9 TIPRF from Test Interrogator. Indicates that a Test
Interrogation is about to be made OUTPUTS: DELOUT Pin 22 A5 input to Delay Counter. Part of Delay Lower Limit Set data SEPOUT Pin 21 A5 input to Spacing Counter. Part of Spacing Lower Limit Set
data DEL_INH Pin 20 Inhibit to Delay and Spacing Error Counters while Ident is
present EFF_INH Pin 19 Inhibit to Efficiency Counters while Ident is present TI Pin 17 Regenerated TIPRF TI1 Pin 16 Part of 2-Stage Shift Register consisting of TI1 and TI2 TI2 Pin 15 Part of 2-Stage Shift Register consisting of TI1 and TI2
TIPRF Retiming TI1 and T12 form a 2-Stage shift register clocked by the 10 MHz clock signal CLK, and with TIPRF as input to TI1. TI produces a positive pulse of one CLK period duration following the positive edge of TIPRF as shown in Figure M-7.
This retimed signal is the “TIPRF" input signal to Delay, Spacing, Rise, Fall and Width Counters.
Inhibit Control for Delay and Spacing Error Counters EFF_INH is active HIGH if either: input INH is active HIGH or input EFF_EN is inactive LOW.
Inhibit Control for Efficiency Counter DEL_INH is inactive LOW if either: input MON_TEST is active HIGH or input DEL_EN is active HIGH while input INH is inactive LOW.
HA72500 APPENDIX M
M-28
Monitor Test of Delay and Spacing Counters While MON_TEST is inactive LOW, DELOUT is the same as DELIN, and SEPOUT is the same as SEPIN. However when MON_TEST is active HIGH, DELOUT is the opposite logic sense of DELIN and SEPOUT is the opposite logic sense of SEPIN.
MON_TEST is used to change the Delay and Spacing Lower Limit Set to the Delay and Spacing Counters respectively by 3.2 microseconds. Since the maximum Delay and Spacing Window Set is 3.1 microseconds, MON_TEST going high should cause a fault indication from both Delay and Spacing Counters if a fault indication had not been present when MON_TEST was LOW. This is used to check correct operation of these two counters.
While output TI is HIGH, outputs DELOUT and SEPOUT are placed in a high impedance state.
HA72500 APPENDIX M
M-29
Figure M-7 Timing Diagram : Monitor Inhibit Device Driver
HA72500 APPENDIX M
M-30
M.16 MONITOR IDENT COUNTER - PLD Type 17A72502 NAME: Monitor Ident Counter TYPE No: 17A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D40 FUNCTION: To filter out the ident pulse pairs from the totality of transmitted pulse
pairs. INPUTS: CLOCK Pin 1 Synchronous clock input - 10 MHz CLOCK Pin 13 Synchronous clock input - 10 MHz DEC Pin 20 Ident Decide CLEAR Pin 14 Clear pulse used to reset Counter TIPRF Pin 2 Timing pulse before arrival of pulse to be checked PULSE Pin 11 Pulse to be checked B0 Pin 23 Accept Window Input B1 Pin 22 Accept Window Input B2 Pin 21 Accept Window Input OUTPUTS: A0P Pin 16 Part of Binary Down Counter A0P to A9P A1P Pin 15 Part of Binary Down Counter A0P to A9P A2P Pin 10 Part of Binary Down Counter A0P to A9P A3P Pin 9 Part of Binary Down Counter A0P to A9P A4P Pin 8 Part of Binary Down Counter A0P to A9P A5P Pin 7 Part of Binary Down Counter A0P to A9P A6P Pin 6 Part of Binary Down Counter A0P to A9P A7P Pin 5 Part of Binary Down Counter A0P to A9P A8P Pin 4 Part of Binary Down Counter A0P to A9P A9P Pin 3 Part of Binary Down Counter A0P to A9P SCNTP Pin 17 Second Count Indicator: LOW when Counter is in Lower Limit
Stage; HIGH when Counter is in Accept Window Stage FLAG Pin 18 Output to indicate that the duration of PULSE is within limits CNT1P Pin 19 Counter Active Indicator
Counter Control Inputs DEC, CLEAR, TIPRF and PULSE are produced externally by a 3-stage shift register clocked on the negative edge of CLOCK (See Figure M-8 to Figure M-10)
Lower Limit Counter A0P to A9P form a 10-bit Presettable Binary Down Counter (A0P is the Least Significant Sit) clocked by the 10 MHz CLOCK. On reaching a count of zero, provided Flip Flop SCNTP is HIGH, counting ceases and the count remains at zero until a positive TIPRF pulse is received. The counter is asynchronously reset to a count of 0 whenever CLEAR is HIGH. While TIPRF pulse is HIGH, the counter outputs are placed in a high impedance state and the binary data fed to these outputs (through series resistors) is synchronously loaded into the counter. Also while TIPRF pulse is HIGH, Flip Flop SCNTP is asynchronously reset to LOW and stays LOW until the start of the second count (i.e. in the Accept Window Stage).
HA72500 APPENDIX M
M-31
After TIPRF returns to LOW, the counter maintains its preset count until the arrival of a positive PULSE input. A HIGH on PULSE causes Flip Flop CNT1P to be set HIGH (on the next CLOCK pulse) and the counter to commence the Lower Limit Stage. While CNT1P remains HIGH, the counter counts down towards zero. When a count of ONE is reached, the next CLOCK pulse causes Flip Flop CNT1P to be reset LOW and the counter counts to ZERO completing the Lower Limit Stage.
Accept Window Counter Provided TIPRF is still LOW, the next CLOCK pulse causes Flip Flop SCNTP to go HIGH and stay HIGH until the next TIPRF pulse. This is the commencement of the Accept Window Stage. If PULSE is still HIGH, this next CLOCK pulse also causes the counter to be loaded with the binary data on inputs B0 to B2 (B0 is the Least Significant Bit) and Flip Flop CNT1P to be set HIGH. (However, if the binary data on inputs B0 to B2 is ZERO, Flip Flop CNT1P is not set HIGH and the counter will remain at count ZERO.)
Provided no DEC or CLEAR pulses are received, continuing from the next CLOCK pulse, the counter again counts down towards zero. When a count of ONE is reached, the next CLOCK pulse causes Flip Flop CNT1P to be reset LOW and the counter counts to ZERO. Since Flip Flop SCNTP is HIGH, counting ceases and the count remains at zero until a positive CLEAR pulse is received. This is the completion of the Accept Window Stage for the case where the duration between the pulse pairs is greater than what would normally be expected for Ident transmission. This is shown in Figure M-10.
Pulse Rate Within Ident Range Provided the next DEC pulse arrives while Flip Flop SCNTP is HIGH (i.e. during the Accept Window Stage) and the counter is NOT at a count of 0, Flip Flop FLAG will be set HIGH indicating that the duration of PULSE is within the preset limits.
