1952chassis te300, te315, models 5204, 5206, 5210, 5211, 5212 22 to 26 (similar chassis te286,...
TRANSCRIPT
Most - Often - Needed
1952
Television
Servicing Information
Compiled by
M. N. BEITMAN
SUPREME PUBLICATIONSCHICAGO
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
FOREWORD
In this new "1952 Television Servicing Information"manual are included circuit diagrams and essential servicefacts on every popular set of this period of all makes.The flattering reception given to the previous volumesof SUPREME TV series, encouraged us to believe that ourselection and editing of factory material for thesemanuals fits your liking and requirements.
The list of Contents is given on pages 3 and 4,while a complete Index by manufacturers and model (orchassis) numbers begins on page 191. Refer to thislist and index to find the TV material you need.
Our sincere thanks and appreciation is extendedto all manufacturers whose television sets are de-scribed in this manual.
March 1, 1952Chicago.
2
M. N. Beitman
THEORY
PRA( Ill F t 2 EXPERII.nct.
THIS IS A MARK OFSUPREME PUBLICATIONS
Copyright, 1952, bySUPREME PUBLICATIONS,
Chicago, Illinois
All rights reserved,including the rightsto reproduce or quotethe contents of thisbook, or any portionthereof, in any form.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
CONTENTS
Admiral CorporationModels using 21B1, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1,21K1, 21L1, 21M1, 21N1, 21P1, 21Q1, 21T1, 21V1, 21W1, 21Y1 5 to 19
Air King Products (CBS -Columbia, Inc.)Model 700-100, 700-120, 700-140 20 to 21
Arvin Industries, Inc.Chassis TE300, TE315, Models 5204, 5206, 5210, 5211, 5212 22 to 26
(Similar Chassis TE286, TE302, Models 4162, 5170-5173)
Bendix Radio and TelevisionModels T171, C172, C182, and C200 27Models T170, T173, C174, C176, C176B, T190, 2051, 2060, 2070,
3051, 6001, 6003, 6100, and 7001 28
Crosley Corp.Chassis 321-4, 323, 331, 356, 357, 359, and 363 29 to 34
(For list of models using these chassis see page 29)
DeWald Radio Manufacturing Corp.Models ET -140R, ET -141R, DTg162R, DT -163R, ET -170,
ET -171, ET -172, and DT -190D 35 to 38
Allen B. DuMont LaboratoriesRA -111A, RA -112A, and RA -113 39 to 42
Emerson Radio and Phonograph Corp.Models 686L, 687L, 696L, Chassis 120142-B 43 to 46Models 699B, 7003,-D, 701B, -D, Chassis 120148B, 120153B,
and 120158B 47 to 50
Fada Radio & Electric Co. 51 to 56S6C55, S6T65, S7C20, S7C30, S7T65, S20C10, S20T20, S1055, 51060
Gamble-Skogmo, Inc.Coronado TV Models 15TV1-43-8957A, -9015A, -9016A
(Similar Models 15TV1-43-8958A, -90204, -9021A)
General Electric Co.Models 17T1, 17T2, 17T3, 17C103, 17C104, 17C105, 17C107,
17C108, 17C109 (for other similar models see page 61)Models 20C150, 20C151, and 24C101
57 to 60
61 to 6667 to 68
The Hallicrafters Co.Models 17804C, 17812, 17813, 17815-H, 17819, 17824, 17825,
17838, 17848, 17849, 17850 (See page 69 for similar sets) 69to72Models 17810, 17905, and 20872 73 to 76
Hoffman Radio Corp.Chassis 180, 183, 184, 185, 186, and 187 77 to 82
(For list of models using these chassis, see page 77)
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
The Magnavox Co.Series 104 (For models see page 83) 83 to 84
Majestic Radio & Television, Inc. (Formerly Garod)Series 106 and 108 (For list of models see page 86) . . . . 85 to 88
John Meek Industries, Inc.Chassis 9021 to 9024, and 9026 (Models listed on page 89) . 89 to 92
Montgomery Ward & Co.Models 15WG-3046C, 15WG-3049A, 15WG-3050, 15WG-3051C . . . 93 to 96
Motorola, Inc.Chassis TS -196, TS -214, TS -228, TS -236, and TS -307 . . . 97 to 104
(For list of models using these chassis, see page 97)Chassis TS -216, TS -314, TS -315 (List of models on page 105) 105-106
Olympic Radio & TelevisionModels 752U, 753U, 755U, 764U, 766U, and 769 107 to 110
Philco Corporation52-T1610, 52-T1612, 52-T1802, 52-T1804, 52-T1808,52-T1812, 52-T1831, 52-T1839, 52-T1840, 52-T1841,52-T1844, 52-T1882, 52-T2106, 52-T2108, 52-T2110,52-T2142, 52-T2144, 52-T2145, 52-T2182, 52-T2245,
52-T1810,52-T1842,52-T2140,52-T2282 111-120
R.C.A. VictorModels 7T103, -B, 7T104, -B, 7T112, -B, 7T122, -B, 7T123, -B,
7T124, 7T125B, 7T132 (Chassis KCS47B, C, D, F, G) . .
Models 4T101, 4T141 (Chassis 61 and KCS-62)Models 17T153, 17T155, 17T160, 17T174 (Chassis KCS-66)Model 16T152 (Chassis KCS-47E)Models 21T176, 21T177, 21T178, 21T179
Raytheon Manufacturing Co. (Belmont Radio)Chassis 20AY21, Models C -2001A, -02A, -05A, -06A, -07A,
Sentinel Radio Corp.Models 438 to 444, and IU-438 to IU-444
Sparks-Withington Co. (Sparton)Models 5107X, 5152X, 5163X, Chassis 26SS171
(For list of similar models, see page 153)
Stewart -Warner ElectricModels 9200, 9202, 9203, and 9204 series
Stromberg-Carlson Co.321 series (317 series is similar)
Sylvania Electric ProductsChassis 1-502-1 (For similar sets and models see page
Western Auto Supply Co. (Truetone)Models 2D1185B, 2D1190, 2D1194, and 2D2052
Westinghouse Electric Corp.Chassis V-2200-1, V-2204-1 (For list of models see
(List of similar sets is given on page 182)
44iZenit1 Radio Corp.Chassis 20J21, 20J22, 21J20, 21J21 (List of models
121 to 124125 to 130131 to 137
138139 to 142
-08A 143-146
147 to 152
153 to 158
p. 181)
p. 185) 185-190
159 to 166
167 to 170
171) 171-177
178 to 180
181-184
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
AdmiralAdmiral SERVICE NOTES for models using 21T1, 21V1, 21W1, 21Y1
21B1, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 2111, 21K1, 2111,
21M1, 21N1, 21P1, 21Q1 and 5D2, 3C1 CHASSIS
THESE IMPORTANT NOTES MUST BE READ AND CLEARLY UNDERSTOOD IN ORDER TOCORRECTLY APPLY MATERIAL IN THIS ADMIRAL SECTION TO VARIOUS CHASSIS.
The basic circuit of Chassis 21F1, 21G1, 21M1, 21N1, 21P1, 21Q1, 21T1,and 21V1 of recent production is shown on pages 10 and 11. This is ba-sically the same circuit as used in all 21 -series chassis, but the maindifferences of types and various production runs are explained under thePRODUCTION CHANGES section, pages 12 to 15, 18, and 19. The early setsof this series used conventional AGC (V304 was a 6AL5), and are similarto the sets described in the "1951 Television Servicing" manual on pages15 to 18. The circuit of recent production sets (in this book on pages10 and 11) shows the TV chassis with 3C1 AM radio, and this circuit usesgated AGC (V304 is now a 6AU6). The straight TV sets of this type omitthe radio and the associated connector plug. For sets that use 5D2 AM -FMradio, refer to the 1951 volume for needed radio data.
Chassis 21W1 and 21Y1 use a similar circuit to those of other sets inthe 21 -series and is shown on pages 16 and 17. The main difference isin the use of a built-in AM radio tuner.
The alignment material presented on pages 6 to 9 inclusive, is appli-cable in the main to all these sets.
Since a great many Admiral television models used more than one typeor run of chassis, it is suggested that in each case you locate theactual chassis number and run number to serve as your guide to the rightservice material. Such chassis information is stamped on the back ofeach chassis. Because of this fact, model numbers will not be listedhere or covered in the index. In general, model numbers have a specialreference only to the cabinets employed.
TOUCH-UP OF RATIO DETECTOR SECONDARYUSING TELEVISION SIGNAL (A7, BOTTOM
SLUG OF T201)This adjustment is accessible through the 1/4" hole
(just below T201) in bottom of the cabinet or the chassismounting shelf, located toward the left side facing therear of the set. Removal of the chassis is therefore notrequired. Adjustment need be made on one channelonly. Proceed as -follows:a. Turn set on and allow about 15 minutes for warm up.b. Tune set for normal picture and sound. Slightly ad-
vance the picture and volume controls until the buzzis audible.
c. Carefully insert a non-metallic alignment tool throughthe opening in cabinet bottom below T201. An align-ment tool with a screwdriver blade or hexagonal endis required depending on the transformer used, see
* note below. When the alignment tool engages thebottom tuning slug A7, adjust the slug for best soundwith minimum buzz level. Do this carefully as onlyslight rotation in either direction will generally berequired. Correct adjustment point is located be-tween the two maximum buzz peaks that will benoticed when turning the slug back and forth about1/4 to 1/2 turn.
d. If necessary, repeat individual channel slug adjust.ment and conclude with retouching the ratio detectorsecondary. Note: If oscillator adjustment is requiredfor other channels, it will not be necessary to repeatthe ratio detector secondary adjustment after oncecorrectly adjusting it.
If ratio detector transformer (T201) has hollow hexagonal coreslugs, bottom slug adjustment A7 can be made from top ofchassis, if you use alignment tool #98A30-7 (available atAdmiral Distributor). Bottom slug (A7) can be reachedthrough the hole in the core of the upper slug (A5).
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Admiral 2161, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1, 21K1, 21L1, 21P1, 21Q1,
TELEVISION ALIGNMENT PROCEDURE
B
GENERALComplete alignment consists of the following individual
procedures and should be performed in this sequence.a. IF Amplifier Alignment.b. IF Response Curve Check.c. 4.5 MC Sound IF Alignment.d. RF and Mixer Alignment.e. Overall RF and IF Response Curve Check.f. HF Oscillator Adjustment.
TEST EQUIPMENTTo properly service this receiver, it is recommended
that the following test equipment be available.IMPORTANT: Many service instruments do not
meet the requirements given below. A list of recom-mended equipment is available from Admiral distributors.Oscilloscope
Standard oscilloscope, preferably one with a wide bandvertical deflection, vertical sensitivity at least .5 volt(RMS) per inch.
Signal Generator4.5 MC frequency.18 to 30 MC frequency range.50 to 90 MC frequency range.
170 to 225 MC frequency range.Must have a built-in calibration crystal for checkingdial accuracy.
Sweep GeneratorSweep generator must provide sweep frequencies from
18 to 30 MC range:50 to 90 MC range:
170 to 225 MC range:Output: adjustable; at least one -tenth volt maximum.Output impedance: 300 ohms balanced to ground.A sweep generator not having constant output voltage
over the swept range and linear sweep, will producecurves which are widely different from the ideal curvesshown in the following pages. If repeated difficulty isencountered in obtaining these curves, the sweep gen-erator should be checked. A simple check is to observethe response curve for a set that is in alignment.
Before suspecting the generator, be sure the alignmentinstructions in this manual have been followed carefully.Vacuum -Tube Voltmeter
Preferably with low range (3 volt) DC zero centerscale and a high voltage probe (30,000 volt range).
ALIGNMENT TOOLSAn alignment tool kit consisting of one metallic and
one non-metallic screwdriver is available under part num-ber 98A30-3. A non-metallic alignment tool with a screw-driver point at one end and hexagonal wrench (for hol-low hexagonal core slugs) at the other is available underpart number 98A30-7.
with at least10 MC sweep width.
IF AMPLIFIER ALIGNMENTTo service TV chassis with radio disconnected, complete the b. Connect negative terminal of a 3 volt bias battery to test
heater circuit by connecting a jumper from pin "L" to pin "K" point "T", positive to chassis.
of socket M503. See schematic. c. Set receiver to channel 12 or an unassigned high channelto prevent signal interference during IF alignment. Set
a. Before starting alignment, be sure IF cover shield is Picture control fully to right (clockwise).mounted to the chassis. If the set does not have a cover d. Allow about 15 minutes for receiver and test equipment toshield, do not use one. warm up.
StepSignal
Gen. Freq.VTVM and Signal
Generator Connections Instructions Adjust
1 25.3 MCVTVM high side to test point "V",common to chassis.Generator high side to 6J6 (V102)tube shield; insulate shield fromchassis. Connect low side to chassisnear 6J6 tube base.
Use lowest DC scale on VTVM.When peaking, keep reducing gen-erator output for VTVM reading ofapprox. 1 volt or less.
mAluman.d A2 for maxi -
2 23.1 MC A3 and A4 for maxi -mum.
3 Make the "IF Response Curve Check" given below.
IF RESPONSE CURVE CHECKReceiver Controlsand Bias Battery
SweepGenerator
MarkerGenerator Oscilloscope Instructions
Set Channel Selec- Connect high side If an external Connect to test Check curve obtained againsttor on channel 12 to 6J6 mixer-osc. marker generator point "V" through ideal response curve in fig. 9A.or an unassigned tube shield. Insu- is used, loosely con- a de -coupling filter. Note tolerances on curve.high channel. Pic- late tube shield ple high side to See figure 7. Mark- Keep marker and sweep out-ture control fully to from chassis, low sweep generator er pips on scope puts at very minimum to pre -the right. Connectnegative of 3 volt
side to chassisground. Set sweep
lead on tube shield,low side to chassis.
will be more dis-tinct if a condenser
vent overloading. A reductionin sweep output should re -
bias battery to testpoint "T"; positive
frequency to 23MC,and sweep width ap-
Marker frequenciesindicated on IF Re-
from 100 mmfd to1000 mmfd is con-
duce response curve ampli-tude without altering the
to chassis. proximately 7MC. sponse curve. netted across theoscilloscope input.
shape of the response curve.If the curve is not withintolerance or the markers arenot in the proper location onthe curve, touch-up with IFsings as indicated in fig. 9B.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
2161, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1, 21K1, 21L1, 21P1, 21Q1, Admiral
4.5 MC SOUND IF ALIGNMENTSee page 4" for touch-up of ratio detector using television signal without test equipment.
a. Connect signal generator high side to point "V" through d. Use a NON-METALLIC alignment tool. If Ratio Det.a .01 mfd. condenser, connect low side to chassis. Transformer (T201) has hollow core slugs, bottom slug ad -
b. Allow about 15 minutes for receiver and test equipment to justment A7 can be made from top of chassis, if you usewarm up. alignment tool #98A30-7 obtainable from Admiral Dis-
c. Set Picture control fully to the right (clockwise). tributor.
Step Signa Gen.Freq.l (MC) VTVM Connections Instructions Adjust
When using a signal generator, be sure to check It against a crystal calibrator or other frequency standardfor accurate frequency calibration at 4.5 MC. Accuracy required is within one kilocycle.IMPORTANT: If a signal generator and frequency standard are not available, alignment can be made usinga TV station signal. Tune in a station and follow steps 1 and 2 below. If necessary use a higher scale on theVTVM.
I
Set toexactly4.5 MC
High side totest point "Y";
common to chassis.Use lowest DC scale on VTVM.
A5' and A6 for maximum (keepreducing generator output tokeep VTVM at approx. 1 volt).
2 High side totest point "Z";
common to chassis.
Use zero center scale on VTVM,if available.
A7 for zero on VTVM (the cor-rect zero point is located between
.a positive and a negative maxi -mum). If A7 was far off, repeatstep 1.
ALIGNMENT HINTAfter becoming familiar with alignment procedure, some servicemen simplify subsequentalignment of sets by merely using the essential alignment data given in figures 7 and 8.
A7-.©
A6-4TEST POINT L301
T V3050,000WHITE WIRE LEAD
6AC7 VOR OHMS65116
330 MMFD-- TOGROUND TO CHASSIS SCOPE
CHASSIS GROUND
DECOUPLING FILTER SHOWN IN DOTTED LINES
L302
Figure 7. Bottom View ShowingTest Point Connections.
21.25MCMARKER
OUT NOT
BE VISIBLE)
AT LEAST 9S'/.
4 SIEC
.4-22 MC MARKER
&APPROX.AS%-1 - -
mfAlutco FROM
Figure 9A. Ideal IF Response Curve.
25.75MCMARKER
50.4
- 30 %MAXIMUMDIFFERENCE IN HEIGHT OF PEAKSSHOULD NOT EXCEED 30').
HIGHEST PEAK
V
AI2INDIVIDUAL ADJ.
(AllovERAAL OSCILLATOR ADJ.
L1030
C104 GAGS6C66
6J6 6BC5C110 ,..,...,-., ,-,,,, C102
@I \;_.--, .5",,,,V102
-.I-WMIXER RF AMP RF AMP
510 A9 A8
V
A423.IMC MAX.
MIXER PLATE
A225.3mC MAX
1ST IF
v301 0 tie Ir
1301 V302
Z Y
A3 Al23.1 MC MAX. e5.3s4c MAX.
2ND IF 3RD IF
C1303 V304 VIDEO NET A 14C (MS)s 04 WM Al (AM
V303IF
64LSCO 4O)
RATIO NT V202
L201
6AU6[0 1 /--Nf- . \....1
Hp if
(UNDERSIDE) jSOUND PRIMARY SECONDARY
TAKE -OFF RATIO5DE T. RATIO
7CET.A6 A A( 4.5MC MAX 4.5MC MAX. 4.5k10
7201
Figure 8. Top View of Chassis Showing Alignment Data.
25.75 MCMARKER
TOUCH-UP OF Al AND A2 DILL CENTRALLY INCREASE PEAR.alt ALSO CHANCE POSITION OF 221IC MAUER.
3
3
25.75MGMARKER
TOUCH-UP OF At AID Al AU CENERALLE INCREASE PEAR.SILL ALSO CRINGE POSITION OF 251514C MARKER.
Figure 9B. IF Response Curves, Incorrect Shape.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
8
Admiral 2161, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1, 21K1, 21L1, 21P1, 21Q1,
RF AND MIXER ALIGNMENTa. Connect negative of 3 volt bias battery to test point "T", erator output at a minimum, marker pipe just barely visible.
positive to chassis. If it is difficult to to obtain a curve ofsufficient amplitude, remove battery and connect a wire c. Connect oscilloscope through a 10,000 011111 resistor to test
point "W" on tuner (Fig. 11). Keep scope leads awayjumper from test point "T" to chassis. from chassis.
b. Connect sweep generator to antenna terminals. If sweep d. Set channel selector to Channel 12.generator does not have a built-in marker generator, looselycouple a marker generator to the antenna terminals. To e. Allow about 15 minutes for receiver to warm up and testavoid distortion of he response curve, keep sweep gen- equipment.
Step Marker Gen.Freq. (MC)
Sweep Gen.Frequency Instructions
.
I
205.25(Video Carrier)
209.75(Sound Carrier)
SweepingChannel 12.
See frequencytable below,
Check for curve shown below. If necessary, adjust A8, A9 and A10 (figure 11)as required. Adjusting A9 will generally shift the center of the response curvein relation to the video and sound carrier markers. A8 and A10 should bealternately adjusted for best gain with flat top appearance. Consistent withproper band width and correct marker location, response curve should havemaximum amplitude and flat top appearance.
2
Set the sweep generator tosweep the channel to be checked. Set the marker generatorfor the corresponding videocarrier frequency and soundcarrier frequency.
Check each channel operating in the service area for curve shown below.In general, the adjustment performed in step 1 is sufficient to give satisfactoryresponse curves on all channels. However, if reasonable alignment is not ob-tanned on a particular channel, (a) check to see that coils have not been inter -mixed, or (b) try replacing the pair of coils for that particular channel, or(c) repeat step 1 for the weak channel as a compromise adjustment to favorthis particular channel. If a compromise adjustment is made, other channelsoperating in the service area should be checked to make certain that theyhave not been appreciably affected.
DIP SHOULD NOT
EXCEED 30% OF101Ai. HEIGHT 4.5 MC
MARKER, VIDEO CARRIER MARKER, SOUND CARRIER
Full skirt of curve will generally not be visible.Figure 10. RF Response Curve.
V
Al2 INDIVIDUAL CADJ.ADJ.
Al I OVERALL OSCILLATOR ADJ.
LI030/C104 SAGS
60866J6 6BC5
C110 C102
V102 V101
W
RF AMP RF AMP
Lllt12_t_;9r±8j
Figure 11. Top of TV Tuner, ShowingAdjustment Location.
FREQUENCY TABLE
ChannelNumber
ChannelFreq.,MC
VideoCarrier,
MC
SoundCarrier,
MCHF Ose.,
MC2 54- 60 55.25 59.75 813 60. 66 61.25 65.75 874 66. 72 67.25 71.75 935 76. 82 77.25 81.75 1036 82. 88 83.25 87.75 1097 174.180 175.25 179.75 2018 180.186 181.25 185.75 2079 186.192 187.25 191.75 213
10 192-198 193.25 197.75 21911 198-204 199.25 203.75 22512 204-210 205.25 209.75 23113 210.216 211.25 215.75 237
OVERALL OSCA4 ADJUSTMENT
All
TUNING ROTOR
SHORNAT HALF ROTATION
Figure 12.
Ii
3
4 FLAT OF SELECTOR SHAFT CENTERED'-iETIIEEN CHANNEL COILS 3 AND 4.
Front View of TV Tuner.
616 TUBE SHIELD
A10
Al2INDIVIDUAL CHANNEL
RH ADJUSTMENT
(TURRET POSITIONED TOADJUST CHANNEL TT
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
21B1, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 2111, 21K1, 21L1, 21P1, 21Q1, Admiral
9
OVERALL RF AND IF RESPONSE CURVE CHECK(Using sweep generator and oscilloscope)
Receiver Controlsand Bias Battery
SweepGenerator
MarkerGenerator Oscilloscope Instructions
Picture Control ful-Iv to the right.Channel selector onChannel 12 or otherunassigned highchannel. Connectnegative of 3 voltbias battery to testpoint "T", positiveto chassis.
Connect to antennaterminals. Set gemera tor to sweepchannel selected.Keep generator out-put as low as pos-sible, to preventoverloading. Se efrequency table onopposite page.
if an external mark-er generator is used,loosely couple highside to sweep gen.era:or lead. Markerfrequencies areshown in frequencytable on oppositep.,ge.
Connect to pointbV" through a de-coupling network asshown in fig. 7.
Compare the response curseobtained against the idyllcurse shown in figure 13A. Ifthe curse is not within toler-once, touch up the IF slugsas instructed below. It shouldnever be necessary to turnslugs more than one turn ineither direction. If the curveis satisfactory on the channelchecked, all other channelsshould also be satisfactor.IMPORTANT: When sweepoutput is reduced, responsecurve amplitude on scopeshould also decrease, hutcurse shape should remainthe same. If curve shapechanges, reduce Sweep outputand/or the scope gain untilthe shape does not change.
ROT IN EARLY SETS
(WITHOUT TRAP 130T)VIDEO CARRIER
MARKER
- - -..it-"
50% AT LEAST
___I --_-_7_ 4
L30% MAXIMUM
DIFFERENCE IN HEIGHT OF PEAKSSHOULD NOT EXCEED 30'4
NEASURED FROM HIGHEST PEAK
Figure 13A. Ideal Overall BF and IF ResponseNote that video carrier (marker) on the "Overall
Response Curve" will appear on the oppositecurve as compared to the "IF Response Curve"This is due to action of the mixer tube.
SOUND
MARKER
OATVISIBLE)
95%
Curve.
sidefigure
Response
CARRIER
NOT BE
POINT
RF-IFof the
9A.
VIDEO CARRIERNARTER T,onO
...----'
MORE IRAN 30%
i
:OW NOT WiTRiN TOLERANCE. CURVE CAN CFNERALLy BF
CORRECTED BY INCREASING CON SIDE CT, Al AND A2
Figure 1319. Overall RF and IF
VIDEO CARRIERv[ (MARKER
SOUND
...---/ CARRIER
MORE THAN 30%
i
DuRBE NOT 011(11 TOLERANCE. MBE CAN GENERALLY BE
coRREDTE0 BY INCREASING TON! SU (III At AO 44.
Cures, Incorrect Shape.
HF OSCILLATOR ADJUSTMENT(Using a signal generator)
HF oscillator adjustment can be made using a crystal calibrated signalgenerator. Note that adjustment "All" (figure 11) is an overall oscil-lator adjustment and should only be made when the mixer -oscillator tubeis replaced. Generally "All" adjusts with about 3/16" of screw threadexposed. Make adjustments as follows:
Receiver Control Settings Signal Generator Instructions
Set channel selector for each than-net to be adjusted. Set "Tuning"control at half rotation. Turn vol-ume control fully to the right(clockwise).
Connect to antenna terminals. Setgenerator to exact frequency of11F oscillator. See frequency tableon opposite page. Set generator formaximum output.
Connect a wire jumper from test point"W" on the tuner to test jack "Z". Seefigure 8. Remove the ratio detector tubeV202 (6AL5). Carefully adjust the in -dividual oscillator slug Al2 until a whistle(beat) is heard in the speaker of thereceiver.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION I
SCHEMATIC NOTESRun numbers are rubber stamped at the rear of the chassis.Numerical symbols Lj, 1], etc. indicate run numbers for 21B1
chassis, numerical symbols ZL,,zt, .zt.. etc. indicate run numbers for21F1 chassis (Th, n, ri), etc. indicate run numbers for 21K1 chassis, andnumerical symbols 0, ®, ®, etc. indicate run numbers for all 21 series.
0 0, 0, 0, etc. indicate alignment points and alignment connections.
SERVICING RADIO SEPARATELYThe radio can be operated without the tele.
vision chassis if a 2PA1 power supply (used inTV-radio.phono models employing the 20Z1 (12")television chassis) is available. To operate theradio, connect a 3,000 ohm, 5 watt resistor (part61A1-15) from pin "M" to "N" on the powersupply socket.
This resistor drops the B plus voltage forproper operation.
0 0
01 1 N
A N
I
1000 51415,51111
Power SupplySocket, (InsideChassis View).
SERVICING TV SEPARATELYIn combination models, to service the television chassis with the radio
disconnected, it will be necessary to complete the heater circuit by con-necting a jumper wire between pins "L" and "K" of socket M503.
_e_----ClI611/1 MOW tort1111 1/If DOES III 11/11 TO -IfIfY/S/01 IVY- *MIS.
L.
11611-111115111
TV TUNER 94C37-1106611 SIIIICK SETTING SELECTS PAIR OFCOILS 001 S 002 101 CRAINFL DESIRED
6E101 OR 68[1 'J.71; gilla4C11-16)1ST 12v115110RI
L106FAMP
AFALICII 111E1.
11015
7 SY
11015 a WI co.1."
)
T;l0
troy6".
104
5-5
CRS
171
LIO2A
.C10151 (1104
L10213
1112
2201
2C22"4--1, {AM, 2201
TO PIN 1
Of 1203 - 4,72)2
1 -4611210 TO PIN 5
13221$2, oF 0204
II irlEt
_1_*01 slit -4-11,-
1
® II42716
5 10 TE1111111. OF ELEC.
270* 1011041521 1422
CIRCUIT .FOR 63B6-3 COUPLATE
10
MEI NUR
7401
4
1303
See page 12 for waveformand voltage data, severalproduction changes, andtop view of chassis.
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
for 21F1, 21G1, 21M1, 21N1, 21P1, 21Q1, 21T1, 21V1 Television Chassis; 3C1 (AM only) radio.Note: This schematic applies only to chassis stamped Run 18 to Run 20.
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONAdmiral data below refers to schematic pp. 10-11.
WAVEFORM DATA(Waveforms given on schematic)
Waveforms taken with picture control set fully to the right, all other controls set fornormal picture (in sync).
Waveforms at video and sync stages obtained with transmitted signal input to receiver.
The oscilloscope sweep is adjusted for 30 cycles (which is one-half of the verticalfrequency), or for 7875 cycles (which is one-half of the horizontal frequency) so that twopulses appear on the screen.
The peak -to -peak voltage readings shown are subject to some variations due to responseof the oscilloscope and parts tolerances.
TV VOLTAGE DATA(Voltages given on schematic)
PICTURE control turned fully clockwise. CHANNEL control set on an unused channel.Other front controls set at approximately half rotation. Vert. Lin. and Height set atapproximately half rotation.
Voltages marked with an asterisk will vary widely with control setting.In combination models, B+ voltages in TV chassis will be slightly higher when set is
switched to radio position. Alternate voltage readings for radio and TV are shown forsound output tube V204 (6V6GT).
Line voltage 117 volts AC.
Voltages measured with a vacuum tube voltmeter between tube socket terminals andchassis, unless otherwise indicated.Voltages at V101, V102, V306 measured from top of socket with tube removed.
Antenna disconnected from set with terminals shorted.
CAUTIONPulsed high voltages are present on the cap of V406, and on the filament terminals and
cap of the 1B3GT tube. NO ATTEMPT SHOULD BE MADE TO TAKE MEASURE.MENTS FROM THESE POINTS WITHOUT SUITABLE TEST EQUIPMENT.
Picture tube 2nd anode voltage can be measured from the 2nd anode connector andshould be taken only with a high voltage instrument such as a kilovoltmeter. 2nd anodevoltage is approximately 12.5 KV. Proper filament voltage check of the 1B3GT tube maybe made by observing filament brilliancy as compared with that obtained with a 1.5 voltdry cell battery.
SERVICE HINTSREMOVING VERTICAL BARS FROM PICTURE
Shadow -type vertical bars (usually at the left of thepicture) can be eliminated or minimized by adding afilter (part number A3459S) to the horizontal outputcircuit. However, before deciding that a filter is required,be certain that the horizontal drive and width controlshave been adjusted according to the instructions onpage 8 of this service manual. Also check to see that thepicture tube cathode lead (from pin 11) is not close tothe horizontal output tube V406. This lead should bedressed as far away as possible from the horizontaloutput tube.
If 'tertical bars are still present after picture tubesocket lead dress has been checked, install a filter (partnumber A3459S) according to the instructions packedwith each filter. This filter should eliminate the verticalbars, or reduce the brightness of the bars to a minimum.
12
PRODUCTION CHANGES
B PLUS AND AUDIO COUPLATECIRCUIT CHANGE
RUN 18 in 21K1 Chassis, RUN 19 in 21F1, 21G1,21M1, 21N1, 21P1, 21Q1 Chassis, RUN 20 in21T1 and 21V1 Chassis
Changes were made in the B+ circuit to thesound amplifier V203 (6AV6) and to the first anode(pin 10) of picture tube V306. The schematic in
this supplement has these changes incorporated.Fuse failure in sets having these changes will resultin loss of both sound and picture.
In some sets audio couplate, part number 63B6-3was replaced with couplate 63B6-5. When couplate63B6-3 is used, terminal 3 is unused and R215(270,000 ohms, 1/2 watt) is connected in series withterminal 5. When couplate 63B6.5 is used, R210 is470,000 ohms, and R211 is omitted. Couplate 63B6-5is shown in the schematic. A sketch of couplate63136-3 is shown at the left of schematic.
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Top View of Chassis
BUZZ CAUSED BY PICKUP THROUGHSHIELDED AUDIO CABLE
High buzz level can be caused by pickup throughcomponents in the audio circuit which are spaced tooclose to components in the vertical sweep circuits. Acommon cause of high sync buzz level is that the shieldedaudio cable (connecting to the volume control R208A)is too close to the vertical output tube (V402). Theshielded audio cable should be dressed so that it will notcome close to the vertical output tube. Also be sure thatone end of the shield is soldered to the chassis.
INTERMITTENT SOUND, PICTURE or SYNC(in sets with socket M509 and plug M510)
Poor contact between the color converter plug M510and socket M509 can cause (1) no sound (2) no sync(3) no picture, sound or raster, or a combination ofthese troubles.
If poor socket contact is suspected as being the causeof trouble, remove the plug and tighten the socket con-tacts with a pair of long nose pliers.
CHANGE to IMPROVE AUDIO RESPONSEon RADIO OPERATION
# Run 2 in 21C1 ChassisR210 was changed from 270,000 ohms to 150,000
ohms, (part #60B8-154) and R211 was changed from100,000 ohms to 47,000 ohms, (part #60B8-473) to im-prove audio response on radio operation.
C433 ADDED to OBTAIN SUFFICIENTWIDTH
*Run 3 in 21C1 Chassis
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
2161, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1, 21K1, 21L1, 21P1, 21Q1, Admiral
PRODUCTION CHANGESAt the start of production, chassis were not stamped with a run number,
therefore some chassis will not have a run number stamp.Production changes are coded RUN 1, RUN 2, etc., as given in the
headings below. Run number (stamped on chassis) indicates that thischassis has the change(s) incorporated which are explained under thatparticular run number heading below, as well as all changes (lower runnumbers) made prior to that time. For example, a 21C1 chassis stampedRUN 4 will also include the changes incorporated in the 21C1 chassisunder RUN 1, RUN 2, and RUN 3.
RESISTOR R303 CHANGED to INCREASEB+ VOLTAGE to RF TUNER
In later production resistor R303 was changed from1000 ohms to 470 ohms, 1/2 watt, part number 60B8-471.Changing this resistor to a lower value increases the B+voltage applied to the RF tuner, thereby providing anincrease in sensitivity. This increased sensitivity will beapparent in fringe or weak signal areas. This resistorchange should be made only in sets having less than 105volts at the RF tuner B+ lead.
R430 WATTAGE CHANGED
examination of this type of interference will reveal thatthe fine lines of the herringbone pattern will vary inaccordance with the speech or music on the adjacentlower channel. This can be checked by quickly turningthe channel selector to the lower channel.
Since FM interference from other sources will alsoproduce a herringbone pattern, it should definitely bedetermined that the interference is caused by the ad-jacent lower channel before installing the trap. Afterinstalling the trap, realign slug A4 (mixer plate coilL103) ; see "IF Amplifier Alignment", page 6.
# Run 1 in 21C1 Chassis CHANGE to IMPROVE SYNC STABILITY
Resistor R430 was changed from 12,000 ohms, 1/2 t Run 5 in 21C1 Chassis, Run 2 in 21B1 Chassiswatt to 12,000 ohms, 2 watt (part #60B20-123) to pre- An RC filter consisting of a parallel combination of avent possible increase in resistance of R430. 270,000 ohm, 1/2 watt resistor (part number 60B8-274)
and a 150 mmfd, mica condenser (part number 65B21-151) is connected between resistor R323 and condenserC308. Resistor R323 was changed from 8,200 ohms to18,000 ohms, 1/2 watt (part number 60B8-183). Thesechanges will improve sync stability (immunity to noise)in areas having low signal strength and a high noise level.
DIFFERENT TUBES USED in 2nd and 3rdIF STAGES
Runs 3 & 4 in 2161 Chassis produced at Cortland*Run 5 in 21B1 Chassis produced at Bloomington*Run 1 in 21D1 Chassis, Run 1 in 21.11 Chassis
Some sets use a 6AU6 tube in the 1st IF stage, andTo obtain sufficient sweep width, C433 (.002 mfd,600V) was added across width coil L402. Do not make
a pair of 6AG5, 6BC5, or 6CB6 tubes, instead of 6AU6
this change in sets with gated AGC.tubes in the 2nd and 3rd IF stages (V302, V303). Forcomplete information on the use of these tubes, seeschematic. Note that these tubes are not directly inter -
HERRINGBONE PATTERN INTERFERENCE changeable, since they differ in pin numbering, in use
t Run 4 in 21C1 Chassis, Run 1 in 2161 Chassis of tube shields, and in use of R330.IMPORTANT: Alignment is generally required after
Later production sets have an Adjacent Lower Chan- replacing IF tubes. Check the IF alignment, and pre-nel Sound Trap (L307, C314) added between the con- ferably, also the over-all RF and IF response curve afternector lug (terminal of C113) on the TV tuner and pin tube replacement.1 of the 1st IF amplifier tube V301. This trap (partnumber 72A102) is pre -tuned to 27.25 MC. C433 CHANGED to OBTAIN SUFFICIENT
This trap will eliminate herringbone interference pat- WIDTH
tern produced by the sound carrier of the adjacent lower Run 2 in 21D1 Chassis, Run 2 in 21.11 Chassis.channel in the same locality, especially when the wanted C433 is .002 mfd, .0047 mfd, or .01 mfd, 600 volts, asstation is weaker than the interfering station. Close required to obtain sufficient width. Increasing the size
This change was incorporated at beginning of production of all other chassis.The 21B1 chassis has been run at two plants. Sets produced at the Cortland plant have "Cortland Plant" printed on the model label. 13Sets produced at Bloomington have "Bloomington Plant" printed on the model number label.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
14
Admiral 2161, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1, 21K1, 21L1, 21P1, 21Q1,
of condenser C433 provides greater sweep width withslight reduction in picture brightness. When adding orreplacing C433 use the smallest capacity possible whichwill produce sufficient sweep width. Do not make thischange in sets with gated AGC.
VERTICAL OUTPUT TUBE (V402)CHANGED
Run 4 in 21B1 Chassis produced at Bloomington*
The vertical output tube 6S4 (V402) was changed toa 6SN7GT. See inset on figure 26 for circuit. Note thatresistance values of R404, R406, and R411 are changedwhen a 6SN7GT is used.
Some sets may also use a 6SN7GT tube instead of a6S4 tube at V402. Note that 6SN7GT pin numberingdiffers from that of the 6S4.
DIFFERENT TUBE USED for SYNCSEPARATOR and CLIPPER (V403)
Run 5 in 21B1 Chassis produced at Bloomington*A 6SN7GT tube is used instead of a 12AU7 at V403.
Note that 6SN7GT pin numbering differs from the12AU7.
DIFFERENT SOUND AMPLIFIER TUBE(V203)
Run 3 in 21D1 Chassis, Run 5 in 21D1 ChassisRuns 1, 2, 5 use a 6AV6 miniature tube in the sound
amplifier stage V203, while Runs 3 and 4 use a 6SQ7metal or a 6SQ7GT glass tube. To prevent pick-up ofhum, a tube shield (part number 87A8) is used with the6SQ7GT glass tube. Note that the 6SQ7 pin numberingdiffers from the 6AV6.
DIFFERENT TUBE USED for SYNCDISCRIMINATOR (V404)
Run 4 in 21D1 Chassis (see same heading at right).
PILOT LIGHT SOCKET ADDEDRun 3 in 21J1 Chassis
A pilot light socket, part #87A6-3 was added, to ac-commodate the 110 volt phono compartment pilot light.
CHANGES to REDUCE AUDIO HUM onTV OPERATION
Run 5 in 21B1 Chassis, Run 8 in 21C1 Chassis,Run 6 in 21D1 Chassis
In some chassis (especially early 21D1 chassis) asharp audible hum can be heard in the speaker with andwithout a TV station tuned in. Check for trouble asfollows:1. If the brightness control also varies hum level, it will
generally be found that the sound amplifier (V203)is a glass 6SQ7 tube which may be used without atube shield. To minimize hum level either use atube shield or change to a metal 6SQ7 tube.
The 21B1 chassis has been run at two plants. Sets produced at theSets produced at Bloomington have "Bloomington Plant" printed on
2. If the vertical hold control also varies the hum fre-quency, the hum is introduced from the vertical out-put stage. Change Condenser C211 from a .047 toat least a .47 mfd., 400 volt condenser. In manycases it may be necessary to use an electrolytic con-denser as large as 10 mfd. to completely eliminatethe hum.
3. If hum (buzz) is only evident when station is tunedin, check IF alignment. In some 21D1 chassis, three6AG5 tubes were used in the IF stages. In order toobtain a good IF curve (with the sound carrier lowenough), it is necessary to change the first IF tubeto a 6AU6, ground pin 2, and re -align the IF stages.Be sure that the 4.5 MC sound IF adjustments arealigned with a station signal as described on page15. Buzz can generally be reduced farther afteralignment on station signal by turning sound takeoff coil L201 slug out about 1/4 turn.
INTERLOCK OMITTED FROM YOKE andFOCUS COIL CONNECTORS USED in19" SETS
Run 1 in 21H1 Chassis, Run 4 in 21J1 ChassisThe 110 volt AC interlock circuit connections were
omitted from the focus coil and deflection yoke con-nectors (M404 and M406) used in 19" sets.
SOCKET and PLUG ADDED for ATTACH-MENT of a COLOR CONVERTER
Run 6 in 21B1 Chassis; Run 9 in 21C1 Chassis;Run 7 in 21D1 Chassis; Run 5 in 21J1 Chassis;Run 2 in 21H1 Chassis
A 9 contact socket M509 was added at the rear of theTV chassis to provide B+ voltages and 110 volt ACpower for attachment of a color converter. See schematic,figure 26 or 27.
Plug M510 fits into socket M509 to complete the B+circuits when a color converter is not used. The plughas jumpers wired between pins 1 and 2, between pins 3and 4, and between pins 5 and 6.
A few of the early sets with socket M509 had electro-lytic condenser C432 (60 raid) connected to pin 8 ofV501 (5U4G) tube.
Note: In some later 21B1 chassis, plug M510 andwiring connections to socket M509 were omitted.
RunRun
DIFFERENT TUBES USED for SYNCDISCRIMINATOR (V404)6 in 21J1 Chassis; Run 4 in 21D1 Chassis7 in 2181 Chassis; Run 10 in 21C1 Chassis;
A 12H6 tube may be used instead of a 6AL5 tube forV404 sync discriminator. A 6H6 tube was also used insome sets. The pin numbering for the 12H6 and 6H6 isidentical; the 6AL5 pin numbering is different.
When the 12H6 tube is used for V404, an auto -trans -
Cortland plant have "Cortland Plant" printed on the model label.the model number label.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
21 B1, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1,
former T502 ( part number 80B32) is used to step up the6.3 volts to 12.6 volts required for the heater of the12H6 tube. The low end (black lead) of T502 connectsto chassis ground, the center tap (green lead) connectsto pin 7 of V408, the high end (yellow lead) connectsto pin 7 of 12H6 (V404).
The circuit for the 6116 is the same as for the 12H6tube except that T502 auto -transformer is not used. Heatervoltage (6.3 volts AC) connects to pin 7 of 6H6 tube(V404).
Replacing 12H6 Tube with a 6H6 Tube. If a12H6 is not available for replacement, a type 6H6 tubemay be used in place of the 12H6 if the followingchanges to the heater circuit are made:1. Remove the transformer lead from pin 7 of the V404
(12H6) socket Tape the lead to prevent it shortingto chassis.
2. Connect a lead from pin 7 of V404 socket to pin 7of V401 socket.
CHANGE in FOCUS CIRCUITRun 10 in 21B1 Chassis
In late 21B1 chassis, a permanent magnet focusingassembly (part number 94C35.1) is used. The partseliminated from the B plus (filter) circuit when the PMfocus assembly is used are focus coil 1A04 and focuscontrol R446. These parts have been replaced with chokecoil L405 (part number 74B18-4) and resistor R449 (100ohms, 7.5 watt, part number 61A1-20) connected inseries. The choke with the resistor in series are in thefilter circuit between filter condensers C407 and C432.
21K1, 21L1, 21P1, 21Q1, AdmiralVIDEO DETECTOR and AGC CIRCUITCHANGED
Run 12 in 21B1 Chassis, Run 3 in 21F1 ChassisLate production 21B1 sets and 21F1 sets employ a
1N64 germanium diode (M301) as a video detectorand a 6AU6 tube (V304) as a gated AGC stage. Thesesets use a 6AU6 tube in the 1st and 2nd IF stages anda 6AG5 tube in the 3rd IF stage. A cover shield is notused on the bottom of the IF amplifier sub -chassis. Forsets with these circuit changes, see figures 18A and 18B.
CHANGE to PREVENT PICTURE CUT-OFFand to STABILIZE PICTURE BRIGHTNESS
Run 13 in 21B1 Chassis, Run 4 in 21F1 ChassisThe following changes were made to the B+ circuit
to prevent possible picture cut-off due to blocking ofthe video amplifier. (This blocking may occur if theTV set is tuned to a very strong TV signal which coulddrive the video amplifier to cut-off. With the video am-plifier at cut-off, B+ voltage applied to the cathode ofthe picture tube will increase thereby making the gridvoltage more negative with respect to cathode, drivingthe picture tube to cut-off. Also since the gated AGCtube is dependent upon voltage from the video amplifierfor its operation, blocking of the video amplifier willcause no AGC voltage to be developed and the systemwill remain blocked.)
Diagrams of voltage distribution and partial schematicsbefore and after the change was made are shown infigures 17A, 17B, 18A and 18B. Note the changes madein the B+ circuit to the 3rd IF amplifier, AGC tube,video amplifier and picture tube. Resistor R336 (4,000ohms, 5 watt).
R319 B+ VOLTAGE
C30T8 3000 15;--"E, FROM PIN 8 OF 5040205101-
C3OTAI
20 IrDI
12
AAA' .44000 55
8+ VOLTAGE
FROM L404 OR R449
V101 V102 V201 V204 V301 V302 V303 V304 V305 V40113 V4036AG5,6BC5, 6J6 6AU6 6V6GT 6AU6 6AU6 6AG5 6AU6 6AC7 6SN7GT 12 AU 7
OR 6CB6 RF OSC & SOUND IF SOUND OUTPUT 1ST IF 2ND IF 3RD IF GATED ACC VIDEO AMP SYNC INV SYNC SEP
RF AMP MIXER & CLIPPER
Figure 17A. Diagram Showing Section of B+ Distribution of 21B1 Chassis StampedRun 12 and 21F1 Chassis Stamped Run 3. Partial schematic shown in figure 18A.
C30TAJ 1C30TB
20 MFMO MID
TL
5 5
V 101 V102 V201 V204 V301 V3026AG5,6BC5 6J6 6AU6 6V6GT 6AU6 6AU6
OR 6CB6,RF AMP
RF OSC &
MIXER
SOUND IF SOUND OUTPUT 1ST IF 2ND IF
R319
3000 15W
0338-vvvv-75C0 511
V303 V3046AG5 6AU63RD IF OM ACC
8+ VOLTAGE
FRON PIN 8 OF 5U4C
Continuedon page 18.
V3056AC7
8
V401 B V4036SN7GT 12 AU 7
VIDEO AMP SYNC INV SYNC SEP
& CLIPPER
Figure 17B. Diagram Showing Section of B+ Distribution of 21B1 Chassis StampedRun 13 or Run 14 and 21F1 Chassis Stamped Run 4 or Run 5. Partial schematic shown
in figure 18B. 15
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION 1
Admiral CorporationAl 0 0,0, etc. indicate alignment points and alignment connections.
VOLTAGE DATA(Voltages given on schematic)
TV voltages taken with function switch on "TV" position. PICTURE control turnedfully clockwise. CHANNEL control set on an unused channel. Other front controlsset at approximately half rotation. Vert. Lin. and Height set at approximately halfrotation. TV antenna disconnected from set with terminals shorted.
Radio voltages at V701 and V702 taken with function switch on "Rad" position;voltages measured from underside of tube sockets. When measured from top of tubesockets (with tube removed), B plus voltage at pins 5 and 6 of V701 and V702 will beapproximately 275 volts.
