radio broadcast engineering in the philippines
DESCRIPTION
Primer on AM & FM Radio Broadcast Engineering in the Philippines based on KBP-NTC Technical Standards, prepared by Engr. Efren T. Pineda, PECE.TRANSCRIPT
Radio Broadcasting Standards in the
PhilippinesEngr. Efren T. Pineda, PECE
Basic knowledge on radio broadcasting Know the present standards in radio
broadcasting as implemented in the Philippines
Expected Outcomes
Broadcasting in General Broadcast Operations AM Radio Broadcasting and Standards FM Radio Broadcasting and Standards Engineering considerations in building a
radio broadcast stations
Topics
Broadcasting in general
The Basic Considerations
It is an art and science of conveying (intelligent) information through electrical means intended for the reception of the general public.
As per RA 9292, under Section 3c, an undertaking the object of which is to transmit audio, video, text, images or other signals or messages for reception of a broad audience in a geographical area via wired or wireless means.
What is Broadcasting?
Studio
• Live• Recorded
Link
• Wired• Wireless
Transmitter
• For Broadcast
The Broadcast Chain
Combo Type – Studio and Transmitter are co-located; link is commonly wired, that is, balanced audio cables, unbalanced coaxial lines for RF video, or fiber optic system.
Split Type – Studio and Transmitter are not co-located; link is commonly wireless via RF or radio waves. For a wired link, a telephone codec is needed; connection is made via PSTN (Public Switch Telephone Network).
Studio-Transmitter Configurations
STL (Studio-to-Transmitter Link) – used to link studio to transmitter if they are configured split type.◦ Usually in UHF range (for radio)
Band A: 300 – 315 MHz Band B: 734 – 752 MHz Band C: 942 – 952 MHz
◦ Maximum power allowable is 15W◦ Modulation is FM Wideband◦ Requires high gain antenna such as Yagi-Uda, Corner
Reflector and Parabolic types◦ Point-to-point communication, that is, from studio to
transmitter only
Auxiliary Broadcast Services
RPU (Remote Pick-up Unit) – used to link remote sites or studio to main studio for outside broadcast (OB) purposes.◦ Usually in UHF range (for radio)
Band A: 315 – 325 MHz Band B: 450 – 451 MHz Band C: 455 – 456 MHz
◦ Maximum power allowable is 35 Watts◦ Modulation is FM Wideband◦ Requires high gain antenna such as Yagi-Uda types◦ Point-to-point communication, that is, from remote
sites or studio to main studio only
Auxiliary Broadcast Services
Coordination, Communication and Control – used as per mentioned purpose.◦ Usually allocated as follows:
Band A: 4 – 12 MHz (non-exclusive for broadcast) Band B: 25.67 – 26.1 MHz Band C: 162.235 – 162.615 MHz, 166.25 and 170.15 MHz Band D: 432.5 – 433 MHz, 437.5 – 438 MHz
◦ Maximum allowable power are as follows: Band A: 100 Watts (AM-SSB) Band B: 160 Watts (FMNB, ERP) Band C: 160 Watts (FMNB, ERP) Band D: 200 Watts (FMNB, for repeater)
Auxiliary Broadcast Services
Studio System(Typical Set-up)
PSTN
ON-AIRSUB-CONSOLE
STUDIOMAIN
BROADCASTCONSOLE
AUDIOPROCESSOR
MICROPHONES
PLAY-BACKPC #1
PLAY-BACKPC #2
FEED TOTRANSMITTER
CD PLAYER 1/2
CD PLAYER 3/4
ON-AIR FEED
OFF-AIR RADIO MONITOR
LOCAL AREA NETWORK
AUDIO CODEC
RPU RCVR
TELEPHONE(FOR CALLERS)
CUE OUT
EXTERNAL INPUT
MIX MINUSOUTPUTS
CALLER’SAUDIO
STUDIOMONITOR
CUE OUT
HARD DISCPLAYER
HARD DISCPLAYER
AUDIODISTRIBUTION
AMPLIFIER
PROGRAM OUT
AUDITION OUT TAPE ON-AIRSPARE OUTSPARE OUTSPARE OUT
Microphones – for the program’s hosts and guests (for live programs)
Play back Sources – for music, and other recorded materials◦ CD players for musical materials◦ Hard disc based and/or PC based play back devices
for station IDs, Program Intro / Extro music, Music Beds, Commercials, Plugs, Voice Tracks, Jingles
Broadcast Console – for control (level and switching), mixing, amplification (at appropriate modulation level), and routing of input signals
Common Equipment
Headphones for solo monitoring Loudspeakers for studio (on-air) and control room
monitoring Power Amplifiers for driving loudspeakers Audio Codec for telephone interface, used to
patch station callers on-air Remote Pick-up Unit for live remote programming Audio Processor for making the sound of the
station good in quality. We can set here the dynamic range, and equalization of sound. For FM Stereo, stereo encoding is included.