Figure M-8 shows this condition. From this timing diagram it can be seen that for times between DEC pulses (and thus between transmitted pulse pairs) in the range 740 microseconds to 746 microseconds the FLAG Flip Flop will be continuously set HIGH.
Pulse Rate Higher Than Ident Rate If the next DEC pulse arrives before Flip Flop SCNTP is set HIGH and while Flip Flop CNT1P is HIGH, Flip Flop FLAG will be reset LOW, indicating that the duration of PULSE is less than the preset lower limit.
Figure M-9 shows this condition. From this timing diagram it can be seen that for times between DEC pulses (and thus between transmitted pulse pairs) of 738 microseconds and less the FLAG Flip Flop will be continuously reset LOW.
Pulse Rate Lower Than Ident Rate If the next DEC pulse arrives after the counter reaches a count of 0 and while Flip Flop SCNTP is HIGH, Flip Flop FLAG will be reset LOW, indicating that the duration of PULSE is greater than the preset upper limit.
Figure M-10 shows this condition. From this timing diagram it can be seen that for times between DEC pulses (and thus between transmitted pulse pairs) of 747 microseconds and more the FLAG Flip Flop will be continuously reset LOW.
HA72500 APPENDIX M
M-32
Figure M-8 Timing Diagram : Monitor Ident Counter - Pulse Rate Within Ident Range
HA72500 APPENDIX M
M-33
Figure M-9 Timing Diagram : Monitor Ident Counter - Pulse Rate Higher Than Ident Rate
HA72500 APPENDIX M
M-34
Figure M-10 Timing Diagram : Monitor Ident Counter - Pulse Rate Lower Than Ident Rate
HA72500 APPENDIX M
M-35
M.17 MONITOR RATE COUNTER - PLD Type 18A72502 NAME: Monitor Rate Counter TYPE No: 18A72502 Issue 2 WHERE USED: 1A72511, Monitor PWB Assembly; D45.
Issue 1 used until June 1995. Issue 2 used from July 1995.
FUNCTION: To determine if the transmitted pulse pair rate is within the preset limits.
INPUTS: CLCK Pin 1 Synchronous clock input - 1 MHz CLCK Pin 13 Synchronous clock input - 1 MHz REPLYA Pin 2 Pulse Input to cause Counter A to count Up by 1 RATEA Pin 11 Pulse Input to cause Counter A to count Down by 1 REPLYB Pin 23 Pulse Input to cause Counter B to count Down by 1 RATEB Pin 14 Pulse Input to cause Counter B to count Up by 1 OUTPUTS: FLAGAB Pin 8 Fault Indicator. HIGH = No Fault; LOW = Fault condition UA1 Pin 6 REPLYA retimed by CLCK UA2 Pin 10 UA1 retimed by CLCK DA1 Pin 7 RATEA retimed by CLCK ENA Pin 9 Count Enable to Counter A A0P Pin 3 Part of Counter A A1P Pin 4 Part of Counter A A2P Pin 5 Part of Counter A A3P Pin 15 Part of Counter A UB1 Pin 19 REPLYB retimed by CLCK DB1 Pin 18 RATEB retimed by CLCK DB2 Pin 17 DB1 retimed by CLCK ENB Pin 16 Count Enable to Counter B B0P Pin 22 Part of Counter B B1P Pin 21 Part of Counter B B2P Pin 20 Part of Counter B
The PLD contains a common output Flip Flop FLAGAB and two sets of essentially identical circuitry. The two sets are identified by the letters 'A" and "B” in the names of the I/O pins.
Input Signal Processing UA1 is a D-Type Flip Flop clocked by CLCK with REPLYA as its input. UA2 is a D-Type Flip Flop clocked by CLCK with UA1 as its input. DA1 is a D-Type Flip Flop clocked by CLCK with RATEA as its input. UB1 is a D-Type Flip Flop clocked by CLCK with RATEB as its input. DB1 is a D-Type Flip Flop clocked by CLCK with REPLYB as its input. DB2 is a D-Type Flip Flop clocked by CLCK with DB1 as its input.
HA72500 APPENDIX M
M-36
Counter A A0P to A3P form a 4-bit Binary Up/Down Counter (A0P is the Least Significant Bit) clocked by the 1 MHz CLCK. It is limited to counting up and down between 0 and 15. Positive edges of RATEA (detected by RATEA being HIGH while DA1 is LOW) cause Counter A to count Down by 1 provided ENA is HIGH. Positive edges of REPLYA (detected by UA1 being HIGH while UA2 is LOW) cause Counter A to count Up by 1 provided ENA is HIGH. The counter is enabled by ENA which is the ORing of the 2 above positive edge detectors but with simultaneous positive edges of both RATEA and REPLYA removed (i.e. simultaneous positive edges of both RATEA and REPLYA produce no change in the count of Counter A).
Thus, while the frequency of REPLYA exceeds the frequency of RATEA, Counter A will count Up to a count of 15 and stay at a count of 15. And, while the frequency of RATEA exceeds the frequency of REPLYA, Counter A will count Down to a count of 0 and stay at a count of 0.
Counter B B0P to B2P form a 3-bit Binary Up/Down Counter (B0P is the Least Significant Bit) clocked by the 1 MHz CLCK. It is limited to counting up and down between 0 and 7. Positive edges of RATEB (detected by RATEB being HIGH while UB1 is LOW) cause Counter B to count Up by 1 provided ENB is HIGH. Positive edges of REPLYB (detected by ENB being HIGH while DB2 is LOW) cause Counter B to count Down by 1 provided ENB is HIGH. The counter is enabled by ENB which is the ORing of the two above positive edge detectors but with simultaneous positive edges of both RATEB and REPLYB removed (i.e. simultaneous positive edges of both RATEB and REPLYB produce no change in the count of Counter B).
Thus, while the frequency of REPLYB exceeds the frequency of RATEB, Counter B will count Down to a count of 0 and stay at a count of 0. And, while the frequency of RATEB exceeds the frequency of REPLYB, Counter B will count Up to a count of 15 and stay at a count of 15.
Output Flag FLAGAB is a synchronous SR-Type Flip Flop clocked by CLCK. It is set HIGH if counter A is at a count of 15 and counter B is at a count of 7. It is reset LOW if either of the counters is at a count of 0.
HA72500 APPENDIX M
M-37
M.18 MONITOR IDENT ERROR COUNTER - PLD Type 19A72502 NAME: Monitor Ident Error Counter TYPE No: 19A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D47 FUNCTION: To extract the Ident Tone, produce an Inhibit signal to the fault
processing circuitry to inhibit Fault generation during Ident Transmission and detect Ident transmissions longer than 10 seconds as a Fault.