B plus voltages at V203 and V204, will be slightly higher when set is switched to "Rad"position. Voltages marked with an asterisk will vary widely with control setting.
Line voltage 117 volts AC. Voltages measured with a vacuum tube voltmeter between tube socket terminals and
chassis, unless otherwise indicated.Voltages at V101, V102, V306 measured from top of socket with tube removed.
5011311 SNOINII TV POSITION
511031
16
TV TUNER 94C37-111111E1 SWITCH SETTING SELECTS PAIN OFCOILS 1101 1 1102 100 CHANNEL DESIRED.
6 BO7 OR 6 BK 1 CHANCED MN11P4
CINO1111001 TUNfA
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LIOIA
1101
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'I-C113
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1102 C102 till'411 31 I 2201
317031 311031 $110304
I 44 17033
1 2 1211 VIII Of FUNCTION SIITCN 61003511030 ALTERNATE 511101 52011113 51111
NEC
C104
5-. 4 -V -11T02 1403 1 '30"1 2211 1200 1200 IT
I 101.1.01...S401 J402 0403
! TOW r, T..,_ ,___,
lit,. 1404
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2405 V401A
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930*
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14411501
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Schematic for 21W1, 21Y1 Televisio
1704
L _
6BE6R6BA6IfCONVERTE LW
V701 /ror 0r T701
?1.1
L _6 7005
Or
C704
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Ir5
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1702
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1309
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7
C406
147 !1111
01
11406
MAC
C40711
6,16IF 1111U
v102A
C101
00I i/7 r,-1411
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CIo9 ITOSC.
V102S+
0II0 er,1411113.5-3 Ctlt
I
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0102 r HOE I T-Nufll
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Am/11101L11
6
SEE -c7331111FLI1401
16115_ 1111LIST 120
M2.11131
1401NU
TEL
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II
111011
151
1.
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_ C31211044
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Of F 1011
16.5A its'sTOTAL 42.211f0
1357
1501
C314
120 1301
3% 101
5% C3011
1304 1000
30TERI
for111.
.or
6AU6SOUND IF
0201 wy
1201
T7011702
03
Z 0111.61211 3031
1204
611.5*MO DE T
V202
6AU6151 IF
V 301
Is,,6
030347
C3011
II )I0015 0415
1301 f.25.310
11
1506 ItIll 1
5301
044
3 1
-Jr.7,
130161
15021 C3021
6AU6210 Ifv302liOr
'Mr.23022325- or
I3
NAI
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1110
12AUTSIX SEP1 CLIPPER
0403JOY
.70.
2111'4
/005
2 Sr
C409
1421
11 NEC
.01
II
1/26SNTCT
1411SV0115YNC. INS.
05" 5 C4I2.001
250Volt
250
_.!
1020
loll5%
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6A15SYNC. 0150
V404ar
0415
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1421
,nt:
4104
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If SIN 0(75 PNW MI orairtr
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
and Radio Chassis. Run 20.
1104vvvv.
211It
CO?005
1::L11- 17,
11106
INC
-J M701 M702
VI
In Run 21 in Chassis 2111to improve function ofwidth control, R437 waschanged to 1 meg. andC431 to 0.2 mfd.
M704 64705 1470P°°°5 TEf110101
541(1019 LEADS
1105
11000
%Floe
9
o
P
587030
FOCUS COIL AND DEFLECTION YOKECONNECTORS USED IN 21W1 AND 21Y1CHASSIS.
TO ENO 11214 AlOF MI6._ TO n1100100
oF 1402
100611 44036011111 VIED
10 0(111E1 104411IT10
OF 1446 6431
TO TO
C40/0 04011
TfaCIPFT.Ilit.00,111,(4.04 T40341/T/ VIII OFT
5,E0j 400 OSIATCST011'11'
BLUE
r
$00411 8405601104 VIEW
PLUG NMP11 VIII
FOC4140400011. L - IL AC1
8201C201 11101-0Dd'c b 08
111 Alia
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- 0206
POI]
031038
Ca
6AV6£4 0E T. (30. 11. LIP
-/Pr
V203 ,404.
6 11209
11 NEC
0210
501111130001 COMM
72Z
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8211
121
530058
10211r -I C212
I .01.005 12101
15011
1211 , 12122410TON0111101.
0216
1002
911-1 VA'
6V6sTSOUND OUTPUT
0204 my
102138201FD
14203
1TuEtT0201' IA 02III Ell
TDOS
L
NG5tl IF 7303303
IJS, Ill
SII50
6 2
13041005
C3031004
0312
1000
50r 11
NOK
6A U6 Ir GATED ACE,
2VVEAL
C30
64 U
166
304
033*OR
3'
WIIIL303 j
IIP r ----I 01
05 '
301 64 ib, . s - -'C301
-33,-
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V3
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61100 6(15_
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11543150 M
1.304
13402161
644) L _
E C310R32,32208011 .041
1 "I
206
1334 a, i
5%PICTURE - 4100
ANN,
VIDEO DE1
1331
2201
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2
11011
133910321Tr T20
!.413231M
501,
VIII
1324
0 Or
P/ClUE AS/ 0111671O III!S Prot reit 501111
mew MIMI 170 ISM)11114
2IEP4A
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11101114111 "091326 0 1321
1001 1001
V306
...1110CIEVWAGE12.5.4121.11.111.51(Min2.11
03076 I 103016201F0 20410 1121: CS
2101 ,13
301 r
3V
01
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431 AMY S 1411
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or-lv
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1
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_J
4.1K1.501
5U4cRECTIFIER
V501/1 1E01
IC
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6SN7CTAOA OSC0405 INV C 20 1434
5 62" 1431C 21 If
6CD6cX01.091111
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I C424
NOR DRIVE
4/OM10160M
V406
144041
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1331 1511St
1B3CTX.Y.RECTIFIER
V407
7404 1443
2.16
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1443
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61(84(11TEM 1101
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SOCKET
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11/ L 5 ?NoC43051
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1000 I
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I III Air If IIIIICAINC(0 WI 5 iu r I""4:1=1-'2I
C421.35
2 14 34
L403 400.
318I6 20 1111
201Nol CCM _- UMT
ROW: 111010 Oif
h'ITEL
99".111010 01
5111038
FOCUS COIL
L404111
71110/4
&Ors 1E0
CREE 1
sdr dr
©04020
©404.6 0
00408
V204
V401
V305
V302
To PIN 5
OF va0/1
74038iTOR 013.
COILRED 14,1011i.
0
430514 8445FARTS
LIST_ MOO
WRITE -
6806CTNOR 011101
0406
/of
1
SW 01r-_
J
005011=05021
111(11000
21501,101 $MK IC
INT
11010 01
P4010OPE
01031 11010
TEL
IN 10 ON
PNONO Off
RADIO
3 TEL.
MIMIC
V403
0 0 0o V3060
o0406
4405 0
V203
C314
L3050 0V301
0303
V304
.043
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.004
51(
4.1
44 °,7
V202TELL°,
0103
V101
1.403
L306
17
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
AdmiralTO 0201.
TO R203
21B1, 21C1, 21D1, 21E1, 21F1, 21G1, 21H1, 21J1, 21K1, 21L1, 21P1, 21Q1,
2000
6AG5HOR
3RD. IF
V303
5
A_.....j. 50V ...Al
HOR.
T-1303 6AU6253110 ORDUGC VIDEO DU,
105Y 11 ..;1,31.30, V304BOY
M301.4 1464
' /051 l'' :I 61 2r R332ott. R33I6 2 2208 6800
L301
7//SY 7 L302
9334/Y
1304
1005
43331508
$17110303 R312 41,1501.004 t 1000
4 VOLTAGE
10151 IF. 2110 IF.AND INNER
10 TEST POI TIT '14-
TO PI11 1 05 0403
3002+C 6
100
O
7/Y
6AC7 L303VIDEO AMP r
V305 j 4320
875
3 #.31,
6
93:'75 3: 5( R 118012)
47001534
5%PICTURE
33I J
L30r4_
R335I470 L_
Co09
1R321
:10K
832411108
11325
5606
*80
C310
.041 002
0
//CLONE lull Y0[IAOIS141(1 MN roll SOCIff
ISNIff If10YE0 !ROM fall
BRICHTNESS I/048321 R326 8327
11323,1111
4700 LOON 100
11336 4000
V306
1611141611417814
170842001420.014
2110 ANODE
IVMOM: NICK
+I C3076
20K0C3081
.047111
Figure 18A. Partial Schematic Showing and Pictureand 21F1 Chassis Stamped Run 3.
TO 0201;0 8203
2000NOR
508NOR.
3RD. IF
V303 25.34C_ PAT)IjkIr.la..31305 V304
100Y1
ri 61 26 2
C311
/113041005
111:13111 S3034501:004
6+ VOLTAGETO 1ST 11.2361F.
AND TUNER
T303
8312
1000
TO TEST Puri'
RSV16
IE.CC731
TO PIN 2 OF 0403
VIDEO DET
1329: 1031527081
115C3111_
L _J2oNFA
11319 3000..ree
ISO
Tube Circuit
6AC7 L303VIDEO AMP 1-10000,
V305 : R320 ,
7.10' 8 "" "K3 *.S1
I4
R315
47005%
105282086)93:6
1500
PICTURE
tNOR.
-4-L50 r7641
G30141 1C3078
20410 -1- 20680
03004
113351
t103014 511
$R3282211
VOLTAGE ON CONEOF METAL TOES.DO NOT GROUND.
By VOLTAGEFROM L404 OR 8449
Br vOLTACEFROM PIN 3 OF SU4C
in 21B1 Chassis Stamped Run 12
43245608
/It IS Y83255604
1 0310'8321 - .047
:1011
470 L __I
i
0329: 1C31527011 -TT150
L _
2
8319 3000IS I
83!11 7500
51
Figure 18B. Partial Schematic Showing BA- and Picture Tube Circuit in 21B1 Chassis Stamped Run 13or Run 14 and 21F1 Chassis Stamped Run 4 or Run 5.
IYerillf loll 1011475
1411,11 1100 OW 500111
ISPC1f1 1110110 /WI IWO
10
RAPTNESS ila1326 R327
100110r±
C31 8320.0471 22K
V306
16814167P417014tc P4
2001420014
2110 ANODE
11.51
CAUTION: RICH
VOLTAGE ON CONEOF METAL TUBES.
00 NO 1 CROUND.
- 8+ VOLTACEFROM L404 OR 8449
114 VOLTAGE
ER011 PI4 8 OF 5040
was omitted from the circuit. Resistor R338 (7,500ohms, 5 watt) was wired in parallel with R319.
To prevent a decrease in brightness when strong sig-nals are received, resistor R324 (in the cathode circuitof the picture tube) was changed from 180,000 ohms to560,000 ohms.
Adding Changes to Prevent Picture Cut-offIf picture cut-off resulting from blocking of the video
amplifier is experienced with a 21B1 chassis stampedRun 12 or 21F1 chassis stamped Run 3, the changesbelow should be made. See figure 19 and proceed asfollows:
1. Remove resistor R336 (4,000 ohms).
2. Connect a 7,500 ohm, 5 watt resistor R338 (partnumber 61A1-18) across R319.
S.
4.
Connect together the positive terminals of filter con-18densers C307A and C307B.
Change resistor R324 from 180,000 ohms to 560,000
ohms, 1/2 watt (part number 60B8-564).5. Erase the old run number from the chassis and mark
in the next higher run number.
STEP
STEP2
STEP CONNECT C30IA 1,C3O7B
3 TOCETHER
CONNECT 7500 OHMS. 55
REMOVE 0336
4000 OHMS
ACROSS 0319
STEP4
CHANCE 0324 TO
560K IONS
Figure 19. Diagram Showing Changes to be Added to Pre-vent Picture Cut-off in 21E11 Chassis StampedRun 12 and 21F1 Chassis Stamped Run 3.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
2161, 21C1, 21 D1, 21E1, 21F1, 21G1, 21 H1, 21J1,
SOCKET M509 and PLUG M510 ADDEDand
AGC TEST POINT WIRED to a TEST JACKRun 14 in 21B1 Chassis, Run 5 in 21F1 Chassis
Color Connectors. A 9 -contact socket M509 wasadded at the rear of the TV chassis to provide B+voltages, and 110 volt AC power for attachment of acolor converter. Plug M510 fits into the socket to com-plete the B+ circuits when a color converter is not used.The plug has jumpers wired between pins 1 and 2, be-tween pins 3 and 4, and between pins 5 and 6. In someearlier production sets, plug M510 and the wiring tosocket M509 were omitted. Note: Sets which have theB+ circuits wired to socket M509 will not operate unlessthe plug (with jumpers connected) or a color converter isplugged into the socket to complete the B+ circuits.
AGC Test Point. To make test point "T" (AGCbuss) available from the top of the chassis, this test pointhas been wired to the test jack adjacent to test jack "Z".See figure 7 and figure 8 for location of test points.
CHANGE TO IMPROVE FOCUSRun 8 in 21B1 Chassis
Some long neck 16TP4 picture tubes (Raytheon andDumont brands) were used in some 21B1 chassisstamped Run 8. In order to obtain satisfactory focuswhen these picture tubes were used, a 10 watt bleederresistor from 12,000 to 15,000 ohms was added from
21K1, 21L1, 21P1, 21Q1, Admiraljunction of resistors R326 and R211 to chassis ground.Important: It may be necessary to remove this resistorto obtain satisfactory focus when replacing an originallong neck 16TP4 tube with a short neck tube.
DIFFERENT TUBE USED FOR VIDEOAMPLIFIER V305
In some late 21B1 sets a 6AH6 miniature tube is usedin place of the 6AC7 tube for video amplifier V305. Nocircuit changes arc necessary when substituting tubeshut the socket will have to be changed.
CHANGE in 3C1 RADIO to IMPROVE TONEQUALITY
The following changes were made in later production3C1 radio chassis for improved tone quality.
Resistor 11709 was changed from 27.000 ohms to82,000 ohms (part number 60B8-823).
Condenser C712 was changed from 250 mmfd. to 100mmfd. (part number 65B6-3). C713 was changed from.01 mfd. to .002 mfd. (part number 64B5-25). C714 waschanged from .002 to .005 mfd. (part number 64B5.12).The schematic figure shows the 3C1 radio with thesechanges added.DIFFERENT TUBE (V703) USED in 3C1 RADIO
Early sets used a 6AV6 tube for V703 (Det-AVC-AF).Later production sets use the 6SQ7metal tube equivalent. Note that 6SQ7 pin numberingdiffers from that of 6AV6.
SERVICE HINTSVERTICAL ROLL in 21D1 CHASSIS
In some sets enough 60 cycle ripple from the verticaloutput stage may be present in the B+ supply to appearin the sync circuits. This ripple voltage will occasionallybe strong enough to trigger the vertical oscillator. If this60 cycle ripple has shifted in phase with respect to theoriginal vertical output signal, it will cause vertical"roll" (loss of vertical sync).
This condition can be corrected by changing the B+connections of the vertical output tube V402 (6W6GT)as follows:1. Locate the red lead from vertical output transformer
T402 which connects to the terminal strip directlybelow the transformer. Also locate the white leadwith black tracer (from the deflection yoke) whichconnects to same terminal. Disconnect both leadsfrom terminal strip.
2. Connect both leads to the junction of C427 and L403,through a 5,000 ohm, 5 watt decoupling resistor,(part number 61A1-8). The decoupling resistor maybe three 15,000 ohm, 2 watt resistors (part number60B20-153) connected in parallel.
3. Connect a 20 mfd, 450 volt electrolytic condenser(part number 67A21-1) from the junction of the twoleads and the decoupling resistor to chassis ground.(Connect the negative of the condenser to chassisgrand.)
SYNC TROUBLE DUE to INCORRECTVALUE of R323 RESISTOR
If sync difficulty or picture fuzziness is experienced,check resistor R323 to see that it is 18,000 ohms.
REMOVING RETRACE LINES
In some areas, where the signal strength is low, it isoften desirable to operate a receiver with the contrastreduced and the brightness turned up.
Under these conditions several bright retrace lines maybe visible in the picture. If the following changes aremade, the brightness control may be turned fully onwithout the retrace lines being visible. To add thischange to the circuit proceed as follows:1. Connect a 270,000 ohm, 1/2 watt resistor (part num-
ber 60B8-274) in series with pin 2 (grid) of thepicture tube and the lead connected from the junctionof C310 and R327.
2. Connect a .05 mfd condenser (part number 64B5-22)from the junction of C406 and R407 to pin 2 (grid)of the picture tube.
NOTE: If picture smears on white screen, use a 47,000ohm resistor in place of the 270,000 ohm resistor. Also,if shading at the top of the picture is evident reduce thecondenser value in step 2 to as low as .001 mfd.
19
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONCBS -COLUMBIA INC. V 4 V5 V7
6BC5 6AU6 1/2 6AL52N0 1 F DE T
23.0MC
C100270
T7
LINE SWITCH GANGEDTO VOLUME CONTROL
117 VAC
1
16.3 VAC
L- 1 -- V - -I
....--wy
.263V
IV I F
5.6K 39RI R2
270
LI ii 264"6
22KR3
2 CIO270
V66AU6
3RD
7.f... 1500 82 82-4.7 1500-.- C4b R5 --1-, C7. R7
C 5b1500
.V.V33 -r-t -r-1- ,25R9 -=.'-- - 200V- C6
3.3m
V 205U4G
RECTIFIER
VI5
6AL5
TO TUNER
PICTURE
CARRIER
SOUNDCAW LER
2 55 25 5975
3 61.25 65.75
4 6725 7175
5 7725 8175
8325 87 75
7
8
17525 179 75
181.25 185759 187 25 191 75
10 193.25 1977519925 20375
12 20525 209753 211 25 215 75
20
- R30120
t2 IN/ U.S
V 14
1213117
NOTE
L 13
V17
6806
V6 CEI.
cue' 1500
()4
V 11
6116
5 TS6406
0 0150
AAA,IMR 10
6 25.4 MC
1500
TC53
82RI2
CII22
It-
o RFCL3
RII5WHITE 82
L6
5
=1ZREO
1500C eb
ALL CAPACITORS MARKED LESS THAN I,IN MFD.ALL CAPACITORS MARKED MORE THAN I,IN MMF, UNLESS OTHERWISE NOTED.ALL CAPACITORS RATED 600V UNLESS NOTEDALL RESISTORS IN OHMS UNLESS NOT EDALL VOLTAGES TAKEN WITH 117 AC LINEAND NO INCOMING SIGNAL .VOLTAGE MEASUREDWITH A DC VACUUM TUBE VOLT METER.GONTRAS1CONTROL AT MINIMUM POSITION.
O C -I00 IS PART OF TUNER IN SOME SETS.e700 -91 ; -93 ONLY, LOW SIDE OF C52 TO HIGH
SIDE OF L8B, INSTEAD OF AS SHOWN.la C72 TO BE USED ONLY WITH VERT. OSC, TRAN-PB-10125
-© IS NORMAL CONNECTION:WITH CONTINUOUS TUNER,IS CONNECTED TO so, C9 IS ADDED, a R100 IS OMITTED;
R I IS 2000 OHMS, 15 W, AND R29 IS 75 OHMS, 15 W.*SOME SETS USE TWO 60 OHM RESISTORS IN SERIES.
SCHEMATIC
700-100,-120, -140
V4
CT-1-1 2 500 01500M. 15 W
R 31
ORANGE
5
I.5KPio
CONTRAST
Cie20AC3450 CI
itC 1 .1
2 01*00450 b
1220KR 33
V156AL5
MORI Z PHASEDETECTOR
NOTER24;R25*R26,C24 C259 C60 IMYBE SUBSTITUTED FOR BY AUDIOCOU PLATE A.K. PART NtP13 2002CONNECTED AS SHOWN.
2.7KR5I
R54 R55100K 100K
C38C6 I .005
4.7KR52
005C39
C40.005
4I
L7
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
V 11 A
1/212BH7tr VIDEO
RI3 Li7SS 47K
R69228IW
C58 C16_1_3
R20120
TI
85R7260
R73
81.1111
V96AU6RATIO DET
DRIVER
478 12
)7V88 5
61.161 2I2KN VIDEO
1421.8 K
'SAN
RED
GREE
L 12
Ri8 cI74.7K .052W
00
RI9
C19005
R21100K
*VOA
-r-C69 500C 59
1.8K
R67
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7
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DC RESTORER, SYNCCLI PPE R. SYNC AMPLIFIER
PHASE SPLITTER
VI4AI/2 12BH7
VERT SWEEPBLOCKING OSC.
04-,A6 R77
1C49IV1V-YELK 8 IGHTNESSR46^I 82K R44 P3 100KV148- 1/2 12f3H7
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6V6-GTAUDIO OUTPUT
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11 10
270 K
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4
R273301W SU
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2.0 ANODETO Hy.
FOCUSCOIL1- 16
IT SPEAKER
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82 flR 28
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154VERT C72 36SPE ED0OI 470K .051MEG R 42005 01 5
C3I C32 C0033
P5 R45.r1F-
R82 I R39 R40 051- 4127K 22K 1.5 Al
3.3KR36
.001 001C29 C30
NOTER38,R39-,R40;C31;C32 a C33 MAY BE SUBSTITUTEDFOR BY INTEGRATOR COUPLATE A.K. PART N1.P8-20150 AS SHOWN
8.2xR37 HEIGHT
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V12 FOR700- ICO 17674A700-120 20CP-1700 -140 EC C
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R704.7 K
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21
RED
PLUG (PIN END!
SOCKET
v 10E0
SYNC.
Clb16.1 40 MFD
450V
C65MF 6B Q 6-GTN2500V HORIZ SWEEP
OUTPUT
80
46
I100K 260KR59 R60
82 5R63
2W150
470K F161R62
C6405
10mFD
25VC 66
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4 daei5K
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KINESCOPE2 na ANODE
CBS -COLUMBIA(FormerlyAir King)Models
700-100,-120, -140.
21
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
ARVIN INDUSTRIES, Inc.
MODELS 5204-5206-5210-5211-5212
CHASSIS TE 300, TE 315The circuit diagram on pages 24 and 25, is exact for a recent production
of Chassis TE315. Chassis TE300 uses a 20" picture tube and is almostidentical in circuit to the TE315. The alignment for these two chassisis the same and is presented here. Refer to the correct chassis viewsas given below and on page 23.
You will find Chassis TE286, used in Model 4162, with a 16" tube, andChassis TE302, used in Models 5170, 5171, 5172, 5173, with a 17" tube,are similar to the sets covered in these pages. There are some circuitdifferences, as for example, V17 is 6SN7GT and not 6S4, cathode of V12is returned to ground and not -12 v. In the main, however, these setsare sufficiently similar for you to benefit through the use of these notesin servicing these additional Arvin sets.
TONEPNONO NEIGHT
CN OFF VERTICAL HCRIZ WENT- CNANNELVOLUME NO, HOLD NESS SWnt'' DISTarCE SELECTOR
CONTRAI I / I/ IVERTICALI'TUMNGLINEARITY
22
DEDI KACE 4D41,,EI
AL'iW0 it
FCCAL,E11 AG)
ION
W LTN 02NTIR.
SWET ERG. TV__r Nt',;
TOP VIEW - CHASSIS TE300
[ C17
NIGH .01.TAGCA402'
(V22;
021
,i aLIN LII
6NCRIZ RILLINEARITY LO
NOCK
7-1C123
T10644E5 El T2,5 IL,
tit6
TO?ifa 0<n01.6M LO CiZruc. (T.)
Irral
4.720 T 113FOW ER
eq, TRANS.
BOTTOM VIEW - CHASSIS TE300
HI -VOLTAGE WARNING -ON METAL PIT TUBE RECEIVERS UNCOUPLE ANODE CONNECTOR LEAD AT SOCKET BEFORE ALIGNMENTI. ALLOW ABOUT 15 MINUTES FOR RECEIVER AND TEST EQUIPMENT TO WARM UP.2 PULL THE AG.C. TUBE, VI4, OUT.3. CONNECT A BIAS BATTERY (-2V) TO THE A.G.C. -- PIN I OF V13, POSITIVE BATTERY TERMINAL TO GROUND.4. Ug A NON-METALLIC ALIGNMENT SCREWDRIVER TOOL.5 GOOD GROUND CONNECTIONS BETWEEN RECEIVER AND TEST EQUIPMENT IS VERY NECESSARY-- A METAL SURFACE BENCH
TOP FOR THE EQUIPMENT TO BE BONDED TO IS HIGHLY DESIRABLE.6 LOCAL - DISTANCE SWITCH IN " DISTANC E " POSITION.
STEP EQUIPMENT CONNECT TO I FREQUENCIES ADJUST INSTRUCTIONS
I. VTVM ACROSS R138 T
ISOLATE VTVM LEAD WITH18K ISOLATING RESISTOR.239R.F SIGNAL
GENERamPIN I , V7 OR TUNERTEST POINT 75 MC
BOTTOM OF T105 8 TIO7 FORMIN.
VTVM ON LOWEST XALE -TUNER ON CHANNEL 2.
3. SAME SAME 47. 25 MC BOTTOM OF TIO9 FOR MIN, r - ,11.6
4542 25
FID 1.
1.145E0 42 75
r I.F. RESPONSE PIN 4 OF via_416 39 7
FIG.2
SEE NOTE 2
4. SAME SAME 47.25MG FOR MIBOTTOM
NOF 7106
.
5. SAMESAME 41.6 MC BOTTOM OF 7103 FOR IN
TUNER TEST POINT 41.3 MC BOTTOM OF 7104 FOR MIN.
6. SAME SAME 42 25MC TOP OF 7104 8 T 1 05 FORMAX.
7. SAME SAME 43.1 MC TOP OF 7107 FOR MAX
8 SAME SAME 45 MC TOP OF 7109 FOR MAX
9. SAME SAME 45.3 MC TUNER UNIT , TI, FOR MAX START WITH CORE IN ANDTUNE OUT.
10. SAME SAME 45.75 MC TOP OF T106 FOR MAX.
II. SAME GROUNDED SHIELDUNDER V7
45 75, 45, 42.75,4225 41.6
USED AS A MARKER GENER-ATOR
12.OSCILLOSCOPE ACROSS RI 38 ISOLATE SCOPE LEAD WITH IRKRESISTOR. SET BIAS AT -3 VOLTS.
13 SWEEP GENERAlIZRANTENNA
TERMINALS CHANNEL 10 TOUCH-UP CORES ON TOP FORDESIRED RESPONSE CURVE.
SWITCH TUNER TEl CHANNEL 10.
14. SAME SAME MARKER 41.6397
TI08 (CATHODE TRAP) SEE NOTE 2
IS. SAME SAME CHECK ALL CHANNELS
NOTE TIO6 6 Ti AFFECTS HIGH FREQUENCY SIDE-- T107 a 0109 AFFECTS TILT ON Top Cl WOVE- - 7104 6 1105 AFFECTS LOW FREQUENCY SIDE
NOTE2. INCREASE SCOPE ON TO SEE SOUND PORCH aeTwEEN 41.6 AND 397 MARKERS DIOS ADJUST TO FLATTEN PORCH - - SEE FIG 2
VIDEO I F AND TRAP ALIGNMENT
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Arvin Chassis TE300, TE315, Models 5204, 5206, 5210, 5211, 5212, continued
SOUND [F. ALIGNMENT TABLE
STEP ECUIPME NT CONNECT TO FREQUENCIES ADJUST INSTRUCTIONS
I. VTVM ACROSS R107 (T101) -5V SCALE
2.SIGNAL
GENERATORPIN 2 OF VII 4.5 MC
TOP B BOTTOM OF T101 8 11DP OF
L101 FOR MAX OUTPUT ON VTVM
SET SIGNAL INPUT FOR
APPROXIMATELY -2V ON OW
3. VTVMJUNCTION OF RI I I ANDRII2 (DISCRIMINATOROUTPUT)
BOTTOM OF T102 FOR MAXIMUM
OUTPUT.SAME INPUT AS STEP 2.
4. VTVMJUNCTION OF RII3 aC115 (DISCRIMINATOROUTPUT )
TOP OF TIO2 FOR ZERO. SAME INPUT AS STEP 2.
5. VTVM ACROSS R107 (7101) -1.50 SCALE
6.SIGNAL
GENERATOR PIN 4 OF V12 4.5 MC ADJUST LI08 FOR MINIMUM.USE 20K ISOLATING RESIS-TOR IN SIGNAL GENERATORLEAD.
NOTE DISCONNECT ALL TEST EQUIPMENT, TUNE IN A STATION FOR BEST PICTURE IF BUZZ IS PRESENT ADJUST TOP OF TIO2 FOR MINIMUM.
roTEST
aTOG ADJ.57S NC.TOOT ADJ
T102 SECDISCIMEPECCR
FOCALIZEN 104
KINESCOPE21111.4
..........
rEtf SOC1iT Efili
OEFL ICIKE SDI (VENT)DEFL. %SEE SEM.(SEEMM-'
ION TRAP
CN-OFF
CONTRAST--..
TONE LOCALLINEARITYPHONO DISTANCE N
VERTICRL HCFRZ 5310.17-HC/LD HOLD/ NESS/ HEIGHT
FINME[1 11
'RPM
124 :127 0123
TUNERUNIT
0177
PPM VOLTAGE CAGE 1(v227.)
.v21)
'* TtD 4
V15 M.0
@ ("G.
4,Z2.26r611 iumc.
47M9m-Z. E11 T 113
POWERTRANS.
WIDTHCONTROL
LII6HORIZ.LOG(
TOP VIEW - CHASSIS TE315 BOTTOM VIEW - CHASSIS 7E315TUNER OSCILLATOR ADJUSTMENT
A High -Channels adjustment, A4, and a Low -Channels adjustment, A5, of the R. F. oscillator is accessible whenthe channel tuning knobs are removed. These two adjustments are shown on the Tuner Unit View.
HIGH -CHANNELS
1. Set the Channel Selector Switch to the highest available station between channels 7 and 13.2. Set the Fine Tuning to mid -position.3. Adjust A4 for best picture definition.
4. The remaining lower "High -Channels" should be within the range of the Fine -Tuning.
LOW -CHANNELS
1. Set the Channel Selector Switch to the highest available station between channels 2 and 6.
2. Set the Fine -Tuning to mid -position.
3. Adjust A5 for best picture definition.4. The remaining lower "Low -Channels" should be within the range of the Fine -Tuning.
NOTE: The design purpose of A4 and A5 is for optimum adjustment for channel 13 and channel 6-for optimumHigh and Low channels coverage. The above procedure gives optimum adjustment for any available stations.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION I
SCHEMATIC DIAGRAM Arvin
HOMIEST SYMBOLNUMBERS ASSIGNED
C '2061227.9
Gi70 JUNCTIONR216 4 C162
10 KEYED *GCWINDING, TH1
PIN 6, Y164
COLORSOCKET
0 0
010 0
COLOR 0,09.YPLUG
1 ST. SOUND I.F.
V/ 6AU6 ,*1205
0913StTO JUNCTIONR219 ANDR214
NOTE. 'GREEN DOT' YOKES0174 IS 68R223 IS 1000
PIN 5,v11
17- - - - -
I.FII
CIRCUIT DIAGRAM NOTES,
L RESISTANCES ARE SHOWN IN 046;K 1000, MEG 1,000,000.
L CAPACITANCE VALUES LESS THAN(I) ME IN MFD AND MORE THAN (I)IN MMFD UNLESS OTHERWISE NOTED.
3.0011. RESISTANCE VALUES LESS THAN(I) OHN IRE NOT MOWN.
4.ARROM AT CONTROLS INDICATECLOCKWISE ROTATION.
6.0.C. VOLTAGES ARE READ WITHVOLTOHNYST USING 100K ISOLAT-ING RESISTOR ON THE PRAE-ANTENNATERMINALS SHORTED -LINE VOLTAGE117 V -GO-. VOLTAGES SHOULD READWITHIN 20% EXCEPT VERY LOWVALUES AND WHERE NOTED WITH ANASTERISK (6).
S.CIAGILLATOR INACTIONS VOLTAGEMEASMED AT TUNER TEST POINT(-1.25 V DC. TO -2.5V.D
ECM/WIT WAVEFORMS TAKEN WITHHMI RESPONSE 900PE STATION.TIDIED M- PICTURE IN SYNC ANDUNBAR; CONTRAST MAXIMUM.!DISHINESS MAXIMUM (FORAPPOSES OF SCOPE CALIBRATION,
6.3 VOLTS itC APPROX. 20 VOLTS P -p).RESISTMICE VALES SHOWN ARE WM
PART DISCONNECTED FROM CIRCUIT.
ARP
S.
LbSWIOX
I RISC,22K
7195
A VOLTAGE MEASURED WITH CONTRAST MAXIMUM.
615636
WHITE.
WIRE &RAID
YELLOW
ci94T 1000
R1611201(
4
-ISV.
NOTE
rE315-2 differs from IE315-1 as follower
1. :1206, 5000 EEF, added to pin 7, V14 to ground
2. R210 changed to 8210-1, 47E
3. 0204 *hanged to 0204-1, 8.2 Ma
24
2ND. SOUND I.F.
V2 6AU6$1105.
A.G. C.TUBE
V146AU6
mem47 K
5 P
V/36A V6
A. G. C.CATHODE
FOLLOWER
RIM 2154
RISE47
Cif?ICo0
"" 11056 4115 59 /SAP
MG
SYNC. SEP SYNC. CLIP
V/522K
LIMITER
1/3 6AU6
2ND. PIX I.F. 3RD. PIX 1.1
tost 5931147.25e15 MC
1112. 455V.
RI73SSS
7SK1U- V 149 1C0"'RIT4315
\ 1,4c.Ovrip
r 50G( ET
L5LSYmNICT.ER
$315 5.
01661.001
350VPP
R11312115 470KKOK
121144.7.MM.
T09,0Ks°
L116
0215
81793300
I§
fl7" ISVPP
0 C 6.IPPLV
L
6SN7GT
21.K
CAN
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
TELEVISION CHASSIS TE315-2DISCRI MIN ATOR
V4 GALS-.4V
:WS 610
541
L104
0141ICCO
HORM
155.50 550)
NB98
011COO
VERT.RI 611 MOLDAMR
R166103K
I ST. AUDIO AMP.
V5 6AV60011
P00/40 7005 T.0053JACK
1104.040 (4.5 MC)
6555.5
4113710 140.6
4146ISO
51661.5 /454
1210.02.5 SEA
A6C 400 0002. Arc PULSE
1A707110K
0115.01
CONT. 811610 ME4
WO 6BA64TH. PIX I.F.
VERT. OSC. VERT. CUTPUT
6SN7GT073
17171HORIZ OUTPUT
MOVPP, V20
6C D6G
R1912.11/55
.354 FUSE
TO COLOR SOCKETP:Nt 114
IL-4f-11HPI Z70 COLOR. SOCKET
011.01 ,,,
AUDIO OUTPUT
V6 6Y6G aiov.
V.
MODELS 5210-5211-5212
50101
16LACK
SLUE 5 31. V.
L107 A L 010.001041 1--,---' 75 1
..--41.-ins n ,._ VIDEO AMP
ciao . 4V icT1, V/25- 5113 7 I 1 '1° 111116
L110330 L 6AC 7 41K
v
24111 66 , CI
1,11:1 DE T R15610
4100
51 VP
V21IB3GT
H7VRECT.
6 W4GT
DAMPER CI11
Y OW450
0114 070311 .077
To PM 5 7ccAolt.
10CKET-
TO 1111N4COLORSOCKET
POWERRECT
Y _
011
sib
loMSS 350ISK
PIXTUBE 2.1AP4
R195 -I 51292204 1704
V235U 4G
1231V
+15 K. V.
CI14 AY
SUCK RED -SLACK
507105SIV104
RIAI92100. A
11615 V 1.1.61%1111.4 1.615 V.
0115 540
25
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
ARVIN TELEVISIONChassis TE300, TE315,
Models 5204, 5206,5210, 5211, 5212,
(Continued)
TUNER UNIT
AI
A5CHANNEL 6'
CENTERING ADJUSTOSCILLATOR
A Centering Crank (see chassis-top view) adjusts centering as follows:Moving Crank to the right moves picture down.Moving Crank to the left moves picture up.Moving Crank up moves picture to the left.Moving Crank down moves picture to the right.
V266AK5R.F. AMP
- V256J6RE. OSG -MIXER
A4CHANNEL 13OSCILLATORADJUST
The Horizontal Hold Control will move the picture horizontally and should be set first to the middle of its range ofmovement of the picture. The Centering -Crank should then be used to center the picture within the mask and removecorner -shadows. If corner -shadows persist, check to see that the Yoke and Mounting Frame are as far forward ontothe cone of the picture tube as possible. When the Yoke and Ion -Trap are positioned properly, the Crank will readilycenter the picture without corner shadows.
HORIZONTAL DRIVEAdjust HORIZONTAL DRIVE TRIMMER (C184) to the point where "overdrive" lines just disappear. "Overdrive"lines appear as a vertical white line in the left portion of the picture. The Horizontal Driver Trimmer is located inthe control grid circuit of the Horizontal Output Tube (6CD6G) controlling operating characteristics of the tube.Turning the Horizontal Drive Screw clockwise reduces Horizontal Drive.
WIDTH ADJUSTMENTAdjust WIDTH CONTROL (T112) to obtain a picture with sufficient width to just fill the picture frame. Maximumwidth occurs when the screw protrudes about 1/2" from the coil mounting -clip. This adjustment regulates the amountof deflection current flowing in the horizontal deflection coils controlling the horizontal dimension or width of thepicture.
HEIGHT CONTROLWhen the picture is too large or too small vertically, adjust the HEIGHT control for size. Note that the adjustmentof this control may require a readjustment of the VERTICAL LINEARITY control.
VERTICAL LINEARITYWhen the picture is not uniform vertically adjust the VERTICAL LINEARITY control until the picture is symmet-rical from top to bottom. The HEIGHT control may also have to be readjusted.
HORIZONTAL LOCK ADJUSTMENT1. Tune in an available station.
2. Set the horizontal hold control at its maximum cour. -_-clockwise position.3. Adjust the Horizontal Lock adjustment on the middle-rear of the chassis until it is in sync. (See chassis
view).
4. Turn Horizontal Lock adjustment clockwise until the picture goes out of sync.5. Turn Horizontal Lock Adjustment counter -clockwise until picture just pulls into sync. The picture should now26 hold sync over the complete range of the horizontal hold control.
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
BENDIX AVIATION CORP. Bendix Radio Division
Models T170, T173, C174, 0176, C176B, T190, 2060, 2070, and 7001use the circuit on this page with a 17" picture tube. AdditionalModels 2051, 3051, 6001, 6003. and 6100, use 14" and 16" picturetubes and are almost identical in circuit to the ones describedon this page. Model 6100 uses a separate radio section which em-ploys only the speaker in common with the TV section.
IF ALIGNMENT
ua
.p XBX
10
0 40P Fb ,
i;irc
rxrf. 011,
API almaOFPOW
4;2
101
OM"
:555.0g44 M . il
0 In some receivers V7 is 6T8, Ratio Let &1st Audio, in this position. In some re-ceivers VI8 (6AT6, 6AV6) will bein this position.
, In some receivers V7 will be 6A1.5, Ratio- Dec in this position. V18 (6AT6, 6AQ6,
6AV6) tberCused as 1st Audio
0413
480
OSC.
1/2 616042
If ALP.6105 0460116
8400 t VI
22f
04002
1.400
AR
3
1C32
L4I2
14110
1110
9
5409
5408
1401
6
1408
1405
1404
3
1403
5
-Nw-4401
221C401
610
I, C102A
*1061I/O 6161
044
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1424II 0405
1423 .5
42209
1121
11
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FINE
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1437
1493
143510
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433
L432
L431
1411 6,106 1430
5
1.411 1429
1411 1421
C403
1421
45
25
1149
2
1148
1440I'01:171
14436 /505
1145 156
1141
1113
1412
1441
1440
NOTES
28
2CIO
I F
60443
Generator Freq. V TVA! Connections Adjustment Remarks24.4 MC23.5 MC
25.0 MC
To Video Test Point & GroundTo Video Test Point & GroundTo Video Test Point & Ground
T2T1L452
Adjust for Max.Adjust for Max.Adjust for Max.
SOUND ALIGNMENTAlignment using AM signal generator and VTVM:
The value of the two 1001( resistors connected in step one should be within I°I of eachother.
Signal GeneratorCoupling
Signal GeneratorFrequency Connect Adjust Remarks
High side to VideoTest Point. Lowside to Chassis,
High side to VideoTest Point. Lowside to Chassis.
4.5 MC
4.5 MC
Parallel C19 with two1001( Resistors. DCprobe of VTVM to pointA. Common lead tochassis.DC probe of VTVM topoint B. Common leadto point A.
L6 andL7
L9
Adjust for maxi -mum reading inorder given, thenrepeat.
Adjust for zeroreading at cross -over.
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BENDIX STANDARD CHASSIS
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
CROSLEY
1.
Models: DU-17CDM, DU-17CHB, DU-17CHM, DU-17CHN, DU -1700B,DU-17COM, DU-17TOB, DU-17TOL, DU-17TOM
(Chassis 356-1)
The material on the next six pages covers service information onChassis 356-1 used in models listed above. The suffix -1 indi-cates a definite production run, so that suffix -2 or othersafter this chassis number would suggest a circuit with but minorvariations. Many other chassis used in models of this same periodare very similar to Chassis 356-1, and therefore this materialmay be used as an aid in servicing these additional Crosley sets.Some of these sets use 16", 17", 20", or 21" picture tubes, may havesimilar -function but differently numbered tubes in some of thecircuits, some are combinations and have switching arrangements,and these various sets may also differ in other respects. In themain, however, these service notes will be applicable to:
Chassis
ChassisChassisChassis
Chassis
Chassis
Chassis
Chassis
321-4, Models S11-447MU, S11-459MU,323-3, 323-4, Models 20-CDC1, 20-CDC2, 20-CDC3,323-6, models 820-CDC1, S20-CDC2, S20-CDC3,331, 331-1, 331-2, Models 17-CDC1, 17-CDC2, 17-CDC3,
17-CDC4, 17-COC1, 17-00C2, 17-00C3,
331-4, Models 511-442M1U, S11-444MU, S11-453103, S11-472B1U,S11-474BU, S17-CDC1, S17-CDC2, S17-CDC3,S17-CDC4, S17-COC1, S17-00C2,9.7-COC3,
357, Models DU-20CDM, DU-20CHB, DU-20CHM, DU-20C0B,DU -2000M,
Models DU-21CDM1, DU-21CDN, DU-21CHM1, DU-21C0B1DU-21COL, DU-21COLB, and DIT-21COM1,
359, Models DU-17PDB, DU-17PDM, DU-17PHB, DU-17PHM,DU-17PHN, DU -17P101,
363 (used with
To Check I.F. Alignment on Oscilloscope:a. Apply a negative bias of approximately 3.5 volts to the grids
of the I.F. tubes V101 and V102. This oias can 'eobtainedby the use of a 5000 ohm variable control with suitable leadsattached (see sketch). Connect one side of the control to -6volts on the lug of terminal board TB9 and connect the otherside to the chassis (ground). Connect the center tap of thecontrol to the AGC terminal (orange lead) on the terminalboard TB1,1ocated close to L102 on the I.F. strip. By adjust-ing the control, bias voltage may be varied from zero to -6volts.
b.
c.
d.
To A. G. C. Terminal (Orange)
To -6 rolls
5000 Oam Control only, Part No. 111260
VARIABLE BIAS CONTROL ASSEMBLYConnect high side of scope to pin 1 of the AGC AmplifierV108, and the low side to ground (chassis).
Remove R.F. Amplifier tube VI to eliminate spurious res-ponses,
Lift the shield on the Oscillator -Mixer tube V2 sufficientlyto clear the socket ground clips. Connect sweep signal gen-erator "hot" lead to the ungrounded tube shield and genera-tor ground lead to the tuner chassis. Leads should be asshort and direct as possible.
NOTE:
362 and 371), Model DU-20PDM.
I.F. ALIGNMENT'e. With the generator sweep set at zero, connect an electronic
voltmeter across the detector load resistor RII7, and adjustoutput of generator to obtain a reading of 2 volts d.c. on themeter.
f. Set generator to sweep from 20 mc. to 30 mc.
g. Set tuner near the low frequency end of the range.
h. Connect marker generator to sweep generator output leadsand adjust to provide markers at 21.9 mc.. 22.9 mc., 24 mc.,25.5 mc., and 26.4 mc.
NOMINAL OVERALL I. F. RESPONSE CURVE
1. Observe curve and position of markers (see nominal responsecurve). The 21.9 mc. marker should be approximately 70%down from the peak and the 26.4 Inc. marker approximately43% down. Slight deviation in shape from the nominal res-ponse curve is permissible, but if any great deviation is noted,it will be necessary to realign the I.F. Amplifier. NOTE: Theresponse curve may be distorted unless care is used in themethod of connection to prevent feedback or regeneration. atmay sometimes be necessary to connect a 1 megohm isolatingresistor at the end of the scope lead to prevent feedback.)
In normal signal areas, align the I.F.'s with the contrast control completely counter -clockwise and the bias as high as possible (re-duced only enough to permit a suitable deflection on the scope or meter). Keep the signal sufficiently low to prevent overloading ofthe 2nd. detector. 29
30
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
CROSLEY Chassis 356-1, Models DU-17CDM, DU-17CHM, and others, continued.
I.F. ALIGNMENT
Disconnect the generators, scope, and the 5000 ohm variablebias control from -6 volts, the AGC terminal and ground.Replace R.F. tube and shield and push Oscillator -Mixer tubeshield into grounding clips.
2. I.F. Alignment Procedure.
a. Apply a negative bias to the I.F. tubes V101 and V102 as in(a) of "I.F. Alignment Check".
b. Connect an electronic voltmeter across the 2nd Detector loadresistor R117.
c. Remove R.F. Amplifier tube VI to eliminate spurious res-ponses. Connect signal generator as in (d) of IF. Align-ment Check".
d. Set tuner near low frequency end of range.
e. Set signal generator to 24 mc. and adjust L105 for maximum
SOUND AL
1. Connect "hot" lead of signal generator to grid (pin 1) of V106.Set signal generator to 4.5 mc. with 400 cycle amplitude modu-lated signal, modulated 30% or greater.
2. Connect scope to picture tube grid (pin 2) through detector probe.3. Connect two 100,000 ohm resistors (matched to within 1%) in
series across ratio detector load resistor, R143. Connect com-mon lead of the electronic voltmeter to the junction of thematched 100,000 ohm resistors, and the d.c. lead of the volt-meter to chassis (ground).
4. Using a high level signal input with the Contrast control set atmaximum, tune the Sound Take -off Transformer (T101) primary(bottom of chassis) for minimum deflection on the scope.
5. Reduce signal input to below limiting in V107 (Sound Detector
(Continued)
meter deflection, limiting meter deflection to 2 volts d.c. byadjusting input attenuator.
f. Reset signal generator to 22.2 mc. and tune L104 in a similarmanner.
g. Next set signal generator to 26.55 mc. and tune L103 formaximum meter deflection.
h. Reset signal generator to 22.9 roc. and tune L102.i. Set signal generator to 25.5 mc. and tune L101 for maximum
meter deflection.J. Repeat steps 5, 6,.7, 8, and 9.
k. Disconnect signal generator, electronic voltmeter and the5000 ohm variable bias control from -6 volts, the AGCterminal and ground. Replace R.F. tube and shield. PushOscillator -Mixer tube shield into grounding clips.