Common Equipment
Distribution Amplifiers used for signal distribution without attenuation and possible mismatch in loading.
Tape Recorders such as PC or hard disc based devices. It can be of DAT (Digital Audio Tape) format or PCMCIA hard disc.
Off-air Tuner for OTA (off-the-air) signal monitoring, this will allow you to monitor if you’re still on the air (via broadcast transmitter)
Common Equipment
AM Transmitter(High-level Modulation)
STABILIZEDRF
OSCILLATOR
RF BUFFER AMPLIFIER(CLASS A)
RF POWER AMPLIFIER(CLASS C)
RF OUTPUT AMPLIFIER(CLASS C)
OUTPUT MATCHING NETWORK
AFPRE-
AMPLIFIER
AF POWERAMPLIFIER(CLASS B)
AF OUTPUT AMPLIFIER
MODULATOR(CLASS B)
AUDIOINPUT
ANTENNA
Note:For low level modulation, replaced RF OUTPUT AMPLIFIER with Class B or Class AB.
FM Transmitter(Armstrong System)
XTAL OSCILLATOR
BUFFER AMPLIFIER
90° PHASE SHIFT
NETWORKBALANCED
MODULATOR
AUDIO AMPLIFIER
AUDIO EQUALIZER
RFAMPLIFIER
FREQUENCYMULTIPLIER
FREQUENCYMULTIPLIER
MIXER
XTAL OSCILLATOR
RFAMPLIFIER
RF POWERAMPLIFIER
AUDIOINPUT
ANTENNA
Note:FREQUENCY MULTIPLIER CIRCUITS are cascaded DOUBLERS and TRIPLERS.
Broadcast Operations
Daytime – refers to that period of time between 2200 Universal Time Coordinates (UTC) to 1000 UTC. Equivalent to 6 AM to 6 PM local standard time.
Nighttime – refers to that period of time between 1000 UTC to 2200 UTC. Equivalent to 6 PM to 6 AM local standard time.
Experimental Period – the period of time between 12 MN to 5 AM local standard time for the purpose of testing and maintenance of the licensee.
Parts of Broadcasting in a Day
Parts of Program Implementation Pre-production – this is the planning stage;
ocular site inspection is part of this if the program is to be held at remote locations.
Production – the implementation stage; live program is broadcasted (from studio or remote location up to broadcast transmitter for broadcast transmission), while recording or taping for TV drama / documentary programs.
Post-production – this is where editing is done, particularly for station produced programs such as TV dramas, or documentary programs.