INPUTS: CLOCK Pin 1 Synchronous clock input - 1 Hz CLOCK Pin 13 Synchronous clock input - 1 Hz CODE Pin 11 Ident Message. Envelope of Ident Transmissions ERR75 Pin 14 Error signal indicating the absence of Ident for longer than
the preset limit IMHZ Pin 23 1 kHz input clock CKEY Pin 2 Ident Keying 1KCLK Pin 22 40 microseconds pulses, one pulse corresponding to each
detected Transmitted pulse pair OUTPUTS: C0P Pin 20 Part of counter consisting of C0P to C1P. Clocked on the +ve
edges of CLOCK C1P Pin 19 Part of counter consisting of C0P to C1P. Clocked on the +ve
edges of CLOCK INHIBIT Pin 21 Ident Inhibit signal to fault processing circuitry CODE2 Pin 17 CODE input retimed by clock CLOCK B0P Pin 15 Part of counter consisting of B0P to B3P. Clocked on the +ve
edges of CLOCK B1P Pin 8 Part of counter consisting of B0P to B3P. Clocked on the +ve
edges of CLOCK B2P Pin 6 Part of counter consisting of B0P to B3P. Clocked on the +ve
edges of CLOCK B3P Pin 5 Part of counter consisting of B0P to B3P. Clocked on the + ve
edges of CLOCK MKERRP Pin 18 Ident error signal A0P Pin 4 Part of counter consisting of A0P to A2P. Clocked on the +ve
edges of IMHZ A1P Pin 3 Part of counter consisting of A0P to A2P. Clocked on the +ve
edges of IMHZ A2P Pin 16 Part of counter consisting of A0P to A2P. Clocked on the +ve
edges of IMHZ IDNTMKP Pin 7 Recovered Ident Keying TONEP Pin 10 Recovered Ident Tone
Ident Tone Extraction A0P to A2P form a 3-bit binary Up/Down counter clocked by the 1 kHz input signal IMHZ. While input CKEY is HIGH, the counter counts Up by 1 on the positive edge of IMHZ to a maximum of 7. While input CKEY is LOW, the counter counts Down by 1 on the positive edge of IMHZ to a minimum of 0. (See Figure M-11)
HA72500 APPENDIX M
M-38
Output IDNTMKP uses this counter to filter the CKEY input signal. IDNTMKP is a synchronous SR-Flip Flop clocked by IMHZ. It is asynchronously reset to LOW whenever input CKEY is LOW. It is synchronously set to HIGH on the next clock pulse on the condition that CKEY is HIGH and the counter is at a count of either 6 or 7. (See Figure M-11)
Input 1KCLK consists of a sequence of 40 microseconds pulses where each pulse represents a transmitted pulse pair. During Ident transmission these pulses will therefore occur at the Ident rate of 1350 Hz. IDNTMKP is used to gate these pulses to produce the recovered transmitted Ident Tone. (Between the Ident transmissions, the 40 microseconds pulses represent the transmitted replies and squitter.)
Ident Inhibit Output C0P to C1P form a 2-bit binary Up counter clocked by the 1 Hz input signal CLOCK. This counter is held asynchronously reset to a count of 0 while IDNTMKP is LOW. While IDNTMKP is HIGH, the counter counts Up by 1 on the positive edge of CLOCK to a maximum of 3. (See Figure M-12)
During Ident Transmission, all replies are inhibited. Unless action was taken the monitor circuitry would therefore generate Fault signals. To prevent this, an Ident Inhibit signal, INHIBIT, is generated by ANDing IDNTMKP being HIGH and the counter being at a count of either 0 or 1. Thus INHIBIT follows IDNTMKP to inhibit Fault signals during Ident transmission, but is limited to a maximum duration of two CLOCK periods (i.e. 2 seconds).
Ident Error Detection Input CODE is the output of a One-shot triggered by the TONEP pulses. It thus provides an envelope of the Ident message. This input is retimed in D-Type Flip Flop CODE2 clocked by the 1 kHz signal IMHZ. The positive transitions of CODE (detected by CODE being HIGH while CODE2 is LOW) are used to asynchronously reset the counter consisting of B0P to B3P to a count of 0.
B0P to B3P form a 4-bit binary Up counter clocked by the 1 Hz input signal CLOCK. While CODE is HIGH, the counter counts Up by 1 on the positive edge of CLOCK to a maximum of 15. (See Figure M-12)
MKERRP is a synchronous SR-Flip Flop clocked by IMHZ. It is synchronously set to HIGH on the positive edge of the next IMHZ pulse if either CODE is HIGH or input ERR75 is LOW when the counter consisting of B0P to B3P is at a count of 0. MKERRP is synchronously reset to LOW on the positive edge of the next IMHZ pulse if input ERR75 is HIGH or the counter consisting of B0P to B3P is at a count between 10 and 15.
MKERRP is thus an Active LOW error signal indicating that continuous Ident or Ident Code has been transmitted for longer than 10 seconds, or that Ident has been absent for longer than the preset time limit.
HA72500 APPENDIX M
M-39
Figure M-11 Timing Diagram : Monitor Ident Error Counter - Ident Tone Extraction
HA72500 APPENDIX M
M-40
Figure M-12 Timing Diagram : Monitor Ident Error Counter - Ident Error Detection and Inhibit Control
HA72500 APPENDIX M
M-41
M.19 MONITOR EFFICIENCY COUNTER - PLD Type 20A72502 NAME: Monitor Efficiency Counter TYPE No: 20A72502 WHERE USED: 1A72511, Monitor PWB Assembly; D49 FUNCTION: To determine if the reply efficiency is greater than the preset limit. INPUTS: CLCK Pin 1 Synchronous clock input - 1 MHz CLCK Pin 13 Synchronous clock input - 1 MHz EINH Pin 10 Inhibit BOTH Pin 17 Input to disable the effect of Counter B on FLAGAB output REPLYA Pin 2 Pulse Input to cause Counter A to count Up by 1 RATEA Pin 11 Pulse Input to cause Counter A to count Down by 1 REPLYB Pin 23 Pulse Input to cause Counter B to count Down by 1 RATEB Pin 14 Pulse Input to cause Counter B to count Up by 1 OUTPUTS: FLAGAB Pin 8 Fault Indicator. HIGH = No Fault; LOW = Fault condition UA1 Pin 6 REPLYA retimed by CLCK DA1 Pin 7 RATEA retimed by CLCK CLOKA Pin 9 Clock to Counter A A0P Pin 3 Part of Counter A A1P Pin 4 Part of Counter A A2P Pin 5 Part of Counter A A3P Pin 15 Part of Counter A UB1 Pin 19 REPLYB retimed by CLCK DB1 Pin 18 RATEB retimed by CLCK CLOKB Pin 16 Clock to Counter B B0P Pin 22 Part of Counter B B1P Pin 21 Part of Counter B B2P Pin 20 Part of Counter B
The PLD contains a common output Flip Flop FLAGAB and two sets of essentially identical circuitry. The two sets are identified by the letters “A" and "B" in the names of the I/O pins.