IGNMENT
Driver) and adjust the Sound Take -off Transformer (T101)secondary (top of chassis), and the Ratio Detector Transformer(T102) primary (bottom of chassis) for peak meter reading.
6. Repeat steps 4 and 5.7. Remove the detector probe and scope from the grid of the pic-
ture tube.8. Transfer d.c. lead only of the electronic voltmeter to junction
of R144 and C133 (top lug of TB6).9. Return to high level input for limiting in V107 and adjust the
Ratio Detector Transformer (T102) secondary (top of chassis)for zero meter reading.
10. Remove the two 100,000 ohm resistors and all test equipmentfrom the receiver.
HORIZONTAL DRIVE
The setting of the HORIZONTAL DRIVE trimmer should bechecked to see that no change in linearity in the center of the pictureoccurs with change in Contrast setting. In adjusting the HORIZON-TAL DRIVE trimmer, it is necessary to observe the picture widthand set the trimmer to the point of maximum width (toward minimumcapacity). To set the trimmer correctly, turn it counter -clockwiseuntil the picture width starts to decrease or until a compression inthe center of the picture is noted, whichever condition occurs first.In the extreme case, the compression in the center of the picturewill appear as a vertical white line.
A check should then be made to see if the horizontal linearityin the center of the picture changes with Contrast control setting. Ifit does, turn the drive trimmer slightly clockwise just enough to
A.G.C. ADJ
Tune in a station witn a weak signal and adjust the AGCTHRESHOLD LEVEL control on the rear apron of the chassis to apoint where the receiver will just begin to overload with the CON -
eliminate this change in linearity.
If the drive trimmer is misadjusted so that insufficient driveis applied to the tube, it will draw excessive current which willseriously shorten the life of the tube. This condition corresponds tothe drive trimmer being adjusted too far in the clockwise direction.
After tube replacement, readjust the drive trimmer as out-lined in the paragraph above. The best horizontal linearity coincideswith the lowest plate dissipation of the horizontal driver tube and thislinearity should be obtained with the adjusting screw of the HORI-ZONTAL LINEARITY inductance as far out of the coil as possible.It should be noted that changing the linearity adjustment makes itnecessary to readjust the HORIZONTAL DRIVE trimmer.
USTMENT
TRAST control set at maximum. If the receiver overloads on astrong signal, turn the CONTRAST control toward minimum to pre-vent overload.
HORIZONTAL BLOCKING OSCILLATOR ALIGNMENT
1. Tune receiver to a television signal and adjust CONTRAST controlfor normal picture below limiting in the video amplifier.
2. Adjust the HORIZONTAL HOLD control and the HORIZONTALFREQUENCY adjustment (top of T106) until picture is in sync.
3. Connect scope in series with a 10 mmf. capacitor to terminal 5of the HORIZONTAL TBO TRAP (bottom of T106) for the follow-ing wave form; keeping raster in sync by adjusting the HORIZON-TAL HOLD control, HORIZONTAL FREQUENCY and/or HORI-ZONTAL LOCK adjustment.
Adjust so that IM peak of pulseis equal or 10% higher thanpeak of sine wave.
4. Turn the HORIZONTAL HOLD control fully clockwise. Adjust theHORIZONTAL FREQUENCY control (top of T106) by turning outuntil the raster is just out of sync, and then turning the FRE-QUENCY control in slowly until the raster is just ready to fallinto sync (indicated by a wide 'black vertical or diagonal horizon-tal blanking bar).
5. Turn the HORIZONTAL HOLD control fully counter -clockwise.Picture should normally be in sync. Remove the signal by tuningoil the station, then return to the signal. If more than seven barsare present, adjust the HORIZONTAL LOCK trimmer slightlycounter -clockwise until five to seven bars appear before the pic-ture falls into sync when the HORIZONTAL HOLD control is setin the extreme counter -clockwise position. If less than five oarsare present, adjust the LOCK trimmer clockwise. As the Lock -intrimmer adjustment affects the horizontal frequency, the adjust-ment of both the Horizontal Frequency control and the Lock -intrimmer must be repeated until the conditions outlined above insteps 4 and 5 exist simultaneously at the extreme positions of theHorizontal Hold control. Check the pull -in range. Pull -in rangeshould be 120° minimum and 220° maximum.
6. The final setting of the Horizontal Hold control should be madewith a very weak picture. Rotate the tuning knob on and off thestations frequency, and set the Horizontal Hold control so thatthe picture returns completely in sync.
The most important points in the Horizontal Oscillator and theAFC Alignment for most stable operation are: (1) that the rasterjust falls into synchronism at the clockwise end of the HorizontalHold control, and (2) that the pull -in range is between 120° and220°.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
CROSLEY Chassis 356-1, Models DU-17CDM, DU-17CHM, and others, continued.
ANT. TERMINALAC. INTERLOCK J101 BOARD
RECEPTACLE I-1 CC]
P102 RATIO DET. SOUND TAANKSE. -0 F FtO UTRANS.TRANS
V114
V107HORIZ FREQ.
O SEC. ADJ. SEC.ADJ:'
VI 7 AOJz SOUND 0 ®47 CY
06SN7
GT® DET. T102
(1:10T101
T1061108
SOUND DET. V106
F101AFC &
HORI Z. OSC. POWERTRANSFORMER
DRIVERV113 DEOVI
AUDIO AM AmPL.
D AGC.DELAY V105
,VI 16 VII5 ES 1::)
2ND. DETHOW. t- a NOISE6 W 46CD6G DAMPER C010i LIMITER ,
GTP103 V 112
AUDIOI LI05
LI I 3
HORIZ. OUTPUT
HORIZ. LIN.ADJUSTMENT
LI20WIDTH ADJUSTMENT
I
3RD
4.--dIIIIIIII,
LOW VOLTAGERECTIFIER
6 W 6 5 TH. I -F ®COILG T OUTPUT
I V104
4 TH.1-1)1AmPL.
1
V 110 1 LkiziVIII 4 TH. I -F COIL
5U4G I VI3I -F
DC. RESTORER8 SYNC
AMPL.
TAKE -OFF1 LI 3
3 RD. 1 F OILVIO 9
I V I 2SYNC CLIPPER6SL7GT
REMOVE THIS PLATE TO SERVICE HVRECTIFIER TUBE V120 UNDER CHASSIS.
C I 20 B;SYNC OUTPUT 2AMPLAMPL.
V108 2ND.
AGC 0 I
AMPLIFIER1 ST.AMPL,
L101
LI1.-F. OIL
VI I
I -F 6AU6
I ST. I -FO TRANSSEC.
4111> riVII86 BL 7 VERTICAL OSC.
a VERT. AMPL.
V2I2AT7 OR 121/7OSC. a MIXERGT
....1 0VI
6CB 6F AmPL.CIR.
ID
ILIll
1
CONTRASTCONTROL ---"
OFF - ONVOLUMECONTROL
R145
Chassis Top View
1 1=a,
R172VERT.HCLDa-
Showing
=1-=--1- 1
R184HORIZ.HOLD
t2,
Tube
,L 1
R133BRIGHT-NESSCONTROL
and Alignment
RI62FOCUSCONTROL
Locations
TUNINGCONTROL
31
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
CROSLEY Chassis 356-1, Models DU -17CDM, DU -17CHM, and others, continued.
AGC LEVEL J101 SPEAKER HORIZONTAL HORIZONTAL
CONTROL jElt, TB 6 SOCKET DRIVE ADSST. LOCK ADSST.
-1R159 r RATIO DE\t.'74 e ll 14 .._. .SOUND TAKE -OFF VI 0 7 TRANS I V114
PRI. ADJ
O.PRI ADJ
C).--0 0
TERMINAL0HORIZ.0
B.T.O. VII76AU6 6A L5 i 0TIOI T102 SOUND
DETECTOR
5 0
ADJ.6S N7
GTTRANS.
SOUNDRI4RDE T. TIO8 O TC6 u
VII3V106
VIDEOAMPL. AMPL ai
ge AUDIO
POWERTRANSFORMER
HORIZ. OSC.B AFC
AGC.V 105 02N DELAY \., /
DET.D
NOISE. ii:RH7
, GREEN LEAD-I (CRT GRID PIN 2)
411,c,0 0 0
VII56 W 4GT
V 116
6CD6G
HORIZ.OUTPUT
LIMITER
L105V104
i
1 P
I \3-(-6v)
V 112 AUD 0
RED GTI 6W 6 OUTPUT
I
HORIZ.DAMPER
L 113
4TH
AMPL,0TB .
0T8 5
VII0
HORIZ. LIN. ,,----\_INDUCTANCE ,fu 0,3 014 0,5 6( 07
LIO4E)
3RD
111 VIII5U4G
T107Q HORIZONTAL
TRANSFORMEROUTPUT 0
I -FAMPL.
L103
DC. RESTORERLOW VOLTAGERECTIFIER O
LI20WIDTH
INDUCTANCE 0'8V 109
2ND6577
GTT105 -Th
1-FAMPL.
SYNC. CLIPPER& SYNC OUTPUT
VERTOUTPUT
C173
0 V108 TRANS.L102 ..----.
1STI 01
i - F
iw
.6,±1
1 0fru
A.G.C.a,--
V 120HIGH VOLTAGE RECT
AMPL .A I-., AMPLIFIER
I B3GT
L101TBI
I`,, 4- \I
I T 104 VERT OSC. VI 18
NNEIIII vERT. 8.T.VERT.
O.&Am PL.
6B 7LG T
111
TRANS,
R -F TUNER 0 P 1i0175
co, :------, c,RI 78 R175 f,,) fa)
..../.- B- (-6v) TB 9 LINEARITYHEIGHTT
C ISWI02}EN -A213 R1458
R162 R133 R184 _ 8172 R I45A
32
f=tiTUNINGCONTROL
Chassis Bottom View Showing
f---1FOCUSCONTROL
Tube
(-=_YBRIGHT-NESSCONTROLS
Socket
(____
HORIZ.
HOLD
and
VERT.HOLD
-c3
Alignment Locations
CONTRAST-CONTROL
t.,, OFF - ONVOLUMECONTROL
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
CRCS= Chassis 356-1, Models DU-17CDM, DII-17CHM, and others, continued.
ADJUSTMENTS
ANTSOCKET
COI
cV
e-
5 5
The DEFLECTION YOKE is positionedasfar forwardas possibleon the cathode ray tube and rotated so as to make the top andbottom of the raster parallel with the top of the chassis.
+150V.
0In>
re)0
Ouc, ameI'
Fz1zt
LII40
-11305D.ME
I -F SUB -ASSEMBLY
CI L24 L3 7'
VI6CB6
270100 000
12
o C16
C4 -e71%/:.
C2 I .8 r R282
0V/7.1500
BROWNL/
st
The FOCUS COIL should be adjusted to be approximately per-pendicular to the cathode ray tube axis with the front surface ofthe focus coil housing approximately 15/32 inch from the rearsurface of the deflection and focus coil mounting bracket.
The ION TRAP is positioned for maximum brightness, with lowto medium settingof the BRIGHTNESS CONTROL and for no neckshadow at high setting of the BRIGHTNESS CONTROL.
Center the picture by adjusting the three FOCUS COIL mountingnuts. Readjust the ION TRAP.
Adjust size of picture to fill the screen by means of the HEIGHT,WIDTH and HORIZONTAL DRIVE controls. When adjustingHEIGHT CONTROL, it is sometimes necessary to adjust theVERTICAL LINEARITY CONTROL. Before ad-justing the HORIZONTAL DRIVE CONTROL, be sure to refer toHORIZONTAL DRIVE information.
HORIZONTAL HOLD CONTROL is adjusted with a weak pictureto center of pull -in range.VERTICAL HOLD CONTROL is also adjusted with a weak pictureto center of pull -in range.
Vertical linearity is adjusted by the VERTICAL LINEARITYCONTROL and the HEIGHT CONTROL. Horizontal size of pic-ture is adjusted by the. HORIZONTAL LINEARITY and WIDTHadjustments.
The FOCUS CONTROL is adjusted for best focus of the verticaland horizontal wedges at the center of the test pattern. If thereis any astigmatism, the focus should be set in favor of the verticalwedges. If corner focus is poor, check position of DEFLECTIONYOKE and ION TRAP.
In later production sets,color converter connections
"'\">1 Also C182 was changed to
J101, C0101, and P103 aredeleted and lug 5 of V108
>is wired directly to L120.
.0082 mfd., 10%, 1000 v.RE TUNER capacitor.
C8
V2A L61/2 12AT7 L5
OR 1/2 12AV7
1-+I3V1
7 5
CS
1500
.L4 6
P 1c9L 78-5.5
L2B
4
11
//5000 if
C6" 5600R5R8/
L _ _NOTESI 1010002 ALL RES STANCE VALUES IN OHMS AND
CAPACITANCE VALUES IN me UNLESSOTHERWISE NOTED.
R. F. TUNER SCHEMATIC DIAGRAMLB 04,81=1
L128.2
I7
3.3
I
R9120
=10
CI8
1500
CII
1(1500
OBLuE
L7
BROWN
.\\ 000
Cl2
LAOO
C13
I( -IC14
6
778-5.5,171
15K
V2B1/2 12AT7 OR1/2 12AV7
7
6
5
CI5
T6
+10501
TO LIOI
TO IF ACC
+8RED
0" HIGH HEATEREILK.13 TEL
33
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONDeWald Radio Manufacturing Corp. TO ADJUST PICTURE I.F.IS:
Models
(Presented
100%70ingTO80%
50%
ET -140R,ET -170,
ET -141R, DT -162R,ET -171, ET -172,
below and the next three23.2 MC 25.2 MC
24.1 MC
22.5 MC 26.35 MC
DT -163R, I. Connect the negative terminal of a 3 volt "A" battery to the
DT -190D. junction of the I megohm and .25 Mfd in the ADC bias line, (pointE on schematic) and positive terminal to a chassis ground. Setthe contrast control to the fully clockwise position. Set finepages) tuning control with flat in horizontal position.2. Set channel switch to channel 3 or any clear channel.3. Connect a VoltOhmyst across the second picture detector loadresistor of 4700 ohms. Plus end to go to junction point of peak-
coil L-5 and 4700 ohm resistor and minus end to other sideof load resistor (junction of 4700 ohm, 1K ohm and .1 Mfd con -denser).
4. Couple the high side of the signal generator to the mixertube of tuner by slipping a tight fitting insulated tube shieldover the tube envelope and connecting the generator lead to it.Connect the ground side of the signal generator to the frame ofthe tuning unit.
5. Set A.M. Signal generator to 25.2 Mc and peak detector I.F.(L-3) and first picture I.F. coil (L -l) for maximum gain onVoltOhmyst.6. Set A.M. Signal generator to 23 Mc and peak second I.P. coil
(L-2) and converter I.P. coil on top of tuner for maximum outputon VoltOhmyst.7. When using an oscilloscope and a wide band oscillator for
NOT, ANT 01 In PLAI ON Tokyo AECPOINT, NAT DE UP TO TOE OIT AND-TILL .IVE GOOD PICTURE Detat.b.
calibrating and checking bandwidth of the I.F.'s, connect sweepgenerator to the point indicated under step 4. Connect theoscilloscope high side (in series with a 40Y ohm resistor) to thejunction of the peaking coil L-5 and 4700 ohm resistor, and theground terminal to chassis. Align the picture I.F. to producea response curve similar to the one shown.
[4 3.85 MC .
NOTE: During picture I.F. alignment the common lead of VoltOhmystTYPICAL OVERALL RESPONSE CURVE is connected to approximately minus 2.5 volts with respect to
OF PICTURE LE'S chassis. Avoid grounding the VoltOhmyst case.
PIN NUMBERS AND VOLTAGES (20,000 OHMS PER VOLT)TUBE POSITION
I 2 3 4 5 6 7 8
5U4G Rectifier 400
6CB6 1st Pix I.F. 1.0 0.5 125*Contract
c
Controlfully
-w
6CB6 2nd Pix I.F. 0.8 125ff .
6C86 3rd Pix I.F. 1.70 1203, 3,
6AL5Video Det.A.G.C. Rect. 3.0 -2.5 -1
. n
6AH6 Video Amp. -2.0 1.8 Cont. Contr. CCW 160 160 1.8
6AU6 Sound Input` 130 330 180 135
Sound Det.# Pin 9 [6T8
1st Audio 125 115 115 130 120
6V6GT Audio Output* 280 300 125
....J95
130
12AU7 Sync. Sep. & Amp.D.C. Rest. 20 0 2.0 Cont. Contr. CCW 70 20 20
6SN7GT Hor. Osc. & Disch. -6.2 100 10 250 10 H -Hold fully ccw
6BG6GT Hor. Output 7 -13.5 270
6W4GT Damper 510 360 135
6AL5 Phase Det. 0 0 8.6 -8.2
6J5GT Vert. Osc. 250 -60 V -Hold fully ccw
6V6GT Vert. Output 280 - 7
V -Lin & Height full
clockwise 14
Kinescope#20
#10 Red325
#11 YellowB'tness Cntrl: cw, 35; ccw, 70
#12 Brn6.3 v, AC
Main B+ Bus 350 v. to 360 v. 35Intermediate B+ Bus 135 v. NOTE: All voltages measured to ground.
PIX INPUT23 M.C.
TUNERFILAMENTS
TUNERFUSE
ELECT RO -STATICSHIELD -...
VOLUME tON -OFFSWITCH
TO II5V.GC ACFION050PPLV
BLIC
_
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION IFRONT - END TUNER
Four types used.TO EL_ECTUNER
II TO TURRET TUNER.
270.n. 1200nL
_JTUNERBIAS
_ _ J
SOUND I.F. AMP
GAUL
PEAK_ AT4.5 M.C. 2 ?IL
PEAK FORMAX.
6
,ttf" I1tL8 7
r 4 1A/Lty- 3
35K 47K1
68
.02.
+360 V. BUS; 1
.005
ttr
PEAK FOR*ZERO
RATIO DET ECT1K TRANSFORMER
+ 140 V. BUSS
1 37. PIX I.F.
GCBG
"0I(
- PEAK ATc." 25.2 mr.
005
0
2ND. poc. I.F. 3RD. PIXPEAK AT MC.
GC BG
`D1
1500L2
0
00co
0
3301L
.005 ZY
I MEC,.
330,n_ 25 4- a VOLT(FOR CRua
SYNC. PHASE INV.
RECTIFIER SPEAKER FIELDG2 _n-5U4G 10-0-ORN. -YEL. YEL
5 V. .5A R-/WV \r-
TEL. 40 40QED
Y 6RD 0
"1g go RED',c*csNd
1/40
GRH.-Red
VERTICAL OSC-. VERT. CDSC it DISCT ERANSFOR MR
RED BLU G J5 3
2a K B2.00 6200
1500
YEL 6RT3
.002 .005 T .005
+I 30 MEP
4700
0o
FZo
U U
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23 =
6.8 MI
OMr
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LK-YE-X
BLK-C.RN
DE WALD ET -00-1117ZDT- 190ET- 140R-141 R.
36 DT- 1628 -163R
500MFD,
13LRID 6.3 V. O
0
NOR. PHASE OCT.
GAL5
4x
.005
fo-NA.M.r-4-70 K
114
.005L9
5600
HORIZ0.5c
4300 5
M OR.OS C
CONTROL
1--
HORI7
15 0030K
_L- .-/\2<V
HOR Hod) CONT
I MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONRATIO DET.
- GT 8
SOUNDVOLUME ,005CONTROL-1(
1330
K
01
C 1500
AUDIO OUTPUT
GVG - GT
0
-'\.AAN-4700
A . F. AMP
lie- GT 8
5
4
390I WATT
c,so
P I X DET.- A.G.C. RECT.PEAK AT 25.2 NIX -
05
.035
20etJI-1<z0 1 1000 MFD
54 K
GAL5
470K =
VERT.OUTPUT
G VG- GT 3
IC.25
'SO
. 002
1(
20,40,
10 KI W.
7
2' 5K2 VERT.
LIN.
3, o.nI W
NORDRIVE
I 2 0 J.4 h
5 MMF.
L5
VIDEOAMPGAH 6
.n2
1.2.5 tIMF.
275 Ai h00000
Lic,c400,A.th
CONTRASTCONTROL
540 560o VERTICAL `fOKE
1-ioalz.oLrrPuT_ctL6 t3G6 -GT
2
HORIZ. OUTPUTH V TRNNSF
T5
NOR. LIN.CONTROLa01
035 1-11 1.05
T2AUDIO OUTPUT
TRANSFORMER
BLU.c,.005
REDO
D. C. REST. - SYNC. 5 t.P.
1/2-12 AU7 a3
H. If. RECTIFIER
I B3- GT
V. or/soz - 109/10
DE WALD
12
ANODECAP
RISC OPE
180KT
Iazoi\A-W"---7ni*o-----\A"He-V.1 MFDT
BRIGHTNESSCONTROL
( ANOPDE Wa IN SOMEI MEG. DA) L9 ,111-V COND.
IS RETURNED TODAMPER PLATE IN-STEAD OF GROUNDI 500 I,IMF
HORIZONTAL YOKE
37
W
OU
TP
UT
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EG
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645
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SIS
Z
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
DU MONT TELESETSRA -111A RA -112A RA -113
Putnam Ardmore BrookvilleGuilford Westerly Revere
Mt. Vernon BurlingameTarrytown
The double -spread circuit shown on the next two pages and the INPUTUNERcircuit on the page following are exact for chassis used in RA -111A. Thechassis used in RA -112A and RA -113 Telesets is basically the same as theone described. The main differences are briefly explained below.
The Inputuner used in RA -112A with serial number under 122696, and inRA -113, under 132211, is electrically the same as used with RA -111A. Thelater sets used a different I.F. transformer in the plate circuit of themixer. These sets also had another type 2204 transformer. The fourthvideo I.F. tube (V208) was changed to 6B05 from 6AU6, and this requiredthat R231 be 220 ohms instead of 120.
The sound I.F. and audio amplifier sections are practically identicalin all of these models. Since the model known as Tarrytown includes AMradio and record changer, in this model certain provisions have been addedto the audio output stage for this purpose.
The coupling of cathode of V209A to the grid of V212, is made througha 20 mmfd. capacitor instead of direct, and a coil is added from grid toground. A "local -distant" switch is added to AGC circuit.
The vertical sweep circuit has these differences: R288 is changed from2.7K to 3.3K, C271 from .003 to .01 mfd., R293 from 1.8 megohms to 390Kohms, R296 from 5.1K to 4.7Kohms, a 30 mfd. capacitor is added in serieswith C248A, the plate circuits of V220B and V221 are returned to terminal5 of transformer T401.
The horizontal deflection amplifier (V215) uses a 6BG6 in RA -112A andRA -113. The high voltage circuit has been modified and uses two 1X2 tubesin cascade. When 6BG6 is used as V215, no cathode bias resistor and con-denser are used, and R271, 25K ohms, is used instead of 3.9K.
The low voltage power supply of RA -112A and RA -113, is similar to thatused in RA -111A, with the following main differences: a separate filamenttransformer is used for 6W4 (V217), a 100K resistor is connected from oneside of the AC line and ground, R280 is now 1200 ohms, and R281 is 1650.
TROUBLESHOOTING HINTSSymptom: Interaction between Con-
trast and Brightness controls; whencontrast is turned up the brightnessincreases.
Probable Fault: L202 in plate ofV210 is open.
Remedy: Replace L202.
Symptom: Setting of contrast con-trol is critical.
Probable Fault: L203, in the gridcircuit of the video amplifier (V210),is open.
Remedy. Replace L203.
Symptom: Fine tuning or fine andcoarse tuning knobs cannot be turnedor are difficult to turn at one pointin each rotation. In some cases theTeleset does not tune as the vernierknob is rotated.
Probable Fault: The tuner dial as-sembly vernier gear is split.
Remedy: Replace the assembly shaftand vernier gear. 39
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION I
TO
SCHEMATIC DIAGRAM
al
for
TELESET MODEL
RA -111A
I ST. VIDEO I.F.
V 205RAU'
Z 204 27.5 MC
E-2 r -,
[r] II 4
2 - 5 V
1'4 II I v
Cfl1 1 1
I RI 2 1 1 219
MixER
a `1 RED -BLUE
175
130 V
C214 C 215 .005 .004
112111 11220 221100 K.
NOTES
I. Issue No. la through m1212. Voltage, resistance, and waveform measurements.
a. Instrument used -RCA Model 195-A Voltohmyst (forvoltage and resistance).
b. Voltage measurements taken to ground, no signalinput.
c. Voltage measurements made with switch in TV posi-tion; contrast end brightness min.
d. All coil readings were taken with coils disconnected.e. Video waveforms measured with contrast set for 30
volts p -p at cathode of CRT.3. Switch section viewed from front end of switch. Rotor
in TV position. Switch positions: I. Phono., 2. TV,3. F.M.
CORD2.5 yyf
11.9 MCTRAP N..,
L 212RED -ORANGE
C 28320 yyf
2 205
L SLUE DOT 3
14 I
112228.2
IS01
.3V
R 22438
2 ND. VIDEO L F
V 206CALM
217.005
R 22310e
175
1300
2111
.004
" I2.5
2 006
Cz I
I ....AP' II1C.4,7111 I
IL. I RIEID DOT
C.00
21114
R226In
II.3 V 0`X"I EILACK -YELLOW
.13 CYELLOW
R 265OMEG.
&25 V
IC.05277
200 V
TOV 203 PING
R NAlle 32'3.2 MEG
S 201
SELECTOR SNITCH SHOWNIN TELE. POSITION
RESISTANCE READINGS OF COILS(Ali readings In ohm.)
All coil readings shown were taken with culls disconnected.
P 201
115 V
Symbol Reading
L201 9.2L202 7.61.203 2.6L204 9.2L212 .2
O®
let
TO R 202NUR V201
T 201
A.0 C.
NARROW RANOSYNC AMPLIFIER
V 212ROAR
ao v
245 8207.7/1C 233
69-6 315 IC OCT270,0. .05 R 246
IK
51250
aRECTIFIER
210SU46
C. YEA.2,,YID
RID
0 032^RED -TEL11.2
O.11o.32
OM -YEE,
USE OF SYMBOLS
Large encircled symbol indicates source of voltage.
Small unencircled symbol indicates point to whichvoltage is applied.
40
SOS V
C 2191 22.005T
1/ 01.4PR319
-I- C226 1.2 NEC.
17
2 209
3 RD. 01020 IF02076AU6
C 221A004 R129
1K
R 251270
C.004221 0
2 207
r
R 230 01 200 V-11
TO S 204 1-PIN 1
EAR V220 A 25 V ..... ...... 125
SECOND SYNC. CLIPPER
6A116 ..T..0 V 220 AV 219
122 65117
2 201
1
L...2 1RED DOT
C 292o ./11.4.
TO 5 201 PINNEAR 0212
4 TH. VIDEO I.I.V 208
AU6
C.006
175 V
C 224 A.004 737
5125V6
R3166OOK
SYNC. e ACCDETECTOR AG.C.
V 213 831860E5 NEAR V212
Li 4
7,.7; -DOT
12-12-.2C 234DOS
IS V
C 233003
2716
I T
v
X
R 249Ie K
.2V
C 238.001
19 V
R 232150
ICSO5js.f
0261 8284.1 100
C 236
"2.111
3
1ST SOUND 1.11
V 201RAU.
C 201 _L.005
R 20210K
C 224 e.004
L
ISO V
C 2012.001
ROODin
R 285 _1.2 NEG. '
28 V
I -510
IC 262I .1 -50
R26612211 I R207
MEG.
I 200 V32V
L 211 L 20810, 67-H-
320 ACV C 245: A
FOCUS
R 2901/00
GAN
..r..3 V
GIN Pt 30822 A
1 201
C 053
50
02591140
00'L 209020-,
201 A_1910 "201
22t".. -711. 200 VC 260 A
30
.1 IT 123 V
R 21122140-,
C Tr A
R 262 A1460
0
11
2 209
3.5 0
23311
K -ELI-71'1
0 + ---.'200 V
201
0
0 o
30V
tea2.7
32 V
6-730 - C 260 D_I 10
75 204
A.G.C.CONTROL
R250250
3.30 3.30R303 302
3000R 3042.
zr C 2g9
LOC.
001ST.
/I 325IS I(
.--S TO R326NEAR V219
70 V191111
te3tt -n-
-600
C 229C
. 0
10
32'V
RA III -AMAIN CHASSIS
I MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
281305
N204IK
200 V
2 202
1 II1 II
1
1
2 ND. SOUND I.F.
V 202SAWS
R 205LP MEG
C 205.05 T C 206
.005
VIDEO DETECTOR
V 209 A1/2 6.1L5
ATO 1212
PIN I
120
0 1
22?
160V r7Z 203
11 5 V
.004
0201IK
207 B004
62001,
®1250
L 203BROWN -BLACK
IP"
2 II
I I
REDDOT
2
2000
SOUND DISC.. FIRSTSOUND AMPLIFIER A.O.C. CLAMP
V 203678
- 50 6200 0
-.5
411
0004_,
- v
0 R 21210 MEG
TO 8316NEAR 0 212
C 27927YVf `L'
C 210.01
SECOND SOUND AMPLIFIER
V 2046A05
C 211.01
R 214 R 213330 K 470 K
R 209PHONO 100 KJ 203
S 201
SWITCH INTEL.
1 O0O
R2;0100 K
C 286.01
VOLUMECONTROL( t
Vpre',YrR 213 IS !II MEG. ! 200 V
C 288
100 K-5Ar=.1 .01
320 1122K
C 270-r 680.1,10
0
0Cie
00 0
135 V 1 C 212.005
140 V
6.30
R 216270
R 3083.9 6
J 201
C 260, C
R 3013.9 K
VIDEO AMPLIFIER R 317180 K
2147 T-3" (. .....
C 2g13
L 202 C 228WHITE 47 Hof
HORIZONTAL AFC SAW GENERATOR 1114/ 1114/
V 214NOT IN INMC. 1210
r -A ..-L - --1
L 201°NIVEL LOW
84!5:3
2.13 V
D.C. RESTORER8:
V 209 8 300 V2111/2 GALS I .;:.; 120P4
%.*
I (---j,.05
C 231275 V
O 240 R 240 'ELL"V 62 X0
O 00 0
6SN7 GT
6 2542.7 MEG.
C 241.002
1200
4 255 = 520
C 240-A10-160
AprNOR.
FRED.(REAR
IONTROL1
70 0 02
vi-150V
0S00a
060
C 242.02
-w
20V
R256150 6
C 243.2
B 2578.2 6
120 V
10 I
ISB it
COOS',210 .258
100K
R 259130K
120 V
1 \ I--J
"R"
823722
_LC 20146
A 264711
263ISO K
2 0-80
C 276.005
CONTRASTR 239 A
IK
24 14.3 K
C24 R 265270 per 47,
1- C 2471000PVT.
26670
300
AASAW
-85V0243I MEG.
C 23 -.05 I
0
O0
50 V
244100
HORIZONTALDEFLECTIONAMPLIFIER
0 21561106
1251(
2318100 K
BRIGHTNESSCONTROL:
-45
-500
II 242. 1006
-50V
Ea70V
0
V
S 201
fH. V. RECTIFIER
T 202 V 2161113 GT
V 82713.9 11 335420v 12 269
-60 V0C°52 0
0.1(N OC 297 0188008 0 0
DRIVE0210 0 .
_:0,;2000 x
-420252 53, 0(
.15
0R 270100
C 064 I50V NOR. HOLD
(FRONT PANEL)
C 24 4.03
R 213 A50 K
26?10 K
4200
R 2725.6 ,s-e*-
46, 0
11310
MEG.
5C 278
.05
LIT;
TUNINGINDICATOR
V 222HALT -GT
r 200 V.7 V
0 0
3. v 4154f1 V
NORLIN.
DAMPER
2176104 GT
13000
275500
26168 K
-50
8 621206
1.2 V
16 TV
65 V100 V VERTICAL SAW GENERATOR
-r4 20
8 2931.5 MEG.
T 203
1310-,
C 261V.L C 267.002 .02 -
C 266.005
V 220
-golno
I
65117
260 r - ,
O
311100
BLUE-
1RE
14,-
RED-. ?R2 L
<3
6
OR 3.
R 313
R 314560"
I I 000C 255 I 8 'L LIN. 2 4
.15 REDI
1 205RED
, C 2561 3.6-, III 0278254 05 72 10
TEL II 5 2.4.,
TEL.
HT.
3.3 6
INSIDE SOCKET
L 206
NOR. SIZEL 207
300 V
COOS.1
VERTICAL DEFLECTION AMPLIFIERV 2216567
O
VERT.
R 292112E6.
C 245 A30
12 V
8 294910 K
2965.1 K
0269.1
VERTSIZE
2954 MEG.
2972.2MEG.
-42V
23000 00 0
-50V 0-38 V 0
C 24823
3.3 V g-r-
T204BLUE YELLOW
590,.-42 V }
RED
-380
R 096560,1-
VERT.LIN.299
1.31(
6.9
GREEN
F 202
1400 0,
6 300SK
175 V
to'A.
- 300 0
41
T 1
01 CS
L 10
1
-(15
1in-
g20
ppf
I. 10
3
O1,
15 p
pf 20 p
pfl.
1102
A
II,
V10
16J
6
8-50
00
0 O
D 0
0
72 CO
AX
L104
O 0
470
pof
470
rio
100
K
100
pp 410
K
L108
L102
8
L105
4.0
PO
LY.
.5-5 PP
f
PO
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.5-5
yNf
12K
410
100
Wei
125
ppf
L 11
3
L 10
2C
100
ppf
I ppf
L 10
7
V 1
026A
K5
goA
oo
I ME
G.
100
K
ISO
K
(- 4
70 p
pfI 0
C5
-÷7
T;0
2pm
TO
I TO
I47
K
I 5O
j0f0
Lps
_ _J
PIN
2
204
-01E
YE
LLO
WA
,G.C
.
470
ppf
L111
RE
D
M 4
70 p
pf
470
ppf
L 10
9
V 1
036
AB
4
0 0 O
RA
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IA C
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ISO
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SIS
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ALL
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S T
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L102
0
1110
1.5
-7vr
if
5 /J
Pf
TU
BE
12
34
56
78
V20
11.
614
00
Fil.
8.2K
7K39
V20
227
0K0
0Fi
l.8.
2K7K
0
*V20
310
0K10
0K20
0KFi
l.0
1.9M
010
MV
204
470K
270
Fil.
09.
5K9.
8KN
.C.
V20
51.
6M0
0Fi
l.8.
2K18
K39
')., 2
061.
6M0
0Fi
l.8.
2K18
K39
V20
7.5
00
Fil.
10K
7K12
0V
208
6.8K
00
Fil.
8 2K
7K12
0V
20o
.510
5K0
Fil.
1M0
4.7K
V21
04.
71(
00
Fil.
12K
75K
1KV
211
01M
V21
2.5
00
Fil.
8.2K
7K34
0V
213
7 2K
7.2K
0Fi
l.27
K0
1MV
214
1M11
0K31
0K26
0K31
0K42
7Fi
l.0
t V21
5N
.C.
0N
.C.
10K
500K
500K
Fil.
527
"V21
6N
.C.
Inf.
Inf.
Inf.
N.C
.N
.C.
Inf.
V21
7N
.C.
N.C
.28
0K28
0K8K
280K
Fil.
0
V2I
8N
.C.
AK
N.0
470
N.C
.47
0N
.C.
8KV
219
1.2M
00
Fil.
27K
2.4K
0
V22
01.
8M -
2.8M
1M -
5M
625
1.2M
5K42
7Fi
l.0
V22
12.
3M14
K1.
7K2.
3M14
K1.
7K0
Fil.
V22
23.
3KFi
l.7K
1.5M
00
03.
3K
910
1112
V21
6tV
215
. V20
335
0K V
211
8.2K
70K
Fil.
Cap
265K
Sele
ctor
sw
itch
in 'T
elev
isio
n' p
ositr
on.
Inst
rum
ent U
sed
- R
CA
Mod
el 1
95-A
Vol
tchm
yst
( fo
r vo
ltage
and
res
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adin
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illio
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oint
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265K
I! K
0
0
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K.0
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I-
V10
2V
103
0 0
0 0
0 0
470
- 47
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Pf
225
V.
D.C
.
L 11
2
111
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106
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6.3
VA
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AS
SE
MB
LY(F
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R C
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CO
UP
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UT
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BA
SE
Typ
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f ion
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ap m
agne
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sed.
ION
TR
AP
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ET
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ER
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IVE
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OA
TIM
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OX
.
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ype
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)
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
E MODELS - 686L687L
me, 696L
CHASSIS - 120142-BTABLE I - I -F ALIGNMENT
STEPSIGNAL GENERATOR INPUT MEASURING
INSTRUMENT ADJUST PROCEDURECONNECTION FREQUENCY
i Marker generatorthrough .001 Mfd. toPin 1 (Grid) of Vl.Low side to chassis.
Marker - 23.8MC.
Connect V.T.V.M. tojunction of L-1 andR-46. Low side tochassis.
T-4 Peak for maximum response.
2 " Marker - 21.25MC.
" T-3(bottom)
Adjust trap for minimumresponse.
3 " Marker - 22.8MC.
" T-3.
(top)
Peak for maximum response.Repeat step 2
4 " Marker - 27.25MC.
" T-2(bottom)
Adjust trap for minimumresponse.
5 " Marker - 25.25 "T-2(top)
PeakRepeat
fosteprmaximum response.4
6 Connect sweep gener-ator through .001 uf.to Pin 1 of Vl. Lowside to chassis.(Marker gen. lightlycoupled in parallel.)
Marker - 25.75,22.25. 21.25.
Scope connected inplace of V.T.V.M.through 10k iso-lating resistor.
T-2(top)
1-3(top)
7-4
Adjust for overall responseas shown in Curve 8.Adjust T-2 (top)to position25.75 Mc. marker accurately.Adjust T-3 (top) to position22.25 Mc. marker.Adjust 1-4 to level top ofresponse.
7 Sweep gen. coupledto converter (V-22)input, using 3 turnloop slipped overtube. Marker gen.in parallel.
Marker - 25.75,22.25.
Scope connectedthrough detector net-work' to Pin 5 (plate)of V-1. Low side tochassis. 'Low im-pedance (zoo-)
T-1 Aand
T-1 B
Adjust for response shownin figure 1, Curve A.
8 ' " Scope connected asin step 6.
T-21-3T-4
Same as step 6.
TABLE II - SOUND ALIGNMENT
43
1 Marker gen. through.01 mfd. to Pin 2.of V-4. Low sideto chassis.
Marker -4.5 MC.(400 cycle AM)
Connect VTVM through10k resistor tojunction of C-17,R-19, R-21. Lowside to chassis.
1-5(top)
Peak for maximum response.Adjust generator input toproduce one volt at gridof V6.
2 Marker -4.5 MC.(400 cyclemod.)
" 7-6(Topand
bottom)
3 Connect sweep gen-erator in parallelwith marker gen.1Marker gen.ightly coupled)
Sweep -4.5 MC.(450 Kc. sweep)Marker -4.5 MC.
Replace v.t.v.m.with scope con-netted through 10Kresistor to junc-tion of R-26 andC-20. Low sideto chassis.
1-7(second-ary)
#7080Top
18
Bottom#708017
Position 4.5 MC. marker atcenter of S -curve by ad -justing.secondary at bottomof chassis. See Fig. 1,Curve C.
4 " 1-7(Primary)
Peak primary for maximumamplitude and linearity.Repeat step 3. See Fig. 1,
Curve C.
10 % 10% MAX. 10% 10%MAX.Continuedon the nextthree pages.
4.51IC
CURVE C
_l___ _L ___L-,---
2I.75Y.C.MC
CURVE
25.75s
1._ 25.75 22.25MC. MC* 21.25MC
A CURVE II
FIGURE I - I.F. RESPONSE CURVES
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
EMERSONSCHEMATIC DIAGRAM
CHASSIS 120142-B
Model Numbers
686L, 687L, 696L
Circuit Modification
Sets coded Triangle C,have R-79 changed from82K to 68K, R-76 is re-placed by a jumper wireWhich is connected to8+230 v. point insteadof chassis.
Sets coded Triangle D,have this change whichis recommended forfringe areas:Remove R-15 (22K), re-place with jumper wire.Remove R-16, 100K. Re-move pigtail of R-2from lug of terminalboard and reconnect toempty lug on strip. Addjumper from R-2 new po-sitiOn to empty lug nearaudio output transformer.Add 1 meg. resistor fromthis lug to Pin 7 of V-4.Connect .25 mfd. fromthis lug to chassis. Re-move pigtail of C-10, 25mmfd. from Pin 1 to Pin7 of V-4. Add 1 meg. Iw. resistor from Pin 1to Pin 7 of V-4. Breakground' connection fromPin 5 of V-8, and con-nect this pin to junctionR-5, R-11, & C-4. To thisjunction also connect 10meg. * w. resistor leadingto Pin 6 of V-6.
Sets coded Triangle G,have the fuse wired ina different manner anda * ampere fuse is used.
T. V. T UlanPT. NO. 4706511
T-12lom -Tv
UT:.
'GP. s'V-21 SAGS"1:1: IUE
62616
V-22 6J6 05C. Cooly
44
1500MME
1ST VIDEOF AMP.
V -I SAWA
IOU
250 010(0F AMP
wOTO
T-2v-2 621149
-2'7.2501=V.
470VA
-
1500MMP
1500.1500
IT -3
4/0
"Mr ISO V.
520 010201.171151P
V-3 6C66
2725V.
220
IWO
5.11MA
2'
-3V. ADC.CONNECTED HERE
YON VOLTAGE *LADINO@
19
34
SYNC OUTPUT1/2 X-IS A U
4.500.
0.35272
CHASSIS -MOO. NO. 120142-8RESISTORS INDICATED IS OHMS. K 1000 OHMS.CAPACITORS 1101640(0 IN 1AOCROF1103 111E1
ISE SPECIFIED.
T 12
TaigT0[D\ LOW VOLTAG
1000V 0-57
mccw.e*A. S!
\f""C
RED 7
2GBV 5
2"ION
X"ON/TEL
DW-ION -OFF SWITCHION VOL CONT.I
2210 V.
40
C 35
0-7010.7 1002
CIAO CIS
3
.04/
I EEEELOCH
+ 40
C- IT
St"-61-==...
4. 40 + 40-T
1250
117.311
7 0
414. .01
12
225 5 11
H 35
OT
-III V
MM
C 5
2504
42 CI
470 12
A t 1900 +230v -
MOONNE
GC LIMO
22
35
0.56
C't7C_L!.
V.206 AX 50T
C}9
50
,2300.
+250v
fa(ji. ill VOLTSAC LINEIGO CPS)
0L
05C.0
NTEGRT1NG NETWORK
50 0.91 4.920/ T V\P 0
1500 VI O. 150
N -40
NC SOPV -I2
GAMS
22M6
230v
2 60.502
7
C 70 C TI C 72/
22 H L
56
UMW
C.50'
0
66
0. 592200
.047
102
N.41 2.42
C.3I110 NSF
1002
302
R 43
VERT OSCV-13 6SN7GT
.0047
0142 -224
11-72
16100K
SYNC A.1/2 V-11MAU? A.5
R:614500
2 IV.
3
.03
C 41
82 NSFC- St .
2200201412 CONTROL TUNE
V- IS 1/2 6S1170T
2
83V
3302
A. T202011
-18 TO -24rI MI6
2.42VERTMOLD
02
152
17-636805
VENTSIZE
N . 75
WYE
MOO
G
fiV".
Na.
05
C5
5- C.54244
3,00
C S6.02 -
HOPIS201.D
2.75
520
19.77502
0.74202
X - 3
NOTE -4P BEFORE TAKING WAVE SHAPES, SEE NEXT PAGE FOP ^NDiTIONS AS TO HOW THEY WERE TAKEN
VIDEO 4160/06 SYNC ROUBLES (LACK OF CONTRAST, TEAR, ovEmt.050, NO 200120111AL OR VERTICAL HOLD, POOR 2C2.0. SITTER, ETC
reillVO VIV140- 4 -
211...
1,),PIRS4,,, ,;-- -UT °c Ps
IIIIM.11112" pi- v .,..
0 TO P 30v
. ' r''' - .'
*VIMP to P N V
, qfrrir.0 to P 1052 P To P 1-/vP to P Soy 111=3.1P to 0 520
7875CPS
' 3".1.K,t
P 7. P 524
i \ ...,IV ..4
P TO 0150r
,A . 1""-- '-im-
7e75CPS
'' A r''V cr.,-
112=1:111
- TM1=11
11
ilT._i!.
P T. PI7 V
li
OM=IMEME
0 0 0 5 0 0
IMOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
OKLA.DOT
L 1EGOUN
4100
SOUNDF AMP.
v -S RAU{
T- 51600
5000MMF
047C-33 MOP
i.e
-i9/1500_,4- 150,
IMF
vIDE 0AMPLIFIER
v-10 6C66V
1,0 V.
CONTRAST
vERT OUTPUTV-14 6W6GT
1047
C 143 R
OUFO
I
AS
B OUNQI.F IIMITERV-6 6AU6
1
DOT
330 01 14.1^
L-3 19-660uN
DISCIITINATOMV-7 GALS
T- 7400
tr
270
11-201000
0
150 1 1 1501/ -
49 R 53
+2300 2307
230VSR
R As+ 1100
VERT"'L. UM
7
GREEN
AUDIOAMPLIFIERV-8 &AVG
11010OUTPUT
V-11 WNW
V. I . V
00
DOS
.0I CC43
199001 1101111
C111VOLUME
CONTROL
BOTTOM VIEW
BLACK0 SOCKET
-1 GREEN
ATV
DEFLECTION TONE 651619LT
L - 5VERT.
Afinrrdri1.11" I 6,
210MAIN,
C-46
0.99
I0 V 220
10011IoR 03C TUNE FR1E0
IS 1/2 65217GT 7-10
0.929200
9-903300
GREENDOT
TEL LOWDOT N01111
1151
10
-CIAO00017. OUTPUTV-16 68050T
330bm, -175G-34 R. 94
920ors
SA
0
01
+ 2300
R-117111100
7013
T-11
3000221iC45
114
YELLOWDOT
t L-11
6 1413011.SIZE
.033
VERTICAL TROUBLES (NO VERTICAL HOLO, NO VERTICAL SIZE POOR VERTICALHOLD, VERTICAL JITTER. POOR VERTICAL LINEAR TV, ETC)
1401712
L -6
00911.
V-1761T40T
300
.01
C IGT
0-302200
150 V
PICTURE TUGSV-23 17BP4A
(..In 9405 VOLTAGERECTIFIER
V -IS
1836T
2 7
32
2
T.11010000
I 9- 2
P-2
SP -1
FILTER TROUBLES (LOW 9 AND 0-, A G IN PICTURE.NO SYNC., NON- LuEAR SWEEPS, ETC
WAVESHAPE OF RECTIFIED AC(RIPPLE)
GOC PS. I\\,
P to P II V
NOTE THE RIPPLE VOLTAGE ATOTHER POWITS IN THEFILTER NETWORK IS LESSTHAN 0.2 VOLTS.
HCAUZONTAL TROUBLES (POOR NOLO, TIM, NO HORIZONTAL HOLD, NO 14110VOLTAGE, POOR HORIZONTAL LINEARITY)
30CPS
IPTIP ITI...