Chief Engineer / Company ECE◦ Head of the Broadcast Engineering & Operations◦ Usually a Registered PECE
Studio Supervisor◦ In-charge of studio operations and maintenance◦ Usually a Registered ECE
Studio Technicians◦ Operates the broadcast console for live programs◦ Log broadcast daily operations◦ Facilitate recording of taped programs◦ Conduct studio maintenance◦ Usually holder of Radio Operator’s License or its
equivalent
Technical Positions, their functions and qualifications
Transmitter Supervisor◦ In-charge of transmitter operations and
maintenance◦ Usually a Registered ECE
Transmitter Technicians◦ Operates and maintains the transmitter of the
station◦ Log transmitter voltages and current hourly◦ Usually a holder of Radio Operator’s License or its
equivalent
Technical Positions, their functions and qualifications
Program Log◦ Time entry each program (live/taped) including
station ID, station promos, commercial spots◦ Brief description of the program such as “music”,
“drama”, “live”, etc.◦ Sponsored programs◦ Origin of the program◦ Actual time to be filled-up by Announcer or
Technicians on-board noting the beginning and end times of a particular aired material
◦ Additional remarks for a particular material or program
Broadcast Logs
Transmitter Log◦ Time entry the transmitter is turned ON as well as
the time it is turned OFF◦ At least at 30 minutes interval, log of operating
voltages, currents and power of the transmitter as well as the antenna current (usually for AM transmitters), signed by Tech on-duty
◦ Entry of each interruption of the broadcasting, its cause and duration
◦ Log shall be kept in orderly manner, and in suitable form, avoiding erasures in any entry
◦ Logs shall be maintained by the licensee for a period of 2 years
Broadcast Logs
AM Radio Broadcasting
Philippine Standard based on KBP(1991 Revised Edition)
Frequency Allocations:◦ 526.5 – 1705 kHz
Channel Bandwidth:◦ 9 kHz
Number of AM Channels Available:◦ 131 channels
Permitted Bandwidth:◦ 30 kHz
Minimum Carrier Separation for Adjacent Stations serving the same service area:◦ 36 kHz
Broadcast Standards
Baseband Frequency Range:◦ 50 – 15000 Hz
Mode of Emission:◦ A3E
Type of Receiver:◦ Super-heterodyne Receiver
Intermediate Frequency:◦ 455 kHz
Broadcast Standards
Location and lay-out considerations◦ Adequate space, ventilation and air-conditioning, and
lighting Transmitter design
◦ Carrier Power Limits: 10% full power◦ Maximum Modulation for Satisfactory Operation: 90%◦ Operating Frequency Limits: ± 10 Hz of assigned
carrier frequency◦ Carrier shift: 5% at any modulation level◦ Carrier Hum and Extraneous Noise Level: 45 dB below
400 Hz tone◦ Total Audio frequency Distortion: <5% harmonics @
0%-84% modulation, <7.5% harmonics @ 85%-95% modulation
Transmitter Standards
Alternate Main Transmitter Considerations◦ Must be co-located with the main transmitter◦ Must be of same parameters as the main
transmitter Auxiliary Transmitter Considerations
◦ Can be co-located or installed at another location◦ Output power maybe less but not greater than the
authorized power of the main transmitter
Transmitter Standards
Site considerations◦ Location in relation to the population to be served
and other communication installations and airports,◦ Conductivity of the soil at and immediately
adjacent to site,◦ Conductivity of the path between the site and the
target area. Design considerations
◦ Vertically polarized◦ Shall radiate an effective field of not less than that
of 60° vertical tower◦ All parts shall be installed so as not to present a
hazard.
Antenna Requirements
NOTE: Transmitters of Metro Manila maybe located outside Metro Manila provided the said area remains within 80 dBu contour of the transmitter.
The station shall not operate more than 5% and not lower than 10% of its authorized operating power.