Input Signal Processing U(A/B)1 is a D-Type Flip Flop clocked by CLCK with REPLY(A/B) as its input. D(A/B)1 is a D-Type Flip Flop clocked by CLCK with RATE(A/B) as its input.
Counter A A0P to A3P form a 4-bit Binary Up/Down Counter (A0P is the Least Significant Bit) clocked by the 1 MHz CLCK. It is limited to counting up and down between 0 and 15. Positive edges of RATEA (detected by RATEA being HIGH while DA1 is LOW) cause Counter A to count Up by 1 provided EINH is LOW. Positive edges of REPLYA (detected by REPLYA being HIGH while UA1 is LOW) cause Counter A to count Down by 1 provided EINH is LOW. The counter is clocked by the negative edges of CLOKA which is the ORing of the 2 above positive edge detectors but with simultaneous positive edges of both RATEA and REPLYA removed (i.e. simultaneous positive edges of both RATEA and REPLYA produce no change in the count of Counter A).
HA72500 APPENDIX M
M-42
Thus, while the frequency of REPLYA exceeds the frequency of RATEA, Counter A will count Down to a count of 0 and stay at a count of 0. And, while the frequency of RATEA exceeds the frequency of REPLYA, Counter A will count Up to a count of 15 and stay at a count of 15.
Counter B B0P to B3P form a 3-bit Binary Up/Down Counter (B0P is the Least Significant Bit) clocked by the 1 MHz CLCK. Positive edges of RATEB (detected by RATEB being HIGH while DB1 is LOW) cause Counter B to count Down by 1 provided EINH is LOW. Positive edges of REPLYB (detected by REPLYB being HIGH while UB1 is LOW) cause Counter B to count Up by 1 provided EINH is LOW. The counter is clocked by the negative edges of CLOKB which is the ORing of the 2 above positive edge detectors but with simultaneous positive edges of both RATEB and REPLYB removed (i.e. simultaneous positive edges of both RATEB and REPLYB produce no change in the count of Counter B).
Output Flag FLAGAB is a synchronous SR-Type Flip Flop clocked by CLCK. It is set HIGH if either Counter A is at a count of 15 or Counter B is at a count of 15 with input BOTH HIGH. It is reset LOW if either Counter A is at a count of 0 or Counter B is at a count of 0 with input BOTH HIGH. In its actual use in the Monitor Module, REPLYB, RATEB and BOTH are all tied LOW and Counter B is thus disabled.
HA72500 APPENDIX M
M-43
M.20 TEST INTERROGATOR COUNTER TIMER - PLD Type 21A72502 NAME: Test Interrogator Counter Timer TYPE No: 21A72502 WHERE USED: 1A72515, Test. Interrogator Main PWB Assembly; D33 FUNCTION: To control signal switching in relation to the 82C54 Counter/Timer
used on the Test Interrogator Main PWB Assembly for measuring equipment parameters.
INPUTS: CLK1 Pin 1 Synchronous clock input - 10 MHz ENABLE Pin 2 Timer Enable - control input from CTU. Active HIGH PARA Pin 11 Time Parameter Input Signal - input from Timer Multiplexer RST Pin 14 Reset. Active HIGH 50HZ Pin 23 Test Interrogations Attenuator Switching - HIGH for high level
interrogations AC0 Pin 22 Control input from CTU. Active HIGH - Efficiency Enable
Override AC1 Pin 21 Control input from CTU. Active HIGH - Delay Enable OverrideOI Pin 20 Over Interrogation. Active HIGH RPLY Pin 16 Detected Replies UNUSED: Pin 13 Synchronous clock input
OUTPUTS: EN1P Pin 3 Delayed ENABLE (clocked by CLK1) EN2P Pin 4 Delayed EN1P (clocked by CLK1) PARA1P Pin 5 Delayed PARA (clocked by CLK1) PARA2P Pin 6 Delayed PARA1P (clocked by CLK1) PARA3P Pin 8 Gating Signal to select second PARA pulse PARA4P Pin 9 Delayed PARA3P (clocked byCLK1) PARA5P Pin 10 Delayed PARA4P (clocked by CLK1) T_STATUSP Pin 7 Timer Status GATEP Pin 15 Gate Signal to 80C54 Counter/Timer TIATTP Pin 19 Test Interrogations Attenuator Switching - HIGH for high level
interrogations EFFPP Pin 17 Gated Reply Pulses for Efficiency Measurement
Timer Status and Parameter Gating See Figure M-13 for the timing diagram. The ENABLE input from the CTU is fed into the shift register consisting of EN1P and EN2P. The rising edge of ENABLE (detected by EN1P being HIGH while EN2P is LOW) causes Flip Flop T_STATUSP to go HIGH. (Flip Flop T_STATUSP is held RESET while ever EN1P is LOW.)
The PARA input from the Timer Multiplexer is fed into the shift register consisting of PARA1P and PARA2P. The falling edges of the PAPA pulses (detected by PARA2P being HIGH while PARA1P is LOW) toggle Flip Flop PARA3P. Flip Flop PARA3P is held RESET while ever T_STATUSP is LOW. Therefore the falling edge of the first PARA pulse after T_STATUSP goes HIGH causes PARA3P to go HIGH and the falling edge of the second PARA pulse after T_STATUSP goes HIGH causes PARA3P to go LOW.
PARA3P is then used to gate out the second PARA pulse as GATEP to the Counter/Timer for the measurement of its duration.
HA72500 APPENDIX M
M-44
The output of PARA3P is internally fed into the shift register consisting of PARA4P and PARA5P. The falling edge of PARA3P (detected by PARA5P being HIGH while PARA4P is LOW) causes Flip Flop T_STATUSP to go LOW to indicate to the CTU that the parameter measurement is complete.
Gated Reply Pulses EFFPP passes the input RPLY pulses when ever the setup conditions are acceptable for an Efficiency measurement; i.e. when 50HZ is LOW or AC0 is HIGH or AC1 is HIGH.
Interrogation Attenuator Control TIATTP controls the attenuator at the output of the Test Interrogator to produce high level interrogations when it is HIGH and low level interrogations when it is LOW. The logic is shown in the table below.
50HZ AC0 AC1 OI TIATTP X X X 1 1 X X 1 X 1 0 0 0 0 0 0 1 0 0 0 1 0 0 0 1 1 1 0 0 0
X = Don't care
HA72500 APPENDIX M
M-45
Figure M-13 Timing Diagram : Test Interrogator Counter Timer
HA72500 APPENDIX M
M-46
M.21 TEST INTERROGATOR BUS INTERFACE - PLI) Type 22A72502 NAME: Test Interrogator Bus Interface TYPE No: 22A72502 WHERE USED: 1A72515, Test Interrogator Main PWB Assembly; D26 FUNCTION: To decode the address lines on the Extended CTU Bus to the Test
Interrogator Main PWB Assembly and produce the required chip select lines.