11Wra--'r"P TO P ,5 V
fl 1 Iswim ),--'trj /'
=Eros P TO P BO V
1
P To P
-460 1
7975 /1 L.../1...a
P To P 35 0
-1AI Vr-P To P soo v LIZZEMM
-1I;
=KM".'----1
P TO P 200V -
TOR THS MEASUREMENT READJUST VERTICAL HOLD TO STOP PICTURE ROLL.
P TO P PEAK TO PEAK
o 45
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONEMERSON RADIO AND PHONOGRAPH CORPORATION
(Continued)RESISTANCE READINGS FOR CHASSIS 120142-BTUBE P I N NUMBERSSYMBOL
PIN 1 PIN 2 PIN 3 PIN 4 PIN 5 PIN 6 PIN 7 PIN 8 PIN 9 PIN 10 PIN II PIN 12V-1 1 MEG 0 0 .1 '14.2 K '14.2 K 58V-2 .2 225 0 .1 '14.5 K '14.5 K 0V-3 .2 225 0 .1 '17 K 15 K 0V-4 29 K 4.8 K 0 .1 1.6 0 100 KV-5 900 K 0 .1 0 '14.5 K '14.2 K 230V-6 50 K 0 0 .1 14.5 K 9.8 K 0V-7 0 100 K .1 0 200 K 0 100 KV-8 10.6 MEd 0 0 .1 0 0 242 K
N.C. .1 '17.5 K '17.5 K 540 K '14 K 0 475__Y_L-9V-10 1 MEG 6.5 .1 0 '22 K '14 K 6.5V-11 75 K 14.3 K 0 0 0 711 K 2 MEG 900 .1V-12 2.3 MEG 0 .1 0 48 K 17 K 0V-13 . 1.3 MEG 2.3 MEG 2200 74 K '156 K 2200 0 .1V-14 N.C. .1 '15 K '15 K 2.2 MEG 820 0 1330V-15 1.5 MEG 170 K 440 K 500 K '370 K 0 0 _j_V-16 N.C.0 N.C. '22 K .5 MEG .5 MEG .1 96V-17 N.C. N.C. '280 K N.C. '15 K N.C. '290 K '290 KV-18 FILAMENT RESISTANCE INFINITY PLATE CAP = '280 KV-19 N.C. .1 26 N.C. 2_6___ L.C. 0-'15 KV-20 N.C. .1 26 N.C. 26 N.C. 0 '15 KV-23 0 0
800 K 240 K .1
'Varying resistance wait until meter settles (about 30 sec.)
CONDITIONS FOR TAKING VOLTAGE AND RESISTANCE READINGS.The resistance measurements listed below are for chassis 120142-B with no triangle codes.Due to component variations, voltage and resistance readings may vary slightly from those
given here. Slight variations may also be noticed if chassis is not coded as mentioned above.
1. Antenna disconnected and antenna terminals shorted.2. Line voltage 117 volts.3. 3 -volt bias battery in A.G.C. circuit. Positive terminal to ground; negative terminal
to junction of C-4, R-5 and R-11 (Voltage readings only)4. All controls in position for normal picture.5. All measurements .taken with a vacuum tube voltmeter and ohmeter.6. All readings listed in tables were taken between points shown and chassis.7. Resistance readings are given in ohms unless otherwise noted.8. N.C. denotes no connection.
WAVE SHAPE ANALYSIS CHART FOR CHASSIS 120142-B
4uuf to 30uut4 FT. OF SHIELDED CABLEAT 35auf PERJut
600V.I
1.5 MEG.+ 5% 100K±5%
FT. = 140uuf.-0
VERT. INPUT
-...TO 'SCOPE
GROUND0
To accurately observe the following wave shapes, the relatively high input capacity of anoscilloscope must be reduced so as not to change the operating characteristics of the televisionset. Failure to do this will result in wrong wave shape readings.The use of a special low capacity probe (circuit of this appears above) , wi I Ireduce this input capacity to a minimum.Connect antenna and tune receiver to channel where best reception has been obtained in thepast.Low end of the probe is connected to CHASSIS and the contrast control is set at MAXIMUMCONTRAST.The 30 and 7875 C.P.S. oscilloscope sweep settings are used so as to permit the serviceman
to observe two cycles of the wave shape.
46 Note: A wave shape seen in your oscilloscope may be upside down from same wave shapeshown here. This will depend on the number of stages of amplification.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Vnerson readokx,(Chassis 120158-B used in Models700D and 701D, and Chassis 120148-Bused in Model 699B are similar toChassis 120153-B described belowand on the next three pages.)
ALIGNMENT POINTS (TOP VIEW)
FRONT OF CHASSIS
PT NO 708017 SECONDARY ON BOTTOMPT NO. 708018 SECONDARY ON TOP I
D4SCRI M I NAT ORT-7
1-2@ TOP BOTTOM
25.25 MC. 27. 25 MC -
T -3@ TOP BOTTOM
22.8 MC. 21.25 MC.
04.5MC.
TOP & BOTTOM
T-6
0T5 45 MC.
O4.5 MC.
OSCCONVERTER
6J6
MODELS - 700B701B
CHASSIS - 120153-B
RF AMP
®6607.46667
Tonal80.111 NOV.........
6W6GT
VERTOUTPUT
Ist
6AU6
VERT OSC 5DISCHARGE
TUBE
6STN1G6CB6
2NdF
163GTH.V.RECT.
HORIZ HORIZ. HORIZ CONTDAMPER OUTPUT 01 OSC
6W4 GT 61306 GT 6SN7. GT
V-2317 HP4
(TELEVISION TUBE /
DEFLECTION!YOKE I
6096
AUDIOOUTPUT6V6 GT
VIDEO DE TAGC D T
3 rdIF
AJOIO AMPAGC CLAMP8 F.441COMIENSAT,L
DISC
6Av6
6 AL5
SOUNDLIMITER
GNUSSOUND
IFGALS 6AU6
12 u7
SEPC
6C136 TERMINAL
SYN 411D VAMP\S"IDEO'"ISARUTI61 SYNC. AMP
CENTERING wB NOR. SYNC!UNIT I , AMP.
ION TRAP
6A X5GTL V
RECT0L .V CID
GA X5GT
RECT
POWERTRANSFORMER
ANTENNACONNECTION
TURRET SWITCH SETTING SELECTS
COILS FOR CHANNEL DESIRED _ _2/
_ _ _ ____T - 7 7 7 7 -ri/ 2 V-21 6607 OR 68K7/ 1
/ I
THESE TUBES ARE/ NOT 1147IICH AAAAAA LEI
/6B07
OR L-42/ 681(7
1/2 V-21
I
I l!..tftI7
AGC L,,..., I GREEN
+225v.0
+125 v.0
6.3 V. 0
SLUE
WN /RED(
SLACK
L
L -I 2.2
5
R-1
47K
NOTES.- -1. L , L-6, L -7 MID L -6
ARE MOUNTED OW INDIVIDUALCHANNEL STRIPS ON TURRET.
F
AMP220x
0.5
IK C113R-6 0-7 6-.4-,
.
L-6I
100ID ,,0
Ci,1;73.
0.513_4_
FCINSE
1
TUNING
IOK
OSC.
1/2V-2 21 6J6
_12000
2- SWITCH POINTS ARE NUMBEREDIN THE ORDER OF THEIR RE SpEcTIVE
LOCATION FROM THE REAR ENOOF THE TUNER.
MIXER1/2V-22
6J6 ID
R-84700
R-92206
TEST POINT
A2 -A13
R -ii
C
P-3 X -2L-'
X-3
3- ALL RESISTANCE VALUES AREIN OHMS AND CAPACITANCE VALUESARE IN MMF UNLESS OTHERWISEINOICATED,
L
11-14:1
10K
SCHEMATIC DIAGRAM OF TURRET TYPE TUNER #470681 USED ON CHASSIS 120153-B
<1=---1
WHITE
WN/GREEN'
OUTPUT
47
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
T V TUNERT M0. 104111
TINST
TINES(- :
.1)ARE NOT
CIWNISAILIEMITER
0159TO
I
V- Eft,C 01
GA
:YOV.61 LIS oiC I.
CONY
P' ID. D. AEC ;0 CA
X
[SON /0100.
1ST vIDIOI TAW
V -I GNUS V-2 GCSEKu lcol
2DOI
NO V. r
- a. At.0 NA TTTTTCONNECTED HERE FORVOLTA{[ NEA0.011111 ONCE
IKlFILTER TROU9LES LOW 9+ AND 6-, A C IS IPICTURE
, NO SYNC , NON-LINEAR SWEEPS)
GO
C PS
T -It
NORIA.OUTPUT RIPPLE I SYNC. AMPLESS THAN 0.2
I 0-11AVOLTS P TO P
Ilit !EAU',
ZOOSR -E.
AND 01010,NIP
IDO V. 190 V.
V-3 IC66 0- SACS V-5 DAVEI SUP LIMITERSOUND
OMuGALIN
SOUNDDETECTOR
390 VIDEO
..e1400
T-5
+ /NOV .05
SYNC. AMPV-119
1/2 12AU7
NOV E
CONTRAST
VERT.V-14
9.0E I R544709 I 410.
IIRIGNTN
6 EA+0300.+0300.
.orC-47
Our PVTGWIEGT
T-0
KEN
O
13W- ION. Off SWITCHION VOL CONTI
OAT
C06009
N.70
C.05047 -
14\:1 H7 VOLTSAC Lila
CPSI
P-3-3
C -NO
I 71"ON
R-73ROOK
RESISTORS INDICATED IN OHMS. 1000 OHMS.CPACiTORS INDICATED IN M.CROFA011971
ISE SPECIFIED.
NOT BEFORE TAKING WAVE SHAPES, SEE 'NEXT
FOR THIS MEASUREMENT READJUSTVERTICAL HOLD TO STOP PICTURE ROLL.
I HORIZ. GAIN ON SCOPE FULLY OPEN.P TO P PEAK TO PEAK
48SCHEMATICOF CHASSIS
120153-B
THIS VOLTAGE IS 110011110 91AND CMPENOS ON THE PROPERDAMPING ACTION OF THE GIR
11.110330
OMENDOT
YELLOWDOT NOME
PHASE
+ 0300
PAGE FOR CONDITIONS UNDER WHICH THEY WERE TAKEN.
Noma OUTPUTV-16 590541
HORIZONTAL TROUBLES ( POOR HOLD, TEAR, NO HORIZONTAL HOLD, NO HIGHVOLTAGE, POOR HORIZONTAL LINEARITY I
111100
7 8 7 5
C PSMP TO P 280V
71.P TO P 96 V.
--irsitP To P. 125V.
...../,,,,----1
P TO P 300V
/A/P TO P 30 V
0 0
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONSOUTTO
0111CIIMMNATOPV./ ISAL5
T.7
BOTTOM UMWOf IIOCICITT
X - I
OEFLECT1011 YOKE ASSENDLY
I aL-5 Sgo1
VERT.
L
T -II
N-
""manslit
C-111
MOM'.
V.17St /ST
C.44
MOO AMP, BSC CLAMP SUMOMO PRINK OUTPUTCO AAAAAAA 55 V -I SVSOTv -s 11511
100T 210
PICTURE YURIV-03 17111.4
00000
EiiI
MI.It 11 FOCUS
CONTROL
1),000TOWS
SCE TEXT
EMERSON RADIO & PHONOGRAPH
MODELS - 700B701 B
CHASSIS - 120153-B
30 CPS 7875 CPS
11011111M INIIMINNIll
KMP To P 5.2V P TO P 5.2V
40i-6Nii;P TO P 93 v
,
P. To -P 96 V
''q...JL-Z.)P TO P 52 V
1:2W11114711
P TO P 52 V.
1.. no..
P To e 37 v P TO e 37 V.
----Tt1 I 1
P. TO P 6 V. P TO P 6 V.
t 1
p To P 14 V. It TO
.
P. 14 V.
_ ?
40Por
P ro P 35 V.
1
....
P. TO P. 19 V
VIDEO AND / OR SYNC TROUBLES(LACK OF CONTRAST, TEAR, OVER-LOAD, NO HORIZONTAL OR VERTICALHOLD, POOR HOLD, JITTER, ETC. )
"FRINGE COMPENSATOR'
X -40
0
\TO PIN 6OF V-86AV6
0C-22
.01
PART505024
0
TO PIN 6OF V-8
VERTICAL TROUBLES ( NO VERTICAL HOLD, NO VERTICAL SIZE, POOR VERTICAL 6 AV6HOLD, VERTICAL JITTER, POOR VERTICAL LINEARITY
JUMPER
JUMPERCUT
30CPS <.( rj.(.7 _I_ Z''..,tke
P TO P 365V. P TO P 70 V :P. TO P. 70 V P To P 9 V. 5P TO P .3 V. P TO P 2 V- _
0 0 0 0 0
YELLOWDOT
TO PIN .6OF V -II12 AU7
R-88 3.3MEG.
TO PIN 6OF V -II12 AUT
To install Part505024 shown,out jumper onX-4, and attach
49
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RESISTANCE READINGS FOR CHASSIS 120153-B
srmsoL
TUBE PIN NUMBERSPIN 1 PIN 2 PIN 3 PIN 4 PIN 5 PIN 6 PIN 7 rim 8 PIN 9 PIN 10 PIN 11 PIN 12
V-1 1.1 MEG 0 0 .05 '11 K '11 K 75
V-2 .1 225 0 .05 '11 K '11 K 0
V-3 .3 225 0 .05 '13 K '11 K 0
V-4 4.7 K 4.7 K 0 .05 1.3 0 900 K
V-5 900 K 0 .05 0 '11 K '11 K 230
V-6 50 K 0 0 .05 '11 K ' 8 K 0
Y-7 0 100 K .05 0 200 K 0 100 K
V-8 10 MEG 0 0 .05 1.8 MEG 3.3 MEG 250 K
V-9 N.C. .05 '13.5 K '13.5 K 500 K '11 K 0 470
V-10 1 MEG 6.5 .05 0 '20 K '11 K 6.5
V-11 10 K 2.2 MEG 0 0 0 55 K 15 K 0 .05
V-12 4 K 2,8 MEG 0 .05 .05 12 MEG 2.e MEG 0 0
V-13 1.3 MEG 1.8 MEG 2600 165 170 K 2600 0 .05
V-14 N.C. .05 '12 K "12 K 2.4 MEG 2000 0 2500
V-15 1.5 MEG 30 K 450 K 500 K '220 K 0 0 .05
V-16 N.C. 0 N.C. '20 K 470 K 470 K .05 105
V-17 N.C. N.C. '160 K N.C. '11 K N.C. '160 K '160 K
V-18 FILAMENT RESISTANCE INFINITE - PLATE CAP = 160 K
V-19 N.C. .05 30 N.C. 30 N.C. 0 '11.5 K
V-20 N.C. .05 30 N.C. 30 N.C. 0 K
V-23 0 0 350 K_'11,5
650 K 250 K .05
'Varying resistance wait until meter settles (about 30 sec.)
CONDITIONS FOR TAKING VOLTAGE AND RESISTANCE READINGS
The resistance measurements listed below are for chassis 120153-B with no triangle codes.Due to component variations, voltage and resistance readings may vary slightly from those
given here. Slight variations may also be noticed if chassis is not coded as mentioned above.
1. Antenna disconnected and antenna terminals shorted.2. Line voltage 117 volts.3. 3 volt bias battery connected to both I.F. and R.F. A.G.C. circuits, positive terminal
to chassis, negative terminal to junction of R-16, C-32. Add a jumper wire from thisjunction to junction of R-11, C-2, R-2 so that bias battery is also applied to 1.F. A.G.C.See Schematic note. BIAS BATTERY USED FOR VOLTAGE READINGS ONLY.
4. All controls in position for normal picture.5. All measurements taken with a vacuum tube voltmeter and ohmmeter.6. All readings listed in tables were taken between points shown and chassis.7. Resistance readings are given in ohms unless otherwise noted.8. N.C. denotes no connection.
WAVE SHAPE ANALYSIS CHART FOR CHASSIS 120153-B
Slight peak to peak voltage differences may be noticed if chassis is triangle code marked.The wave shapes shown here are arranged so as to give the serviceman an easy method of
signal tracing. The peak to peak voltage given may vary slightly depending on signal strengthand component variations.
To accurately observe the following wave shapes, the relatively high input capacity of anoscilloscope must be reduced so as not to change the operating characteristics of the televisionset. Failure to do this will result in wrong wave shape readings. This is accomplished by usingan Emerson low capacity probe as outlined previously in the service note for Models 686L, 687Land 696L using chassis 120142-B.
Connect antenna and tune receiver to channel where best reception has been obtained inthe past.
Low end of the probe isconnected to CHASSIS and the contrast control is set at MAXIMUMCONTRAST.
The 30 and 7875 C.P.S. oscilloscope sweep settings are used so as to permit the service-man to observe two cycles of the wave shape.
Note: A wave shape seen in your oscilloscope may be upside down from same wave shapeshown here. This will depend on the number of stages of amplification in the oscil-loscopes0 used.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
FADA RADIO & ELECTRIC CO., Inc.Models S7C20-S7C30-520C10-S20T20
The service material on the models listed above is presented belowon this page and on the next five pages. You will find that thismaterial is applicable to a large degree to Models 51055, S1055X,S6C55, S6T65, S7T65, and S1060, and may be used to guide you inservicing these additional television sets.
ALIGNMENTPRECAUTION
Disconnect the antenna. Set picture control for minimum.Adjust channel tuning to a non -assigned channel 2-3-4 onthe low band, 7-8-9 on the high band depending upon thelocation to prevent television signals from interfering withalignment.
For all IF Alignment, insert a 47K ohm resistor in series withthe VTVM probe; also, a 47K ohm resistor should be insertedbetween the take -off .point and the oscilloscope lead fordecoupling.
SOUND RATIO DETECTOR AND IF ALIGNMENT
1. Connect probe of the VTVM to the diode plate of theratio detector tube V20B (6T8, pin 2). Common to ground.See Figure 7.
2. Connect high side of the signal generator to the grid ofthe ratio detector driver. V21 (6AU6, pin 1). Common toground. See Figure 7.3. Tune the signal generator to exactly 4.5mc and attenuatethe generator so it does not exceed 8 volts on the VTVM.
4. Peak L16 bottom core (FIG. 7) for maximum.
5. Peak L17 top core (FIG. 8) for maximum.
6. Adjust attenuator of signal generator to give exactly eightvolts on the VTVM.
7. Move probe of VTVM to junction of R35, C28 and C29.(FIG. 7).
8. Adjust L17 top core (FIG. 8) for exactly 4 volts on theVTVM.
9. Move signal generator to video output tube V8 (6AG7,pin 4) (FIG. 7) and repeat steps number 1 and 3.
10. Peak L12 bottom (FIG. 7) and L13 top (FIG. 8) formaximum.
11. Repeat with care steps 1-3-4-5-6-7-8.
ALTERNATIVE PROCEDURE FOR STEPS 6-7-8:
1. Connect common lead of VTVM to junction of R33 andR34. (FIG 7).
2. Connect probe of VTVM to junction of R35, C28, and C29.(FIG. 7).
3. Adjust L17 top (FIG. B) for zero reading on the VTVM.
PICTURE IF TRANSFORMER
Rough Alignment1. Remove the shield cover from the converter tube V2 (6J6)(FIG. 8). Compress the sides of the shield slightly betweenfingers to form an oval, slip cover back over converter tubeV2 (6J6) carefully making certain that the shield does nottouch chassis ground. Connect the output of the signal gen-erator to the floating shield. Ground generator to rear apronof RF unit.
2. Connect the probe of the VTVM to the Junction of L11and Rib (FIG. 7). Common to ground.3. Set the signal generator to 23.4mc. Output of signalgenerator to be kept low as possible.4. Peak first video IF coil (located on RF Tuner), and thethird video IF coil L6 (FIG. 8) for maximum.5. Reset signal generator to 25.7Mc.6. Peak second video IF coil L3 and the fourth video IF coilL9 (FIG. 8) for maximum.
PICTURE IF FLAT -TOPPING
1. Remove signal generator and VTVM.2. Connect the sweep generator to the ungrounded convertershield (FIG. 8).3. Connect the oscilloscope probe to the junction of L11 andR16.
4. Place signal generator lead near converter tube V2 (6J6)shield. Ground all equipment to rear apron of the RF unit.5. For best results the video IF should be aligned on anon -assigned channel, 2-3-4 on the low end, and 7-8-9 onthe high end, depending upon location. If signal pips arenoticed on the curve, adjust the channel tuning control untilthe pips are eliminated. The shape of the IF curve shouldnot change when the tuning control is adjusted.6. Set the signal generator to zero output and connect theVTVM probe to the A.G.C. buss. See FIG. 7. Vary the outputof the sweep generator until the VTVM reads minus 1.5 volts.7. Set the signal generator to 26.lmc. and advance theoutput until a marker pip is visible on the video IF curve,on the oscilloscope. Adjust L3 and L9 so that the marker pipis at the 50% point. See FIG. 6. IF CURVES AND MARKERS.8. Set the signal generator to 23.8mc. and flat -top video curveby adjusting the first video IF coil (located on RF Tuner)and the third video IF coil L6 (FIG. 8). Marker should benear end of curve. See FIG. 6. IF CURVES AND MARKERS.9. Repeat steps 7 and 13 until an acceptable curve isachieved.10. Set the signal generator to 21.6mc., this marker pipshould appear at the bottom of the curve as shown in FIG. 6IF CURVES AND MARKERS. The exact position of the 23.8mc.marker is governed by where the 21.6mc. marker falls.Should the 21.6mc. marker be more than 5% up on thecurve intercarrier buzz will result, and if the marker is toolow weak audio will result. The 21.6mc. marker should bekept as low as possible and yet give enough audio signal.
23.8 MC 231 MC
21.2 MC1116 % DOWN
MAX. 20%
21.6 MC85 %DOWN
FIG. 6.
01P
26.1 MCSO %
51
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
FADA RADIO Television Models S7C20, S7C30, S20C10, and S20T20, continued.
52
52.66
HORI 2. MOLD
VERT. MOLD
ISSN?A- VERT.016.
SYNC, INV.
V 15654 PROBE
VERT.OUTPUT
V175U46
POWERRECT.
52.69 52.64OFF 8 ON
BRIGHTNESS -VOLUME 8 SWITCH
-.IV-PICTURE
AUDIO OUTPUTTRANS.
AUDIO
OUTPUT6 K 6
V TVMGROUND
C28 C29
.-R33 R34
PROBE 37.253RATIO CET
RATIOV 21 DET.
6AU6 0000 DRIVER0
SIGNALGEN..
37. 2524.5 MC
TAKE OFF
V9 A686 W 4 ( A) SYNC. SEPARATOR
HORIZ
DAMPER
HORIZ.
OUTPUT
52.68 52.2437. 246 VERT. HORIZ. DRIVEWIDTH LINEARITY HEIGHT L 13 I . 11
(B) CLIPPER
MOR1Z.05 C.
01 SONAR
HORIZPHASE
DE T.
HORIZFRED. CONTROL
37.233
VIDEOOUTPUT
- CHANNEL SELECTOR
BAND SWITCHHIGH 8 LOW
42.64R.F
TUNER
AGG BUSS
/,-
V 56A
22.79
V 16PROBE SUGG
VIDEO DET.A GC
V7 paleGALS
SIGNALGEN.
0 42.61
POWERTRANSFORMER
POWER
RECT.
NOTE:INDICATES A 8 0 CHANGE ON
PAGE 56
FIG. 7. BOTTOM VIEW OF CHASSIS
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
FADA RADIO Television Models S7C20, S7C30, S20C10, and S20T20, continued.
CHANNELSELECTORBAND SWITCH
HIGH & LOW
VOLUMEPICTURE
52.64
SWITCH
42.64AR.F. TUNER
VI6C86
I ST. RE
v2A- OS C.8- MIX.
I ST.VIDEO
LE C OIL23.4MC.
GROUND GEN. LEADS ONTHIS APRON.
22.795OMFD.475V40
3A0. VIDEOI.F. COIL L23.4 M
V6
L9(),LITH VIDEO
LE. COIL
V16 v7 A SR 25.7 MC.
0
O
V4
2 UD.VIDEO,- I.F. COIL
L325.7 MC
OFF & ON
/ TUBE SHIELD \
SEE NOTE:
( 37 253117 83 U I 025 00 J. t 4.5 MC.
22.8020MF0.450V80 " 350V10 " 300V
5U 40POWERRECT.
A- VID.DET.B - A.G.C.
nr)42.61POWER
TRANSFORMER
V8
6A07VIDEO
OUTPUT
NOTE:INDICATES A Et D CHANGE ON
PAGE S6
V 21
L1337252
V10
V19V20 A 88
RATIO DET.
L 17
RAT. DET.DRIVER
BRIGHTNESS
52.69
117.74500 IN
117.74500"
NORMLINEARITY
COIL37. 250
V9
A- SYNC. SEPARATOR
HORIZ. 8- CLIPPERPHASEDET.
RECI. CONTROL37.233
J ()HORIZ.DRIVE132.18
VII6SN7
'NORM08C.
DISC.
A.C. INTERLOCK
V18
63117A -VENT.
08C.SYNC.INV
SPEAKER PLUG
42.53VERT. BLOCKING
0 SC . TR ANS.
117. 74 V15500A.
6 S4VERT.
OUTPUT
HORIZ. HOLD
VERT. HOLD52.66
42.62VERT. OUTPUT.
TRANS.
6W4 - GTHORIZ.
DAMPER
HORIZ. DEFL.OUTPUT TRANS.
37.255
V12
6006GHORIZ.
OUTPUT
52.24HEIGHT
FIG. 8. TOP VIEW OF CHASSIS
V 17
5U4GPOWERRECT.
H.V. CONDENSER17.116
52.68VERT.
LINEARITY
/V 14H.V. RECT
183 OT
37.248WIDTH
53
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
FADA RADIO & ELECTRIC CO., Inc.ALL VOLTAGES MEASURED WITH VACUUMTUBE VOLTMETER WITH NO SIGNAL INPUT,THE CONTRAST CONTROL AT ITS MAXIMUMCOUNTER- CLOCKWISE POSITION, AND ANORMAL RASTER. VOLTAGES SHOULD BEWITHIN ± 20 %, WITH 117 V A.C. SUPPLY
DIRECTION OF ARROWS AT CONTROLSINDICATE CLOCKWISE ROTATION
K 1000 11
ALL CONDENSERS IN M MF UNLESSOTHERWISE SPECIFIED.
CONNECT TO ANTENNA TERMINALFOR OPERATION ON INDOOR ANTENNA.
BUILT - INCABINET ANTENNA
23.4..cLE INPUT 4
R F UNIT
42.64 B+
FIL.
&G C.
I5 KRI
ISSV
SPEAKER
20C2OAT-
VI9AUDIO OUTPUT
6K6GT
1.22 vV4
I ST I.F.
6AU6
20 orC31
000,-0A.005urC2
MA,100 .n.R3
rR 55 654 R46
2I 8.2K 8.2K 22K 3.
.°711W1-1-1\WrAiv-ToI C42 041 C40
.005w .0054F .002W 1
I1
L____ - - JC 69.005w
a
MEG60
VERTICALHOLD
CONTROL
47 KR61
SWITCHSI
ON OFF
INTERLOCK
117 V 60 K.SUPPLY
54
10 1650
T5
TI
MEGR 58
.005urT CI 33011.
V\ArR4
25. 7 mcL 3
--.005wC 3
V 20AAUDIO AMPL
26 T8
C4120
220KR38
8.2 KR 5
2ND 1 F
V5 6AU6
C26005urC 27
C2801..,
500K 003964R36 "T" C29
SOUND
C7120
10011 005 Mr 100 11R 7 C 6 1_ R 8
212I MEG
V2.08RATIO DET
6T8
3RD I.F
V6 6CB6
7
005wC8
.005wC9
0 i hAf
Ci2
6572.5 MEG
VERTICAL OSC.6SN7 GT
V IBA
.05w
C43
C44
HEIGHTCONTROL
HI
H2X
V16RECT.
5U4G2 +
30
VERTICAL OUTPUT6S4.3110V
V15o v 6
2.2MEGR64
vERTICI.LINEAR,'CONTROL
5K8.2 K R66R 63
+ 3408 1+ 20wC 45C
7 2600.COOKS
0
T6
33011R65 T 100w .2018
C 45D
500 ftR 112
20141+75I'sR67 C45A1-
401.FC628
3300
4. I .10 V
BOA,
iC 20 8
J
.005w
C 37
.05.
C47 T R705.6 K
r
VIRTIC1.Toot
HOR I Z OSC. B DISCHARGE
VII 6SN7GTC48
R52 3304708
8 7
8
I.2
R 70
4 -6
47KR73
100 KR71
150 KR75
50 K
MORIZORTAL 6 y R72FKOLIVICT
110311.MOLD
COPITROL 3900 CORTR01.11 .8ft 1046L20
15 K
R79
1
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONThe schematic diagram on these two pages is exact forFada Television Models S7C20 and S7C30. The circuitfor Models S20010 and S20T20 is almost identical, buta 20CP4 picture tube is used. In S20T20 terminals 1and 3 of L23 -L24 are reversed, and terminals 4 and 6of Ll8-L19 are reversed.
4 5myL17 L16
2
BETWEEN 123.3
SEE NOTE
CIO120
168.
.C85 9
RI 14
10.
3 5 v
2013
005.4CH .1.
016,C24
4 7K ---1931
o
VIDEO DET
6AL 5
3
25 7.L9
10011
7v 2
680K813
R11
L 10
5C15
005uCI4
o39K914
CIE
6A L=A.GC. V7B
4
2 L 131C 75 5.6
L121
V8 4VIDEO OUTPUT
6AG78
8 2KR16
7 80L23
7 enL24
HORIZONTAL DEFLECTIONTORE COILS
HORIZ. OUTPUT
V12 6CD6G
4v R 181200
4
L11
680C19
C18
47KR 30
(
A3
6
`1 21ATIO DET.DRIVER6A U 6
IMFC 76
L
VOLTAGE Al THIS POINTSEVER TO CAGEED 1000.
10
470 KR
330K107
12
10V
2 c 2oc-X. 1°.`
I '',IT"L 3891 9
RI7750 ILTAPPED AT25011 FROMCATHODE
Art
V 10NOR. PHASE DET.
64t5
C38
4.7MEG851
C 50270
T 390_l_ C49
4170K
876
20sm-C458
HORIZONTALDRIVE CONTROL
25-280C51
PULSED VOLTAGEDO NOT MEASURE
1013R
R 78
C54 C5520 20
-1(-4
C52
61AF
-05317.5KR80
39KR20
0LI
5KR21
39KR22
+zoo, I B MEGR99
C 361000
100K049
MK050 (35
1000
1(
I T4
+ 401241,7
SYNC. SEPARATOR
V9A
3 3R98K
+.0,4
22K8 101
siaovSYNC INVERTER
+ SO
1K8103
3
8108
2
V22
17BP4
IMF
22K
50KR93
+.0947K895 02s 39 K BRIGHTNE SS
C72 R97 CONTROL
8 8 MEG 88 100
-6SN7 GT2
VI8B
+E
4I do00I.40
171I o
EA00
Imo<7.
ma
III
111
III
III
II
III
III111
11 I
I a III
III10
I
0001
E6a
L
III
III
II 1
IIIIII
8813 311
R104CAP V14 22K
2
IB3GT8016 +.
N. V RECTIFIER 71,sx
4.4v.C73
6 8 MEGR 102
CLIPPER
V9B
TN CONTROL
L2226116.BK890
5
HI H2
0
V13DAMPER
6W 4 GT
RIOK
13 K V.
5061::11 \_jsir.:411.17:...0111. :T. TEO
I05
HORIf
nn COOTTOT 033L21 q C58
C57
IN EARLY MODELSV6,6CB6, 3RDLE WAS 6AU6
Fun10--Cr\P-AP +554v
NOTE:WHEN RATIO DETECTOR COIL 37.253 IS USED C25 IS 625 MIA FAND R32 IS ELIMINATED.WHEN RATIO DETECTOR COIL 37.230 IS USED, C25 BECOMES330MMF AND R32 330 OHMS IS ADDED.
RIOS68K
5IC79
4140v
SS
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONFADA RADIO Television Models S7C20, S7C30, S20C10, and S20T20,cont.
TUBE CHANGESLarge RED letters stamped on rear apron of chassis indicate one of, or a combination of, the follow-ing changes:
The letter "C" indicates a 6CB6 is being used in place of a 6AU6 in the 3rd IF.
TO TM
0411ZT
V 20 AAUDIO AMP
7 B 6
zp,2:86*ME837 005.r
C27C29Olr
14-5R°13°:OLV:IOCOOT..
0039 orC29
V 20BRATIO DE T.
6AL5
I -5 MC LIL 7 S
4.76R 31
4. 1403
The letter "A" indicates that a 7B6 and a 6AI.5 have been substituted for the6T8-V20 A & B -Audio Amplifier and Ratio Detector.
56
Li
SD
6BC5 6AG5ORD i.r.
V6
6AL5VIDEO OCT.
V7A
The letter "B" indicates that a 6AG5 or a 6BC5 hasbeen substituted for 6AU6-V6-3rd I.F. stage.
The letter "D" indicates that a 6AT6 and a 6AL5 have been substituted for the 6T8-V20 A & B-Audio Amplifier and Ratio Detector.
MODEL 42.64 TUNER
Ce
S- -A
V
i400010006-BtgiL2gli,yowo
S4 S3 52
2-1 L
t C26
L4
L6
GIG
RA
R5
POINTOKER
CI7
110
RS C25 0C21
05
TC4
/ LT
NOTES -I. SECTIONS Si TO S ARE PARTS OF A TWO
POSITION SLIDE SWITCH AS PICTURED.Y. SWITCH SHOWN IN POSITION FOR +BAND RECEPTION.3 REVERSED CONTACTUM SNORT CONTACTLO LONG CONTACT®MOUNTING LUG
11.09
I'V27littATEPI
La_ G? 0T--0
L9
-0
PIK. LE
SPARE
0+
GNW
6.3 V.
A G.C.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Gmn0.1ifte-Z =Ate.
15TV1-43-8957ACORONADO TELEVISION RECEIVER MODELS 15TV1-43-9015A
15TV1-43-9016A
The material on pages 57 to 60 is exact for models listed above. Theadditional models listed below, are similar to these in their televisioncircuits and incorporate an additional AM tuner.
15TV1-43-8958ACORONADO TELEVISION RECEIVER MODELS 15TV1-43-9020A
15TV1-43.9021A
PRE -ALIGNMENT PRECAUTIONS1. If sweep generator does not have a balanced output, connect a 150 3. Connect signal generator thru a 1000 mmf capacitor.ohm resistor in series with the ground lead and 150 ohms minus the in. 4. Set Picture control to maximum.ternal resistance of the generator in series with the hot lead. 5. When aligning the I.F. Amplifier be sure the tuner is tuned to a2. Connect a 1000 mmf capacitor across scope terminal and a 10K ohm high band channel (any channel).resistor in series with hot scope lead.
VIDEO IF ALIGNMENTStepNo.
SignalGenerator
Freq. (mc.)
SweepGeneratorFreq. (mc.)
SignalInputPoint
OutputPoint
Adjust Remarks Response
1 26.5 ConverterGrid
VTVM at pin7 of tube 8
(12AT7)
L-11
L-13
Adjust generatorfor output of Maximum
approx. 1 volt Reading
2 24.1 ConverterGrid
VTVM at pin7 of tube 8
(12AT7)
L-12L-14
Adjust generatorfor output ofapprox. 1 volt
MaximumReading
3 25.4 ConverterGrid
VTVM at pin7 of tube 8
(12AT7)T-1
Adjust generatorfor output ofapprox. 1 volt
MaximumReading
4 25.5 ConverterGA
VTVM at pin7 of tube 8
(12AT7)
SENSITIVITYGenerator output should be
less than 100 microvolts(If not repeat alignment)
1 volt VTVMReading
(above,noise )
526.75
23.7525.0
ConverterGrid
Scope at pin7 of tube 8
(12AT7)
SELECTIVITY001
Ti for proper Markers should be as 14 00
I. ratio as in #6 shown in response , ,.
below column (If not repeatalignment).
6
Connect scope and sweep generator as in step 5. Connect VTVM as in step 4. Adjust marker gener-ator until marker reaches peak. Record VTVM reading (V1), keeping generator output constant,adjust marker generator until marker reaches shoulder. Record VTVM reading (V2). The ratio ofthe response V1/V2 should be between 1.4 to 1.6.
7Channels 2-4
6-7-10-12AntennaTerminals
Scope at pin7 of tube 8
(12AT7)
Check channelsfor band width
(2.8 mc to 3.2 mc)
Me
-.1..
.1._ am.
Picture I.F. frequency 26.75 mc - Sound I.F. frequency 22.25 mc.
57
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Gamble-Skogmo Models 15TV1-43-8957A, 15TV1-43-9015A, 15TV1-43-9016A
TUNER WIRE TERMINALS
ANTENNAINPUT
6 AG5R F AMP
220
RI
C 3T WC. R4
Wit
T.
L3
R61000
.C5.00
TUNER CHASSIS
5.10
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C16
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coof
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ralf:TVM
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C22
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C21
TUNER A 6 C.
R 373800
VIDEO AMPLIFIER
R38000
R136IT 6
IPK
58
R 72
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155
0.
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R133IT 6
C 62I-.01 NI 0.
R36 .1.
R3256
C 94 .A
C Frq
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HORIZONTAL DEFLECTION.
PICTURETUBE
CT
R51536
R44ASK
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VERTICALDEFLECTION
R140*owAWA
AUTOMATICFREQUENCY
CONTROL R82C99
REG
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T4
6126
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PRODUCTION DEVIATIONS-Due to procurement difficulties the chassis components may deviateslightly from that shown in the schematic diagram. Parallel and series combinations of componentsand value differences may be noticed. When replacement is necessary, replace with the value shownin the schematic diagram.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION15TV1-43-8957A
CORONADO TELEVISION RECEIVER MODELS 15TV1-43-9015A15TV1-43-9016A
t"Wi515, 17. 15, 21,23, 25 010 27 MAT It*OOP. RESISTORS OR R. F CMOKE74411 R.F. 0.10103 APE USED. CAO, C 05MAE .00.3 mfd 4.110 047. CSI ARE MOTIMOOM4TRATED.
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---------------SCHEMATIC DIAGRAM
NOTE: R15, 17, 19, 21, 23, 25 or 27 may be either 1000 ohmresistors or RF chokes. When RF chokes are used capa-citors C-40 and C-49 are .005 mfd and C-47, C.51 arenot incorporated.
RED
TRUAX meDmen Tun 14T4 tom or MI rLTv01,EvEN Kiln% POINTS 14.0Il Ye CAMPS40.11444. 141407.04, NO Slaw. .5241
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SCHEMATIC DIAGRAM P. 4
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Continued onthe next page.
8104,014
59
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONGamble-Skogmo, Coronado Models 15TV1-43-8957A, etc., continued.
TROUBLE -SHOOTING
Trouble Probable Location Trouble Probable Location
No Raster 1. Phono TV switch defective or in No Horiz. Sync 1. Defective tubes 15, 16.
No Sound 2.
"DOWN" position.Defective 5U4 tube (20).
Picture otherwisenormal
2. Defective resistors R-82-83-84-85-86-87,and capacitors C-98-99-100-101-102-
3. Defective power transformer (T-7). 105-125-139.4. Defective filter choke (L-25 or L-28). 3. Defective Horizontal transformer 1-6.5. Defective filter condenser (C-61 or C-94).6. Defective fuse.
No Vertical 1. Defective tube 14.
Sweep2.
3.
Defective transformers T-9, 1.4, T -5A.Defective capacitors C-92, 95, 116 and
No Raster 1. High voltage lead disconnected. resistors R-75, 78.Sound Normal 2. Ion trap magnet incorrectly positioned.
3. Yoke plug not in place or loose.4. Insufficient or no high voltage.
Picture cannot1.
2.
Defective ion trap magnet.Defective focus magnet.
5. Defective resistors R-46-47-48-100or capacitor C-67.
be Centered 3.
4.
Defective picture tube.Focus magnet not centered on
6. Defective picture tube. picture tube neck.
1. Defective antenna or lead-in. Picture cannot 1. Focus magnet not properly located orNo Picture
No Sound2.
3.
Defective tuner tubes (tor 2).Defective tuner. be Focused
2.
centered on the picture tube neck.Ion trap magnet not properly adjusted
Raster Normal 4. Defective tubes 3 to 7. or defective.5. Improper voltages or resistances at 3. Defective picture tube.
sockets of tubes 3 thru 7. 4. Improper high voltage.6. Improper alignment.7. Open coils L16, L19, L30 or resistor R37.
No High 1. Defective tubes 16, 17, 18, 19.1. Defective tubes 11, 12, 13 and 21 or Volta e 2. Defective transformer 1-6, yoke T -5B.No Sound associated circuits. g
3. Defective capacitors C-108, 112, 113,Picture Normal 2. Improper voltages or resistances a+sockets of tubes 11, 12, 13 and 21.
or resistors R-90 through R-98 andR-112-118-119-120.
3. Speaker leads broken or not in place.4. Defective speaker.5.
6.
Defective transformer T2 or 18.Improper alignment of transformer T2,18.
Bunching orfolding at side
1.
2.
Improper adjustment of horizontal drivecontrol C-109.
Defective tubes, 17, 18.of Picture 3. Defective C-115 or H. Linearity coil.
No Picture 1. Defective tubes 7, 8, 10.
Raster Normal2. Improper voltages or resistances at
sockets of tubes 7, 8, 10. Audio in Picture1. Improper alignment and ratio of video
carrier to sound response.Sound Normal 3. Defective capacitors C-64 and coils
L-20-21.2. Microphonic tubes 3, 4, 5 or 6.
4. Defective AGC.
Snow or poor 1. Insufficient signal input.No Sync
1. Defective tubes 8, 9, 10.Signal 2. Defective antenna or lead-in.
2. Defective capacitors C-103, 121 andresistors R-45, 114. 3. Improper alignment of Cl and C2.
3. Defective AGC.4. Defective capacitors C59, C62 or coil
L21.No Vertical Sync 1. Defective capacitors C-71, C-90, C-95. 5. Weak tubes 1, 3, 4, 5, 6 or 8.Picture otherwise 2. Defective tube 9.
normal 3. Defective resistors R-73, R-77, R88.
A.G.C.A defective AGC system may not affect the sound
but over -load the video amplifier circuit and the resultwill be a loss of both horizontal and vertical sync andvery weak video. This condition can easily be noticedand checked by measuring the AGC voltage and thevoltage at pin 7 of tube 8. Under normal operatingconditions these two voltages will be approximately the
60
same. A defective AGC system will cause a large in-crease in voltage at pin 7 of tube 8 and a decrease inAGC voltage.
To determine the cause for trouble check the 6AU6tube, capacitors C-70 and C-59 and resistors R-44, R-50and R-51. To check the AGC winding of the horizontaldeflection transformer, place a scope on pin 5 of theAGC tube and a horizontal pulse similar to wave shapeshould be obtained.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
GENERAL 1 ELECTRICThe chassis in models 17T4, 17T5, 17T6, 17C112 and 17C114
are very similar to the chassis used in models 17T1, 17T2. 17T3,17C103, 17T104, 17T105, 17T108, and 17T109.
VIDEO 1-F
1. Connect a bias battery from junction of C261, R263 andthe Picture control to B-. Connect positive of battery to B-.Adjust contrast control to give a -2.7 volts bias at the grid pin1 of V4 measured with a VTVM. Disconnect VTVM leads duringalignment. Adjust sweep generator output for 34 volt as shownin Fig. 21.
2. The sweep generator should be properly terminated in itscharacteristic impedance. Couple the signal to the point of inputthrough a .01 mf. capacitor.
3. The traps L227 and L253 must be detuned before aligningthe amplifier by turning the cores all the way out of the coil.Retune these traps to 47.25 mc (as in step 6) for minimumamplitude. This adjustment is greatly enhanced by increasingthe scope gain.
4. Set the Channel switch to Channel #12 or #13. Check foroscillator influence by turning the tuning control. If the shapeof the response curve changes, switch to another channel whereoscillator influence is not noted.
MODELS 17T1, 17T2, 17T3, 17C103, 17C104,17C105, 17C107, 17C108, 17C109
Models 16T5, 160117 are similar.
ALIGNMENT5. In most cases it is only necessary to perform an over-all
alignment of the video i-f, as in Step 7 of the Video AlignmentChart, to obtain i-f response curve of Figure 21-E.
When aligning the i-f coils, L251 will adjust the audio or lowfrequency side of the i-f response curve, while L252 will adjust thevideo or high frequency side of the i-f response curve. L226 andL254 should be adjusted simultaneously to reduce the saddlebackat the peak of the curve and to give maximum gain and retain45.75 mc and 42.50 mc markers at the 50% mark.
6. It is necessary to detune the i-f coils by shorting as notedin the alignment chart to prevent the coil preceding the signalinput point from influencing the response curve.
7. The 45.75 mc marker should fall at the 50% point td giveproper sideband response. See Fig. 21-E.
8. After adjustment of the two adjacent sound traps, readjustas in step 7 to obtain the proper curve and marker as illustrated.
VIDEO I -F ALIGNMENT CHART
StepMarker
GeneratorFrequency
SweepGeneratorFrequency
Signal InputPoints
Between
ConnectOscilloscope
BetweenAdjust
SeeNoteNo.
2 44.50 MC
3 45.75 MC
4 42.50 MC,45.75 MC
5 44.2 MC
6 47.25 MC
7 41.29 MC,42.50 MC,45.00 MC,45.75 MC,47.25 MC
40 to50 MC
Detune L227 and L253 by turningcores out of coil. 3
Point B (Fig. 29)V6 grid (pin I) thru .01 mf. cap.and B - on head -end shield.Short L252.
Point C (Fig. 29)V5 grid (pin 1) thru .01 mf. cap.and B - on head -end shield.Short L251. Remove short onL252.
Point D (Fig. 29)V4 grid (pin 1) thru .01 mf. cap.and B - on head -end shield.Short L226. Remove short onL251.
Point D (Fig. 29)Junction L215 and L216 on sec-ond r -f switch wafer thru .01 mf.cap. and B - on head -end shield.Remove short on L226.
Models 17C1131 17C115,17C120 are similar incircuit to these models,but their tuner is likethe "head end unit" ofModel 20C150 of the nextsection.
Fig. 21. Video I -F Curves
NaNMIEms emus Ems mos L..MY.
Point A(Fig. 30)Junction
L256, R265,C268 andR266 thru10K ohmsand B - onV7 socket.
6511111111 MIMI= .r12CRISMIN11511
oMmimPIMEMEM:MimmiMMMMM
it
VOLT
Core of L254 for curve of Fig. 21-1A.
Core of L252 for curve of Fig. 21-B.
1, 2, 4,6
Core of L251 for curve of Fig. 21-C.
Core of L226 for curve of Fig. 21-D.
Cores of L227 and L253 for min. out-put at 47.25 MC (Fig. 21-E).
1, 2, 3,4, 7
Cores of L25I, L252, L254 and L226for curve of Fig. 21-E.
uH mmmmmmmmmmMIN MMMMM HOME NUM EMS 1101111MMOM MON MUmmoma.rftmommes
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Service materialcontinued on thenext five pages.