Maximum Power Allocations
Area Maximum Power (kW)
Metro Manila (see Note) 50
All other areas 10
FM Radio Broadcasting
Philippine Standard based on KBP(1991 Revised Edition)
Frequency Allocations:◦ 88 – 108 MHz (20 MHz total BW)
Channel Bandwidth:◦ 200 kHz (for mono)
Number of AM Channels Available:◦ 100 channels
Permitted Bandwidth:◦ 180 kHz (for mono), 300 kHz (for stereo)
Minimum Carrier Separation for Adjacent Stations serving the same service area:◦ 800 kHz
Broadcast Standards
Baseband Frequency Range:◦ 50 – 15000 Hz
Mode of Emission:◦ F3E
Frequency Deviation:◦ ± 75 kHz @ 100 % modulation
Pre-emphasis:◦ 75 μsec time constant
Pilot tone:◦ 19 kHz
Broadcast Standards
Type of Receiver:◦ Super-heterodyne Receiver
Intermediate Frequency:◦ 10.7 MHz
Broadcast Standards
Location and lay-out considerations◦ Should be chosen that line-of-sight can be
obtained from the antenna over the principal city or cities to be served
◦ Adequate space, ventilation and air-conditioning, and lighting
Transmitter design◦ Frequency Swing: ± 75 kHz @ 100 % modulation◦ Pre-emphasis: 75 μsec time constant within 50 –
15000 Hz of audio frequency◦ Audio frequency harmonics: < 3.5 % (within 50 –
100 Hz), < 2.5 % (within 100 – 7500 Hz), < 3 % (within 7.5 – 15 kHz)
Transmitter Standards
Other considerations◦ Construction considering its enclosure, grounding
of controls, and interlocks on doors◦ Wiring and shielding◦ Metering equipment◦ Indicating instruments◦ Installation◦ Other data
Transmitter Standards
Must be Horizontally Polarized, however, circular or elliptical polarization may also be employed,
Must be installed or constructed such that it is clear from obstructions that would cause shadow problems,
For a common tower shared by 2 or more licensees, the owner of the tower shall assume full responsibility for the maintenance of the tower structure.
Antenna System
Main Channel: L+R (50 – 15000 Hz) Pilot tone: 19kHz ± 2Hz @ 8%-10% of the
main FM carrier Stereophonic Channel: L-R (23 – 53 kHz)
modulated using DSBSC-AM Stereophonic Sub-carrier: 38kHz (2nd
harmonic of the pilot tone) Subsidiary Communication Authorization
(SCA) channel: 59.5 – 74.5 kHz Multiplexing: FDM
FM Stereo Broadcasting Standards
Class A◦ Authorized power <= 25 kW◦ ERP <= 125 kW◦ Antenna height <= 2000 ft above average terrain◦ Minimum transmitter power of 10 kW◦ Allowed in Metro Manila & Metro Cebu
Class B◦ Authorized power <= 10 kW◦ ERP <= 30 kW◦ Antenna height <= 500 ft above average terrain◦ Minimum transmitter power of 1 kW◦ Implemented in other areas not covered by Class A
Classification of Powers
Class C◦ Authorized ERP <= 1 kW◦ For non-commercial, community station
Class D◦ Authorized transmitter power <= 10 W◦ For educational stations
NOTE: All classes of FM stations shall be protected to the 1 mV/m or 60 dBu contour.
Classification of Powers
Engineering Considerations
Be sure you have the franchise approved by the Senate and Congress of the Philippines. To have these, you must prepare a feasibility study to be submitted in Congress and then Senate.
Obtain Provision of Authority (PA) to the authority, in this case National Telecommunications Commission (NTC). To have this, a public hearing is conducted for new stations. All affected parties will be informed and given a chance to oppose on your application. In public hearing, you need to present the legal, technical and financial capacities of your company.
Pre-requisites
The technical part is prepared by ECEs; as per RA 9292, only PECEs are allowed to sign and seal an engineering plan. So in case of technical witness, only PECE is allowed to testify on technical matters.
After the hearing, the NTC will further check the submitted evidences. A PA will be grant as temporary permit for the applicant’s construction and operation of a radio station.
Apply additional permits such as Permit to Purchase, Radio Construction Permit, and Permit to Possess.
Pre-requisites
Acoustics and Noise Control for Studio Evaluation of appropriate equipment for
Studio and Transmitter, depends on programs’ requirements (based on your system’s design)
Evaluation of equipment suppliers; consider after-sales support
Training Installation and Commissioning Operation and Maintenance
Other consideration
Thank you for listening…
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