INPUTS: CLK1 Pin 1 Synchronous clock input - unused CLK2 Pin 13 Synchronous clock input - unused RD Pin 23 Read Signal from Extended CTU Bus. Active LOW WR Pin 3 Write Signal from Extended CTU Bus. Active LOW DT_R Pin 4 Data Transmit/Receive Signal from Extended CTU Bus.
When LOW, data is read out of the PWBA; when HIGH data is written to the PWBA
DEN Pin 5 Data Enable Signal from Extended CTU Bus. Active LOW during memory and I/O accesses
A0 Pin 6 Address Signal from Extended CTU Bus. Active HIGH A1 Pin 7 Address Signal from Extended CTU Bus. Active HIGH A2 Pin 8 Address Signal from Extended CTU Bus. Active HIGH A3 Pin 9 Address Signal from Extended CTU Bus. Active HIGH A5 Pin 10 Address Signal from Extended CTU Bus. Active HIGH BS Pin 11 Board Select Signal from Extended CTU Bus. Active LOW RES Pin 14 Reset Signal from Extended CTU Bus. Active HIGH GUNIT Pin 17 Locally Generated Bus Enable Signal. Active HIGH UNUSED: Pin 2
OUTPUTS: BUFEN Pin 22 Data Bus Transceiver Enable LEN_00 Pin 21 Test Interrogator Control Outputs Select LEN_02 Pin 20 Test Interrogator Control Outputs Select BEN_04 Pin 19 Test Interrogator Status Read Select LEN_06 Pin 18 Test Interrogator Control Outputs Select CS_MEAS Pin 15 Timer Measurement Select CS_FLT Pin 16 Fault Detector Test Signal Generator Select
Data Bus Transceiver Enable BUFEN enables the transceiver for the data bus. Active LOW when inputs BS and DEN are active LOW, RESET is inactive LOW and A5 is LOW.
Test Interrogator Control Outputs Selects LEN_00 enables write access to an octal latch driving control outputs to the Test Interrogator circuitry. Is active HIGH when inputs: BS and WR are active LOW and the address is 00H or 10H.
LEN_02 enables write access to an octal latch driving control outputs to the Test Interrogator circuitry. Is active HIGH when inputs: BS and WR are active LOW and the address is 01H or 11H.
LEN_06 enables write access to an octal latch driving control outputs to the Test Interrogator circuitry. Is active HIGH when inputs: BS and WR are active LOW and the address is 03H or 13H.
HA72500 APPENDIX M
M-47
Test Interrogator Status Read Select BEN_04 enables read access of status signals from the Test Interrogator circuitry. Is active LOW when inputs: BS and RD are active LOW and the address is 02H or 12H.
Timer Measurement Select CS_MEAS enables read and write access to the 82C54 Counter/Timer used for measuring equipment parameters. Is active LOW when inputs: BS and DEN are active LOW and the address is in the range 08H to 0BH or in the range 18H to 1BH.
Fault Detector Test Signal Generator Select CS_FLT enables read and write access to the 82C54 Counter/Timer used to generate Fault Detector Test Signals. Is active LOW when inputs: BS and DEN are active LOW and the address is in the range 0CH to 0FH or in the range 1CH to 1FH.
HA72500 APPENDIX M
M-48
M.22 CTU PROCESSOR WAIT STATE GENERATOR - PLD Type 23A72502
NAME: CTU Processor Wait State Generator TYPE No: 23A72502 WHERE USED: 1A72552, CTU Processor PWB Assembly; D13 FUNCTION: To generate wait states for the 80C186 microprocessor to slow it down
when it accesses slow peripherals. It also provides some address decoding.
INPUTS: CLOCK1 Pin 1 10 MHz Clock from Microprocessor CLOCK2 Pin 13 10 MHz Clock from Microprocessor - phase inverted DEN Pin 21 Data Enable from Microprocessor. Active LOW during
memory and I/O accesses by the microprocessor RD Pin 23 Active LOW Read strobe from Microprocessor WR Pin 14 Active LOW Write strobe from Microprocessor PCS0 Pin 11 Programmable Active LOW Peripheral Chip Select from
Microprocessor (CTU Front Panel and RCMS I/F PWBAs) PCS1 Pin 2 Programmable Active LOW Peripheral Chip Select from
Microprocessor (Transponder I/O on CTU Processor PWBA) PCS2 Pin 10 Programmable Active LOW Peripheral Chip Select from
Microprocessor (Configuration I/O on CTU Processor PWBA) MCS1 Pin 9 Programmable Active LOW Mid-Range Memory Chip Select
from Microprocessor (Extended CTU Bus to Transponder No.1)
MCS2 Pin 8 Programmable Active LOW Mid-Range Memory Chip Select from Microprocessor (Extended CTU Bus to Transponder No.2)
OUTPUTS: XRD Pin 17 Extended Read XWR Pin 16 Extended Write WR_PCS1 Pin 6 Write Signal for Peripheral Chip Select 1 WR_PCS2 Pin 7 Write Signal for Peripheral Chip Select 2 DEN_PCS0 Pin 5 Data Transceiver Enable for Peripheral Chip Select 0 DEN_MCS1 Pin 3 Data Transceiver Enable for Mid-Range Memory Chip Select 1DEN_MCS2 Pin 4 Data Transceiver Enable for Mid-Range Memory Chip Select 2SRDY Pin 22 Synchronous Ready to Microprocessor CT0 Pin 18 Part of BCD Counter consisting of CT0, CT1, CT2, XIPL CT1 Pin 20 Part of BCD Counter consisting of CT0, CT1, CT2, XIPL CT2 Pin 19 Part of BCD Counter consisting of CT0, CT1, CT2, XIPL XIPL Pin 15 Part of BCD Counter consisting of CT0, CT1, CT2, XIPL
Extended CTU Bus The Extended CTU Bus is an extension of the CTU Processor bus stowed down so that peripherals up to 2 metres from the CTU can be accessed by the CTU Processor. The timing of the Extended CTU Bus is controlled by the Wait State Counter.
Wait State Counter The counter consisting of CT0, CT1, CT2, XIPL (CT0 is the least significant bit) is a BCD counter (counting from 0 to 9) clocked by input CLOCK2. It is normally held at count 0, but is enabled to start counting from count 0 whenever any of the chip select input signals PCS0, PCS1, PCS2, MCS1, MCS2 goes active low.
HA72500 APPENDIX M
M-49
Extended Bus Input Data Latch Clock XIPL provides a positive clock edge at the beginning of count 8 of the Wait State Counter. This clock is used to latch read data on the Extended CTU Bus into latches to be then read by the CTU.
Extended Bus Read XRD goes active low whenever the input signal RD is active low and the Wait State Counter is at counts in the range 3 to 8. Extended Bus Write XWR goes active low whenever the input signal WR is active low and the Wait State Counter is at counts in the range 3 to 8.