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61
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONGeneral Electric Models 17T1, 17T2, 17T3, 17C103, 17C104, etc., continued.
AUDIO I -F ALIGNMENT
1. Audio i-f alignment is performed by putting in a 4.5 mc± 500 kc sweep and viewing the response curve as noted in theaudio i-f chart.
2. As a final check, step 12, the secondary of T402 adjustment,should be checked on a television signal if possible. Try severaloperating television stations and if buzz in the audio is heard,the secondary of T402 should be readjusted as follows:
Tune in the station and adjust the contrast control for a weaksound output. Readjust the secondary of T402 until the buzzis a minimum or disappears, and the best quality audio is ob-tained.
3. Keep the input of the sweep generator low enough so thatlimiting does not take place, otherwise the response curve willbroaden out, permitting slight misadjustment. Check by increas-ing the output of the sweep generator; the response curve shouldincrease in amplitude.
4. T401 is adjusted for maximum amplitude and symmetryof the response curve about the 4.5 mc marker as shown inFigure 23-A.
5. The secondary of T402 is adjusted for the curve of Figure23-B. This adjustment should give as straight a slope as possiblebetween the positive and negative peaks of the curve with thecenter of the 4.5 mc marker falling midway between the peaks.
6. The primary of T402 is adjusted for maximum of the posi-tive and negative peaks with as straight a trace as possiblebetween the peaks. If necessary, readjust the secondary of T402so that the marker falls midway between the peaks.
7. An alternate method to the visual alignment is the soundoutput method using an operating television station, preferablywhen transmitting tone modulation during the test pattern.
(a) Tune the receiver for optimum detail.(b) Keep the input below limiting level by reducing the con-
trast by the Picture control or by using a resistor pad inthe antenna circuit.
(c) Adjust primary and secondary of T401 for maximumsound output. Adjust primary of T402 for maximum audiooutput.
(d) Adjust the secondary of T402 for best quality audio (lowdistortion, least noise) and for minimum buzz in the out-put.
Step
8
9
10
11
MarkerGeneratorFrequency
4.5 MC
SECONDARYTOP
2=-4
AUDIO ALIGNMENT CHART
V2
25L6GT
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CZTIGG5716)0
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Fig. 22. Tube and Trimmer Location
25806
SweepGeneratorFrequency
Signal InputPoints
Between
ConnectOscilloscopeBetween
AdjustSee
NoteNo.
Point F (Fig. 29) Point G Primary and secondary of T401. 1, 3, 4Pin 1 of V17 through Junction of R404 and See Figure 23-A.
4.5 MC..01 mfd. cap. and B -. C404 8s sec. of T401
through 10K and B -.±500 KC -
Secondary of T402. See Figure 23-B. 1, 3, 5keep signalbelow limiting
level of Point I (Fig. 29)receiver. Point H Junction of R408, C411
Primary of T402. See Figure 23-B.Pin 1 of V18 through.01 mfd. cap. and B-.
and R411 through 10Kand B -. 1, 3, 6
Secondary of T402. See Figure 23-B. 1, 3, 512 Recheck a ignment of step 11 on operating station as in note 2.
A
62 "4--- 4.5 MC MARKER
Fig. 23. Audio 1.F Curve
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
General Electric Models 17T1, 17T2, 17T3, 17C103, 17C104, etc., continued.
R -F
R -F Alignment Notes
1. Disconnect the transmission line to the antenna terminalsat the head -end. Couple the input of the sweep generator tothe head -end terminals through balanced output adapter G -EST -8A and a 430 -ohm pad, or equivalent. Couple the adapterto the 430 -ohm pad with a piece of 300 -ohm transmission line.Terminate the 300 -ohm line in a pad, as shown in Figure 20A.
If a balanced output is not available for the sweep generatora matching network as shown in Figure 20B may be used. Abalanced output is recommended since a matching network asshown in Figure 20B may introduce frequency shift and causea misleading tilt to the response curve.
Ro shown in Figure 20B is the terminating resistor. If thisresistor is not already incorporated in the output of the sweepgenerator, it should be added to the matching network as shown.
1. It is necessary to connect a bias battery from the junctionof the Picture control, C261, and R263 to B-. Connect plus ofbias battery to B-. Adjust the Picture control to give a -2.7volts bias measured from pin 1 of V2 to the head -end chassis B-.
3. Shunt L226 with a 680 ohm, watt resistor during r -falignment to prevent the oscillator from influencing the responsecurve. In order to reduce the effect of hum on the response curve,connect a 100 -ohm resistor in series with the head -end B+ andconnect an electrolytic capacitor of approximately 400 mf, 350volt from head -end B+ to head -end B-.
ALIGNMENT4. On all channels the picture carrier marker should not be
less than 75% of the peak of the r -f response curve. The soundcarrier marker should not be less than 50% of the peak of theresponse curve. However, the two minimum values should notoccur simultaneously. On the high channels the picture carriermarker should ride up nearer to the top of the curve providedthe sound carrier marker does not go below 50%. On the lowchannels the picture carrier marker should ride as high up on thecurve as possible and still keep the sound carrier marker above50%.
5. Coils for Channels No. 12 through No. 7 are fixed induct-ances. Check the alignment on these channels as in steps 16through 21 for proper response curve. Readjust L210 and L217on Channel No. 13 and C207 and C220 on Channel No. 7 ifnecessary.
6. Coils for Channels No. 5 and No. 4 are fixed inductances.Check the alignment on these channels for proper curve. Readjustcoils L208 and L215 to give proper curve on Channels No. 6,No. 5 and No. 4.
7. The coil for Channel No. 2 is a fixed inductance. Check thealignment on this channel for proper curve. Readjust L205 andL212 to give proper curve on Channels No. 3 and No. 2.
8. The trimmers C207 and..C220 may be used to compensatefor differences in tube capacities which affect tracking when it isnecessary to change the tubes VI or V2. The variations in tubecapacities normally have little effect on the over-all performanceof the head -end.
R -F ALIGNMENT CHART
StepNo.
MarkerGeneratorFrequency
SweepGeneratorFrequency
SignalInputPoint
ConnectOscilloscope
ChannelSwitch
Adjust SeeNote
13 211.25 MC, No. 13 with No. 13 Screw of L210, screw of L217, for 1, 2, 3, 4215.75 MC 15 MC sweep Fig. 24-A.
14 175.25 MC, No. 7 with No. 7 Trimmer C207 and C220 for re- 1, 2, 3, 4179.75 MC 15 MC sweep sponse curve, Fig. 24-A. 8
15 211.25 MC, No. 13 with No. 13 Readjust screw of L210 and screw215.75 MC 15 MC sweep of L217 for curve, Fig. 24-A. 1, 2, 3, 4
16 205.25 MC, No. 12 with No. 12:09.75 MC 15 MC sweep
17 199.25 MC, No. 11 with No. 11203.75 MC 15 MC sweep
18 193.25 MC, No. 10 with No. 10197.75 MC187.25 MC,191.75 MC181.25 MC,185.75 MC
15 MC sweepNo. 9 with15 MC sweepNo. 8 with15 MC sweep
Antennaterminals
at head -end(see Note 1.)
Point JFig. 29
Junction ofL226, C217
and R218 thru10K resistor
No adjustment. 519
20
No. 9
No. 8
21 175.25 MC, No. 7 with and B - at No. 7179.75 MC 15 MC sweep head -end
22 83.25 MC, No. 6 with chassis. No. 6 Screw of L208 to place 83.25 MC 1, 2, 3, 487.75 MC 15 MC sweep marker and screw of L215 to place
87.75 MC marker as shown inFig. 24-B.
23 77.25 MC, No. 5 with No. 581.75 MC 15 MC sweep
No adjustments. 6
24 67.25 MC, No. 4 with No. 471.75 MC 15 MC sweep
25 61.25 MC, No. 3 with No. 3 Screw of L205 to place 61.25 MC 1, 2, 3, 4
65.75 MC 15 MC sweep marker and screw of L212 to place65.75 MC marker, as shown inFig. 24-B.
26 55.25 MC, No. 2 with No. 2 No adjustment. 7
59.75 MC 15 MC sweep
LOWER LITRES FOR=WD SOUND
Fig. 24. R -F Alignment Curves
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
GENERAL %j ELECTRICModels 20C150 and 200151, continuedCAUTION -- Remove the two 5U4G rectifier tubes be-fore removing the chassis from the cabinet. Thesetubes will not clear the wing bolt of the picturetube mounting board.The chassis has been jigged in place in factory
installation for proper control shaft alignmentand control knob clearance through the knob escut-cheon mark its position upon the mounting boardbefore removing the board for chassis servicing sothe chassis may be readily relocated upon rein-stallation.
L106, I -F CHANNEL TRAP -- This trap reducesor eliminates F -M or A -M interfering signals ati-f frequencies (41-47 mc) that are picked up bythe antenna system. This type of interference maycause moving ripples or diagonal streaks in thepicture. Interferences eliminated by this trapare not affected by the receiver tuning.
To adjust the trap, turn core of L106 to give aminimum interference pattern.
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AUTOMATIC GAIN CONTROL ADJUSTMENT -- TheAutomatic Gain Control (AGC) is the screwdriveradjustment of potentiometer R425 which is locatedon the rear apron of receiver chassis. The chceenposition for setting of this control will dependupon receiving conditions at the location of thereceiver installation relative to the strength ofthe signal received. The normal use of the AGCcontrol will be in some range toward or at itsmaximum clockwise setting.
In fringe areas and areas of moderate signalstrength the control should be set to maximumclockwise position. This setting will providebest noise rejection, an advantage in reception ofthe weaker stations. However, reception from astation of the strongest signal should also bechecked to determine picture quality with thePicture control advanced fully clockwise. Loss of_sync may occur in some receivers as evidenced byan irregular displacement of elements of the pic-ture (picture distorts) at this setting of thePicture control. This condition indicates re-ceiver circuit overload and the AGC control shouldthen be back -off progressively from its maximumclockwise position until the picture returns tonormal.
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LOCATION OF OF TUBES AND MAJOR COMPONENTS
9
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
the hallicrafters Co.MODELS 17804C, 17812, 17813, 17815-H, 17819, 17824, 17825,
17838, 17848, 17849 & 17850 CHASSIS - LsooDRUNS I thru 3
Models 14808, 14808A, 20823, 20823B, are similar to the sets describedon the next four pages, but use other size picture tubes.Models 17811-H, 17816, 17817, 17860-H, 17861-H, are combinations whichuse a very similar television circuit with a switching arrangement forthe AM tuner and changer.
I -F AMPLIFIER ALIGNMENT FOR CHASSIS USING 1D1055 TUNERS
1. Connect a VTVM between test terminal OA and the chassis.
2. Connect the high side of a signal generator to the shield of the OSC./MIXER tube (6J6). This connection willcapacitively couple the generator output to the tube. Make sure that the shield is ungrounded by raising it abovethe grounded clips that hold it in place. Connect the ground return of the generator to any chassis point near thebase of the tube.
3. Set the CHANNEL SELECTOR to any vacant channel.
4. Set the signal generator output (unmodulated) for a two volt, dc reading on the VTVM and adjust the three i-ftransformers, L-113, and L-9, according to the I -F AMPLIFIER ALIGNMENT CHART shown below. Readjust thesignal generator output as required to maintain the two volt potential at the VTVM.
I -F AMPLIFIER ALIGNMENT CHART
Signal GeneratorFrequency VTVM
(No Modulation) Adjustment Location Indication
25.6 mc T-102 (top) Fig. 22 Maximum23.1 mc T-103 (top) Fig. 22 Maximum24.5 mc T-104 (top) Fig. 22 Maximum21.75 mc T-103 (bottom) Fig. 25 Minimum24.5 mc *L-113 Fig. 22 Maximum24.5 mc **L-9 Fig. 22 Maximum
*NOTE: Hold the CHANNEL SELECTOR between two channels when making this adjustment.
**NOTE: Return the CHANNEL SELECTOR to the normal position on any vacant channel and shunt the 4700 ohm gridresistor (R-101) of V-101 with a 1000 ohm resistor, when making this adjustment. Remove resistor afteradjustment is completed.
5. After adjusting the 21.75 mc sound trap (bottom slug of T-103), recheck the setting of the top slug of T-103.
6. Tune the signal generator from 211mc through 26.25 mc and observe the change in indication on the VTVM. If thegenerator output is set to the level where a 1.5 volt meter reading is obtained at the peak i-f amplifier response,the reading should not drop below one volt between the two peaks normally obtained with this i-f amplifier. If theband-pass response 'Is unsatisfactory, repeat the procedure or try slight modifications of the recommendedsettings to obtain the desired results. Avoid resonating the coils with the iron core at the bottom end of the coilform (adjustment screw near limit of its travel). Final adjustments can be made much more easily if a sweep typesignal generator and oscilloscope are used.
7. Check the two carrier i-f responses, 21.75 me and 26.25 mc. The 21.75 mc response will be approximately 20 dbbelow the peak response (approx. 0.15 volt) and the 26.2F mc response will fall approximately 6 db below the peak,(approx. 0.75 volt). Refer to Fig. 14.
To determine the i-f amplifier sensitivity, connect a signal generator to the OSC./MIXER tube as directed in step 2 ofthe I -F AMPLIFIER ALIGNMENT procedure. Set the generator frequency to either i-f peak. If a generator output of800 to 1500 microvolts produces a one volt de reading on a VTVM connected between terminal and ground, 69the i-f amplifier sensitivity is normal.
6CB6
6AV666071
L V RECT
eI -F ALIGN
TEST TERM evba6
.:016CB6 6AL5os 6:00® C'03 ,I04 0 I6AU6n
102
6CB66,41_501
24.5MJ
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION I
hallicraftersRF60,63AhlAtieER
2-/Roo
ID1055 TUNER
Ota MISER
r
=
Is'71 tsrona ,9,20.000
T.,
24.5MCLs
Ill
.1161 C1 .S EINNTE0 ON SOW TUNERS IT THE USE
OF A 3TO 9 NNE TRINdapi T CE
PICTURE TUBE GRID 6CATHODE VOLTAGE CHART
P
'
N
CONTR/STmit t
6/ROSMIN.NEISS
BRIGHTNESS CONTRAST
MAX. MIN. MAX. MN.
II 155 140 F40 140
2 130 65 65 65
PHONOINPUT
50102
See next page, over, forschematic of another tunerused with these sets.
0,1
AUDIO AMP
T110
O )
((g,,.L113 6AG5
L9 2g2gRF AMP.
C2
6J6C3
osc/mtx
C5 C4
FIG. 22. TOP VIEW ALIGNMENT
LOCATIONS (WITH ID1055
TUNER IN PLACE)
70 LAST R SYMBOL R-19LAST C SYMBOL 0-167LAST L SYMBOL L -114LAST 7 SYMBOL -112
3RD I -F AMP
24.5 MC
VIDEO DET.
viol24.75 MC ecee
1ST IF AMP
T101
r -IV
24.5MC 4.5 MC1,13 LIMITER GRID
,--(3 L
25.6 MC
429T102
110512,000
)1-1co5000
01026CB6
2ND IF AMP
01096AU6
AUDIO IF AMP.
21.75 MC
7
T103
7-
4.5MC
v1036C86
3RD IF AMPtt50
C1066000
102150
24.5MC
O.
.102POO
VIDEO AMP
4.5MC LIMITER GRID ADJ
4.5 MC TRAP ADJ23.1 MCAUDIO I -F AMP
2ND I -F AMP
SECONDARYADJ.
25.6 MC1ST I -F AMP
FM DET.
24.5MC
ALIGNMENT ESTPOINT 9
0102
010
.30 AOTO TVTUNER
Rai
50101
7PL 102
11ITE BLOCHCONNECTOR
PL 101
40-1300. to ,T. m 0 DB
L112
0143I,
1130 AtFROM POWERTRANSSORNER
Rios160
0011.011AFD6000.
0164,05000.
APPROX.26 DB.
I .000
vM
^meloo 100
0104GALS
VIDEO DE T.
10
Rios160
7110
AILS.fr
'6.3
V0114
LOW V:: -G7 LOW VOLT RECT(6051 5114G
1.0
1110
r 6.C
TO.117 F1L.
3DB MAX.
21.75 MCSOUND CARRIER
1-F AMP FREQ.
FIG. 14.
Comm
Rift00
130000
'101
LI09FILTER
CHOKE
J
II
I asor 1335Nv P3,00,
RTV CI360 _L 0_,1244 ClHC'' .7o I INPE 090 I
RECEIVER I -F RESPONSE
APPROX. EQUALPEAKS
4.5 MC
APPROX. 608.
26.25MC-21.75MC.4.5 MCFOR SOUND I -F FREQ.(INTER CARRIER SOUND
SYSTEM)
I-F AMPLIFIER RESPONSE
26.25 MCPICTURE CARRIER
I -F AMP FRED.
IMOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
MODELS 17804C, 17812, 17813, 17815-H, 17819, 17824, 17825,17838, 17848, 17849 & 17850
VIII V112
6AV6 (6 50 7)1ST AUDIO AMP
115v
IF.1530 MEG, I
of Mr20
C.,- 10
6000.154
1 NIG 1VOLUME
+150 V.
.011D.2S0 81-
GAO 5AUDIO OUTPUT 1)09
Coe ft, - Itfi4 ,t
L..7V 2'. 4. '1356 , "103
- 7 2 lv / '''''N .135'
.0 MED
wmoCOUPLING
RETwoRS
1111/S, 15 000
,o.
P1,55
II
LSioi
.137.1 RFD
SI I clop,FON yr, Tact
40,
L107
100011
C11.2.2
son
/7./FY
'iPR°FOCUS
VERT
Roo
1106
DEFLECTIONYOKE
cos ties.01 o 700
CHASSIS - L800D
00012
PLIO4
V 119
PICTURE TUBE
2,510V
.1300
FRONT VIE):
114100 ..12. 54100
2v/
.120 .113 .12115,000 47 2200
HV105 -:,,,e2 -6C2I6 -ULU DIDJAL
VIDEO AMP13 rYL 'OS 1104 1105
4.5MC Rot,,, TRAP 10,000
tov
CitiT
174
Pii2500
CONTRAST
1412
.114 ..[7:31IV
220 1220,000 G 113
-CROWD50011.
Ti,. 1. .1E52.2 WO 270,000
.128620.000
35V
.11A .135
'71r ,..11.. .124II0'00q7,'07,7,,. r .13050,000
_CMS BRIGHTNESS 41,000. .1 r, ocaL.,,^ it, = .0. lo1 VERTICAL INTEGRATING NETWORt2200 .5
220001 9200 1 11200 1
: Z: Z71 .1% :
ViG 512 Ai/7(0N 7GT1
NC. CLIPPER A VERT OSC.
12 AU 701161 (655570T)
SYNC. AMP5 SYNC. SEP
T4,7
1 -0102
600V
T ISO
60511. HOLDRIM5 Ti Aire120,000 BO 000 611,000
HORIZ. DRIVE I coo.174 .176 92
12.000 50,000
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.041110
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t0
CAPAG170. VALVES ARE IN NNW UNLESS orwro761 SPECIE..R(5.1s0OR VALuES ARE IN OWNS t/2 NATI RATING DINESS nrw/orrst SPECIFIEDTv-N.03O Sony IH PHONO POSITIONALL vOLTGES AWE ME &5011110 BF IRE EN TDB( SOCKET TERMINALS "CHASSIS WITH ,ENO SIGNAL 13,1LINE VOLTA0E,111ACALL VOL TACKS ARCM AND POSITIVE ow.155 OTHERRISE SINCHI10DC VO TAGUS*/ .4(Asoloo NITH yr..
11 -M-NOT READABLE vOl TAG" MESONDAT THE SERRNINALS GENLOILT MEANINGLESSCONTROLS Sit Fort Norm. PICTURt rwtRomom uNLESS OTHERNISE SPECIFIED.
10 lo LEADS ARE SHOWN IN HEOT LACA LINES. NOT FOUND IN ALL 61751 VARIES 10/1114 ASSOC$ATE0 CONTROL St 11130
f t DC 113sr3TANce yam* DO NOT MEAN,. VOLTAGE AT TINS POINT.
HOME.LINEARITI
T."5,011510 63040ov
V
W4 GTDAMPER
SLUE
Me
0,21"1455140
600v NEG.
753.10
Vt0Et654
VERT AMP
1000 5000
- VERTICALLINEARITY
4770 ,
t t T10LLIE
:;,00
c,.T DONE 5
6000.
.14I NEG.
1462.5 mcc
HEIGHT
7LillS.'1' WIDTH
95
1)12 VIIS1215- GT
HI. VOLT RECT.
, 32200
111-10LINE
Ctsv0314E0
00,1LON
CfO915F0
RN,E0
-162 -500
20,000v I
VALUES AND TOLERANCES SHOWN ARE NOMINAL AND VARIATIONS MAY BE FOUND.
IT IS RECOMMENDED THAT THE VALUE OF ANY REPLACEMENT CORRESPOND TO THE
NOMINAL VALUE OF THE PART BEING REPLACED.
FIG. 27. SCHEMATIC DIAGRAMFOR MODELS 178014C, 17812, 17813, 17815-H, 17819,178214, 17825, 17838, 178148, 178149 & 17850;RUNS I THRU 3
71
TS,0
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONThe Hallicrafters Co. Models 17804C, 17812, 17813, 17815-H, etc. continued.
PRODUCTION CHANGESVarious electrical and mechanical changes on the chassis are signified by the appearance of any of the following stampson the rear apron:
LI High voltage adjusted by screwdriver -set potentiometer. Horizontal linearity and width coils have screwdriveradjustment. Color adapter socket mounted but not wired.
LIX High voltage adjusted by switch on rear apron of chassis. Horizontal linearity and width coils are adjusted bymeans of a separate sliding rod attached to each powdered iron core.
L2 Same as LI except that R-191 replaces R-139. Also, C-166 has been added, and C-140 has been deleted. (Referto Fig. 27, Schematic Diagram.)
L2X Includes circuit changes of L2, and does not have color adapter socket.
L3 Tuner 1D1055 and L-113 used in place of Dynamic tuner and T-101. (Refer to Fig. 27, Schematic Diagram.)
HORIZONTAL OSCILLATOR ADJUSTMENTIf the HORIZONTAL HOLD control on the front panel fails to restore synchronization, the HORIZONTAL RANGE andHORIZONTAL LOCK adjustments should be reset. Procedure for these adjustments is as follows:
1. Turn the HOLD control to the full clockwise position. Adjust the HORIZONTAL RANGE adjustment until a verticalbar appears in the pattern.
2. Turn the HOLD control to the full counterclockwise position. Momentarily switch off the station. Three or fourhorizontal bars should then appear on the screen. If too many or too few bars appear, the number may be de-creased by turning the HORIZONTAL LOCK adjustment in the clockwise direction, or increased by turning theHORIZONTAL LOCK adjustment in the counterclockwise direction.
3. Repeat step 1.
4. Check the action of the front controls on all active channels. Repeat the first three steps if necessary, to maintainstable synchronization.
If the above procedure fails to restore stable synchronization, make proper horizontal oscillator waveform adjustmentswith the aid of an oscilloscope.- - - - - -
SCHEMATIC DIAGRAM OF TV TUNERS11:1961,1A107? IDIOM
10110IRON IliCCet ul
1-51I/ C10
c,.
11120 TIMICI1,10MUTW
ALTERNATE TV TUNER INPUT CIRCUIT
220
ESE11
72
6CB6RF AMP L2
5 ii05,1109
lr.nr111-110
TIC%
I2
= II
CLOCelef
7:,
Lzz
Cercir-OriTL--.-0,1.29
'YL0:'-rrrs
J
'ilL11-51oPiern.'1
1000 1.
100
FINETUNING
L..
L,
OSCILLOSCOPETERMINAL
Ap10,000
c.c R. C22611500 Y1001., I
tOpoo
6.3,1. AC
1
moo
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
the hallicrafters Co.MODEL 17905 TELEVISION RECEIVER
Models 17810C, 17810M, 17810MG, 20872, use circuits which arc similarto the Model 17905 covered by the material on pages 73 to 76. Youwill find this material of aid in servicing these additional receivers.
HORIZONTAL OSCILLATOR ALIGNMENT
If the HORIZONTAL HOLD control on the front panel fails to restore synchronization the HORIZON-TAL RANGE adjustment should be reset as follows:
1. Position the HOLD control, located on the front of the receiver, in the center of the range overwhich it may be rotated.
2. Adjust the HORIZONTAL RANGE ADJUSTMENT on the rear apron of the chassis (See Fig. 1).until proper synchronization is obtained.
3. Test the synchronization on all other active channels. The picture should remain in synchroniza-tion when switching from one active channel to another without any adjustment of the HORIZON-TAL HOLD control.
4. Repeat steps 1 and 2 if necessary.
If the above procedure fails to restore stable synchronization, a waveform adjustment may be madewith the aid of an oscilloscope.
5. Connect a V.T.V.M. to test point ® (See Fig. 6) and adjust the HORIZONTAL DRIVE capacitor(See Fig. 1) for a -22.5 to a -25 volt reading.
6. Connect the oscilloscope as shown in Fig. 4. Adjust the TERTIARY WAVE FORE slug (locatedunder chassis) until the sine wave is equal in amplitude to the peak of the sawtooth (See Fig. 5),while maintaining the picture in synchronization with the HORIZONTAL RANGE adjustment.
This adjustment is very important for correct operation of the circuit. If the broad peak of the waveon the oscilloscope is lower than the sharp peak, the noise immunity becomes poorer, the stabilizingeffect of the tuned circuit is reduced and drift of the oscillator becomes more serious.
On the other hand, if the broad peak is higher than the sharp peak, the oscillator is overstabilized,the pull -in range becomes inadequate and the broad peak can cause double triggering of the oscillator,when the HORIZONTAL HOLD control approaches the extreme clockwise position.
7. Remove the oscilloscope and repeat step 5.
8. Repeat steps 1, 2, and 3 if necessary to provide positive synchronization on all active channels.T106
HORIZONTAL r - - - TERTIARY WAVEFORMRANGE ADJ ADJ. (UNDERSIDE
A :
OF CHASSIS)
HORIZONTALDRIVE ADJ.
CIW RM411000 100,000
R163+B
FIG. 4. ALIGNMENT CONNECTIONSUSING AN OSCILLOSCOPE
INCORRECT
CORRECT
FIG. 5. WAVEFORMS FOR TERTIARYWINDING ADJUSTMENT 73
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
The Hallicrafters Co.
Model 17905
OFF - ONVOLUME
5101
TIOIV106 - - - - - -6AU6 I
Lt AAUDIO K 4DRIVEF
5ov 3,
50M ^
I 1550
4.5 MCSOUNDADJ.
3 L101
5,034
cross
01.1 4000
To tuner, circuitshown on the nextpage, over.
CONTRAST HORIZONTAL BRIGHTNESS VERTICAL CHANNELHOLD HOLD SELEC"OR
'FIG. 2. FRONT CONTROLS
VERTICALLINEARITY
HEIGHT FUSE COLORATTACHMENT
SOCKET
HORIZRANGE
HORIZDRIVE
ISLEEVECOVERED
Dm/WHITE
3,cWHIT
FINETUNING
HORIZ. HOR1Z,WIDTH LINEARIT1
FIG. I. REAR VIEW SERVICE ADJUSTMENTS
74
LIIO
15'0
-0.8v
jR11792,000
00
,5)151:F.
=
Vi076AL5AUDIO
FM DETECTORNi .1°3
0.000
Vi016CB61ST If
2500
5101
513.WO
41:43v1
50101
PL102
PLIN
110 -120V 60,1JAC
C1371111,D
I1000
0109
01 MFD
VOLUMECONTROL
/ 23.75MC
"D000
V TUNER,VI I4 FIL.8153
LTIOR
T103
10,000
-070
01026C862ND If
V1086 AV6 650 7)
1ST AUDIO AMP
2131157;:
24.75MCT104
2500
0124ISO
5000
01205000
0120
100
1,101
15000
00
C
005 MFD600Y
0109
F101 L107
4T3114 -1.--C7:7,_I 604.4,0
C130 - =1500
C '' 'OW F102 9,90
_LEL, 0105
166 3°C..
:rt'T v. ,,,,), V110 V105 '403 V106 VI04 VK)2 V101 V10725AV5 12BH7
(25806) 25L6 - 12SN7 (12SN7)6C86 6AU6 12AU7 6C86 6C06 6ALS
250V
11012
'°°"\v/ T{0 MFD
(71 121 (7) 181 9 - I 5000
NOTE, COLORS REFER TO TRACERS IN TV TUNER LEAD INSULATION.
I. B+LEADS ARE SHOWN IN HEAVY BLACK LINES.
2. CAPACITOR VALUES ARE IN MMF UNLESS OTHERWISE SPECIFIED.
3. RESISTOR VALUES ARE IN OHMS AND HAVE 1/2 WATT RATING UNLESSOTHERWISE SPECIFIED.
4. ALL VOLTAGES ARE MEASURED BETWEEN TUBE SOCKET TERMINAL ANDCHASSIS WITH ZERO SIGNAL INPUT AND ANTENNA TERMINALS SHORTED.
S LINE VOLTAGE -I I7V. A.G.
6. ALL VOLTAGE READINGS SHOWN ARE D C.AND POSITIVE UNLESS OTHER-
WISE SPECIFIED.
2300 T102
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
the hallicrafters co.
,0925L6 -GT
AUDIO OUTPUT
RHO
390,0005%
2700005%
150V
50102
1.5101
ISOV
150V
.150,000
0103
c.2. 6CB6
L103 5ro VIDEO AMP1550
5
-.46127-
L104 2485,000
8129 t0 220,000 0.05_,_...
-Fn11-
8150
C175IOGO
6123
5 MED
I MEG6112
2500
30V
1;2:
CONTRASTCONTROL
S'.9)0,03vi
C143005 MED600 V
RI55
1000
R19312,000
#19412,000
8200#1 c5 C'7:MED
7-
G162 -
YOO
5 SIG60MED
0171 y 6,37100 I 33,00
CO7L105 WOell -51,600V 01 04
SYNC. SEP
55
L 112
0110125147-GT
HORIZ OSCCONTROL
#133L a AMP
33.000 : L10609V
8133 81903300k 9220." I
R738 j144,3300 tW00
05MFD 8191 =2.2 MEG
2 0
VERT
440V
70 V
61283%000
= if, 8196 6114
'5 610 50000 47900600vBRIGHTNESS
#138 R192 /12,4330,000 5,000 I MEG
IOU
81 398200
5MFD
1
81342200
W
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0117
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T106 p164- - - .1ock000
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8162 :Ov 8200 s
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-- 4 .50 39,0008161 /R19750,000 547,000 Ri65 *
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82,000 HOLD _cmTIMED
IA
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560
HORIZMODEL 17905
WLI04
12,500v
VI I 4
PICTURETUBE
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300
3122,000 8200 6200 ,
VERTICAL CHL101-C1291 0184
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002-
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1.441.0003
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= C178 220,000
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6 8164;- c0,000
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750 1213H7 (12SN7-GT)VERT OSC
OUTPuT.,
2.5ME2 3
0 0 0WHEN A 12SN7-GT IS USED FDR 0105 THE CONNECTIONBETWEEN POINTS 162 IS REMOVED AND POINTS 263ARE CONNECTED TOGETHER.
BOTTOM VIEWSVIII
25AV5-GT(25806-GT)HORMOUT PUT 2 os
47-2408166
70,000
5 CAM DO NOT MEASURE "VOLTAGE
6141 1400
6151
7141
2- .0510D6000 y
16136151
42002.2430 = NEC = 3
62190 VERTICAL14LINEARITY
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To
WHEN A 123.617-0T TOMEIS USED FOR 01056170 IS CHANGED TO1000 011103,2W.
81704700SW
7 DC VOLTAGE WAS MEASURED WITH A VACUUM TUBE VOLTMETER
8. 'NR' NOT READABLE VOLTAGE AT THESE TERMINALS GENERALLYMEANINGLESS.
9. V114 2ND ANODE VOLTAGE MEASURED WITH PL104 CONNECTED.
10. VOLTAGES MEASURED WITH REAR CONTROLS SET FOR NORMAL PICTURE
AND FRONT CONTROLS IN EXTREME COUNTERCLOCKWISE POSITION.
HORIZONTAL
LINEARITY
FIG. 6. SCHEMATIC DIAGRAM
MODEL 17905
0161
T 1000
LAST R SYMBOL R -I99LAST C SYMBOL C-178LAST L SYMBOL L -I12LAST T SYMBOL T-108
75
CD
"0m
I -F
AM
PLI
FIE
R A
LIG
NM
EN
T
I.
CONNECT THE V.T.V.M. FROM TEST POINT(:)TO CHASSIS GROUND.
2.
PLACE A TIGHT FITTING SHIELD OVER THE OSC./MIXER TUBE (V$31 AND CONNECT THE UNGROUNDED RF LEAD OP
THE SIGNAL GENERATOR TO THE SHIELD.
THIS SHIELD SHOULD NOT BE GROUNDED.
CONNECT THE GROUND SIDE
OF THE SIGNAL GENERATOR LEAD TO THE FRAME OF THE TUNING UNIT.
3.
TURN THE CHANNEL TUNING CONTROL TO ANY VACANT CHANNEL.
4.
SET THE SIGNAL GENERATOR OUTPUT (UNMODuLATED) TO DEVELOP APPROXIMATELY 2 VOLTS AT THE V.T.V.M.
ADJUST THE
I -F AMPLIFIER COILS, ACCORDING TO THE FOLLOWING CHART. FOR MAXIMUM DC VOLTAGE AT THE
V.T.V.M.
ATTENUATE THE SIGNAL GENERATOR OUTPUT AS NECESSARY TO MAINTAIN THE 2 VOLT METER READING
I -F
AM
PLI
FIE
R A
LIG
NM
EN
T C
HA
RT
SIGNAL GENERATOR FREQUENCY
ADJUSTMENT
(NO m000L4TioN)
(REFER TO FIG. 3)
25.75 MC
23.75 MC
24.75 AC
FM
SO
UN
D C
HA
NN
EL
ALI
GN
ME
NT
L-9
(1sT IF)
T.I03 (2ND IF)
T.104 (DETECTOR IF(
Connect the signal generator output through a .005 mfd. capacitor from test point
ground.
See Fig.
3.
o chassis
2.
Connect the VTVM from test point
to chassis ground.
3.
Set the signal generator to 4.5 MC. and adjust the unmodulated generator output
level to give a
1
volt reading on the VTVM.
4.
Adjust the 4.5 MC.
SOUND ADJUSTMENT and the primary of T-101
(bottom core) for a maximum indication
on the voltmeter.
Reduce the output of the generator as the alignment progresses to keep the volt-
meter reading at approximately
Ivolt.
5.
Connect the VTVM from test point 0D
to chassis ground and adjust the secondary of T -I01
(top core)
'or a zero reading on the VTVM between a positive and negative peak.
If the zero reading occurs at
more than one setting, use the position nearest the top limit of the tuning slug.
6.
Shift the signal generator frequency an equal amount on each side of 4.5 MC and touch-up the primary
of T -I01
for approximately equal peaks.
Al
a
517
s wm 8E :1 'Om °
M 0
AI
2
'4 8
CI
z mP
O
IA CO -4 C P
A'S
41k
Connected to main schematic
gi IP
03
-
0 dsp
N'`
0:$ 0
CI 6
1
N)
3cp
0 to
O Cla
0 (3,
CD
1-1 0 CJI
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
CHASSIS 183 - MODELS: 636, 637, 880, 881, 882, 883,884, 885, 886, 88 7,
CHASSIS 184 - MODELS 953, 954, 955.CHASSIS 185 - MODELS 893, 894, 895, 896, 897.
CHASSIS 186 - MODELS 963, 964, 965.
The material presented applies to chassis listed above. The
circuit diagram is exact for Chassis 183 and 185. Chassis 184and 186 incorporate a 3 -tube AM -FM radio tuner integrally mountedat the left front portion of the chassis. A switch network per-mits selection of TV, AM, FM, or phono operation. In Chassis186, a separate audio power amplifier sub -chassis is used.
Chassis 180, used in Models 637, 638, and 639, with 14" picturetubes, uses almost the same circuit as Chassis 183.
Chassis 187, used in Models 24B707 and 24M708, uses 24" picturetubes, but its circuit is very similar to Chassis 183 describedon these pages and this material may be used as an aid in servicingthese additional Hoffman television sets.
6V/ 4GTV705
59
68G6GV703
5-90
5U4GV801
1390
6SN7GTV702
wig
EU
EN
MCI
560ACI
360ACi
LEM
ii)CM
MCI
EN16.3A51
MCI
°FM
Zipo oro .3*
IBM MD
85
0.2
UEEM
02
50
(57I6SN7GT
V502-701 X3851
10
[6.3A0
4 6 3AC
o
o
#00,
68L7GTV601A-8
163ACI
6CB6 6CB6 6086 6086 6AL5V201 V202 V203 V204 V205
KEY.
VIV2V2V3
OTHERTUBES
ALL
VOLTAGE AT PINS WHEN OPERATINGIN FM POSITION.
VOLTAGE AT PIN S WHEN OPERATINGIN AM POSITION.
1390L-()
VOLTAGE AT PIN 8 WHEN OPERATINGIN TV POSITION.
A - MEASURED RELATIVE TO OTHER HEATER PINB - PIN USED AS A TIE POINT ONLY.
- MEASURED WITH A VACUUM TUBE VOLTMETER.
Composite Bottom View Tube Layout111:111 113
1
260
115
27
1
701
240
-08°
I
EMICIO
6K6GTV105
6 3AC
6 3ACj
6S07V104
CCI
ouoo
13M13
trivrOoo14%62°'
6AL5V103
CMI
mu ED mu
4110OEEEI
6AU6V501
1:14E121 o0 eat Baa
6CB6V301
112
106
260260
6.5AC6 3AC
0-0.25
6 3AC6 3AC
plpt419.1,
I
6AU6V401
6AU6V102
MEIMZEI
4E110euO
ANNWimp
BEI EEG
6AU6V101
1740
ArolGtot000
V36AV6
o-6.2
VI68E6
1.40.3
O
6.3A01
6 5AC6 3AC
O 250O 250
0
71L.6fo
V2
117
93
6BA6 0.90
All voltages are DC values obtained with a 20,000 ohm/volt meter unless otherwise noted. Opera-ting conditions are rated line voltage, signal level that developed -3 volts AGC bias, normal setting ofall controls. Variations are to be expected due to variations in operating conditions and componentnominal values. 77
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONHOFFIvIAN Alignment (Continued)
SignalGenerator o
.005 mf) To Grid
Figure 7. Signal Generator Isolation
Voltmeter0-0
10K
To OutputTo Ground
Figure 8. Voltmeter Isolation
Figure 9. Ratio Detector "S" Curve withAM Modulated Marker
PICTURE I.F. ALIGNMENT
Tune the coils by setting the coil frequency on theCW generator and adjusting the coil for a maximum meterreading. Remember to attenuate the generator signallevel so that the DC output voltage of the video detectorremains at 1 volt as the coils are tuned. The order oftuning is from the last L F. stage toward the TV tuner.Before tuning the grid coil of the 1st I. F. stage, tem-porarily detune the TV tuner converter plate coil.This coil is L17 on the continuous tuner. On the turrettuner it is L4, the coil in the rear left-hand corner ofthe tuner as viewed from the shaft end. After the con-verter plate coil has been tuned, repeat the trap andL F. alignment procedure until no additional change intuning is noted.
When this condition is obtained, turn on the sweepgenerator and tune it to about 25 mc center frequencywith a 10 mc sweep. Replace the meter with the oscil-loscope, using the 10K isolating resistor at the end ofthe vertical input lead. Check the shape of the responsecurve. See Figure 10. Tune the marker generator to26.1 mc and note its position on the skirt of the curve.It should be at approximately the 50% point. If this isnot the case, tune the converter plate coil so that thiscondition is obtained. If the top of the response curvehas a tilt, tune L201 until the top is horizontal. Move
78
1
4-
26.1 21.6
10% Limit3.9 min*-4-4 on Tilt4.1 max.1
1
1
1
50%
6 db Down
26.
Frequencywmc
1
271.6
p10% Limit onDip
23.0 25.0
10% Limit onon RoundedCorners at fre-quencies indicated
Figure 10. Picture I.F. Response Curve
the marker to the 50% point on the opposite skirt. Notethe frequency calibration of the marker generator dialand subtract this value from 26.1 mc. The differenceshould lie between 3.9 mc and 4.1 mc, the bandpasslimits taken at the 6 db points. If the bandpass doesnot lie within these limits, touch up the other L F. coilsuntil the correct curve is obtained. Any appreciabletouch-up requirement should be taken as an indicationthat the L F. section is not operating normally and shouldbe checketl for defects.
Figure 11. Detector Network
WARNINGThe strap holding the picture tube in this receiverwill shrink on removal. Do not attempt to restretchit over the tube rim. To reinstall, follow these steps
Immediately hook one end ofthe strap to chassis and re -stretch to required length.
Stretch as shown to approxi-mate total length required.
C.) Maintain tension on the strap,bring it over the tube, andhook the free end while hold-ing top.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
HOFFMAN TV ALIGNMENT PROCEDURE (Continued)
StepNo.
SignalGenerator
FrequencyMC
ConnectSignal
ToOutput
Indicator Adjust InstructionsSpecial Connections
and Settings
SOUND I.F. AND RATIO DETECTOR
1 21.6CW
Pin 1of
V101
Meter acrosspin 7 of V103
and ground
T101Pri.,Sec.
T102Pri.
Tune for max.reading onmeter.
Load secondary of T101 with 10Kresistor. Signal level should below enough to obtain approximately6.5 to 7 volts on meter. Use iso-lation networks shown in figures 7and 8 throughout steps 1 through 14.
2 21.6CW
" Meter acrossjunction of R108and R109 and
switch side of R106
T102Sec.
Tune for zerometer reading;use same signallevel as in step 1
Repeat tuning of T102 primary andsecondary until adjustments do notchange. Remove 10K load after corn -pleting step 2.
PICTURE I.F. AND SOUND TRAPS
3 21.6CW
Screw of C10on Tuner
Voltmeter topin 1 of V301
L204 Tune for min.reading onmeter.
Apply -3V bias to AGC bus.Removehorizontal oscillator tube V702.
4 21.6CW
L207 ' Detune L204 with fingers whiletuning L207.
5 20.1CW
L209 '
6 27.6CW
L203
7 23.0CW
L208 Tune for max.reading onmeter.
Set contrast control for maximumcontrast. Adjust signal level through -out I.F. alignment so that a 1 volt dcoutput is maintained at the videodetector.
8 25.0CW
" " L206
9 22.25CW
L205 " Adjust signal level throughout I.F.alignment so that the video detect-or is maintained at 1 volt.
10 25.8CW
L202 '
11 22.6CW
" " L201 I f Detune converter plate coil.
12 24.25CW
Con-verterplatecoil
" Converter plate coil located ontuner.
13 Repeat steps 3 through 12 until adjustments do not change.
14 Approx. 25with 10 mc
Sweep.Marker
required.
ConverterTube Grid(See textfor correc-tion.)
High gainscope topin 1 of
V301
Converterplate coiland L201
first.Othercoils if
necessary
Set 26.1 mcmark at 50%point with con-verter platecoil. Eliminatetilt with L201.
Use markers to determine bandpassat 50% points. Bandpass should bebetween 4.1 mc and 3.9 mc. Adjustother I.F. coils to obtain proper curveonly when absolutely necessary.
15 4.5CW
Pin 1of
V301
Meterconnectedthroughdetectornetwork
to junctionof L302and L303
L301 Tune for min-imum readingon meter.
Detector and isolating networksshown in figures 7 and 11.
79
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION I
2 201
HOFFMANTUNER
VIDEO AGC
F L. B
o o
C 20i.005 .61(___44
113 V
60
INTERLOCK
C 801.01
V Id V102 V103 V1046AU6 6AU6 6AL5 6S07GT
10 SOUND I.F. 2nd SOUND 1.F. RATIO DETECTOR AUDIO AMPLIFIERSOO. R ii2
TV PHONO I MEG--
C - 101.005
R102I IL
7 101 a
CO2.005
100
1500 AAIw
.
!Tio4;::
L
III 1
21.6 MC Aj
R11747
IDS
1622I 330MK
R104IK
C106O 05
R103100
.6+140
R106DK
Vs"..
9R105 30C MMF270
5-T ice
,1
icafTsc,LA
21.6 MC-C OS1500 MMF
8108106
F
C0047005 0047
R 107220 6
C III 500 6
C O5.005
Rill10
EG
C 11647MMF
3
210
R 201IX
22.6111 120iMC le
R 2024.3 K
tad1st PICTURE I F
0202.005
R100 K
40283303
R 205
C 205220MMF
202
-C 206
820366 I r2173 ---'
-11;165F R 2065.6 6
-.n04; L ; I
R 20426004 I ."E -,-I
:4'I .Tc2ovi50 1,_-1 1 10276 IMFMC
62nd. PICTURE 1 F
R 20120
RN8
C 20920.004
C 210220MME 22.25 MC
C2i1LA F
_L
4.204 130
"VU314 PICTURE I.F.
213005
Fida)4 84053.311
V13015U4G
LK.RECTIFIER
COLOR CODE
WI4 _ _ _ _ _WHITEBL BLUEGEN _GREENTEL YELLOWOR _ORANGERED REDBR -BROWNOLK -BLACKGY _OKAY
R 80160
+ 350TO
11[0 0J3010
C 803f C 804
3 3 3
010703 0702vso 0105 0104 v 05 0205 v204 0/03 020 0101
Owl 2 B 2 7 8 8 4 4 4 4 4
V NECONVERTER
(REAR).
80
+ POD +195 +MO5(2 OK 46L
RFC001
OR
3 3
VolIMx v Kit 0103
NOTES* THESE NUMBERS REFER TO THE 1x2 PIN NUMBERINGt S 101 AND S3OI ARE GANGED
v 502 AND V701 OCCUPY SAME ENVELOPE- - - - ASSEMBLY
SHIELD (DASHED LINE AROUND V -NUMBER INDICATESEXTERNAL TUBE SHIELD)
BUS VOLTAGES ARE FOR 115 V LINE, AVERAGE SIGNAL( 3V. AGL) ANDNORMAL CONTROL SETTINGS.