Synchronous Ready SRDY, on going low, causes the 80C186 microprocessor to generate wait states until this signal goes high again. This signal is low whenever either input RD or WR is low and the Wait State Counter is at counts in the range 1 to 8.
Write Signal for Peripheral Chip Select 1 WR_PCS1 is an active HIGH latch control signal for data written by the microprocessor at the address(es) selected by input PCS1. This signal is only high when both inputs WR and PCS1 are active LOW and the Wait State Counter is at counts in the range 4 to 8.
Write Signal for Peripheral Chip Select 2 WR_PCS2 is an active HIGH latch control signal for data written by the microprocessor at the address(es) selected by input PCS2. This signal is only high, when both inputs WR and PCS2 are active LOW and the Wait State Counter is at counts in the range 4 to 8.
Data Transceiver Enable for Peripheral Chip Select 0 DEN_PCS0 is an enable signal to the data bus transceiver for the extended CTU Bus to the CTU Front Panel and RCMS I/F. The signal is active LOW whenever both inputs DEN and PCS0 are active LOW.
Data Transceiver Enable for Mid-Range Memory Chip Select 1 DEN_MCS1 is an enable signal to the data bus transceiver for the extended CTU Bus to Transponder No.1. The signal is active LOW whenever both inputs DEN and MCS1 are active LOW.
Data Transceiver Enable for Mid-Range Memory Chip Select 2 DEN_MCS1 is an enable signal to the data bus transceiver for the extended CTU Bus to Transponder No.2. The signal is active LOW whenever both inputs DEN and MCS2 are active LOW.
HA72500 APPENDIX M
M-50
M.23 CTU PROCESSOR IDENT TONE AND KEYING - PLD Type 24A72502
NAME: CTU Processor Ident Tone and Keying TYPE No: 24A72502 WHERE USED: 1A72552, CTU Processor PWB Assembly, D2 FUNCTION: To control the switching of the Ident signals on the CTU Processor INPUTS: R_SEL1 Pin 14 Received Ident Select Control Signal R_SEL2 Pin 10 Received Ident Select Control Signal R_TON1 Pin 18 Received Ident Tone from Monitor 1 R_TON2 Pin 17 Received Ident Tone from Monitor 2 R_KEY1 Pin 16 Received Ident Keying from Monitor 1 R_KEY2 Pin 15 Received Ident Keying from Monitor 2 A_SEL1 Pin 23 Associate Ident Select Control Signal A_SEL2 Pin 19 Associate Ident Select Control Signal M_OUT1 Pin 21 Master Output of Ident Generator of Transponder 1 M_OUT2 Pin 20 Master Output of Ident Generator of Transponder 2 2440HZ Pin 2 Input Clock TMROUT Pin 11 Timing Signal from Microprocessor A_IN Pin 22 Associate Ident Input Signal OUTPUTS: TN_TXFR Pin 8 Ident Tone Output to RCMS I/F Transformer SPEAKER Pin 9 Ident Tone Output to Speaker in CTU DET_KEY Pin 7 Detected Ident Keying (to EXT I/O PWBA) M_IN1 Pin 3 Master Ident Input to Transmitter of Transponder 1 M_IN2 Pin 4 Master Ident Input to Transmitter of Transponder 2 M_OUT Pin 5 Master Ident Output to Associate Navaid IDENT_ON Pin 6 Status Signal to CTU
Ident Switching for Outputs: M_IN, MA_OUT, TN_TXFR, DET_KEY
INPUTS OUTPUTS A-SEL M_IN
2 1 2 1 MA_OUT TN_TXFR DET_KEY
0 0 0 A_IN M_OUT1 R_TON1 R_KEY1 0 1 A_IN 0 M_OUT2 R_TON2 R_KEY2 1 0 0 0 0 0 0 1 1 0 0 0 0 0
HA72500 APPENDIX M
M-51
Ident Switching for Output: SPEAKER
INPUTS OUTPUT A_SEL
2 1 SPEAKER
0 0 R_TON1 0 1 R_TON2 1 0 2440HZ 1 1 TMROUT
Ident Switching for Output: IDENT_ON
INPUTS OUTPUT A_SEL R_SEL 2440HZ IDENT_ON
2 1 2 1 X X 1 1 X 0
0 X 0 0
X 0 ↑ R_KEY1
0 X 0 1
X 0 ↑ R_KEY2
0 X 1 X
X 0 ↑ p
X= Don't care ↑= Low-to-high transition P= State of IDENT_ON at previous
low-to-high transition of 2440HZ
HA72500 APPENDIX M
M-52
M.24 CTU FRONT PANEL ADDRESS DECODER - PLD Type 25A72502
NAME: CTU Front Panel Address Decoder TYPE No: 25A72502 WHERE USED: 1A72553, CTU Front Panel PWB Assembly; D9 FUNCTION: To decode the address fines on the Extended CTU Bus to the CTU
Front Panel PWB Assembly and produce the required chip select lines.INPUTS: CLOCK1 Pin 1 Synchronous clock input - unused CLOCK2 Pin 13 Synchronous clock input - unused XRD_N Pin 20 Read Signal from Extended CTU Bus. Active LOW XWR_N Pin 21 Write Signal from Extended CTU Bus. Active LOW DEN_N Pin 19 Data Enable Signal from Extended CTU Bus. Active LOW
during memory and I/O accesses XRES Pin 18 Reset Signal from Extended CTU Bus. Active HIGH A1 Pin 16 Address Signal from Extended CTU Bus. Active HIGH A2 Pin 15 Address Signal from Extended CTU Bus. Active HIGH A3 Pin 23 Address Signal from Extended CTU Bus. Active HIGH A4 Pin 14 Address Signal from Extended CTU Bus. Active HIGH A5 Pin 11 Address Signal from Extended CTU Bus. Active HIGH A6 Pin 2 Address Signal from Extended CTU Bus. Active HIGH PCS0_N Pin 10 Board Select Signal from Extended CTU Bus. Active LOW OUTPUTS: FP_DEN_N Pin 17 Data Bus Transceiver Enable DIS_EN Pin 22 Display Select SSC Pin 3 Key Switch Select ALARM Pin 4 Alarm Delay Switch Select A_REG1 Pin 8 Alarm Register Write Select 1 A_REG2 Pin 5 Alarm Register Write Select 2 C_STAT1 Pin 9 Control Status Write Select 1 C_STAT2 Pin 6 Control Status Write Select 2 M_STAT Pin 7 Miscellaneous Status Write Select
Data Bus Transceiver Enable FP_DEN_N enables the transceiver for the data bus. Active LOW when inputs PCS0_N and XDEN_N are active LOW and XRES and A6 are inactive LOW.
Display Select DIS_EN enables read and write access to the LCD Display. Is active HIGH when inputs: PCS0 is active LOW, either XRD or XWR is active LOW, XRES is inactive LOW, and the address is in the range 00H to 01H.
Key Switch Select SSC enables read access to keypad interface PLD. Is active LOW when inputs: PCS0 and XRD are active LOW, XRES is inactive LOW, and the address is 02H.
Alarm Delay Switch Select ALARM enables read access to the two BCD Alarm Delay setting switches. Is active LOW when inputs: PCS0 and XRD are active LOW, XRES is inactive LOW, and the address is 03H.
HA72500 APPENDIX M
M-53
Alarm Register Write Selects A_REG1 enables write access to an octal latch driving alarm indicators. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 04H.
A_REG2 enables write access to an octal latch driving alarm indicators. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 05H.
Control Status Write Selects C_STAT1 enables write access to an octal latch driving status indicators. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 06H.
C_STAT2 enables write access to an octal latch driving status indicators. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 07H.
Miscellaneous Status Write Select M_STAT enables write access to an octal latch driving alarm indicators. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 08H.
HA72500 APPENDIX M
M-54
M.25 CTU FRONT PANEL KEY SWITCH INTERFACE - PLD Type 26A72502
NAME: CTU Front Panel Key Switch Interface TYPE No: 26A72502 WHERE USED: 1A72553, CTU Front Panel PWB Assembly; D5 FUNCTION: To detect operation of the momentary action push button keys on the
front panel of the CTU and supply this information to the CTU via the CTU Extended Bus.
INPUTS: CLK1 Pin 1 Synchronous clock input - 1221 Hz CLK1 Pin 13 Synchronous clock input - 1221 Hz 10KHZIN Pin 23 Dedicated Key input from ”10kHz” key 1KHZIN Pin 14 Dedicated Key input from “1kHz" key CSN_RDN Pin 4 Chip Select for outputting Key data to the Extended CTU
Bus. Active HIGH DEBNZIN Pin 3 Debounce input ROW1 Pin 9 Input from switch matrix ROW2 Pin 10 Input from switch matrix ROW3 Pin 2 Input from switch matrix ROW4 Pin 11 Input from switch matrix OUTPUTS: COL1 Pin 8 Output to switch matrix COL2 Pin 7 Output to switch matrix COL3 Pin 6 Output to switch matrix COL4 Pin 5 Output to switch matrix KEY0 Pin 15 Key Status Output to Data Bus for keys in switch matrix KEY1 Pin 16 Key Status Output to Data Bus for keys in switch matrix KEY2 Pin 17 Key Status Output to Data Bus for keys in switch matrix KEY3 Pin 18 Key Status Output to Data Bus for keys in switch matrix KEYON Pin 19 Key Status Output to Data Bus for keys in switch matrix 1KHZOUT Pin 20 Dedicated Key Status Output to Data Bus 10KHZOUT Pin 21 Dedicated Key Status Output to Data Bus DEBNZOUT Pin 22 Debounce output
Switch Matrix COL1 to COL4 are active LOW signals with only one LOW at a time. They feed a 4 X 4 switch matrix (through a pull down diode) with the row signals as inputs back into the PLD. With no keys pressed, the LOW column signal repeatedly cycles from COL1 through COL4. The rate is controlled by the CLK1 input signal (1221 Hz). If a key is pressed when the corresponding COL signal goes LOW, that COL signal stays LOW until all keys in that column are released.
DEBNZOUT is an active LOW debounce signal. It is LOW while ever one and only one key in a column is pressed. This signal is externally delayed (nominally 14 ms) and inverted and fed back into the DEBNZIN input.
Thus when a single key in a column is pressed for longer than the debounce delay, the column and row data will be stable with only one each of the column and row signals LOW, and DEBNZIN HIGH.
HA72500 APPENDIX M
M-55
If more than one key in a column is pressed, DEBNZIN will remain low. If keys in more than one column are pressed, the column in which the first pressed key is detected will be the one which remains low (while the key remains pressed). Pressed keys in other columns will remain undetected while the detected key remains pressed. DEBNZIN will go HIGH indicating a valid key input provide only one key is pressed in the selected column.
Bus Interface While input CSN_RDN is HIGH, the seven output signals KEY0, KEY1, KEY2, KEY3, KEYON, 1KHZOUT and 10KHZOUT are in a high impedance state. When CSN_RDN is low these seven signals become active and drive the data bus.
1KHZOUT and 10KHZOUT are just the buffered input signals 1KHZIN and 10KHZIN.
KEYON, when HIGH, indicates that valid key data is present on KEY0, KEY1, KEY2 and KEY3 from the switch matrix.
KEY0, KEY1 provide a binary code (KEY0 is the least significant bit) for the column of the pressed key as follows:
COLUMN KEY1 KEY0 1 0 0 2 0 1 3 1 0 4 1 1
KEY2, KEY3 provide a binary code (KEY2 is the least significant bit) for the row of the pressed key as follows:
ROW KEY3 KEY2 1 0 0 2 0 1 3 1 0 4 1 1
HA72500 APPENDIX M
M-56
M.26 RCMS INTERFACE ADDRESS DECODER - PLD Type 27A72502 NAME: RCMS Interface Address Decoder TYPE No: 27A72502 WHERE USED: 1A72555, CTU RCMS I/F PWB Assembly; D1 FUNCTION: To decode the address lines on the Extended CTU Bus to the CTU
RCMS I/F PWB Assembly and produce the required chip select lines. INPUTS: CLOCK1 Pin 1 Synchronous clock input - unused CLOCK2 Pin 13 Synchronous clock input - unused XRD_N Pin 20 Read Signal from Extended CTU Bus. Active LOW XWR_N Pin 21 Write Signal from Extended CTU Bus. Active LOW DEN_N Pin 19 Data Enable Signal from Extended CTU Bus. Active LOW
during memory and I/O accesses XRES Pin 18 Reset Signal from Extended CTU Bus. Active HIGH A1 Pin 16 Address Signal from Extended CTU Bus. Active HIGH A2 Pin 15 Address Signal from Extended CTU Bus. Active HIGH A3 Pin 23 Address Signal from Extended CTU Bus. Active HIGH A4 Pin 14 Address Signal from Extended CTU Bus. Active HIGH A5 Pin 11 Address Signal from Extended CTU Bus. Active HIGH A6 Pin 2 Address Signal from Extended CTU Bus. Active HIGH PCS0_N Pin 10 Board Select Signal from Extended CTU Bus. Active LOW UNUSED: Pin 8 Pin 9 Pin 22 OUTPUTS: RCMS_DEN_N Pin 17 Data Bus Transceiver Enable M_STAT Pin 3 Miscellaneous Status Write Select RSTAT_2 Pin 4 RCMS Status Write Select BITOUT_3 Pin 5 Built In Bus Test Write Select BITFB_2 Pin 6 Built In Bus Test Read Select RCONT_1 Pin 7 RCMS Control Inputs Select
Data Bus Transceiver Enable RCMS_DEN_N enables the transceiver for the data bus. Active LOW when inputs PCS0_N and XDEN_N are active LOW, XRES is inactive LOW and A6 is active HIGH.