**CHASSIS MS ONLY. MELT CONNECTIONS USED IN CHASSIS 183DENOTES PLASTIC AS DISTINGUISHED FROM SAME COLOR IN COTTON
R 212
R 21068
R 21150 -
.002,45
C402.005
C 21520 .005
250 MC
NNE
C 216
ix
t,206
100Mh
6686418 PICTURE I F
220MMF V5016AU6
Is? SYNC. SEPARATOR
+KO
R 501io MEG
V 7011i6SN7GTosc CONTROL
8 701 R 707
3.36 4.7N
.p 4t 706OOK
C 702 C 71330 MMF 7p4 .d
686
^C 704005
Schematic Diagram For Chassis 183 and 185
V 502{65 N7GT
2nd SYNC SEPARATOR1195
C502047
R505 R 5086 8 K
R 70822 8
85076.86
V 7026SN7GT
HORIZONTAL OSCILL ATOR
702ISO 6
Lja_lat zgrollmF
C706 _C707I
C 7100047
711 R 71286 470 K
IMOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
PHONOINPUT
8 215IK
R 2165.60;
iTC218
__J MF
L20
230 MC
22200
2 501
F5739 R SIO R 51122K 132K B2K
1.3 C08,04
1 .S4?5r
R76.2 X
CT250 MMF
T220MMF
C T12
V 105
6K6GTAUDIO OUTPUT
6P,0VIDEO DECTECTOR
V60IAi6BL7GT
VERTICAL OSCILLATOR
V 70365060
HORIZONTAL OUTPUT
R 715100
R 714K
R 71120
AMP
+280
17:27-Mnr-'
IC42f 3 ,
MMF
12 K
C 403.0005
H
V 3016GB6
VIDEO AMPLIFIER
51-m--.'.47 MF
V 601131-6BLTGT
VERTICAL OUTPUT
R 6032.5 MEG
C ,E4QT3
R605GME
R 606+ 56 4U VERT
-C604 LIN30
R 607
330
R 610136
V 4016AU6
A.G.C. KEYER
+195
L 303v--"
350 R 305 R 306ph 3.9K 12
R30347
R611100
R 61210011
V704 V 705X24 6W4G1
H V RECTIFIER DAMPER
C 717500 MMF
ItafirinSERVICE DATA
TELEVISION CHASSIS
183, 184, 185, 186
C 303.22
R 307330 K
TV
effiGHTNESS
TO Br CIRCUIT
X X
5301 PHOND
Z 30i1 ..21
M 501
Y01Er "
8613560
REA560
LHORIZ. L703 DEFL.
V302
gilAtj FOR MODEL 163
0issP,A FOR MODEL BB
PICTURE TIME
For chassis parts layout and alignment points see next page.
an
81
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Hoffman Chassis 183, 184, 185, and 186, continued.sioi-S 301
UHF TV PHONO R 608ADAPTER PLUG SWITCH VERT. LIN.
PHONO I R 603 R 602 L701INPUT VERT SIZE VERT. HOLD HORIZ. HOL
RATIO DET.V 1036AL5
0TIO2
O21.6 MC
2ND SOUNDI.F.
6AU6V102
- -
82
1ST SOUND I.F6AU6
V101
AUDIOOUTPUT
SYNC. AMP.HORIZ. OSC. CONT
6K6 GTV105
V 104
T6016S07
1ST OUTPUT
VERT.OSC.AND
OUTPUTV 6 A -B
SYNC. SEP. 6BL017GT
6AU6V 501
L 301
4.5 MC
V 401 V 3016AU6 6CB6
AGC KEYER VIDEO AMP
CONTRASTR 302
OFF -VOLUMER 110
Note:
L209
20.1 MC
6SN7GTV 502-V 701
HORIZOSC.
6SN7GT
L801
FOCUS COIL
L601 L 703
?":'% DE FL. YOKES
L207 21.6 MC L204e) 21.6MC
R 308 R 709BRIGHTNESS HORIZ. DRIVE
R 804FOCUS
F801 LFUSE WIDTH702(UNDE
CHASSIS)
AC PLPHONO
UG
F 701HY. RECT. 1/4 AMP,,,n
T 7010 HY. TRANS. 'llIX 2 DAMPERV704
5U4GV 801
L 203
27.6 MC
L608 L206 1_85 L12O
230 MC 25.0 MC 225 MC 25.8 MCV 205
HORIZ.OUTPUT
V 204 V 203 V 2026AL5 6C B 6 6CB6 6CB6VIDEO DET. 4TH I.F. AMP. 3RD I.F. AMP 2ND I.F. AMP
6W4GT
T -80I
POWER TRANS
V201
4AL 201W22.6MC
6CB6I I.F. AMP
(CONTINUOUS TUNER SHOWN)
* 6J6 USED ON CONTINUOUS TUNER
6BC5
ALTERNATE TUBES USED6CB6 ON TURRET TUNER
PICTURE TUBE
CONY. PEAKINGL17
24.25 MC
OSC- CONV.6J6
CHANNEL INDICATOR
TUNING
Figure 12. Top View Parts Layout For Chassis 183
C10
TUNING UNITR.F.
AMP.
The parts layout shown in Figure 12 is representative of Chassis 183. Chassis 184 parts layoutis similar with the following exceptions. An AM -FM Tuner is included. Location of the AM -FMTuner and front panel controls is identical to Chassis 186, TV-PHONO switch,mounted on the rear apron, is deleted.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
104 Series1,Iodel numbers below.
A*
AO!
AN
ACP
A9
P19
PII
PIO
19
THE MAGNAVOX COMPANY
6BC5114VI
7--40
1/2 I2AT7MIXERV!A
V2 I2AT7OSG.V2B 700354
R -F UNIT
The Magnavox 104 series TV chassis are all 20 tube receivers including a directview picture tube. The CT 301, 303, 305, 307, 309, 311 and 313 include audio
amplifiers and speaker. The CT 302, 304, 306, and 310 have no audio amplifieror speaker, but are used in combination with a radio chassis audio system. Theaudio output stage also serves as a voltage regulator in all models.
VOLTAGE CHARTPin No. 1 2 3 4 5 6
V101 6AU6 -.8 202 152V102 6AL5V103 6SN7 -.7 24 0 -23 200 +4V104 6V6 400 425 112V106 6CB6 -8.2 0.2 140 140V107 6BC5* -8.2 .12 140 140V108 6BC5' 0 1.5 140 140V109 6AL5 0 -4.2 3.3V110 6CB6 +.7 1.7 140 110V111 6SN7 -33 100 0 0 7.4 48V112 6C4 135 -43V113 6V6 400 400 0V114 6SN7 -66 252 0 -1.2 45 0V115 6BG6 0 -32V117 6W4 600V118 5U4
7 80
-37
143
-3.8
035
300
400
2:0V 3119V 39011 400V
C16IA
AI4°WTSAI,
5U 4GL V. SECT.
0118
J102BR
5,01ON 8126
AA & BA1C4 SERIES
v. OR
0
0P0
0U
(76 0
0Al0
s
00 0O aS
rA43 000
00
m43 Al
M
O Mg-1 W
O 0F-1 mO a
-1-3 N0
Eta 0
r-I
0- 0M
0
0 tor_1.
rd
nos
2100
ALL ELECTRICAL VALUES SHOWNARE IN MMF OR OHMS UNLESSOTHERWISE SPECIFIED.
NUMBERS 16 BALLOONS REFERTO WAVEFORM PHOTOS.
83
M
AM(
NOV
4..0
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
7 - 2100
1/2 SN7GTSYNC CLIPPER
VII4A
The Magnavox Company *41-*
6AU6SOUND I -F
V101
6AL5souk° DU
WOE
101
11145 18 102 111103
1136 1000 EEO
6101396
G10151
6CB61ST V0E0 14
V106
27105.3MG.2
104 Series, continued.1/2 6SN7GT 6V6GT
1ST A -F OUTPUTV1034 V104
41101110
aW
0
0160
111011 1072 MO 047011 IMES 4700
6BC5 OR 68G5 OR 6AL56465 64G5 VIDEO DET
240 VIDEO I -F 3RD VIDEO I -F & A.G.C.0107 V108 C1511 VI09
255 MC7104
PittMEG
6SN7GT V2 6SN7GTSYNC. AMP SYNC. SEP SYNC. CLIPPER
74., V1114 VIIIB V1I4A
FOR 10484 SERIES
MC101
5 21K 4E00
L.
000 .002
6135K17E.1 -e"
G143se_ _ J
1/2 6SN7GTNOR A F C
11038
0146
84
0159200
INGOSOK
61.1IOOR
r 60101
04-001194
5
01361 .0047
EEK 9200 9200 W 105
Eq.r .
oN(II8
...,002 .005 005
L
111411SEE TABLE
000 HGLat
1( If".0143
i44
.47 MPMI
11190
O 173
111441
O 147
PARTNO.
OMIT
100039647004700
AA SERIES
156
33001011
65005600
IA 110010$
ELECTRICAL VALUES
1/2 6SN7GTNOR. OSC.
V1148
8166 0153 61573300 OK 1500
111511
Boo ).61511)3500
T109
r9162
1
92001-ISO147
0
SE
IR3900IK
rj--j_ MIC151
14
RI4Y415MI.
68666HOP OUTPUT
V115
YE
G153
I-7
07TUG.
0110.047 kW
L1 11,R06-4 in
MEM
111260106
GONTR
101
6CB6VIDEO AMP
VII0
6C4V 050.
VII2
000
137.047
0146SEETABLE
5173SEETABLE
395V
0126
7'5 390
G1311.047 ME
R147SEE TABLE I
MEG5HEIGHT
01600Ay0 Mr
/±-107
L1011106
11143 L s'
54
3900
6V6GTOUTPUT0113
61400.0 MEG.
1836TKV. RECT
VII6
171
MEG.
400v
C1312.500
500
Y
L110 \
24, X
P.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
TV I -F ALIGNMENT1. Tune receiver to quiet portion of TV High Band.2. Set contrast control fully counterclockwise.3. Apply 3 v. negative bias between the A.G.C. bus (at C22A)
and ground. (Use 2-1% v. cells.)4. Connect TV I -F Signal Generator through a 1500 MMF
condenser to Test Point (A) of tuner unit; low side toground. (See schematic diagram and Note #1 below.)
5. Connect negative lead of V.T.V.M. (or meter of 20,000 ohms -per -volt, or better) to 4.7K diode load resistor TESTPOINT (B); positive lead to ground. (See schematicdiagram.)
6. Feed 23.3 MC [23.31* (±.05 MC) from Signal Generator,and adjust T4 for maximum deflection on meter. MaintainSignal Generator output so low that meter reads no morethan 1.5 volts at peak.
7. Feed 22.1 MC [22.11* (-±-.05 MC) from Signal Generator,and adjust T3 as above.
8. Feed 24.3 MC [24:21* (±:05 MC) from Signal Generator,and adjust T2 as above.
9. Feed 24.7 MC [24.51* (-±-.05 MC) from Signal Generator,and adjust T1 as above.
10. Replace the meter with the vertical input of an Oscilloscopethrough a 10K isolating resistor, low side to ground.
11. Remove Signal Generator. Feed a video I -F Sweep Gen-erator (20 to 28MC) through loosely coupled shield of 6J6converter tube, making sure shield is not grounded. (Referto Fig. 3.)
12. Loosely couple high side of a TV I -F Marker Generator tothe high Sweep Generator Lead; low side to ground.
13. Feed I -F Sweep, and observe response on 'scope. (SeeFig. 5.) Use marker frequencies 20.25, 22 and 24.75 MC.
14. If response does not approximate that shown in Fig. 5,repeat steps 3 to 9, making sure that frequencies are pre-cise, and that the Signal Generator output voltage is keptlow. Continue with steps 10 to 13. A slight touch-up ofindividual slugs may be required to approximate the recom-mended curve of Fig. 5.
Majestic (Garod) Series 106 and 108 Receivers.See page 86 for a complete list of models.
TV SOUND ALIGNMENTNOTE: TV-phono switch must be in TV position.
1. Connect a 4.5 MC Signal Generator (±.01 MC) through a1500 MMF condenser to the 4.7K video diode load resistorTESTPOINT (B); low side to ground. See schematicdiagram.
2. Obtain two resistors of approximately 100,000 ohms each,whose resistances have been matched accurately with anohmmeter. Connect them in series across the 18K resistor(R107) at the 6T8 tube socket (V9A).
3. Connect negative lead of V.T.V.M. to junction of matchedresistors of step 2; positive lead to ground.
4. Feed 4.5 MC (71-.01 MC) from signal generator, and adjustL22, sound take -off coil, for maximum deflection onV.T.V.M. Two points of maximum deflection may be foundwhen making this adjustment. Correct adjustment is at-tained when screw is at most inward maximum readingposition.
5. Adjust the bottom slug of T10 for maximum deflection onV.T.V.M.
6. Connect positive lead of V.T.V.M. to junction of C96, andR106 TEST POINT (C), leaving negative lead of V.T.V.M.connected as in step 3. See schematic diagram.
7. Adjust top of T10 for zero output on V.T.V.M. betweentwo opposite polarity peaks.
IMPORTANT: Keep the sweep generator and markergenerator outputs at minimum to avoid curve dis-tortion. Marker pips should be kept barely visible.
*NOTE: If 3v fixed bias is unavailable and zero fixed bias isused, set signal generator at [ J bracketed frequencies values.Subsequently, marker frequencies of Fig. 5 are 21.9 and 24.6MC, respectively.
,F SWEEPGENERATOR
TOPOT FM,OT SCOPE EEL, j.
COUPLED
,F MARKERGENENATOR
1.0.21 PC, MONK.
EA Fs mc
(1
OSE.LOSCOP
5NW-,01100 N
TO
APE 'EPEEFREE.
STNERPTCP
FIG. 3. IF ALIGNMENT BLOCK DIAGRAM
TABLE I RF ALIGNMENT FREQUENCIES
CHANNELNUMBER
SWEEP GEN.CENTER PRE°.(10MC.SWEEP)
MARKER GENERATOR FREOUENCES
VIDEOCARRIER
SOUNDCARRIER
2 57 MC. 55.25 MC 59.75MG.
3 63 MC 61.25 MC. 65.75 MC.
4 69 MC. 67.25 MC. 71.75 MC.
5 79 MC. 77.25 MC. 91.75 MC.
6 95 MC. 93.25 MC. 67.75 MC.
7 177MC. 175.2 514C. 179.75 MC.
a 18314C. 181.25 MC. 165.75MG.
9 189 MC. 117. 25 MC. 191.75 MC.
10 195 MC. 193.25 MC. 197.75 MC.
11 201 MC. 199.25 MC. 203.75 MC.
12 207MC 20525 MC 209.75MG.
13 213 MC. 211,25 MC 215.75 MC.
TV RFRESPONSE
FIG. 5. RECOMMENDED RESPONSE CURVES. 85
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMajestic (Garod) Series 106 and 108 Television Receivers.
V8 IIIAT23-DER-LMS®r'?1ALT,ERNATE PART WI 552.'SOUND I.F AMPLIFIER 07MV8 6AU6
RATIO (LEI TRH*** ALTERNATE CONNECTIONS OF MULT-SECTIONEDCAPACITOR UNITS.IMOUNTED ON TOP 0PGHASSIS1NOTE DETERMINE WHICH METHOD IS USED
r
L
METHOD I (SCANS) ALT METHOD (2 CANS/PART NO SECTION SYMBOL PART NO SECTIott
68
Al .
C62C63
A
A
A....
5.435-3 .... c104 5418 TUB.CAP(.. C3I SAW TUELCM
( Mk C72 B Ak
5435-4 j 1 C64 8
.. 029 B A
5 429-2{ AL.
...C50C102
A
B
.16
.4.
A. 54351
ANTENNATERMINAL
STRIP
REPLACEABLEANTENNA COLUNITS(CONSISTS OF08L21
C2
216.435.2
+ ALTERNATE V9 CONSISTS OF TYPE 6/1L5 AS RATIODETECTOR AND TYPE RATE OR 6AV6 AS AUDIOAMPLIFIER BELOW IS GIVEN A TABULATION OFCORRESPONDING TUBE ELEMENT PIN NUMBERS.
6Te 6/116/5AV6 6ALSPIN NO, PIN NO PIN NO
7
2 2
S 5
4 3 35 4 4
6 77 2,5,6 I, 69 I
9 7
TO CONNECT EXTERNAL ANTENNA-.I. LOOSEN ANTENNA TERMINALS2 -REMOVE THE BUILT-IN ANTENNA LEADS.
-CONNECT 300 II LEAD- IN FROM EXTERNAL300A INPUT ANTENNA TO THE ANTENNA TERMINALIMPEDANCE STRIP, AND TIGHTEN THE SCREWS.
L_ 2
C94
V9A3
C92 39 _10%
GfrxZ= )5000 L 2?
3.2111
R106 156
NOTE WHEN AeOvE0710 ALT. ISUSED, R105 -22011 RESISTORIS NOT USED.
TURRET SWITCH SETTING SELECTS COILSFOR CHANNEL DESIRED ri es.? sic
I r ----,i cg -°-:1 !
1w c440T
I
,.
7R F AMPLIFIER
Te.if VI 6AG5/6BC5/6CB6
10
L2
.5-3
NOTE NUMBERS NEARTURRET COIL TERraNALSCORRESPOND TO SEQUENCEOF CONTACTS ON TURRETSWITCH READING FROMFRONT To BAG I(.
5-3
OSCILLATOR -MIXER
V2 6J65),_, REPLACEABLE
NnIccnt,,T,11... OF L4,L5 L6 /
I r C6(00
6 5I
L5
R42200
STANDARD COIL TUNER
H7v 1:11D60 CYCLEA C ONLY
SERIES 106 - 17" RECT TUBEMODEL DESCRIPTION
70 TABLE MODEL LEATHERETTE
772TABLE MODEL BLONDE"
70700MAHOG
1 BLONDECONsoLETTE NI
712 CONSOLETTE MAHOGANY715 CONSOLE FRUITW000717 CONSOLE BLONDE710 CONSOLE MAHOGANY
F
3 AMPLINE Fly
INTERLOCKON BACK
87 AzpHONOMOTOR
OUTLET
T7
107
=.00IMF RB
4700
5
C123-5
FINE TUNPIG
8C4.4ogITE
Oft6.3
L.V. RECT.VI8 5U4
.YELC61 3v AT 3 Amps
500 TEL
ON -OFF SWITCHGA N GE D TOVOLUMECONTROL
R74100K110%
trV AT 1.8 AMPS. ELAJE ,1, 2
GRo 6 Z10 AT 6
GR.1
CIRCUIT SCHEMATIC DIAGRAMSERIES 1064 - 17 "RECT TARE
MODEL DESCRIPTIONI7FA TABLE MODEL MAHOGANY17J CONSOLETTE MAHOGANY172 TABLE MODEL LEATHERETTE7,70 TABLE MODEL LEATHERETTEA712 CONSOLETTE MAHOGANY
719 CONSOLE BLONDE17062 CONSOLETTE MAHOGANY(OAT TABLE MODEL MAHOGANY17L TABLE MODEL 2 TONE LEATH86
SERIES 108- 20 "RECT TUBEMAH
800001 CONSOLETTE BLONDE802803BOA
CONSOLE
CONSOLE
MAHOGANY
MAHOGANY
ssn290V
SERIES 1013 20"REGT.TuaEMODEL DESCRIPTION
2078320782 TABLE MODEL rItHEODGNYK
20C120C153
CONSOLETTE MAHOGANYLIMED OAR
CI5.001 MF
20L TABLE MODEL 2TONE LEATH.2084 CONSOLETTE MAHOGANY200C CONSOLETTE MAHOGANY2OUT TABLE MODEL MAHOGANY
SERIES 108A 20" RECT. TUBE20LA CONSOLE MAHOGANY
SERIES 1088 - 20.RECT.TUBEMODEL DESCRIPTION20UAT TABLE MODEL LEATHERETTE
20 X TABLE MODEL LEATHERETTE
SERIES IOBC - 201RECT. TUBE
.20 K TABLE MODEL LEATHERETTE
RED -WHITE
FOCUS CONTROL-.CVO
® tt
RI21081,10%2W
RI3OKt00%2W
0
C2I45000 5000
i,L,A,41,11.
762250R73 1w 470R 10 .% 7w
35011GRW
IR 73
1800_10%2w
R8011208110%
RIO0478 I? 101
100
C938-5000
C 94
70'01.5MC.
,40
!PRIB7
4.5 MC.L__
5000
4102478 -10% 1W
I ST. VIDEO LE
V3 6CB6
R 164.711
110t
15000
Ril7
RIB530
Igg 51%701
02213
24.3 MC.72 GleN
,1
R48154! 10%
R492206110%
R198.26E10%
V'I.
OCr
RI 05220
C95150C
500V8104
2 ND.VIDEO I.F.V4 6CB6
R2047
R21100
T 2C;
SYNC -SEPARATOR SY NC. A MPL .
VIIA 1/2-68N7 VIIB I/2-6SN
HORIZ.OSCILLATOR
V14 6SN7
R7933M±101.
COT022 ME
HoR HOLDCW--8.
06825 ME200VR81
8.2e,05.
R78506
' 1506±10%
R5o5.68110%
R85478±10% 1W
VNA
R.521.8 K
E 10%
022 C43
NOR FRED ADJ R8847K10%
78w.
R831000,5%
R841808E10%
3En
NORSTABIL
( C69 -I330T10%croOIMF 1C71
600V I200,06,
r3
R89470K
225
.1
10 DET.
IMOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMajestic (Garod) Series 106 and 108 Television Receivers.
AUDIO AMPLIFIER AUDIO OUTPUT
V98 VIO 6K6i
1 C974 MF
1/2 - 6T8
9
. OF7 filoi,
50 V02C2/..06 IM4 _ 500vPHONO JACK
1500
--\ "!RI26156
C961500I
L500V
TEST POINT
Tv wPHONOSWITCH
22.IMCT3 Kw.
4.7 wall 4123
02185000
CS8 5000±99 5
047MF RRO4706
RIO9 Tr C1008108 10M 12.20
CW MVOLUME
- CONTROL
3 RD.VIDEO I.F.V5 6AU6
140 v
1325100
23.331C 687874
.#22406.10%Vv%
,,i 611
Rill706 Rill
560210%rw.
.C104*
2.- 4 MF
t16.102*
T5MF50v
450V170.5
470KJ
VIDEO DET.V6 A 1/2- 6AL6
4
L I/
TEL DOT
5A
126 SID%
ri L12
C2833 T TEST POINT
100
V610:-6AL5 zrTh5
A.G.C.
<.1!- _t c34
5000
842796 1 0 %
CONTRASTCONTROL
R301.56
- C27
VIDEO AMP.V7A
112-12AU7
R06220 K
10%
R27100
SLUE DOT
R100
?CR
645220Kt10%
R33 336!NA",
COLOR...STANDARDSWITCH
o4-01
L(133!IMF
COLOR CO NVERTERRECEPTACLE
L13 VIDEO AMPYEA. DOT ,,M713
I/2 -12 AUR32
8 26210% C30MF.
834R51 M3.38±10%
;FE:90 Pigs
R35
1401,5027 310; iOW
* C29 *140MF
4500
R403 38
225 v
ICAL INTEGRATING NETWORKC47 700710%
54 #55 #56 2
26 8.2 6 8.2 6- -J- -44 T C45T C46000 5000 5000T
_J
CW
J
Yft ALo
"°'' 11 '''''R57 0,4 SLUE
850
VERT. OSCILLATORVI 2 6C4
75VERT.OSC TRANS
1.5 M10%
R692206
11M.
- 1 VERT HOLO
275 V
4 3
1-5
1648
R71126.110%
.047MF600V
R6I2.53.
VERT. SIZECONTROL
.1 ME
VERT.OUTPUTVI3 6V6
R60 R624706 6.88
CWC50 *
IOOMF.50 V.
T6vERT.Ot/TPUT TRA
I .1IIIEEL6006 C52
I MF
615 F GREEN
V
ps,REDR6656010,R67 3,560
R63220
LW VERT.LINCONTROL
R6456
R6547010%
I W
5
4
1166VERTDEFLCOILS
1006
CW
1342476
115Y L 0DOT
R
±10%I W
R393.362w
R41 R4370 K
CONTROLRSS
.13 12F
'1. v2
12
10
PICTURE TUBE
V 19
C53.I MF600V
.71-I 072-I 450SAC
V
t5%I. HORIZ. OUTPUTV15 6 AV 5
:73360510% 100 ,
742-3toOR.RIVE ,T
;7517
R91
R901 NI
H.V. RECT.
V17 I B 3
5:T9 11933.3
7a
C75
600 V.
F2AMP
OVERLOAD FUSE
4
R925.6K
t 10%2 W
R70 3308
C31
Z44 ;117V
R944701( 1W
R6810K
047 MF600V
tligal
SIZE1: IFre TWNTE
C7717-5%
1:4 2KV
it: 6
C7025 Mr.200±
R96 150
C 79SOO
-E,0 KV
L668POOR.
DEFL.COILS
VI
C8039-10%
2000V
HOR. DAMPERV16 6 Vig 4
120NOR. LIN.Im
008!On
C81 182.0411116 .035 MF.1102,600V. 600V.
275V
390 V.1100ST
R 95
KEY TO SCHEMATIC'1' KILOHNS "PeMEGONMS
ALL CERAMIC AND MICA CAPACITORS ARE IN PAWAND RATED 450 v/ v UNLESS OTHERWISE SPECIFIED.
ALL RESISTORS 112W AND ALL PAPER B MOLDS D CAP-ACITORS ARE 400 wv,UNLESS OTHERWISE SPECIFIEDAU. RESIS.t 20%,UNLESS OTHERWISE SPECIFIEDPOINTS DESIGNATED BY CIRCLED NUMBERS ,CON -NE c T TO STANDARD COIL TUNER AS SHOWN. IFSARKES TAR ZIAN TUNER IS USED THESE PARTSCONNECT TO CORRESPONOING CIRCLED NUMBEREDPOINTS SHOWN IN F IGO PAGE 10 OF 'INSTALLATION SERVICE NOTES -FOR THESE SERIES RECEIVERS.
4706 t 10%
se g i803t --2000 vi
DEFLECTION YOKE AND FOCUS COILPLUG AND SOCKET CONNECTIONS
T. C3o 7: C 75
275v {
TO 17113
2250
ORA
GREE
T:. ; 079i LTB P
,;1 O V:-%8YELLOW TO VERT
OUT x -F1.15
SOCKETBLUE
PLUG,VELITI3EFLA.10A 7
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
88
Majestic (Garod) Series 106 and 108 Television Receivers.(Continued from previous pages
TO ANTENNATERMINAL STRIP
^4..".. SWITCH ACTIONAVTOMAT.0 BETWEENCHANNELS 6 E,
O
0
4.?
(-4
LOW s
RANO
SEOUEMCIE OF WAFERS I TO IS FROM FRONT TO BACK OFTIMER
ADJUSTMENTS LI, L391 L 4ARE ACCESSIBLE FROM THETOP OF THE TUNER IN LATERPRODUCTION MOOELS
VI
R F AMPLIFIER
6 C B6
0011A F
if
025
v 2 A
CONVERTERI/2 6.16
L TT TVNINOCONTROL
C---114 ER ICIS 70
--\.(\d%R9
6.16
.47 M F
V 2 13
oSC6J6
Ou T.
AGC
CieI00
J
114SAO
Why C
C194 °15.300
15000
C196 I
C.)
10. B. SARKES TARZIAN TUNER - USED IN SOME MODELS.
CIRCLED NUMBERED POINTS CONNECT AT CORRESPONDING NUMBERS ON MAIN SCHEMATIC.
TUBE COMPLEMENT AND VOLTAGE CHART (SERIES 106 and 1011)
IPIA.CIL ,UNCTION TR.."'" PIN I PIN 1 PIN 2 PIN A PIN l PIN I PIN / PIN . PIN VI KY AMPLIFIER SAG6/61101/1016 -1 0 ILIAC 0 90 W 0 -VS OSCILLATOR-MIIER WI 90 70 (SAC II -3 te-43 -4 to -0 0 - -VI 1ST VIDEO IF ICEM .4 0 ILIAC 100 100 0 - -V4 13(0 VIDEO IF WU .4 0 (SAC 101 101 I - -VI 3RD VIDEO IF 0AU6 0 0 0 6..6AC 101 GE 1.0 - -VI AGC AND VIDEO DETECTOR {Ali 0 -1 6.3AC 0 IA 0 -V7 VIDEO AMPLIFIER 'SAW Itt -13 0 (SAC {SAC 10 1 0
VI SOUND IF AMPLIFIER SAU4 0 0 (SAC 230 11/ .3 -VA RATIO DETECT. AND AUDIO AMP. ITS -13 43AG 0 0 0 -1.0 44
VS
Alum.RATIO DETECTOR GALA 0 -It (SAC 0 -.1 0 -.6 - -AUDIO AMPLIFIER OATS/SAVO -IS 0 6.3AG 0 0 0 11 - -
VIO AUDIO OUTPUT SKI NC 0 236 630 0 45 (SAC IIVII SYNC AMPLIFIER ISM 0 U 1.7 ZS 13 II (SAC 0
VII VERTICAL OSCILLATOR C4 IMP 0 0 LUC III --i1 0 -V13 VERTICAL OUTPUT
..En NC 63AG MO FM -24 4 0 SI -
V14 HORIZONTAL OSCILLATOR WINS -410+4 ISO II -66 t0-06 100 0 0 {SAC -VI6 HORIZONTAL OUTPUT RAVI -107E--43 (SAC 0 - III 0 140 -VII HORIZONTAL DAMPER 1W4 ISO NC SW NC 176 116 116 MS
.;.1.2ACVII HIGH VOLTAGE RECTIFIER l33 mum u.ny ituy _ 11.6EV - 11.01EY 11.11V -VII LOW VOLTAGE RECTIFIER 0U4 NC 1110 NC ruc 170 twAC 170 400 -6.0AC*4
VII PICTURE TUBE In niPIN II PIP. II PIN If
376 I60 :. (JACYOKE AND FOCUS SOCKET SW 166 su - 196 0 0 -
NOTES1. Tune receiver to unused channel - no signal 6.applied.2. All front panel controls at maximum clockwise
positions.3. Maintain line voltage at 117 Volts A.C.4. All voltages measured with V.T.V.M. unless other-
wise specified.5. Values shown are D.C. voltages, measured from
socket to ground, unless otherwise specified.
7.
NC designates no connection on pins, thus de-noted.Dashed lines designate the non-existence of thepin, thus denoted, on this tube type.Use high voltage insulated probe only.Top value is D.C. voltage to ground. Bottom value,negative lead of meter connected to pin 7 of 5U4.Top value is D.C. voltage to ground. Bottom value,negative lead of meter connected to pin 8 of 5U4.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
John Meck Industries, Inc.
9021 - 9024 CHASSISThe circuit shown on page 91 is exact for Chassis 9021. The
other chassis numbers listed above cover slight variations ofthe 9021. For instance, the 9022 uses a three tube I.F. stripand is being used in 14" models. Chassis 9023 and 9024 arechanged to supply higher voltage to operate 20" picture tubes.These chassis are used in Models XSC, 614T, 717C, 717T, 720C,720T, and other models. Chassis 9026 is similar to 9021, beinga slightly revised circuit of these earlier sets. This Chassis9026 is used in the JM-700 series covering sets such as JM-717C,JM-717T, JM-720C, JM-720T.
IF ALIGNMENT PROCEDURES
The I.F. amplifier contains five tuned circuits and five differentalignment frequencies are used. The video carrier is passed throughthe I.F. amplifier at a frequency of 26.1 MC. and the sound carrierat 21.6 MC. Extreme care must be taken in alignment to assure thatthe sound carrier be attenuated substantially below the video carrier.This is necessary as further insurance against the possibility thatthe A.M. modulation on the sound I.F. carrier due to picture modula-tion will be sufficiently low to be removed by the detector, and notproduce spurious phase modulation of the sound I.F. See figure below.A bandwidth of 3.6 MC. is attained (6 DB. down) with a stage gain of12 to 15 times.
An I.F. alignment signal is best introduced in the 9021 chassisby means of a suitable cup or tube shield floated over the mixer tubeto produce capacity coupling of the signal to the plate circuit. Itmay be desirable to disable the local oscillator, to prevent R.F.harmonics from distorting the trace on the 'scope screen. (A dummy6J6 may be substituted for the mixer tube, with the #1 pin removed,or pin #2 when a 12AT7 is used, to acoomplish alignment.) Contrastcontrol is set at 80% of full on. Metering may be done on the AGCline, keeping input attenuated to produce no more than a 2.5 to 3volt reading.
PEAK AT1st I.F. 25.9 MC. Unmodulated2nd I.F. 25.6 MC.
3rd I.F. 23.1 MC.
4th I.F. 22.9 MC.
5th I.F. 24.4 MC.
Alignment continued on page 90.
22.5 26.1 MC
21.6
I.F. RE ONSE CURVE
89
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
John Meek Industries, Chassis 9021,
SOUND ALIGNMENT1. Connect 4.5MC generator to the grid of the
video amplifier tube (here again, low signal level is im-portant, so that limiting action does not occur . Meter-
ing may be accomplished at the sound take -off point ofthe ratio detector (at the juncture of the 15,000 ohmresistor and the 3900 mmf capacitor) with meter groundconnected to pin No. 8 of 6V6GT tube.
2. Adjust the slug on the sound transformer formaximum negative meter indication.
3. Adjust primary of ratio detector (top slug) formaximum negative reading.
4. Move meter ground to the juncture of thetwo 6900 ohm resistors in the sound detector circuit,and adjust bottom slug on ratio detector to Zero voltage.Other meter lead remains connected as in step 1.
SOUND TRAP ALIGNMENT
1. With 4.5 megacycle generator connected as
above, switch on modulation, and increase the generatoroutput control until modulation bars are observed onthe C.R.T. screen.
2. Adjust trap core for minimum indication onC.R.T. screen.
NOTE-For this adjustment, ,over 50% AMmodulation is desirable. If generator modulation is
fixed, full R.F. output may be required to produced read-able modulation on C.R.T. screen.
PICTURE ADJUSTMENT - CENTERING
This receiver was shipped from the factory with allthe picture adjustments set and locked at the time ofshipment. However, due to the weigh of some of thecomponents, and in cases of picture tube replacement,some re -adjustment may be necessary.
(1) The deflection yoke should be placed inposition closet to the "bell of the picturetube, as far forward as possible. Thefocus coil should be positioned approxi-mately one -quarter inch from the rearof the yoke - concentric to, and at rightangles with the tube neck. The four wingnuts on the side of the bracket shouldnow be tightened.
90
9022, 9023, and 9024, continued.
(2) With the set turned on, the brilliance
control at 80% of maximum and the con-trast at minimum, the ion trap may beReduce the brilliance control to slightly
more than normal brilliance and adjustthe focus control for sharpest horizontalsweep lines. The ion trap may now beadjusted for brightest response.
(3) Connect the antenna and tune in a stationShould centering be necessary, the 3 cen-tering spring bolts on the rear of the focuscoil may be adjusted. In extreme casesof poor centering, loosen the 4 screwsmounting the bracket to the chassis andpoint yoke and focus coil slightly off 90°.
P.M. FOCUS COIL ADJUSTMENT
On some models a permanent magnet type focusunit is used. This unit provides an easy method for bothfocusing and centering adjustments.
The unit is spring mounted for ease of positioning.A brass, screw driver slotted rod, is located to the rightof the CR Tube Socket at the rear of the set, and maybe adjusted for best focus. If the focusing ring (outerring) is drawn completely to the rear and a focus isapproached, but not attained, the entire assemblyshould be moved to the rear. This may be accomplishedby loosening all 3 wing nuts on the spring mtg. assem-bly. Conversly, if focus is approached with the focusring completely forward, tighten the 3 wing nuts. Theraster may be centered by movement of the positioningring (inside of the focusing ring) with the "WobbleStick" which is taped to an eletrolytic condenser on thetop of the chassis.
PICTURE TUBE DAMAGE RESULTINGFROM INCORRECT ION TRAP
MAGNET ALIGNMENT
Of major importance in the installation of a tele-vision set, is the proper adjustment of the ion trap magneton the neck of the cathode ray picture tube. Improperpositioning of the magnet may result in circular areas ofdiscoloration developing on the face of the bulb.
John
Mec
k In
dust
ries
, Inc
.C
HA
SSIS
902
1
a
IVIDEO
6AU 6
All resistance values in ohms,
1,000
1 1,000,000
All resistors are i watt size
unless otherwise specified.
All capacitance value. less
than One ere in microfarads,
and greater than One are in
micromiorofarads, unless
otherwise specified.
1011
1.00
1 w
LYR
EC
T.
604
44
I50
TO
200
-,10
W04
,
Rio
3500
2ND
Nomolo
6AU6
VJI
DIJ
AT
mV
IDE
O
6086
6066
SS
MC
2 O
IMC
22 9
4Cqo
2445
,1C
t20
VA
MP
6AC
7
a-
.,45M
C _4
AMP IF
AU6
SO%
RATIO
..
1651_5u
14
CO
O
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ON
TR
OL
,.M
r"AU7
12A
U7
65247
1111*1
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ER
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TO
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ET
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one
oo
200
RIGHTNESS
COGHTNTROL
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6
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SIZE
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hyd
153
H°RFIVA'olta" a
.46SN7
6SN7
SA
ISM .DoZ
i
Ma
1%
OUT UT
6866
w1D
TH
CoN
TR
OL
AIZ
DO
NN
tTP
ER
ANOR
UN.
43000
C
eI
INW
John Meek Industries, Chassis 9021, 9022, 9023, and 9024, .continued.
NO
SIG
NA
L V
OLT
AG
E M
EA
SU
RE
ME
NT
S
1. W
here
rea
ding
s m
ay v
ary
acco
rdin
g to
con
trol
set
tings
, min
. and
max
. rea
ding
s ar
e gi
ven.
2. M
easu
rem
ents
are
from
soc
ket p
in to
cha
ssis
, unl
ess
othe
rwis
e st
ated
.
3.A
ll m
easu
rem
ents
take
n w
ith li
ne v
olta
ge m
aint
aine
d at
117
A.C
.
X 0 W Pi O PI
1-3
L1 Z di til tli el til
TU
BE
AP
PLI
CA
TIO
NP
in 1
Pin
2P
in 3
Pin
4P
in 5
Pin
6P
in 7
Pin
8P
in 9
Fa W
6AU
61s
t. I.F
. AM
P.
- .1
00
6.3
AC
+ 1
40+
140
+ .7
5cn
6AU
62n
d I.F
. AM
P.
- .1
00
6.3
AC
+ 1
40+
140
+ .7
5N Ili
6CB
63r
d I.F
. AM
P.
0+
2.2
06.
3 A
C+
140
+ 1
400
Li el
6CB
64t
hI.F
. AM
P.
0+
2.5
06.
3 A
C+
140
+ 1
400
m6A
C7
VID
EO
AM
P.
SH
ELL
0+
2 to
+ 1
20
to +
8+
2 to
+ 1
2+
150
6.3
AC
+ 2
00C 04 H
*6A
U6
SO
UN
D I.
F. A
MP
.+
7+
7.5
00
+ 2
20+
55
+ 7
.5W
I 0*6
AL5
RA
TIO
DE
TE
CT
OR
- 2.
5-
2.5
00
0N
C+
4M
12A
U7
SY
NC
. AM
P. -
CLI
PP
ER
+ 2
40
to -
5+
5 to
+ 1
16.
3 A
C6.
3 A
C10
0-3
00
M M6A
L5H
OR
IZ. P
HA
SE
DE
T.
+ 9
to +
15
- 10
6.3
AC
00
NC
0
CY
J6S
N7
HO
RIZ
. OS
C.
+ 1
.6+
330
+ 1
2-
8 to
- 1
3+
120
+ 1
20
6.3
AC
MI A
6BG
6H
OR
IZ. O
UT
.N
C0
+ 8
to +
10
NC
- 10
to -
20
NC
6.3
AC
+ 2
80C
AP
Do
not m
easu
re
14 M6W
4D
AM
PE
RN
CN
C+
500
to +
575
NC
+ 3
60N
C+
140
+ 1
404.1
111
6SN
7V
ER
T. O
SC
. B. S
YN
. SP
LIT
.+
24
+ 8
5+
23
- 7
to -
60
+ 6
0 to
+ 2
000
6.3
AC
0Z
6SN
7V
ER
T. O
UT
.+
.2+
390
to +
500
+ 4
to +
9+
.2+
390
to +
500
+4
to +
96.
3 A
Co
0*6
SQ
7A
UD
IO A
MP
.S
HE
LL-
1.6
00
0+
140
00
74 X'6
V6
AU
DIO
OU
T.
NC
019
020
0-
4N
C0
040
5U4
LV. R
EC
T.
NC
+ 4
00N
C36
0 A
CN
C36
0 A
CN
C+
400
14 1 e11
1B3
H.V
. RE
CT
.D
O N
OT
ME
AS
UR
E'R
eadi
ngs
Tak
en F
rom
Pin
Soc
ket W
ith +
140
As
Com
mon
Neg
ativ
e R
efer
ence
.N
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
T-34.5 MC
SOUND RATIOITEr. TRANS.JACO/LORRY
L-945 MCTRAP
T-24.5 MC
SOUND I -F TRANS.
L-15SOUND T4.
MCANA OFF COIL
T-925.9 MC
ZOO PILL IF COIL
T-8231kg
sr PIT I -F COIL
25.1 MCCONVERTERPLATECOIL
/ FRONT AFRO
O
Fig. 11 - Top Chassis Video andAudio 1-F Adjustments
PICTURE CENTERINGCONTROL
P.M. FOCALIZERTIN SOME RECEIVERS A P. M.FOCAL /ZER IS USED IN PLACEOF AN ELECTRICALFOCUS CONTROL.)
PHONO R-77INPUT HORIZ DRIVE
CO PH iv-lat
etftM
L-170 HOERQ1Z
L-19o r1WIDTH CONTROL
oiP
L-18HORIZ LIN.
Models 15WG-3046C and 15WG-3051C
These models with a "B" suffix differ mainlyin mechanical items from the "C" series. Setswith suffix "A" are of earlier production withslightly different I.F. section and verticaloscillator circuit.
Models 15WG-3049Aand 15WG-3050A & B use essen-tially the same circuit as shown on the nexttwo pages, and this material may be used inservicing these additional receivers.
Adjustments Rear of Chassis
SUIO
4.0-0T
0.1 $0 WO. 1,..0,4111U1[1::011,10
;VA:11:111fr 'I: MI ANL 04.0
giff 41.o. LI!, SPRIO SOL
MVs7r==.,Iti"eAve
Bottom Socket Voltages
SERVICE PRECAUTIONS - To service the receiver remove thechassis from the cabinet. To do so, remove the knobs, thecabinet back, disconnect the leads from the speaker,remove the antenna terminal board at rear of cabinetand then the 5 chassis mounting bolts.
ALIGNMENT PROCEDURE
PIX I -FA. Unmodulated R -F signal into Converter Grid by means
of tube shield insulated from
base. VTVM with filter in lead
of 10 K ohms and 5000 mmf
connected to pic. det. load
resistor, (R-18) 5600 ohms, in
10 K
vr1vm
02509
Fig. 13 - VTVM Connections
series with peaking coil (L-6) from Pin 7 of 6AL5. Input
signal level should be such that output is less than 2 volts
DC. Apply -3.0V battery Bias on AGC line.
Continued on page after diagram. 93
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
MODELS
1514/G -3046C
IPA/G-3051C
GREEN
WHITE
irro-BL/rTO
I
R -F UNIT
V -9A 65N7-GTvVERT. PHASEOSC. SPUTTER
6
R-28.210
IK
V -I
6CB61ST PIX. I -F
C-2I1000
V
I 6-44A
L
5
R-411(
V-1
6CB6
T-81ST P/X.I -F COIL C-6
R-5 R-6I K 221(
V-2
6CB6RHO PIX. I -F
C-11,000
V-2- 6C86
T-91ND PIX.I -F COIL C"
4A3 3 4
C-34 L-121000
R -1I2410 K
R-440 R -44C 1C-39
22 It 8.2 K 8.2 K 4700
38E1 .....C -38CT-002
R-42 R-453.3 K 3.3 K
R-463.3 K
0150V
ALL RESISTANCE VALUESIN OHMS,
K.1000
ALL CAPACITANCEVALUES LESS THAN 1.0IN MF AND ABOVE 1.0IN MME, UNLESSOTHERWISE NOTED.
COIL RESISTANCEVALUES LESS THAN 1.0
OHM ARE NOT SHOWN.
94
T.°"'R-491.5
MEG.
R-481 MEG
VERT HOLD
-r C-351000
L-17HORIZONTALFREQUENCY
707
470 K
C-63
R-10 .005
4.7 MEG.
2.2 MEG
CBwoo
00150 V
V 3
6C1363 RD PIX.1-F
R-IO R -II
22 K 180
L-13
C-iI.2
0.25
0-51 "4.11( I.8
MEG.
C-40THEIGHTMF,
R-47CONTROL
2.5 MEG.
1.5 MEG.
1 0 37 0 VR-77 DRIVE
HORIZONTAL
C-68 150 K4700
V -I6
6SN7-GTHORIZONTAL
O SC.
R-7233 K
C-640.25
C-65 1000
100 K
C-67.05
C-66111000
R-78 1 C-69
5.6T 0 25 C-70R-76 1801(
1
C-7341
V -11
6 AL5HORIZONTAL PHASE DET.
1390 V330
C-72330
R-79
82
riC -7I C-76.-470 1301
R-8110K
* iR-82
I MEG._
L-3PLATECHOKE
V-36CB6
J A 4
I C-361000
R -I21.5 K
C -ISwoo
T-10RO PLIt.
C-16 I -F COIL
L-14
-r
V -4A d V -4B6AL5
.LAt4./
H
T -C-371000
V -4A
6AL;P/X. DE
C -IS5
C191.5 "n'
V -I0
6S4VERT. OUTPUT 8w(
700 V
------- 370 V L-15 r ---11--,A
.1 1-4 -f- SOUND'6 TAKE-OFF
1
1 !PEAT. COIL 1 .4OUTPUT
R-53
TRANS. r° P/N .6 OF X-1 I___TO PIN V6 OF P-1 ---
C' GRN. I
- - - -820 .0 I
C> IR-55 .... L-16c> I 560
R-54 ,C' 1 I
VERT.710N
5 K -- -1 R -I09 I COILVERT PE° 560 ...CM.
T1C-74
I 01
R-80251(
HORIZONTALHOLD
C-75
11-(AMEIt-.05 R-86
R-85 15 K
27
C-1720 MF
R-894701(
R-87470 IS
167.74-47 -1P -I
T-5HORIZONTAL 014114.V. TRANSFOA
6BG6-GHORIZONTAL OUT
" IC-19 I C 07.05 7 1000
_LC -785 MR r
0300 VO-.81
6.886.8 K
S
450V
PHON00
1:1T 0NSWITCH /
R-910
X-1
BOTTOM VIEW OCTAL SOCKETON CHASSIS TO RECEIVE PLUGFOR YOKE AND FOCUS COILCABLE.
Power Supply 105-125 Volts AC60 Cycles Only
Power Consumption 220 Watts
Power Output 2 4 Watts (Max.)1.8 Watts (10% Distortion)
00L-5
.00 MU H'EL Dor
18.6-167
C-2068
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
V 5A 12 AT7 V-SB1ST VIDEO SYNC. AMP.
11-19 AMP. 23
.05 8-26
7 C-28 2.2 K1
0.1105 MU H.
L-6 oBROWN DOT
GRNDOT
3 d9
L'1.' + R-20 R-21 R-25 R-27 R34 R-38
R-18 C-2222 K I MEG 12 K 47 K 6 28
5.66 5 MF.H 100 820K
25 V r 0-31' 5275 V CONTRASTI
CONTROL r,/50V 0.1..-. C -2I
Rib I. 360 6-29 R-30
226 I I-- 9 TRAP T 3 K I MEG.11
11C-24 --..WAr-2. R-33 R-40 /2 1
v-86AU6 .0 5 C-931FAIIF. R 102 100 K 22 K L____,R07 A.O.C.2.2 6 3.9 MEG
z ::C.30__.1 R-22 R-98 0
0.147 6 470 6 ...,,,,3 .,. 320 V
8-15C-25...
C-94 T R -I01 0N5OV R-32 015
33 K 7 , 1000 390 K 0.5 22 K 500 68-31 BRIGHTNESS C-271. R -4I
C-921 T 47 6 CONTROL 05 T 2 2 6H 3275 V 0.25 T R I00 0.150 3 -
Models 15WG-3046C and 15WG-3051C
II
Mt50;V P PII V-6 A 12AU7 V-68
SYNC. VIDEOSEPARATOR OUTPUT
17 7
L
.275 V
L-7RANGEDOT'90 MU H
L-8REDDOT
?15 H
R-142.7K
1501,
V -4B
6AL5D.C. RESTORER
6AU6T-2
SOUND /-F TRANS.ST SOUND /-F
-5600
3
lc 461147
C-47 R-60
T .005
R-103
5.110
L-18HOR/Z. LIN.
CONTROL.86
9-19
1B3-GTH. V RECT.
R-104I MEG.
A.,S6..C-83500
3 V-20
6W4-GTDAMPER
100 K
1 -*-11R-36
190 MUM 4.7 Kwporroor.4010,4 C-32
R-37 .0510 K
2 R-63C-58 .5.6 K
5MF -R-64
5 5.6K
R -6I4'0 K P HONO
-14r V-PHONO
SWIrcHPHONOINPUT
(rf,' gf L-20
L-19 ro PIN .1 OF P-1WIDTH CONTROL ro PIN .1 OF
"C-82 C-8411--.03 1399 vo 0.25
P I 9-9310 K
TOP VIEW PLUGFOR YOKE ANDFOCUS COIL CABLE.
f150 VO
R-92K
C-857 56
R-941500
C-88 B80 MF.450 V
C56440
IMF.
C-59-Al01
5
R-39I MEG.
V-7Pa. TUBE
T-11AUDIO OUTPUT
TRANS.
R-67I 6
V -I4
6AQ5AUDIO
R-66 OUTPUT390
VOLUME v-is6AV6ICONTROL AUDIO AMP.
R -I05I MEG.
R-10668 K
C-99 R -I15 C-54.005T I MEG .005
V -2I
HOR/Z. 5U4 -GDEFLECTION L V. RECT/F/ER
WHEN P M. FOCALIZER ISUSED L-21. R-96 L R-97ARE REMOVED.PIN'? /8 OF 0-1 & P-1ARE NOT USED.A 500,.. RESISTOR ISCONNECTED BETWEENR-951 L-22 TO PIN .4 OF
70 PIN .8 or 9-1 FUSE
TO PIN .2 OF a -I cr\j}-0\0
0 r50
.175 V 0320 70 PIN .2 OF P-1 ,0390 V
7-Z)
L7,775
L-21 " s"s L-22
R-684500 K
C-61.01
R 68B500 6
8-69 C-6247 6 08
3275 V
T-6 ON -OFFPOWER TRANS. SWITCH
FOCUS COIL FILTERC-89 A
__,AAAN- CHOKE30 MF. R-96 .... C-56 B
500 I"450V'-VVVVN.,
R-97 4 KFOCUS CONTROL
7
R-95500
450 V
C-89 B80 ME.450 V
8LX
EL
__J
C-86 A.01
C-86 B.01
INTERLOC
lin some receivers C-99 and R-115 are not used.
95
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMontgomery Ward
FREQUENCY
1. 25.1 MC
2. 23.1 MC
3. 25.9 MC
ADJUST
Converter plate coil (on top oftuner) for maximum dc at pic-ture detector.
1st picture I -F coil (T-8 abovechassis) for maximum dc at pic-ture detector.
2nd picture I -F coil (T-9 abovechassis) for maximum dc at pic-ture detector.
T-34.5 MC
SOUND RArioDE T. TRANS.
RR/MARY
BACK APRON
T-1024 I MC.
3RD P/X /-F CO/L
T-24.5 MC
SOUND /-F TRANS.
FREQUENCY
4. 24.1 MC
5. 21.7 MC
96
Fig. 12 - Bottom Chassis Video andAudio I -F Adjustments
10 K_n_
5000MMF.
ADJUST
3rd picture I -F coil (T-10 belowchassis) for maximum dc at pic-ture detector.
3rd picture I -F trap (T-10 in canabove chassis) fcr minimum dc atpicture detector.
SHIELDED CABLE
Fig. 14 - Oscilloscope Connection
SCOPE
Models 15WG-3046C and 15WG-3051C.ALIGNMENT PROCEDURE (continued)
B. I -F Sweep Generator into converter grid by means oftube shield insulated from base.Connect oscilloscope across R-18 (in place of VTVM).Apply -3.0V bias (DC) to AGC line (battery).Tuner should be switched to dead channel so as notto cause interference.
21.7Fig. 15 - Overall Response Curve
Observe overall I -F response, which should be as shownabove: A slight touch-up may be required. At no timeshould the trap coil be re -adjusted, nor should it be neces-sary to turn any of the picture I -F coils more than 1/2turn of the slug. The following comments are suggestionsonly:
1. The height of the 26.2 MC marker is controlled by the25.1 MC (Converter Plate Coil on tuner) and the25.9 MC (2nd P.I.F.) coils.
2. The uniformity of response (flatness across top andposition of 23.5 MC) marker is controlled for themost part by the 24.1 MC third picture I -F coil.
3. The 23.0 MC marker position is controlled by thefirst picture I -F (23.1 MC coil). However, it is NOTadvisable to change the setting of the coil, due toits effect on sound rejection. Its adjustment shouldbe avoidea unless believed to be absolutely neces-sary.
VIDEO
With 4.5 MC unmodulated signal from a high impedancesource, (10,000 ohms in series with generator), into plateof pix det. tube (Pin 7 of 6AL5 second detector) andVTVM on picture tube grid, tune 4.5 MC trap L-9 (top ofchassis) for minimum response. VTVM on 0-10V AC scale.
AUDIO I -F
Ground sound AGC (bottom of sound take -off coil) Withsignal generator set to 4.5 MC and dc V.T.V.M. connectedto ratio detector (6AL5 Pin No. 7) adjust sound take -offcoil (L-15), sound I -F primary and secondary (T-2), andratio detector primary (T-3 bottom) for max. voltage.Select output levels on signal generator which will maintaind -c voltage about 10 volts.
With same setup as above except dc V.T.V.M. is con-nected as follows: Ground side of V.T.V.M. is connectedto junction of 5600 ohm resistors (R-63 & R-64) across pins5 and 7 of 6AL5 ratio detector and high side of V.T.V.M.is connected to ratio detector audio output at junction of68,000 ohm resistor (R-62) and 470 mmf condenser (C-55).
Align ratio detector secondary (T-7 Top) for crossover (0voltage) as read on V.T.V.M. lowest scale (3 V.).
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
PICTURECENTERING
LEVER
The description of Chassis TS -236,used in the models listed at right,appears below and on the next sevenpages. Chassis TS -196, used inModels 17T3, 17K11D, is the same,but uses 017" glass picture tube.Chassis TS -214, Model 17T5A, is thesame, but uses a 17" glass electro-statically focused picture tube.Chassis TS -228, used in Models 17T5C,17T6F. 17T6BF, 17K8A. 17K8BA, 17K9A,17K9BA, 17K10, 17K10M, 17K11A, 17K11BA,is the same, but uses a 17"metal electrostaticallyfocused picture tube.Chassis TS -307, used inModels 20T2A, 20T2BA, 20T3,20T3B, 20K6, 20K6B, isthe same, but uses a 20"glass picture tube.
2ND. ANODECONNECTION
HOROSC
YOKE ADJUSTMENTTHUMB SCREW
CHASSIS
TS -236MODELS17K817K8B17K1117K11B17K11C17T5D17T6C17T6D17T6BD
FIGURE 2.
SERVICE ADJUSTMENT CONTROLS
HOR VERT 410HOLD HOLD
HORSIZE
0GU
0 0
BRIGHT- FOCUS VERT VERTNESS LIN SIZE
YOKE ADJUSTMENTTHUMB SCREW
(TO LEVEL PICTURE)
PICTURE TUBESUPPORT BRACKET-
ADJUSTMENT SCREW
POWERTEST SOCKET- INPUT
An octal socket on the rear of the chassis (see Figure 2)provides the following test points:
DEFLECTIONYOKE
Pins #1 and #6, from the horizontal oscillator coil,should be shorted when making the horizontal oscil-lator adjustment.
Pins #1 and #8 are connected to 13+Pin #2 is connected to the 6.3V filament line.Pin #7 is wired to the output of the video amplifier stage.
FOCUS COILPOSITIONING
ADJUSTMENT STUD
PICTUREI. -CENTERING
LEVER
FOCUS COILCCENTRIC
ADJUSTMENT STUD
ION TRAP
FOCUS COILPOSITIONING
ADJUSTMENT STUD
FIGURE 3. PICTURE TUBE ADJUSTMENT LOCATIONS
97
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
0
as.1-I
98
;
7
Es!
°11.2°Vi,;
L. pi
ft
-14
3
I.
81 13!Lig
15 -.114-L7-'TnNo ;
S ;
g
g
g
g
i2
Ii
39
SI 1
ti
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMotorola Chassis TS -236, Models 17K8, 17K11, 17T5D, 17T6C, etc., continued.
DEFLECTIONYOKE
FOCUSCOIL
V1512AX4GTDAMPING
DIODE
V14613066T
HORIZ OUTPUTa H.V. GEN.
C49
C50 -
R 37-
E4ION TRAP
T6
VI 36SN7GT
HORIZ OSC
HORIZ VERTHOLD HOLD
FIGURE 4. TOP VIEW OF CHASSIS
FOCUS COIL
TEST I HORIZSOCKET SIZE
I_ 6HORIZ
OSC
V96W6GTAUDIO
OUTPUT
The focus coil should be spaced I/4" from the deflectionyoke when it is parallel with the yoke, with its opening con-centric with the neck of the tube. The position of the focuscoil is changed by loosening the nuts on the top and bottomof the coil and sliding it forward or backward in the slottedbrackets on the coil mounting plate. See Figure 3. Theopening in the focus coil can be made concentric with theneck of the tube by loosening the nuts on the studs whichsupport the focus coil mounting plate and turning the studswith a screwdriver in the slots provided, The studs are
V1717C P4
PICTURE TUBE
BRIGHTNESS
L4.5NCTRAP
V 26AL5
PHASEDET
L 3SOUND
TAKE -OFF
V 06SN7GT
1ST 8 2NDCLIPPER
V76A L5
RATIO DET.
ANTENNARECEPTACLE
J2GENERATOR JACK
V36666
1ST (F AMP
T2 1ST IF(PRI-TOP)(SEC-BOT)
V86C4
1ST AUDIO AMP
T4 RATIO DET(PRI-TOP)(SEG BOT)
V46686\ 2ND IF AMP
L821.9MC TRAP
V 66AU6
AUDIO DRIVERLIMITER-T76AH6k VIDEO AMP
\\,
SPEAKERLEADS
651 TESTRECEPTACLE
V 1
128H7VERT BLK OSC
8 VERT OUTPUTeccentric and move the coil both vertically and horizontally.They should be used only to center the neck of the tube inthe opening of the coil.
TEST RECEPTACLE
A three -',,in receptacle, accessible frbm the top of thechassis (see Figure 4), is provided for checking sensitivityand AGC vcltage. The video detector load resistor is con-nected to pin #3, the AGC line is brought out to pin #1, andpin #2. is grounded. 99
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Motorola Chassis TS -236, Models 17K8, 17K11, 17T5D, 17T6C, etc., continued.
SECTI MIXER IF
PRI
J2GENERATOR
JACK
V36C8
V86C4
12 1ST IF(PRI -TOP)(SEC -8011
V46C86
V76AL5
T4 RATIO DET(PRI-TOP)(SEC -80T)
13 2ND IF
VI J1 V26C86 GENERATOR 6U8 CONTRAST VOLUME
JACK
V66AU6
TESTRECEPTACLE
V56016
C51
11
VERTSIZE
GENERAL
VERT FOCUSLI N
VII1213117
BRIGHTNESS
V 06SN7GT
L11 HORIZSIZE
V 26AL5
ALIGNMENT
The chassis should be mounted on angle iron brackets(Motorola Part No. 7X700210) so that all connections andadjustments may be made easily.
Since the power cord circuit is broken by the interlockwhen the cabinet back is removed, it will be necessary toobtain an extra power cord with the female interlock recep-tacle in order to make a power connection to the receiver.Order Motorola Part No. 30B470756.
100
E2
E3
C49
V16B3GT
T9
T5
V1461306GT
C50
VI 5I2AX4GT
1114 arais
V136SN7GT
- "
LI 3
V96W6GT
VERT HORIZHOLD HOLD
TESTSOCKET
FIGURE 5. BOTTOM VIEW OF CHASSIS
As one side of the power line is connected directly tothe chassis, it is important that an isolation transformer beused between the receiver and the line when any test equip-ment is attached to the chassis. This precaution is espe-cially important if grounded test equipment is used. NEVERGROUND THE RECEIVER CHASSIS DURING TESTING OP-ERATIONS OR INSTALLATION UNLESS AN ISOLATIONTRANSFORMER IS USED.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMotorola Chassis TS -236, Models 17K8, 17K11, 17T5D, 17T6C, etc., continued.
ORDER OF ALIGNMENT
1. Audio Take -Off & Ratio Detector
2. 4.5 Mc Trap
3. IF & Mixer Transformers
4. Oscillator & RF Sections
AUDIO TAKE -OFF & RATIO DETECTOR ALIGNMENT
Equipment Required:
AM Signal Generator: Accurately calibrated at 4.5 mc(Optional) Adjustable output
DC Meter: Low range electronic voltmeter
Refer to Figures 3 & 4 for location of adjustments.
1. If possible, it is desirable to align the audio section froman actual station signal, since the 4.5 mc alignment fre-quency will be exact. To permit operation below the limit-ing level of the audio driver tube, for sharp alignment, thefine tuning trimmer should be turned off the station slightly.
Z. If a signal generator is used, tune it accurately to 4.5mc, and adjust the output to approximately 10,000 micro-volts. Connect the high side of the signal generator througha 1000 mmf capacitor to the grid (pin 1) of the video ampli-fier tube V-5, and the low side to chassis. The followingsteps apply whether the station signal or signal generator isused.
3. From either side of electrolytic capacitor C-43 (10 mf)through a 10K ohm decoupling resistor, connect an elec-tronic voltmeter to chassis.
4. Set CONTRAST control for maximum gain (fully clock-wise).
5. Peak audio take -off coil L-13 for maximum reading onmeter.
NOTE: As adjustments are brought to resonance, it is ad-visable to reduce the signal generator output to preventoverloading.
6. Peak ratio detector (T-4) primary (top core) for maxi-mum reading on meter.
NOTE: Both the primary and secondary of the ratio detec-tor transformer have two tuning points. Only one, with thecores at the outer end of the windings, is the proper point.
7. Move the meter and decoupling resistor from C-43 tothe junction of R-33 (33K) and C-44 (1000 mmf).
8. Adjust T-4 secondary (bottom core) for ze,o responseon the lowest scale of the meter. This corresponds to thecross -over point of the FM detector curve. If desired, thesymmetry of the curve may be checked by tuning the signalgenerator 25 kc above and below 4.5 mc and noting the plusand minus voltage produced, reversing the meter connec-tions, as necessary. For proper balance of the ratio de-tector system, the voltages in each direction should be ap-proximately equal. If not, check the tuning of L-13 and boththe primary and secondary of T-4, the ratio detector trans-former. U necessary, replace the ratio detector tube V-7.
AUDIO SENSITIVITY MEASUREMENT
1. Connect the signal generator to the grid (pin 1) of V-5,the video amplifier tube, through a 1000 mmf capacitor.
Z. Turn CONTRAST control fully clockwise.
3. Connect the electronic voltmeter from either side ofelectrolytic capacitor C-43, through a IOK ohm decouplingresistor, to chassis.
4. Set the generator at 4.5 mc.
5. With a 10,000 microvolt signal, the AVC voltage readon the meter should be greater than 5 volts.
4.5 MC TRAP ALIGNMENT
1. Connect the signal generator, through a 1000 mmf ca-pacitor, to the grid (pin 1) of V-5, the video amplifier tube.
2. Connect the voltmeter and the germanium crystal detec-tor, as shown in Figure 6, between the cathode of the pic-ture tube (yellow lead) and chassis.
3. With the signal generator accurately set at 4.5 mc andmaximum output, adjust trap L-11 for minimum reading onthe lowest voltage scale of the meter.
It
VTVM
DC PROBE 220K IOOMMF
I N34220K
FIGURE 6. ELECTRONIC VOLTMETER CONNECTIONS
IF AMPLIFIER ALIGNMENTEquipment Required:
IF Sweep Generator meeting the following requirements:
1. 18 to 30 mc, approximately 1Z mc sweep width
2. Output constant and adjustable to at least 0.1 voltmaximum.
3. Accurately calibrated, adjustable markers
Cathode Ray Oscilloscope - preferably one with a cali-brated attenuator
NOTE: If there is no built-in marker in the sweep genera-tor, loosely couple the output of an accurately calibrated AMsignal generator to the IF strip. At all times, keep themarker output low enough to prevent the marker from dis-torting the response curve.
If a wide band scope is used, the marker will be moredistinct if a capacitor of 100 to 1000 mmf is placed acrossthe scope input. Use the smallest size possible, since toolarge a value will affect the shape of the curve.
Procedure:
1. Replace the high voltage generator tube V-14 with an80 ohm, 10W resistor connected between terminals 2 and 7of the socket, to eliminate RF interference in the oscillo-scope. The tube may also be replaced with a similar typewhich has all pins clipped off except the heaters.
Z. By means of an external battery, apply a negative 3 voltbias, through a decoupling resistor of 47K ohms, to the AGCline, which is connected to pin ;1 of the test receptacle. SeeFigure 4 for receptacle location.
101
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMotorola Chassis TS -236, Models 17K8, 17K11, 17T5D, 17T6C, etc., continued.
21 9MC
24 75MC
A
IF RESPONSE CURVE(DAMPED)
21 9MG
24 75MC
B
OVERALL RESPONSE CURVEFROM MIXER (DAMPED)
FIGURE 7. IF AND MIXER RESPONSE CURVES (DAMPED)
3. Connect an 820 ohm damping resister across the pri-mary winding of the 2nd IF transformer T-3 (across ter-minals 1 & 4 of the transformer).
4. Through a 47K ohm decoupling resistor, connect the os-cilloscope across the video detector load resistor R-19(5600), which may be reached from pin #3 of test recep-tacle. If a stronger output is required, connect the scopebetween picture tube cathode (yellow lead) and chassis. Thecurve seen at this position will be the reverse of the polarityshown in Figure 7.
5. Using leads as short as possible, connect the sweepgenerator, through a 1000 mmf capacitor, to jack 3-2, feed-ing into the grid of the 1st IF tube V-3. See Figure 4. (Donot use the loose or "spraying" method of coupling). Set thegenerator center frequency to 24.6 mc, with a sweep devia-tion of 10 mc.
6. Tune the primary and secondary of the 1st IF trans-former T-2 to a center frequency of 24.75 mc. See Fig-ures 4 & 5 for core locations and Figure 7A for responsecurve.
NOTE: If a distorted or unstable curve is seen on the scopeduring alignment, it may be necessary to stop the oscillatorby placing a shunt wire across the oscillator inductance(from position 2 to position 13 on the band switch).
CAUTION: A. Keep the signal input low, to prevent flat-tening the top of the curve, due to limitingin the video or scope amplifiers.
B. The dressing of plate and grid componentsin the IF circuit affects tuning. Do not moveindiscriminately.
C. The resonance point of the IF transformersand trap will be found at two settings of thecore. The correct setting is the one withthe core at the outer end of the winding.
7. Tune trap L-8 for maximum attenuation on the curve at21.9 mc, as in Figure 7A.
8. Move the generator to jack J-1, connected to the grid(pin 2) of the mixer tube V -2B. See Figure 5.
9. Tune the primary and secondary of the mixer IF trans-former T-1 to a center frequency of 24.75 mc: See Fig-ure 7B for response curve.
10. Remove the 820 ohm damping resistor from the 2nd IFtransformer T-3. Adjust the core in T-3 until the responsecurve of Figure 8 is obtained.
102
21.9MG
140%i
55%22.9MC
40%50%
26.4MC
MARKERS TO FALL INRANGES INDICATED.
FIGURE 8. OVERALL RESPONSE CURVES FROM MIXER
BANDWIDTH
The IF bandwidth may be checked with an AM signalgenerator, if desired. Connect the generator, through a1000 mmf capacitor, to jack J-1 in the grid circuit of themixer tube V-ZB, and an electronic voltmeter across thevideo detector load resistor R-19 (5600). Set the genera-tor frequency to 24.6 mc, and adjust its output for a 1 voltreading on the meter. Double the output of the generator.Tune to both sides of 24.6 mc and note the frequencies atwhich the meter again reads 1 volt. These frequencies in-dicate the 6 db bandwidth points and should be 22.9 mc and26.4 mc. By watching the meter while tuning slowly throughthe band, any serious peaks or holes in the response curvecan be detected.
REGENERATIONAfter the mixer and IF stages have been aligned, a check
for regeneration in the IF strip should be made as follows:
1. Remove the battery bias and observe the response curveon the scope as taken between the picture tube cathode (yel-low lead) and chassis. The bandwidth may change with thebias removed, but should not change more than 0. 2 mc.
If the bandwidth does change more than 0.2 mc, checkthe cathode resistors or change tubes.
2. Set the contrast control at maximum gain (fully clock-wise).
3. Decrease the generator input until the output signalshows a marked decrease.4. Any regeneration present will be indicated by sharppeaks on the overall response curve.
NOTE: The oscillator should be stopped, as describedabove, during this procedure.
MIXER & IF SENSITIVITY MEASUREMENTS
1. Connect an AM signal generator, set at 24.6 me, to thegrid (pin 2) of the mixer tube V -2B through a capacitor of1000 mmf
2. Remove the oattery bias from the AGC line.
3. Put the oscillator back into the circuit.
4. Connect the electronic voltmeter, through a decouplingresistor of 100K ohms, across the video detector load re-sistor R-19 (5600).
5. Turn the station selector switch to the low channel posi-tion which gives the lowest noise reading on the meter.
6. The signal required to produce 1 volt on the voltmetershould be less than 250 microvolts.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMotorola Chassis TS -236, Models 1788, 17K11, 17T5D, 17T6C, etc., continued.
TUNINGANTENNA, RF, & OSCILLATOR COIL ALIGNMENT
NOTE: The IF circuits must be aligned before the oscilla-tor section can be properly phased.
Equipment Required:
Sweep Generator having:
1. Frequency range 40-220 mc2. 10 mf sweep width3. Output constant and adjustable4. Adjustable markers (markers should be calibrated
occasionally by checking against an accurate signalgenerator).
Oscilloscope: Preferably one with a calibrated input atten-uato r.
AM Signal Generator having:
1. Frequency range 40-220 mc2. Accurate frequency and attenuator calibration3. 400 cycle, AM modulation
FREQUENCY CHART
Chan Frequency Picture Sound Oscillator
2 54-60 55.25 59.75 81.653 60-66 61.25 65.75 87.654 66-72 67.25 71.75 93.655 76-82 77.25 81.75 103.656 82-88 83.25 87.75 109.65
174-180 175.25 179.75 201.658 180-186 181.25 185.75 207.659 186-192 187.25 191.75 213.65
10 192-198 193.25 197.75 219.6511 198-204 199.25 203.75 225.6512 204-210 205.25 209.75 231.6513 210-216 211.25 215.75 237.65
ANTENNA & RF ALIGNMENT PROCEDURE
I. Remove the high voltage generator tube V -I4, to elimi-nate RF interference in the oscilloscope.
2. Remove the antenna lead-in from the chassis, and con-nect the sweep generator to the antenna receptacle. Keepthe leads from the generator to the socket short. Use in-ternal markers or an accurately calibrated external signalgenerator for markers.
STATION SELECTOR
ANTSECTION L3E L3D L3C L3B L3A
LIA
L5EL5L5CL58L5A
RFSECTION
OSCSECTION
SWITCH
L B L7A L6
LIF
VI6C86F AMP
L4C10
JIENERATOR
JACK
V26U8
XER-OSC
13
FIGURE 9. ANTENNA, RF, AND OSCILLATOR COIL LOCATIONS
3. Connect the oscilloscope, through a decoupling resistorof 47K ohms, to jack J-1, in the grid circuit of the mixertube V -2B. See Figure 9.
4. Short the AGC line to chassis (ground pin #1 of test re-ceptacle).
5. Stop the oscillator by placing a shunt wire across theoscillator inductance (from position 2 to position 13 on theband switch).
6. Refer to Figure 9 for the location of the trimmers andcoils. The chart listed above gives the picture and soundcarrier frequencies.
7. The antenna coils are tuned to the video carrier fre-quency and the RF coils are tuned to the sound carriers.Figure 10 shows the shape of the curve which should ap-pear on the oscilloscope.
8. Set the screw, in channel 13 RF coil L-4, midway in thecoil.
9. Turn the station selector switch to channel 7. Set thecenter frequency of the sweep generator to the center fre-quency of channel 7 1177 mc).
5-15'70- :75-15% 5-I5V-CHANNELS 2-6
IDEAL WAVEFORM
RF WAVE SHAPESTO BE OBTAINEDWITH BOTTOM SHIELD
FIGURE 10. RF RESPONSE CURVES
5-15% 5 -I5% -CHANNELS 2-6
PERMISSIBLE VARIATIONS
V-- 1 It
5 0,73.0Q
t_/25%t -T %
CHANNELS 7-13
PERMISSIBLEVARIATIONS
103
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONMotorola Chassis TS -236, Models 1758, 17K11, 17T5D, 17T6C, etc.,
10. Adjust ceramic trimmer C-10, so that the video andsound markers appear on the response curve within the lim-its shown in Figure 10.
11. Move the station selector switch to channel 13, and setthe generator to the center frequency of the channel (213mc). Adjust the screw in coil L-4 for the proper responseon channel 13 (see Figure 10).
12. Recheck channel 7 for proper response. Readjust trim-mer C-10, if necessary.
13. Checkchannels 13 through 7 and compare with curvesin Figure 10. The peak of the curves may be sharpened orbroadened by changing the position of the grounded end ofthe high frequency matching bus L -1F. It should be approx-imately 3/16" from the switch shield. For minor adjust-ments, bend the bus to increase or decrease the amount ofwire extending through the switch shield. Note the responsecurve.
NOTE: If the response is checked with the cover on thetuner, the picture marker will move up the left side of thecurve a short distance, but the markers should be withintolerance.
14. Move the station selector switch to channel 6 and setthe generator to the center frequency of the channel (85 mc).
15. Compress or spread the channel 6 antenna coil L -1Cand RF coil L -5E to obtain the proper response. See Fig-ure 9 for coil locations and Figure 10 for response curve.The antenna coil affects the video carrier and the RF coilaffects the sound carrier.
16. Align channels 5 through 2, in that order, in the samemanner as channel 6. As the coils are in series, the properphasing of channel 6 will simplify the alignment of the lowerchannels.
CAUTION: Make certain the bandswitch is on the correctcnannel before checking bandpass.
OSCILLATOR ADJUSTMENT
I. Put the oscillator back into the circuit.
2. Connect the oscilloscope, through a 47K ohm resistor,across the video detector load resistor R-19 (5600), whichmay be reached from pin #3 of the test receptacle.
3. Ground the AGC line.
4. Refer to Figure 9 for the locations of the trimmers andcoils. The sound carrier frequencies may be obtained fromthe chart above.
5. Set the fine tuning trimmer to mid -capacity.
6. Turn the station selector switch to channel 10.
7. Set the sweep generator to channel 10, with a centerfrequency of 195 mc. Keep the output low enough to showno evidence of limiting in the overall response curve.
NOTE: The curve shodld be substantially that of the mixer,as in Figure 8. Any consistent tilting of the response curveindicates that the mixer and IF stages are not properlyaligned.
8. Introduce a marker corresponding to the sound carrierof channel 10 (197.75 mc). Keep marker signal as low aspossible.
104
continued.
9. Adjust the oscillator trimmer C-13 to place the soundmarker slightly higher in frequency than the 21.9 mc trapdip. This allowance must be made for the shift caused bythe bottom shield being off. When the shield is replaced,the sound marker will move down into the trap dip. Thepicture marker will then be approximately one-fourth toone-half down from the base line on the opposite side of thecurve.
10. Check channels 7 through 13, noting whether the soundmarker falls just above the trap dip, with the fine tuningtrimmer within 30 degrees of mid -capacity. (Each numberon the station selector switch knob represents 30 degrees).
11. If more than a 30 degree change in the fine tuning trim-mer was needed in step 10, adjust the channel 13 oscillatorcoil L-6 by spreading or compressing the turns. If L-6 isis adjusted, it may be necessary to readjust trimmer C-13on channel 10. Coil L-6 has more effect on channels 10 to13 than on channels 7 to 9.
12. Turn the station selector switch to channel 6, and setthe sweep generator center frequency to 85 mc.
13. Set the fine tuning trimmer to mid -capacity.
14. Introduce a marker corresponding to the sound carrierof channel 6 (87.75 mc).
15. Compress or spread the channel 6 oscillator coil L -7Euntil the sound marker is placed just above the dip in the21.9 mc trap.
16. Align channels 5 through 2, in that order, in the samemanner as channel 6, so that the sound marker falls justabove the trap dip, with the fine tuning trimmer within 15degrees of mid -capacity.
NOTE: Since the oscillator coils are in series, it is neces-sary to adjust the high channel coils first, before proceed-ing to a lower channel.
OVERALL SENSITIVITY MEASUREMENTS
An overall measurement of sensitivity is made as fol-lows:
1. Connect an AM signal generator to the antenna recep-tacle on the receiver chassis, matching the generator to thereceiver with a resistor network. In the case of a genera-tor with a 5Q ohm output impedance, insert a 100 ohm re-sistor in series with the output terminal, and a 150 ohm re-sistor in series with the ground terminal.
2. From the cathode of the picture tube (yellow lead) tochassis, connect a calibrated oscilloscope. NOTE: Tocalibrate scope, connect it across the 6.3 volt filament sup-ply. The peak -to -peak amplitude on the screen will then beapproximately 18V (6.3 x 2.8).
3. Short out the AGC line to chassis (ground pin #1 of thetest receptacle).
4. Set the contrast control for maximum sensitivity (fullyclockwise).
5. Set the signal generator for 30% modulation at 400 cycles,tune it to the mid -carrier frequency of the channel beingchecked, and rotate the fine tuning trimmer for maximumoutput.
6. The generator signal necessary to produce 20 voltspeak -to -peak on the scope should be less than:
a) 35 microvolts for channels 2 through 6b) 100 microvolts for channels 7 through 13
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
frh-te,,o4CHASSIS
TS -216MODELS
The circuit diagram of Chassis TS -216, used in Models 14T4 and14T4
14T4B, is shown on the next page. Chassis TS -314 used in Models 14T4B
17T5E, 17T6G, and 17E10E, is the same as TS -216, but uses a 17"picture tube. Chassis TS -314A is the same as TS -314, but has anadditional I.F. stage. Chassis TS -315, table Model 17T5F, is thesame, but uses a 17" metal picture tube. Model 14P1B is a portableusing Chassis TS -216. For carrying out alignment work on any of thesesets, you may refer to the full alignment information presented underChassis TS -236, in the previous Motorola section. The procedure isexactly the same.
SERVICE ADJUSTMENTS
FOCUS CONTROL
Adjust FOCUS control until the fine horizontal line struc-ture of the raster is visible over the picture area. The con-trol should be turned through the correct point several timesuntil optimum focus is obtained.
CENTERING
Center the picture in its mask in the following manner:
1. Place the two arms, on the magnetic centering device,together.
2. Center the picture horizontally with the HORIZONTALCENTERING control, on the back of the chassis. If the con-trol comes within 1/4 rotation of either end of its range,move both arms of the centering device simultaneously un-til the picture is centered horizontally and the range of thecontrol is adequate. It will be helpful, during centering, ifthe picture size is reduced until all four edges are visible.CAUTION: Do not center the raster - use a picture on thescreen only.
3. Separate the two arms until the picture is centered ver-tically. NOTE: The two magnets interact, and adjustingone may necessitate readjusting the other.
4. Make a final adjustment of horizontal centering with theHORIZONTAL CENTERING control.
VERTICAL SIZE AND VERTICAL LINEARITY
Adjust the VERTICAL SIZE control until the picture fillsthe mask vertically. Adjust the VERTICAL LINEARITYcontrol for best overall vertical linearity. Adjustment ofthe VERTICAL SIZE control will require a readjustment ofthe VERTICAL LINEARITY control and possibly of the VER-TICAL HOLD control.
HORIZONTAL SIZE
Adjust the HORIZONTAL SIZE control until the picturefills the mask horizontally. As this control also affectsvertical size, it may be necessary to readjust the VERTI-CAL SIZE control.
HORIZONTAL HOLD ADJUSTMENT
The HORIZONTAL HOLD control should have a syncrange of approximately 1800. If the control is too critical,adjust as follows:
1. Short out HORIZONTAL OSCILLATOR coil L-16. Thismaybe done with the chassis in the cabinet by shorting pins1 and 6 of the test socket on the rear edge of the chassis.
2. With HORIZONTAL CENTERING control, move the pic-ture to the left so that the right edge of the raster can beseen. Adjust the HORIZONTAL HOLD control to about themiddle of its range and note the width of the blanking pulse.(The blanking pulse appears as a gray bar at the right edgeof the raster),
3. Remove short from HORIZONTAL OSCILLATOR coil.
4. Adjust HORIZONTAL OSCILLATOR coil until the sameamount of blanking pulse can be seen as was noted in step 2.
VERTICAL HOLD
Adjust the VERTICAL HOLD control for the center ofthe vertical sync lock -in range.
BRIGHTNESS
Adjust the BRIGHTNESS control, in combination with theCONTRAST control, for the most pleasing picture. Keepthe brilliance as low as possible, to protect the fluorescentscreen of the picture tube and to prevent poor picture detail.
ADJUSTMENT OF THE ION TRAP
Under conditions of rough shipment, it is possible forthe ion trap to become misaligned. To prevent serious dam-age to the picture tube, the following method of adjustmentshould be used.
Place the magnet on the neck of the tube so that it is po-sitioned over the internal pole pieces on the gun structure.With the BRIGHTNESS control at low intensity, move themagnet a short distance forward and backward, at the sametime rotating it, to obtain the brightest raster. If, in ob-taining the brightest raster, the ion trap magnet has to bemoved more than 1/4" from the gun pole pieces, the magnetis probably weak and should be replaced. Never correct fora shadowed raster with the ion trap magnet if such correc-tion results in decreased brightness. The ion trap is al-ways adjusted for maximum brightness and, if shadowsoccur at this setting, they should be eliminated by adjust-ing the magnetic centering device on the neck of the tube.
CAUTION: Keep the brightness control at low intensity un-til the ion trap is properly set.
DEFLECTION YOKE ADJUSTMENT
If the deflection yoke shifts, the picture will be tilted.To correct, loosen the thumbscrew on top of the deflectionyoke and rotate yoke until the picture is straight. Beforetightening the thumbscrew, make certain that the deflectionyoke is as far forward as possible. 105
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
OLYMPIC RADIO & TELEVISION TRANS
OLYMPIC TV MODELS 752U, 753U, 755U, 764U, 766U & 769SERIAL NUMBERS STARTING WITH 9-500,001 & S-600,001
0 LINE CORD
105-120 V A.C.60 CYCLES
Ord -OFF SWITCHON SOUND - VOLUME
INTERLOCKCONTROL
SOCKET PLUG OrdGRASS
The circuits shown here and on the nextthree pages are exact for the modelslisted above and are very similar toOlympic TV Models 752, 753, 755, 764,766, 767.
ANTENNA POSTS
ELECTRICAL SHIELD___
au,!>
N.
20
3:=
0IF)
ITOuT IRE OF TURRET CONTAININGTWELVE (ID) SETS OF FIVE (5)COILS EACH
STATIONSELECTOR
300 n LINE
TESTPOINT
SHIELD
"IC 302375- 30.14
6AG5OR
6BC5VI
RFAIEPOE.ER
6J6V 2
R.F. OSC 5 CONVERTER
WELD, T5
"IC 304.5- 3 up f
FINETUNING
CONTROL
47511
L30i22.25mc
12 CHANNEL R. F. TUNERPART NO CL -2262
5V21NEGT
IF HRFILTER CHOKE
624400.1.S! 100
1"2
3605 Ac 420v.
6.3 V 0.0 AMP.
TO ALL 6 V TUBES(EXCEPT KINESCOPE
X J El 6V6/GT TUBES)
I- TO RINESCOPE TUBEB IS V6/GT
V
On this page is shownthe power supply andthe tuner circuits.On the next two pages,in a double -page
ABC g spread, is the mainXXI* circuit; while on the
page following is thecircuit of the audiosection. These sec-tions connect together
VIDEOIF. in the manner indicated6 by the numbers 1 to 7,
and X for filaments.The separation of thecircuits in this man-ner is for printingconvenience and doesnot imply such sepa-ration in the actualchassis.
4.140 V. 7
FIL AMENTS
wrim/mA,T.,,v tl,,E01no L13
*20 INSULATEDSOLID WIRE12 TURNS ONIn" FORM 107
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONCONNECTIONS TO AUDIO SEC
2- 3 SHows. ON NEXT PAGEOLYMPIC RADIO et TELEVISION, INC.4" 5 ,AGE
WON
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7 +14.04
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ACC. SOUND
8.- Tow an
FORMER 023TRAP 330.144
6AG5OR
6BC52.1FlaVIE9AMPLIVER
25010
131 V.
s
26 SIAC.
L6BIF1LAR RIO. IFTRANSFORMER
P
.PIC 2P-' NO
Un
L7CATHODE
SOUND TRAP1.25 NC
.r<NO
6AG5OR
6BC5V10
3V 4,4 4141.ifif30 V.
a
30
nO
NOTES
I ALL RESISTORS I 20% TOLERANCE, '/2 WATT, UNLESSOTHERWISE SPECIFIED
2 ALL MICA AND CERAMIC CONDENSERS t 20 % TOLERANCE.UNLESS OTHERWISE SPECIFIED
3 ALL VOLTAGES ME ASURED RETAKEN POINTS INDICATEDAND cHASSiS 1EKCEPT WHERE OTHERWISE NOTED), VOLUMECONTROL FULL ON AND ALL CONTROLS TURNED COUNTER
44CLOCKWISE, USING AN ELECTRONIC TYPE VOLTMETER. ALLVOLTAGE READINGS *15%, MEASURED WITH INPUT VOLTAGEOF 117 VOLTS, SO CYCLES, A.G. AND WITH NO INCOMINGSIGNAL.
4. RED ISTOR R 34 WAS 3,300.0. 211. ON EARLY PRODUCTION.5. PHONO- TV AND SENSITIVITY SWITCH ARE USED
ONLY ON MODEL 764. ON ALL OTHER MODELS BOTHSWITCHES ARE OMITTED AND WIRING OF MONO -TV SWITCHCONNECTIONS ARE MADE DIRECTLY TO THE TV POSITION
6. ON SERIAL NUMBERS R -500,00I TO R-515,800 AND 5.400,001TO S-604,400, R53 WAS CONNECTED TO 4- 215 VOLTSINSTEAD OF 140 VOLTS.
LI5 R62FOCUS COIL 33ft511-\2.LAA, 350 V
FOCUSCONTROL
2,25015WIRE WOUND
-tANVS.
NOS
R6139015 110%-SANP-4I..
6SN7/GTV14
trot 1410.1f1C14 z2Colf
03705/600 V-I I -
fM
MI v.
E0
54
F 039DOS/60I0 v
ros1 C40
005/500 v.ss 11
511
nC
041.00t/600 V.
SI
nC
5US v.
MOTE T ON SOME MODELS THE VERTICAL INTEGRATOR NETWORKWITHIN DOTTED AREA IS REPLACED BY A PRINTEDCIRCUIT CRL TA 402 00EA, AS SHOWN BELOW.
R45 R46 R472121t15 5.10015 5.20015
3INPUT OUTPUT
C41 C40 C39
1
108
soo6/680vT o05/9901T
O
P.J 35oeof
11
V
C54 C5622opmf oot/NDov.
HORIZ. LCONTROL1
05710-
0
;C55
1501.114
6 SN7/GTv16
4041ii fC I 1401112 015C
ID
HORIZONTAL OSCILLATORCOIL PART 52 TR- 229
ID
B
9.
IPM
Irw
SO KA
HORI? HOLDCONTROL
.000
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
25.0 MC.
L 8 6AL5211F IL AR PDC IF VIITRANSFORMER T1117417filot:__
1_74]
Al.2
tANOS
10
OLYMPIC TV MODELS 752 J, 753U, 755U, 764U, 766U a 769SERIAL NUMBERS STARTING WITH
COIL WOUNDAROUND RESISTOR
(ALOE Dor)
L9,to ph
- ' 926
-iV,....
wog22 Kll
3. -,5/5/V5.O
R 29560K114 101.
R IS470R10
R - 500,001
12 AU7 (oR 6SN7/GT)V12
108211S V.0(0 ANIPL.I.11
13.0K
PICTURECONTROL
5 Kft
a S-600,001\ COIL WOUND\ AROUND RESISTOR
IlaOlt DOT)
\ L12viaoptl_
50 V
1850
O 0,,
2K
LII 1
L4 5 MCTRAP
C 3205/6000 NOTE
cTo
SEE 2'
SEE NOTE
LOCAL FRINGE
BC'
SENSITIVITYSWITCH
[40
601R37
y -0"
150 0
RECTANGULARI6KP4 OR 16 RP4FOR 16 MODELS.I7BP4 OR I7BP4A
FOR 17" MODELS.V13
KINESCOPE
R36 C34IRn 25/400V
oo
COLORCONVERTER
SOCKET175 v
150 v
VERTICAL OSCILLATORTRANSFORMER
O444/
EE NOTE 7BELCW
12BH7(oR 6SN7/GT)V15
VERT. ONE VI.. OUTPUTGOY 550 0
*02ENT. HEIGHT ao£CONTROL
MEG 11
C 430041/600 V 105.
-514
EDPncliKeOUNSOMEa'ir. MODELS
r if
I MIER A
VERT HOLDCONTROL
VERTICAL OUTPUTTRANSFORMER
Woe 6
S Eta
Eli
row61WC23
f.5+
VERT. LINEARITYCONTROL
SI
ONM
C45.29/400
fryO
'V
500 K11.
5403
350 V_
BRIGHTNESSCONTROL
0
C 7405/600v.
YOKEVERTICAL DEFLECTION COIL
400V.
12.ORIVE.N TOOL
C67
A,_3,0,f
6BI:36/GTV17
How/ ouTPuT8.000 P41.14
00 NOT IMAUMI
R787-Got
j£o
1650.
C6605/400 ,
2 Fil:=2
2 "of
2 uO
I B 3/GTV1
MUG.. 1101.TOC AWN**
PART NS TR 1193HORIZ. OUTPUT
HIGH VOLTAGETRANSFORMER
8241
Q.
11,0000.
240
AMP.
FUSE
HOR12. LINEA/ITTCONTRCS.
10THCONTROL
6 W4/GT gV IG IT!
540 V.
5000
SPA%
CONNECTIONS FOR V12 USING
6SN7/GT
CONNECTIONS FOR V 15 USING
6SN 7/GT
YOKEHORIZONTAL DEFLECTION COIL
C7I
109
Mal
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C3
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
PHILCO CORPORATIONVarious Philco models of this period were made in the form of dual
chassis. The Deflection Chassis employed contained power and sync.
circuits, while the R.F. Chassis contained the balance of circuits.Some models were changed from one type of chassis to another duringproduction and are so listed in the table below.
To find the service material you need, first look up below themodel number of the set you are servicing, and find out what R.F.and Deflection Chassis are used.
Philco Model No. R.F. Chassis Deflection Chassis
52-T1610, 52-T1612 33 or 32 Cl
52-T1802, 52-T1804, 52-T1808, 52-T1831,52-T1839, 52-T1840, 52-T1841
33 C2
52-T1810, 52-T1812, 52-T1842 52-T1844 33 or 37 C2
52-T1882 35 or 38 CP1
52-T2106, 52-T2108, 52-T2144 41 D1
52-T2110 41, 35, or 38 Dl or F2
52-T2140 41 D4
52-T2142 35 or 38 F2
52-T2145, 52-T2182, 52-T2245, 52-T2282 44 D4
After having looked up what R.F. andsee the list below for reference to pagesinformation is presented.
R.F. Chassis
Deflectionin this
StandardTuner Part
in tuner,It II II
It tt tt
Tuner Partfor power
sect.
radio pn
1X2.
118 to 120is exact
tuners usedthrough
Chassismanual
Tuner,
audio
76-6440-176-6777-276-7070
isforin
are used,where this
76-5411No. 76-5747uses 76-6440-1
" 76-6777-2" 76-6777-2
No. 76-7070output.
Tuners
32 -- Similar to 33, pages 112-113, uses33 -- See pages 112-113, Figure 14, uses35 -- Similar to 33, pp.112-113, main diff.37 -- "
tt tt tt II II It
38 -- "It i It 1/ It t
41 -- See pages 116-117, Figure 37, uses44 -- Same as 41, pages 116-117, except
Deflection ChassisCl -- Similar to C2, page 115, diff. pwr.C2 -- See page 115, Figure 15.CP1 -- Similar to C2, page 115, has AMD1 -- See page 114, Figure 38.D4 -- Same as Dl, except for AM radio provisionF2 -- Similar to C2, page 115, uses two
Alignment information given on pagesthese sets. The specific Tuner Alignment76-7070, but is very similar for otherThe Philco material in this manual is reproducedof the Philco Corporation.
76-5411 Standard Tuner76-5747 See page 112
See page 118
See page 116.
correct for allTuner Part No.these models.
the courtesy
111
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
BUILT- IN C523 AERIALAERIAL TUNING
- 20 75 OHM UN -300 OHM BALAN- BALANCEDCEO INPUT INPUT
-03 10
6 '00000L500
2 40fR500
18001 30
LIU r-OL501
1C 500
IrLs'-'01:17czto.
FM TRAP TAPERED LINE ASSEMBLY
6AU61ST V IF
44C200
R222
6606
R2231.0M
USED IN 37CHASSIS ONLY
112
I
6.6VI.45A8110
W 7PILOT LAMP1100
PART OF 100 SECTION ONR F CHASSIS
*6800 OHMS IN 37 CHASSIS
SECTION 5RF
TC 502
WS50004F7
6CB6R F AMPL
R503I MEG
TC504
W5500001/
C202
I( 6AU6
2ND VIF
.5V 3 4R20468
8205
330
Tuner Part No. 76-5747
TCSO4
4.135V
21.8514CTRAP
C507.66 OF
R5071006 C5I1
0.5-3
C5 280V
1/212AV7L526 OSC 6
C514 C515TEST T1500 15
POINT =4 41,
01125V TC507
23 5IAC
1/2 12AV7MIXER
R506 8
C513
T 220
C509
T33455008(n
NOTE:
SWITCH SHOWN INCHANNEL 2 POSITION
TC 506
R50810
40K
sf0,21.4iL919. tw,_
'7 111\ L523W"" TC505
WS500CUll W5500E1(14)
330 330C204
Tiso.