RCMS Control Inputs Select RCONT_1 enables read access of the RCMS control inputs. Is active LOW when inputs: PCS0 and XRD are active LOW, XRES is inactive LOW, and the address is 20H.
Miscellaneous Status Write Select M_STAT enables write access to an octal latch driving RCMS status outputs. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 22H.
RCMS Status Write Select RSTAT_2 enables write access to an octal latch driving RCMS status outputs. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 23H.
HA72500 APPENDIX M
M-57
Built In Bus Test Selects BITOUT_3 enables write access to an octal latch for test purposes. Is active HIGH when inputs: PCS0 and XWR are active LOW, XRES is inactive LOW, and the address is 25H.
BITFB_2 enables read access of the data written to the above test latch. Is active LOW when inputs: PCS0 and XRD are active LOW, XRES is inactive LOW, and the address is 27H.
HA72500 APPENDIX N
APPENDIX N
RF CRYSTAL SPECIFICATION
N-i
HA72500 APPENDIX N
TABLE of CONTENTS
N. RF CRYSTAL SPECIFICATION .............................................................N-1 N.1 CRYSTAL FREQUENCIES AND PERFORMANCE REQUIREMENTS N-1
N.1.1 RF Generator Crystals.................................................................................N-1 N.1.2 Receiver-Video Crystal................................................................................N-1 N.1.3 Procurement Specification...........................................................................N-1
N-ii
HA72500 APPENDIX N
N. RF CRYSTAL SPECIFICATION N.1 CRYSTAL FREQUENCIES AND PERFORMANCE REQUIREMENTS Six oscillator crystals are installed in each equipment. For each, the crystal frequency is one-twelfth of the RF frequency being generated.
N.1.1 RF Generator Crystals Five crystals are installed in the RF Generator board in the Test Interrogator module, as follows:
CRYSTAL INTERROGATE FREQUENCY
CRYSTAL FREQUENCY
G1 Fo Fx G2 Fo + 160 kHz Fx + 13.3 kHz G3 Fo - 160 kHz Fx - 13.3 kHz G4 Fo + 900 kHz Fx + 75 kHz G5 Fo - 900 kHz Fx - 75 kHz
Each crystal has a frequency equal to one-twelfth of the interrogate frequency.
Example: Channel 84X interrogation frequency = 1108 MHz = Fo hence crystal frequency = 1108/12 = 92.3333 MHz = Fx
N.1.2 Receiver-Video Crystal The sixth crystal is installed in the RF Source board in the Receiver-Video module and has a frequency equal to one-twelfth of the reply frequency.
Example: Channel 84X reply frequency = 1171 MHz hence crystal frequency = 1171/12 = 97.5833 MHz
N.1.3 Procurement Specification Replacement crystals should be ordered to the following specification:
• Frequency in kHz;
• Fifth overtone;
• Series resonant;
• Accuracy +5, -15 parts per million;
• Temperature range -20 degrees C to +70 degrees C ±10 parts per million;
• Holder type HC-50/U.
N-1
HA72500
LIST OF DRAWINGS
DRAWING TITLE DRAWING NUMBER
1A69737 Attenuator CIRCUIT 69737-3-24
1A69758 Power Supply System, Single AC INTERWIRING 69758-3-23
2A69758 Power Supply System, Dual AC INTERWIRING 69758-3-28
1A69873 250W RF Amplifier CIRCUIT 69873-3-09
1-3A72500 LDB-102 DME 1kW System BLOCK DIAGRAM 72500-2-26
1A72505 Rack Assembly, Single 1kW DME INTERWIRING (3 sheets) 72505-2-06
Transponder Wiring INTERWIRING 72505-2-37
2A72505 Rack Assembly, Dual 1kW DME INTERWIRING (3 sheets) 72505-2-17
1A72510 Monitor Module INTERWIRING 72510-3-06
1A72511 Main PWB Assembly, Monitor Module CIRCUIT (14 sheets) 72511-1-01
1A72512 Peak Power Monitor CIRCUIT 72512-3-01
1A72514 Test Interrogator INTERWIRING 72514-3-04
1A72515 Main PWB Assembly, Test Interrogator CIRCUIT (5 sheets) 72515-1-01
1A72516 RF Generator CIRCUIT 72516-2-01
1A72517 RF Filter CIRCUIT 72517-4-02
1A72518 Modulator and Detector CIRCUIT 72518-2-01
1A72519 Reply Detector CIRCUIT 72519-3-01
1A72520 Receiver Video INTERWIRING 72520-3-04
1A72521 Main PWB Assembly, Receiver Video CIRCUIT (5 sheets) 72521-1-01
1A72522 RF Source CIRCUIT 72522-3-01
1A72523 IF Amplifier CIRCUIT (2 sheets) 72523-1-01
1A72524 RF Amplifier CIRCUIT 72524-3-01
1A72526 Main PWB Assembly, Transponder Power Supply
CIRCUIT 72526-1-01
1A72530 Transmitter Driver INTERWIRING 72530-3-03
1A72531 Pulse Shaper PWB Assembly CIRCUIT (2 sheets) 72531-1-01
1A72532 Exciter CIRCUIT 72532-2-01
1A72533 Medium Power Driver CIRCUIT 72533-3-01
1A72534 Power Modulation Amplifier CIRCUIT 72534-3-01
1A72535 1kW RF Power Amplifier CIRCUIT 72535-1-07
1A72540 1kW PA Power Supply INTERWIRING 72540-1-03
1A72541 Control and Status PWB Assembly CIRCUIT (2 sheets) 72541-1-01
1A72542 DC-DC Converter PWB Assembly CIRCUIT 72542-1-01
1A72544 1kW PA Connector PWB Assembly CIRCUIT 72544-1-01
1A72545 RF Panel - Single DME CIRCUIT 72545-3-04
2A72545 RF Panel - Dual DME CIRCUIT 72545-3-05
1A72547 RF Panel PWB Assembly - Single DME
2A72547 RF Panel PWB Assembly - Dual DME CIRCUIT 72547-1-01
H4A71110 REVISION RECORD
1A72549 Power Distribution Panel - Single DME CIRCUIT 72549-3-06
2A72549 Power Distribution Panel - Dual DME CIRCUIT 72549-3-16
1A72550 Control and Test Unit INTERWIRING (2 sheets) 72550-1-03
1A72552 CTU Processor PWB Assembly CIRCUIT (5 sheets) 72552-1-02
1A72553 CTU Front Panel PWB Assembly CIRCUIT (2 sheets) 72553-1-02
1A72555 RCMS Interface PWB Assembly CIRCUIT (2 sheets) 72555-1-02
1A72556 Transponder Subrack Motherboard CIRCUIT 72556-2-01
1A72557 External I/O PWB Assembly CIRCUIT 72557-1-01
PelorusAustralAsia
PelorusAustralAsia
PelorusAustralAsia