COLOR CODE
BLACK
ORANGE
GREEN
YELLOW
6AU63RD VIF
135VA
R209AA".330
L206RFC
10014
C210
T.22µF
0520FINE
TUNING
m.C211MM221.I.F
CHANNEL 13L534
TC514
L532O
TC511 TC510WS 500A(F) CHANNEL 6
6CB6VIF
WS 500AIR)
90A
7
C2I3
R2154 7°5600
SECTION 2- VIF
r
L_
C36
SE
t2AUAGC
VIDEO1ST S
125V2
R40150
040012014
PART
I = 400 S
C215
71500
Figure 14. Schematic Dia
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Philco R.F. Chassis 33
:TION 4 - SOUND
1- 1
C402
1600
145 MC8 I
-J
6AU62ND SIF
64026806
1600
5
60V
=C401r..,,
R403
1K IW
2401
®
Ise
R405
228IW
C40645-370
R406 8407
1/2 678DISC
AUDIO
CONTROLSOCKET
220
1/2 6781ST
AUDIO
410
C412
02K Y
9 65V
41 5
1011E6
006811FMIA
7C5AUDIO
290V > OUT
8441 N
R415+106WA"
106
LUG VIEW
1400 J401
L3031OLLII
C301
.047LLFL300TC3004.5 MC
126VTRAP 41
1/2 12AV71ST VIDEO
46 88V 4
MN 7:4; o9
C302
(TITR302
2700
C304
83033300
6305L301 i 8mEG
EI8OLLH
6405VIDEOOUT
7
afry
ON 3 -VIDEO 250V
2
0 TO 9V
C306
4250v .047I(
uLF
5 1601/s, k,
6 `4,
a
6 308A>2500
CONTRAST
4 N
C307
.4711F
+mm C303C40LIF
60 CPS
C R T17BP4A
T ss900
1pmF
S
300
1933001
N GN0
FCCII
10 4,2
25 TOIN 11105M 12
BR EN
30001
TO HIGH
VOLTAGE
POWER SUPPLY
R313
1300
R3129W
1006
1006
BRIGHTNESS
,TJ
P L400AUDIO
CONNECTOR
AUDIO SECTIONON DEFLECTION
CHASSIS
4IC
0503 02
3306 LUG VIEW
L208405tH n r-
ww.02178
VIDEOTESTJACK
- J200
60 CPS
3V
8646,,NevNe47K
6
1806
R603
S R248
3300
L209
1001.1.11
R219330
R221150 6
R22016
1006
m1/2
12AU71T NOISE
`$^H 175V.1SSE
P
SYNC NGATE
2
60 CPS
4
R604C607 --nAm"--
633 .8MEG 210
6-1111 40602 9605
270K
-1.4
7V
70.
3
ny 200
60 C PS
.01311F
SECTION 6 - SYNC
6
1/2124072 ND SYNC
SEP
PL IOUPIN VIEW
18V PP
60 CPS
BR
0
0320V 2
1BL 21V
ON -9
3
os
W 6 3VAC
F6.3 VAC
250V
m, 33
NOTESRESIISTOR VALUES ARE IN OHMS, 1/2 WATT, AND CONDENSER VALUES IN LIME, 6000UNLESS OTHERWISE STATED.
K INDICATES 1030 OHMS, MEG INDICATES 0300,000 OHMS.WAVEFORM VOLTAGES ARE PEAK TO PEAK VALUES. THE FREQUENCY IS THAT OF THE WAVEFORM. NOT THE SCOPE SWEEP RATE.WAVEFORMS TAKEN WITH A MODIFIED PHILCO MODEL 7019 OSCILLOSCOPE.VOLTAGES MEASURED WITH A 20,000 OHMS PER VOLT METER. RANGE Of VOLTAGES INDICATES MAXIMUM VARIATION WITH CONTROL SETTING.9 INDICATES LESS THAN ONE OHM.
6
P1100
113
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
PHILCOFigure 5. FM TEST Jack Adapter
VTVM OR24000 -OHMS -PER -VOLT
VOLTMETER
GND
TO OSCILLOSCOPE
PLUG PART NO.27-4785-3
PINS AND5
38. Deflection Chassis D-1, Schematic Diagram
TOP VIEW
VOLTMETER
MINIATURE SHIELDPART NO.
56 -5629FA3
SHELLPART NO.56-1146-I
PLUGNO. 27-4785 3 NN PINS I AND 5
REMOVED
GND
NOTE: CONNECTIONSINSULATED WITHSPAGHE TTISOLDERED
OSCILLOSCOPE
TERMINALSTRIP
1/4- HOLE
SOLDERED
SECTION 6 - SYNC1/2 INTSYNC INN
.R617:111E4
4618
106
rww C604AV 047
9f.
C407341
451
_L
4611
82004610 1W
126200
R613 RIMS 0605 8616
06 4100
NIA4700
R6126600
.079F4700
4700
SECTION 7- VERT SWEEP
vtg/P,'j1C C702690047VERT OUT
Bt.
90 onus-TOW 40
-w
1700 380
6 I 6350 OHY5 -- 2._r-5
9712
00.022ME
9700804
9701
259( 0ERT
HOLD
156
470654E1,
HEIGHT
ILLE
497021.5
?,14EG
"I 46C101ILIF
0703680
T701 4300 PL600
2504
R704 V. -19EG
FST117t S 8105i 2204rE9.,1
8
4
R708
2
all J P1611
O330MS:
9709
226291
4.K/04
141
DEFLECTIONYOKE
12 19710OHMS 1,000
Y5
14111
000
RCs7,g,1
1J800 70
71610 L2!____J
C803
0800
C600 ' 57120 _J._
R806124
R1101 480282K 754
SC HORIZ1815A
O HOLD
723`011:C 8 01
2200 491
1804
180
6597GTPHASE COMP
130AND HORIZ
05C
/10477=/. --LOCK- IN45-370
S 86103.34E0
809 R811
!L2E. 4.
2 5
904 390KX5% 1-5%
TC805 .R806.15u0 :4704
R9138200
C8060/2uf
1900rPO
480
BL
L602124
:0HY5
?X805
60nOHMilS.2
0807
(-44.L
BR
C27005''t X T
14807186
R 144706
464
4700
0911
°V4E1
`37- 7i5/41.
R8151042W
DO NOT
4
210OHIAS
SECTION 8 - IHORIZ. SWEEP
MEASURE
6006G OHMSNORI2 OUT
06
4820
8207449
TH
1601A
S6C
905WW1
IX827
3031910(7,
0606-f 000 6
20 OHMSRFC
643DAMPER 2
0800 ---1
PL800PIN 7
0803
: 113CM
4.4 PINS080041.
11Ep 0 HOR121 YOKE
J800 L804PIN 3
DEFLECTION OHMSYOKE p,,9
0800 Ft KO
REIS686
Rata47
C812 38004414E 4441.-[ PINS
LLCMST 104E
0800LUG VIE
240
IA. L807:20 OHMS
RIO
2
REG°.
24
614 AC
-12
07041004
R105
220K
0100
---/ 000045 0X45
25H
1..003100
R102
4 1101120071500
7.515w
0102
1500
SU RECT
CR101
-300V
..R102 RAT'R100
x50°V 50V
E
Ill 1~e
3400 F102
1 0100LUGPEIV
0100
114
15.924WIRE
F101
001(01IVEHEATERLINKS
5.1V
3.5
OHMS
77006047
s,po
0101
'EP 573 PL Ill
1114
60 CYCLES
142DOUBLER
SECTION 1-POWER
C105
500
RIO'2.5 MEG
91072.5 MEG
C104
I(500
15301HV RECT
T801
B
11
mv AIgBE
NOTES
RESISTOR VALUES ARE IN OHMS WATT AND CONDENSER VALUES
ARE IN 401,600 v,uNLE SS OTHERWISE INDICATED
4.1000 :7000,000 OHMS F. LES S THAN ONE OHMS
VOLTAGES MEASURED WITH A 20.400 -OHMS-PER-VOLT METER.
RANGE OF VOLTAGES INDICATES MAXIMUM VARIATION WITH
CONTROL SETTING.
SIGNAL PATHS ARC SHOWN Br HEM CONNECTING LINES
16±
PP
60 C
PS
C60
3.0
41 V
"
R60
8
ME
G
R60
9 /1
1110
6 _.
67
+45
1,1
SE
CT
ION
61/
27N
1S
YN
C6
SY
NC
INV
R61
286
14C
605
R6I
5
2Y
R61
0
276
2W
10K
R61
1
15K
2W C60
4
7.11
1F
4700
.011
1F
R6I
34
700
4 70
0
rC 6
0600
47LI
F
8702
15K
180
OH
MS
T 0
0
oow0
131.
42V
6 -6
1 -A
rt
OH
MS
ON
0
211
1044
8100
00S
EC
TIO
N 7
-I/O
ON
VE
RT
SW
EE
P3
OS
CV
ER
T
C 7
02 'W
ory
041
10-
60 C
P S
eo-
v
30C
PS
8701
250K
VE
RT
HO
LD
200V
mo
x2
R70
3U
."'
1 M
EG
8704
2.5
ME
G
HE
IGH
T
6705
5600
8V
24T
OV
C70
6 30F
45
R 7
07R
708
2500
VE
RT
LIN
820
1W
C70
3.0
15 11F
R70
918
061W 65
4
VE
RT
OU
T
f,;
J801
P4
ZLI
301
P4
+.1
.C
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Tuner Part No. 76-7070Philco
U. CC 1-7141 30
5
1
OI =5,21
8ga
M t.YPtc0t)Xi;
719
2.2HL,2
8D
CL
OKNCL
BUILT-IN AERIAL
C527AERIALTUNING
___J
I MEG
300 01$BALANCED
INPUT
R512
470 0500
ILIL 534 MI
RF AMPL
7 7150 01111LINE
SECTION 5- R F
502211
PAP.01
147
04G007-521 0501
470
TC5
1502
EM TRAP
mmC50020
TAPE- RED LINE 03163M15
2500
C 531000
R5034700
-COOS
iC506 :L5105-3 m RFC
=
1300
IMEG
C5061 N504 C507mm02 P19 1MEG
0 R505
IA
C532 C510150 7 150
C5011.0ISO GPI
11
7E37POINT 016 C317
Isoot IS
59 GI
11506100N
664C 5 31.11 39
C514.1.1.5
0515
526 C519
R507
IC 30123.5 MC
V2 12427NOIR
504
C5211150T
V2 12AZ05C
10520T 150
C5221
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100
12121
L5311
SOOT.
5 4 5
L335 537
C5251003
7 BR
1.3v AC
L534
* PARTS NOTLOCATED IN
TUNER
514 -CHASSIS
4.1 7
2NR5i4
C524* ....1414527 1052FINE
T.1-6 T 7.5TUNING
NOTE ALL SNITCHES SHOWNIN CHANNEL 2 POSITON.
WSSIMC IR / R5005(6/
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1511
520
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TC513
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111
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2113301
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= Figure 2. Aerial -Input Matching Network I
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Figure 37. R -F Chassis 41, Schematic Diagram
1/2 12407151 SIF
150 , .5 SC
1100-1 0402
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1 1500
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11
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115
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USE OF EH OR PWSPEAKER IS OPTIONAL
PL 400AUDIO
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NOTES
RESISTOR MUMS ARE IN ONUS, IVINTLPIC CONDENSER +ALMS
ARE 111 11111,1038, UNLESS OTHENOISI 1NOICATED
itriO00 PINS hi A1p04000 ONIES limESS THAN ONE 010$VOLTAGES MEASURED *ITN A 20,000-01114-PIR -VOLT METER.RAMC OF VOLTAGES NOICATES 5431141211 VARIATION WM
CONTROL SETTING.
SIGNAL PATHS AK MORN NI NERVY CONNECTING LINES. P1100
01111 TIEN)
.150
120* OR !IL
10
5-110
2401/ OR
3V AC 0
-120
34011 -37 N
P1.100
CHANNEL SELECTOR
PINE TUNING
CENTERED014 CHANNEL
TUNING SCREW
TC SOO(MISER GRIDCHANNEL 11)
Figure 6. Television Tuner, Oblique View,Showing Location of Adjustments
TC SO5(RE PLATE CHANNEL 13)
TC 503(AERIAL CHANNEL 13)
TCSO(Rf PLATE CHANNEL 41)
TCSOS(AERIAL CHANNEL 6)
117
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONPhilco Schematic Tuner Part No. 76-6440-1
BUILT-IN C527 AERIAL R507AERIAL
-.-
TUNING
- - i6607
C504 R F4014 3 3 AMP1GNC506 71.5- 3 fa
42300. L510
RFC
TEST COIN
POINT 1500
C511
C517330 46'
130V
1526 C519I F OUTPUT
o1
120
6= .56 gig G1
iI I
I
1000 125VTC 508 12A1/1 6807I.. 2 R510
2501I
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MIXER9 5 4 15
78500 1
".3 BIF IL AR
ma i 7 CHOKE 'R502 4.4. wl SECTION 5-
30009M
-04 20BALAN-,g,
75 OHMUNBALANCE
INPUT
_i4 2
3 1
4 moc1
IC505
6-1 (---4
-
C 508220
"cq:,, a . "
cm.../I
C526- R F 2 20 or100y C 522 -L-
C52T 220
10 0 1 l
220
-a-. .1.- =_-,- = .T_
ri IC521 220
6 3VAC
r-Ir T L525
.5 -3IVc r 0. -05 Po , C523
jtS R503R505
C503 3301400
R F C I CHANNEL 13
3 0111111L501 330 To.; 220
R512
*8110 10
T
1533
C524 TC 515 'I1527C509
, nil 9 ,-1000
-6508wv2200 1/2 12AV 7 7--" -130 Fici
FINETUNING
IIC
o...R511y35V OSCC 52gT
TC51412
111 WIg o ,
15K--1--
TAPERED LINE i FM =
'0.)' ' t= ASSEMBLY ?TRH1509
1517TC505
L524 1 /f,
Z. 500 TC5031511 -- TC507
L503 . - MI .-5I8s = /11.
105,, 2VI il ,L504
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j1IP L 521
% 7 .:6 tk L 22, 0
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WS500A IF) CHANNEL
0C501
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1507WS500EIFI TC 502 WS500C l F 1
C512 Ts WS5008 ( F/
TC506
1.5
0 * 2-1.- -1- 0 AP
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QWS500D I 17)
6
WS500E 1 R)6
WS500C 1 R) ALL SWITCHES SHOWN W S50013 (R) WS500A(R)IN CHANNEL 2 POSITION
TELEVISION TUNER ALIGNMENTThe following simplified procedure may be used to 1. Disconnect the white (a -g -c) lead from the
align the oscillator when the television i-f alignment tuner, and connect it to the negative terminal of a1.5 -volt battery. Ground the positive terminal.is satisfactory and a station signal is available.
2. Connect a 3300 -ohm resistor in series with the1. Mechanically preset the fine-tuning cam to the red lead from the tuner. Connect the "hot" lead of
center of its range (see figure 6). the oscilloscope to the junction of the red lead and2. Tune in the highest -frequency channel to be the 3300 -ohm resistor.
received. 3. Connect a 330 -ohm resistor from the green lead3. Adjust the tuning core for that channel, or the to ground.
next highest, for the best picture; that is, starting with 4. Connect the FM (sweep) generator to the 300 -sound in the picture, turn the tuning core until the ohm aerial input through an aerial -input matchingsound disappears. Repeat for each channel received network. See figure 2.in the area.
BAND-PASS ALIGNMENT PROCEDUREA 330 -ohm resistor is shunted across the 1st
i-f coil, to eliminate the absorption effect of this coil 1. Set the CHANNEL SELECTOR and FMon the response curve. (sweep) generator to Channel 12 (213 mc.). Adjust
CRYSTAL 22011LIF the generator for sufficient sweep to show the com-PART NO. PART NO54-6001 62-122001001 plete response curve.Hi I (-0.
OSCILLOSCOPETO,P0A%0TOONOOHMS :7AORUT
66-4108340
2. Establish the channel limits (see figure 7) byusing the marker (AM r -f ) signal generator to pro-
Li:. 1,0A040TOONOOHMS
INPUT duce marker pips on the response curve; set the62-147001001 66-4108340 generator first to 210 mc., then to 216 mc.T
3. Adjust TC505 and TC507 (figure 6) for aFigure 3. Wiring Diagram of Crystal Detector symmetrical, approximately centered pass band. Set
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONmarker generator to 213 mc. Detune TC507 counter-clockwise until a single peak appears. Adjust TC505until the peak falls on the 213-mc. marker. It maybe necessary to increase the output of the generatorduring this adjustment. Then adjust TC503 for mind -mum curve height and symmetry of the single peak.The aerial circuit is now tuned for the high channels.
4. Readjust TC505 and TC507 for a symmetricalresponse, centered about 213 mc.
5. Set the CHANNEL SELECTOR and FM gen-erator to Channel 7 (177 mc.).
6. Establish the channel limits by using the markersignal generator to produce marker pips on the re-sponse curve; set the generator first to 174 mc., thento 180 mc.
7. Note the response curve, with respect to tilt andcenter frequency. The curve should be centered inthe pass band, and should be symmetrical. If not,it will be necessary to make the adjustments given instep 8. However, when making these adjustments,the effect of Channel 13 adjustments on Channel 7must be taken into consideration. This is done byover -compensating with the trimmers, so that, whenChannel 13 is adjusted, Channel 7 is nearly correct.
8. Adjust C506 and C515 (see figure. 36) toobtain a response curve which is the mirror image(tilt in the opposite direction) of the original. Thisis the overcompensation mentioned in step 7.
9. Set the CHANNEL SELECTOR to Channel 13,and retune the generators. Readjust TC505 andTC507 for a symmetrical and centered band pass.
10. Set the CHANNEL SELECTOR and generatorsto Channel 7, and check the response for center fre-quency and symmetry. Repeat steps 8 and 9 as manytimes as necessary to obtain the most symmetrical andcentered response curves on Channels 13 and 7. Chan-nels 8 through 12 are now correctly aligned.
11. Set the CHANNEL SELECTOR and sweepgenerator to Channel 6 (85 mc.).
II MC MA1(4.5 MC MIN
RESPONSE MUSTFALL INSIDE SHADEDARE A
CHANNEL CARRIERSMUST LIE BETWEENTHESE LIMITS
Figure 7. Television -Tuner Response Curve,Showing Band -Pass Limits
12. Establish the channel limits, using the markergenerator to produce marker pips on the responsecurve; set the generator first to 82 mc., then to 88 mc.
13. Adjust TC504 and TC506 for a symmetrical,approximately centered pass band. Set the markergenerator to 85 mc. Detune TC506 counterclockwiseuntil a single peak appears.
Adjust TC504 until the peak falls on the 85-mc.marker. It may be necessary to increase the outputof the generator during this adjustment. Then adjustTC502 for maximum curve height and symmetry ofthe single peak. The aerial circuit is now tuned forChannels 5 and 6.
14. Readjust TC504 and TC506 for a symmetricalresponse, centered about 85 mc.
`"?TB500
TC4013
Z400S F TRANS
0TC300 5MCTRAP
TC402 TRANS)5
2ND SIFFM DET
1ST VIDEO1ST SYNC SEP
ALIGNTEST JACK
J200
4TH IF
(K6,151.4c
BOTTOMrc 401 1STAG
AC'UDC1431_ ATP"-
VID OUT
AGCVID DET1ST SIF
2ND SYNC SENOISE GATE
3RD IF
® 7228°53MG TRAP
*I 2022C6.6 MC
6AU6 2ND IF
*23 01/40C
OTC201
6AU6
28 1 MC1ST IFTRAP
VOLUME CONTROL
AUDIO OUT
SPEAKERPLUG
PL4 01
AUDIOOUT
TRANS
T400
R3096
R309A
7(.5000FM TRAP
@ C52 5
TC508cV23.5 MC
132)RF
AMPLC 506
12AZ7
MIXER-OC 527 OSC
BRIGHTNESS
Figure 36.
CONTRAST
119
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONPhilco TELEVISION I -F ALIGNMENTBefore proceeding with the i-f alignment or mak-
ing an alignment check, observe the following pre-liminary instructions:
1. Connect the oscilloscope to the 2200 -ohm re-sistor from the ALIGN TEST jack adapter.
2. If additional attenuation of the marker signal isrequired when using Visual Alignment GeneratorModel 7008, insert a 10,000 -ohm resistor in serieswith the output lead, or use a 2nd harmonic of BandA, which will give a marker of lower amplitude.
3. Preset the television controls as follows:a. CONTRAST control fully counterclockwise.b. BRIGHTNESS control to give a dim raster.c. Function switch to TV position.
4. Insert the FM TEST jack adapter into J402.5. Insert the ALIGN TEST jack adapter into J200.
I -F ALIGNMENT PROCEDURE1. Preset TC201 and TC203 fully counterclock-
wise. See figure 36. Preset TC200 and TC202to the center of their ranges.
2. Connect the oscilloscope to J200, pin 2, throughthe 2200 -ohm resistor from the ALIGN TEST jackadapter, and connect the AM generator to G1 (mixergrid on tuner).
3. Feed in a 28.1-mc. AM signal, and tune TC201for minimum output (use first minimum). Use zerobias during this adjustment.
4. Feed in a 21.85-mc. AM signal, and tune TC203for minimum output (use first minimum). Use zerobias during this adjustment.
5. Tune TC205, TC204, TC202, TC200, and TC507for maximum output at the frequencies indicated infigure 36. Use 3 volts of bias, and attenuatethe generator to keep the output below 2 volts, peakto peak.
0
50
100
120
IE
60 5.5SOUND / (A
CARRIER 59.35
Figure
(8157.35
FREQUENCY IN MC
55
EC/55.25VIDEO
CARRIER
9. Over-all R -F, I -F Response Curve,Showing Tolerance Limits for Channel 2.
6. Feed in sweep and marker signals to Channel 2through the aerial -input terminals. The tuner passband should be checked, and the tuner aligned, ifnecessary. Touch up TC205,TC204, TC202, TC200, and TC507. See NOTE below.
IMPORTANT: Do not turn any of the i-f tuningcores excessively after they have been set to the ap-proximate position by the use of the AM signal gen-erators; to do so may cause poor transient or phaseresponse, resulting in trailing whites or smear. If aresponse within the limits shown cannot be obtainedby a slight adjustment, carefully repeat the AM ad-justments, and, if necessary, trouble -shoot the i-fsystem. It is preferable to get a response curve withinthe tolerance range WITHOUT touching the adjust-ments made with the AM signals at the specified fre-quencies.
NOTE: TC205 rocks top of curve.TC202 controls level of carrier.TC204 controls dip or peak on carrier side.TC200 controls bandwidth (sound side).TC507 controls dip or peak on sound side.
S -I -F ALIGNMENT PROCEDURE
1. Remove the first i-f tube, and connect a v.t.v.m.or a 20,000 -ohms -per volt voltmeter to the FM TESTjack adapter. Adjust the VOLUME control formoderate speaker output.
2. Feed in an accurately calibrated 4.5-mc. AMsignal through the 2200 -ohm resistor in the ALIGNTEST jack adapter to pin 2 of J200.
3. Tune TC400 and TC402 for maximum indi-cations on the meter. The point of maximum meterindication for TC402 should also be the point of mini-mum speaker output.
4. Tune TC402 for minitnum speaker output.
5. Connect an r -f probe or crystal detector to thegrid (pin 2) of the picture tube. See NOTE below.
6. Tune TC300 for minimum indication on oscillo-scope. If a crystal detector is not available, TC300may be adjusted for minimum beat pattern, observedon the picture tube, with a station picture present.
7. Replace the 1st i-f tube. Tune in a station anduse the speaker output as an indication.
8. Turn the FINE TUNING control clockwise toobtain a slightly fuzzy picture.
9. Tune TC402 for minimum AM (noise) output.NOTE: The r -f probe, Part No. 76-3595, is usedas a detector of the 4.5-mc. signal, and the oscillo-scope as an indicating device. An alternate crystaldetector may be made up.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCAVICHASSIS DESIGNATIONSKCS47BKCS97F In
KCS47C .. . In Models 7T112,KCS47C In Models 7T1l2B,KCS47D
The models listedservice materialaddition Model 7T143,
CIn ModelsModels 7T103B
7T122,7Tl22B. 7T1235
aboveincluding
TO7T103 and
and7T123 and
andIn Model
using
using
RMODELS 71103, 7T103B,
7T104, 7T104B, 71112, 7T112B,
71104 7T122, 71122B, 7T123, 7T123B,7T104B
7T124 7T124, 7T125B, 7T1327T1253
7T132Chassis Nos. KCS47B, KCS47F, KCS47C, KCS47G or KCS47D
the chassis as stated are covered by thisthe main and supplementary schematics. Intelevision Chassis KCS-48A, uses the same
circuit except thatModel 9T147, using
the audio section of the radio section is employed.Chassis KCS-60A, has this same difference, but uses
a 19" picture tube. Model 7T111B, using Chassis KCS-47GF-2, is similar
to the "B" seriesmentary circuitadditional receiver.
sets such as 7T103B, and this material plus the supple-will be of aid in case you are called on to service this
Models 9T105, 9T126, 9T128, using Chassis KCS -49B
or KCS-49C, are also similar to the "B" series sets except that some of
the parts differ and a 19" picture tube is used.
ALIGNMENT TABLE
STEPNo.
CONNECTSIGNAL
GENERATORTO
SIGNALGEN.
FREQ.MC.
CONNECTSWEEP
GENERATORTO
SWEEPGEN.FREQ.
MC.
CONNECTOSCILLOSCOPE
TO
CONNECT"VOLTONMYST":0
MISCELLANEOUSCONNECTIONS
ANDINSTRUCTIONS
ADJUSTREFER
TO
DISCRIMINATOR AND SOUND I -F ALIGNMENT
1 2nd sound i-f grid(pin 1, VI16)
21.00.1 voltoutput
Not used Not used In series with 1
meg. to pin 7 ofV117
Meter on 3 volt scale Detune T112 (bot.)Adjust TI12 (top) formax. on meter
Fig. 12Fig. 9Fig. 8
2 " " Junction of R192 5S103
Meter on 3 volt scale T112 (bottom) forzero on meter
Fig. 12Fig. 9
3 " " 2nd sound 1-1 grid(pin 1, V116)
21.00cen'er
.1 v. out
Junction of R198 65103
Not used Check for symmetricaliory ,posltive 6. negative).adjust T112 (top) until
response wave-It not equal
they are equal.
Fig. 12Fig. 9
4 1st sound i-f grid(pin I, V115)
21.00 1st sound i.f grid(pin 1, V115)
21.00reducedoutput
Terminal "A" ofTill in serieswith 33K.
,. Sweep output re-duced to provide 0.3volt p -to -p on scope
i T111 (top and hot.)for max. gain at21.00 me.
Fig. 13Fig. 10Fig. 9
PICTURE 1-F AND TRAP ADJUSTMENT
5 Not used Not used - Not used Junction of R102 &R201
Connect bias box tojunction of 8102 &R201 and to ground
Adjust potentiometerfor - 3.0 volts onmeter
Fig. 10
6 Terminal D ofT101
21.00 " - ,, Pin 2 of V106 andto ground
Meter on 3v scale.Rec. between 2 5 13
T103 (top) for min.on meter
Fig. 10Fig. 8
7 " 21.00 " - " T105 (top) for min. Fig. 8
8 27.00 - " " " TI02 (top) for min.
9 " 27.00 " - " " " T104 (top) for min. "
10 " 19.50 " - ' " " TIO1 (top) for min. "
11 " '24.35 " - " " L103 (top) for max. "
12 22.5 " - " " " T104 (bot.) for max. Fig. 9
13 " 21.75 " - " " ,, T103 (bot.) for max.
14 " '25.3', - T102 tbot.) for max. "
1.41.---.6
( :..' VI14
c 'N
1,10POWERT PLANS.
V4 TRAP
'UPSRECT.®00
.--- v2
'2°` : Ai:`AMP
7. iiTEST
42
LLS2-?.)
JEOSC.ON
CTI
SUPGPLCT.
T110POWERTRANS.
\.. I CONN. .."----Thua
V 101,,, T101 1 T112
F
1
"NL06.
T112tlOONe
0T111
PAU6
UN
"U. ®
T101IS.S0 NCPERM
I -FTRANS.
I.TRANS.
4i v101 .:Z.6,1,16
1102 2 Ep., LI: i - 4.1,4r ' N'27'th-TIC
SeN D.
..: ZDISC'
24JS
TIO0Dr
.;"' 6'11L103
NC 0.)-t,,-,,__-----------..----
SNCL
OISCR.I 210014CSNO.TRAP
Tr221,0,:us PIXI- F TRANS.
""* SNO.
P
. SNO
,,,,P
44"4?P.
1-F
ram..OISCII.P/
0)T103
21.00MC31R PIP
TRANS-
..:T10.2
2E00 MCV102 21R PIA6c06 1., TRANS.
01
I -F AMP.
G .0
212.1 .3
ZI4P. "8.vile
,...e,....,11:5N0.1,T103
SI.75.AC
3-E3.E.IF.,TRANS.
S.P...t...../V 03
.41-gF ' ..""
TRANS
--Tx;2.?NC
..J.N-..,CI PIPPFTRANS...
PIE_"6Ce. '''''
Figure 8-Top Chassis AdjustmentsFigure 9-Bottom Chassis Adjustments 121
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
ANT TB
300ELBALANCED
P300A-NIREARView
TOANT 72 IL
COAX
P300/3-NiREARVIEW
ANT. MATCNIN-G1UNIT
L200 1201
.1200-F T200 c202. C200FRONT ANT 100 lbVIEW TRANS
1.37
L36
51-4 1.35FRONT
133
1203
51 -4 REAR
51-3 I 51-3 REARFRONT
127 ,012 1 ..A 4270 L28 L26 55
,Ao129 125 O 05
04L30 L24 A,
e . 5 13I L23 .6149 1.22
R5 CIO100K 390
TESTIONS
51-2FRONT
LIS
117
LI4
Lt3
11AT.*
KCS47B AND KCS47C CIRCUIT SCHEMATIC
7T103,7T104.7T112,7T122,7T123.7T124
12.-F UNITv2
C20 6C B 6 Ri i RIO270 R -F Ampt_ 3900 ISO 3
c 22 s ..161--.--;7-'$C21 51187-30 7 57 1 5000 4. 10 MEG
22K rWy r t1.2174 -LC ta. +120011500 11500
51-2O R4 01 REAR
15 °10018
.3 . 11aow04 8112 1°.
A, 8200 5.1s*,
L12 5
0.8414
05C.6J 6MIXER+1350.
LSOfoe WI)
563300
C86.8
L44
T1 1
CONY WITRAK 75A.
COAX
C144.0I
71011ST DIN. I -F
TRANS.
DCarzoi4,103 D A -0.8V
C10611.15.2:5E1 gdar OCI(O
5C
%ins
6AU6151 SOUND
I F AMPL.T111
SOUND 1-FTRANS.
e-1
-C185
CiEsli 518415001 82
C102 51 8203
1500
'C186500 =.2D
V101
6AU61ST PIN. I- FAMPL.
81851000
C107270
41200
1->N
211./RAPI:Lisl.F-RSV
4 3. . , 24es eiE, ...:;aLTc4i7o.s$8aloos:
RsS.:1C 105A A 24'233K IX.' Rk11*
-11C106118104 C10515 R219,n.C10:11.-C;1381.74. 4V,Ici:9:0
1500 1000 I.01 1000$ T1500 1500
4.230V. - 1101 +2.30,4
121 v
J-
C222.
IM0=
6AU6.
V102
6CB62ND. ME. I -F
5187A7K
/ARL C110270
5 1040.7 5110 5108
475 12K15.tCiny
192 C154
1.011.01
81109(000 SS
15520%1
5203 100100 .11 NV*
L47s r_.. "846-1-"21 ID R2K 07 .1222Kf 7tsooTT s MF
C I84A 14-L43 1500 T
'14. r r1 CHANNEL SELECTOR +120V. +375V.Cl +2500
0.8-1.41 L2 FRONT AND SHOWN CS P21 -1 CSSW (S1) VIEWED FR074
1.5 MC .j POSITION
39 -11004Aliet -,-
.S.hEiIN CHANNEL 2 (54- GO
,..1.4 C23To.Et3 82
C146
C3 -120 IS -
121
018 -CI9, 15001 11500
PRODUCTION CHANGES IN KCS47B AND KCS47C
In some receivers, T1 I I had on:y a single winding. C170 was SO mmf. andwas connected between V115-5 and V116-1. R186 was 100K and was con-nected between V116 -I and and. C222 was omitted.
In some receivers, 8118 was 2.2 meg., R133 was 6800, R201 was 33K andC130 was .0015. V105.5 was connected to and. and C224 was omitted. A229,10K and LI15. 500 muh, which were connected in parallel, were removed andwere replaced by 8139. 81239 was omitted and R228 was connected 10 gnd.C223 was omitted.
In some receivers, R173 was 1 meg.
In some receivers, RI83 was 10011 and was conneced from 115 v. supplyline. to and.
In some receivers, 8149 was 1.2 meg. 8148, 3.9 meg., was removed. It wasconnected between the yellow lead of T106 and gnd.
Due to a severe resistor shortage during the production of this series ofreceivers it was found necessary to substitute resistors of different values fromthe nominal, value shown on the schematic. These substitutions were ap-proved by the engineering department for each particular application in thecircuit only if the change in value did not impair receiver operation. In somesuch instances, these substitutions involved a change in the value of 5%. 10%,20% or in a few instances even greater change.
In critical circuits where a change of value could not be tolerated, theproper resistance was obtained by the use of series, parallel or even series -parallel combinations of resistors in order to obtain the correct value of re-sistance or wattage.
It it should become necessary to replace a resistor or group of resistors, thevalues shown in the schematic and parts list should be employed.
Chassis KCS-47B and KCS-47C.
122
-1
C1131500
8143 C137 C138 013922.C. '002210047 10047
5137 = vISK
5138181 f. C135
0,47
+120 V
65N7-GT 5144 5145 5148 C 140SYNC. AN, 12K. 8200 8200 .01*4601236 5 ci31011 .01
7v
R165 65N7 -GTCONTR. ItiGn. wit 3515W HOR SWEEP82K , tAt 3 1-Y - OSC.CONTR 050.WillirM2214.16.
_ C150.047
C,4.13 . 132161
C147A10 -NONowt's. 1 516o R162 R164 C131 -
LoCia..6r fISOK 85015 >821C .0221RANGE
IICONTR.,-
5147I MEG
VERTICAL-(01.D
CONTROL
5146 VII050 K
1404.14010
T1OGVERT. 05C.
TRANS.
5151
NINNTCONTR.
7101550510. 05C.TRANS.
CN9.047
5V.I
CtS2
+225 v5169
85V 82004
0.47CiS3 -5167
3900r5(-)15° iao --lf-
C154
51653301
.01
51738205
C156-Oct
:1-V1
+373 V.
0.21
All resistance values in ohms. K = Coil resistance values less than 1
1000. ohm are not shown.All capacitance values less than 1 in Direction of arrows at controls indi-
MF and above 1 in MMF unless other- cates clockwise rotation.wise noted.
1
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
T112SOUND DISCS.
TRANS.r -
tee VP121`A&
-C171 -C172T!SOOT 1500
11033.4 FIK1-F TR0
21.75 21.0MC MC
.1'¶5.0
120v
9'
5190100
FRONT
V103
6A U 63RD. PIX. I -F
AMPL
-01
vulGALS
SoUN 0DISCS
10174yT1 94
c,594
C 2
j NOOK
-CI76
CII7270
94V 0115--1(
1500
01935. I
5103 REAR
cr,7.0047
R1951.5 MEG
VOLCONTR
VIOL
3 C1782 .01 w102
1
MEG i27K
50o0R194A 250 10
'CI79 < 9213.015 I> 2215
J103PHONOINPUT
GCB 6410 PIK I -F
AMPL.
T104.Pla
I -F TRANS 00 trL c472 7 A 5 0.1 MC TP/-CI96 C3118C I
< - 1)- SOuNOTIOS
811112 L'Iks .45GIP)
RIII St1,4 P- 75C,3547CK 5000 1000 I .0,
1102180
C111 A,500
-C 116
R2250199 33K.047+
2500 8122 +5.50
C1881.0082
Vile6Av6,51. AUDIO
AMPL
7 4.8.1.v
.01
RI99470K
01010027
C180f --1
I R1981-4
270 T 13301(
C125 C128270 100
LIC7374STIR% Pee1-11021C.7.
24.15MCm9
Ri If 1?22K -
+2500.
vio5GALS250. ()ET A -G -C SECT.
20
V119
6K6 -6TAUDIOOUTPUT
3.480 EL
C21 3CI20 MF
4.1200,
V106
12AU734 1542ND1ORN.wH, VIDEO AmPL.
2 5 V0.5
C126
022414.01
R1255600L105
500 MU11ORR-WO,
RI26220
C220100 2
C I 13 .741500 8123
RI283500
PI21 CONT18 K
Ic127 ct292uF1+ 1816 1501
+250v
R235 R2223300 471
C2120
F102- FREAR916,4
4340 V BEN 4,1
OR GAN >-
C 212C10 MF.
L10636 MISR
BLK
C 19 c22,
R224100 K
J 102-MPIN
VIEW
T1I3AUDIOOUTPUTTRANSr
0210470
+375V
RED L _P
SPEAKER
KCS47B and KCS47CDiagram
FUNCTION 510 VIEWED FROMFRONT AND SHOWN IN POS 1(mAx. COUNTER CLOCKWISE)
POS. I -TV MIN HIGHS.2 - Tv NORMAL3 - Tv PAIN. LOWS4 -PmoNo MIN HIGHS5 - PHoN 0. NORMAL-
-PHONO Mist LOWS
v 0712 A U 7
DC RESTORER.I SYNC. SEP.
L109 0190120 MOH .047
02151 -0 -We
R220390 820K
R2305 547000129 CI32
560K o.1
RI27220
C130.0033
1200 J105 t 20VVNA.R124150K
..) 1108500612.21MAT
82234 220K
5106A -G -C CONTROLC 3 POSITION)
01354700
C133.047,
7.8133
4701,
51.5 RED
R231220 K
02223270
RI4147K
RZ32220K
010515
65N7 -6TVERT. SWEEP050. 4 DISCI.
13950 2
RI7447
C 143.04.7 2.2
R152 -MEG121
C142.0.221F-4
V109
6K6-GTVERT SWEEP
OUTPUT4-365 0.
C141 4. R1575 MF. + 2201
T104 F316BG6-G TRHAVN5.1HORtE. SWEEP
OUTPUT
V
R154VIII 1501
329V
01475 N 2 7 019710 -IRO P. T 100MORIEDRIVECONTR
/0175100
11'720K
WIDTHCONTR
FI011/ti AMP
0150.047
.021133K
CIGO.022 L110
MoR,LNERT-Ittce,,...a,k
1107VERT OUTPUT
TRANS.1 01_
220K I I
R155 I
I I
I GRN0145
L._
.022T
RISE5000 R159f C2IVERTICAL 1000 120 NIF.LINEARITYCONTR.
Vil2183-GTm -v SECT.
CIA500
-+375 V.
10101- nitPINVIEW
e.4.4-GTDAMPER
In some receivers, substitutions havecaused changes in component lead colorcodes, in electrolytic capacitor valuesand their lug identification markings.
0 142.047
0163.04.7
.1101- FREARVIEW
R178
LN5FILTERCHOKE
37.50. ..2500 1120,4 +5.SV
[a'
C211C,_10 MF
R03127K
CZt 215 35 PAR
35 MFC2114
.35 NE2.0oo V
R2284300
C2136510 MF
513150 K
BRIGRT11155CONTROL
Cl 2435 MF
3101ON -OPT
vita51.144G
SECT.
C166 C15747 .047
All voltages measured with "Volt-Ohmyst" and with no signal input.Voltages should hold within ±20% with117 v. a -c supply.
R13GISO K 74v.W.
412ov.
0.1
GLASS
METALSMELL
,r
4 T110
5102iNTERLOCK.
.),) a
375 0
..11wELLIONT
bL n
CHANNEL /3105IND4C 1.1614T
LIGHTS ONCONSOLE MODELSONLY
NS Y.SUPPLY
See next page for differencesin KCS-47D, KCS-47F, KCS-47G,and the circuit shown here.1123
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
FOCUS MAGNETNOT ON "El"
MODELS
FOCUSMAGNET
MOUNTINGSCREWS
7T103, 7T103B, 7T104, 7T104B, 7T112,7T112B, 7T122, 7T122B, 7T123, 7T123B,7T124, 7T125B, 7T132
CENTERINGLEVERLOCKINGSCREW FOCUS
CONTROL
COMPRESSIONSPRING
ADJUSTINGSCREWS
.()3R253FOCUS
CONTROLON "Er MODELS
ONLYA. LINEARITY1
CONTROL
IN 77132ONLY
©J105
5102 +
an,HORIZONTAL
JI03 siio4 5106 12,51 0156 SI e DRIVE© 0 0 0 WM" 0 CI474PIO AUX. AGC HEIGHT VERT. C*NTR"- HORIz.JACK SWITCH CONTROL LINEARtly LOCKING RANGE
Rear Chassis Adjustments
SND.DISCO.
RESPONSE
APPROX.400 KCBETWEENMARKERS
Figure 12Discriminator
Response
21.00MC
D.
RESPONSE
Figure 13Sound 1-FResponse
CONNECT ttVOLTONMYSTOS SCOPE HERE TOALIGN SOUND DISCO.
CONNECT SIG.OEN.OR SW R OSC.HERETO ALIGN SOUND
DISCO.
CONNECT SCOPE
0114_ HERETO ALIGNSOUND hF
TE30NR -FUNITMEASURE B -F BIAS
05 03 oi StOoft 02
Owl] GONNECro VOLTOMATST"
O HEREMAIIGNSR D. DISCO.
OVIOIo
071020
O
CONNECT OSCILLOSCOPEHERE TO ALIGN
PI% I- F
CONNECT BIAS BOOAND.VOLTONMIST"
HERE TOMEASUREI -F BIAS
TO R201 TIC
Figure 10-Test Connection Points
owls.o 00
Circuit showing audio.section of ChassisKCS-47D used in Model7T132, as being dif-ferent from the mainschematic shown onprevious page. Inother ways ChassisKCS-47D and KCS-47Bare the same.
6193
C187IS°00
GRN
C1713.01 W102
I
5POK
CI77.0047
R1951.5 WEB.
VOL.CONTR. 0194
PO
MEG.
von J 104AUX.
v tie6AV6isr AUDIO
AMPL.
C 162.01
- CI811 .0033
)
10180 R19B5 R204 C218 R208560
470 330K 120KMM.
.022 470K) A ;
C2I3C- C217+375 V. +120V 20 MF. -r . 00 1 5
J 103 8237 (+505 os P0000) 4-- ,71221So K
6\614'PHASEINVERTER
6Aula9 5AUDIOOUTPUT
R206 E3 4 RE05 68K 3
4700
R238 C1931.5 MEG I .001
6AOSAUDIO
OUTPUT
PI02-F JI02-14 T113REAR PIN AUDIOVIEW VIEW OUTPUT
TRANS.
S R218.-141C212C470 iS I 10 MF.
.375V.
Pm.5PKR
r106'ERT 0SC.TRANS.
5Lu
C T
RED
81512.5 NEC.WEIGHTCONTR
1
DI C1155560
J R173820K
Circuit of power supply used in Chassis KCS-47F and RCS -47G of Models7T103B, 7T104B, 7T112B, 7T122B, 7T123B, and 7T125B. Balance of circuitis the same as shown on previous page for Chassis KCS-47B.
V i40878
TORT. SWEEPOSC. 4 DiScH
+395 V
2
R174
2
V 109
6K6-GTvent- SWEEP
OUTPUT
3-.365 V.
OV S
C 1420.22 71.
Cra-i1---.
R153.047 2.2
R152 MEG
12 K
7 2 81555 1500
WV2130
T $0 Aff-
R21015 K
CI4I - R1575 MF T+ 220K r
Rt5 4vili 150 K.
6BG6-GHOR17 SWEEP
OUTPUT
47 33V
C 14700-160
jHoRIEft DRIVE
CONTR
y y
C156001 R177 0159
r 20 K .015
'2511./aIZS costsWIDTH
C IGO
3 .022 L110NOR LIHER7Y.,ft
24.7t.1,111F101 CONTROL a/
329V
C19710011-*
Ct 58.047
3
T to,VERT OUTPUT
TRANS.1 "'EL
1220K 1 1
Rise I I
t . t
1 I GANL.-C145 o
.0227 OM
RING5000 R159 C2134VERTICAL 000 20 MFLINEARITYCONTR.
V112
163-GTH -V RECT.
) III wiCIGS vERVOILSII
['EFL La T56YOKE A 4
: 0164 '1
L° 27°TI-R 211
375 V.
I9
R25210 MEG
R25325 MEGFOCUS
CONTI?
375v .250V +120Y
AC2IIC
0 MF
R21554 K
.55V3
R2284300
R23122 0
213GO MF
C2125A 35 MP.
.C12I IBL113 35 MFFILTER C2IIACHOKE
ta35 NF.
4 .12,000V
013150 K
11116HTHEISCONTROL
023213 2508254 -IBMEG.
1V2. UT
V123
FOCUS RECT
C1E,I500PIN VIEW J101-6
REARC 42. VIEW
ELK -RED
6w4-GTDAMPER
.04.7
c143.047 R178
MEG
L_
v114
514GRECT.
4.34.
6
1.1/
1.2.4 h..W_ .1L ataltooli
SIOION -Off
SW.C 166 C167.047 .047
,50K,74v
GLASS
METALSHELL
1
4 TIIO
20
176R4KINESCOPE
JEWELLIGHT
LK (11161
CHANNELu6wT
34
-375v
5105
LIGHTS ONCONSOLE MODELSONLY
SIO2INTERLOCK
115 tiSUPPLY
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Service
RCA VICTORmaterial on Model
MODEL 41101Chassis No.
4T101, using Chassis 61, appears
61
below and on the
next five pages. You will find that Model 4T141, using television Chassis
KCS -62, uses exactly the same circuit except the audio section of the radiounit is used and 6AQ5 is omitted and 6AV6 is used for bias only.
ALIGNMENT TABLE
STEPNo.
CONNECT SIGNAL ! CONNECTSIGNAL , GEN. SWEEP
GENERATOR 1 FREQ. GENERATORTO ] MC. TO
SWEEPGEN.
FREQ.MC.
CONNECTOSCILLOSCOPE
TO
CONNECT"VOLTOHMYST"
TO
MISCELLANEOUSCONNECTIONS
ANDINSTRUCTIONS
ADJUSTREFER
TO
DISCRIMINATOR AND SOUND I -F ALIGNMENT- -
1 I 2nd sound i-f grid1 (pin 1, VI16)
21.00 I Not used.1 voltoutput
- Not used. In series with 1
meg. to pin 7 ofVll7
Meter on 3 voltscale
Detune Till (bot.)Adjust Till (top)for max. on meter
Fig. 12Fig. 9Fig. 8
2, - Junction of 16192
6 5103Meter on 3 voltscale i
T111 (bottom) forzero on meter
Fig. 12Fig. 9
" " 2nd sound i-f grid(pin 1, V116)
21.00center
.1 v. out
Junction of R1926 SI03
Not used Check for symmetr'callorm (positive 6equal adjust Tillequal
response wave-negative). It nottop) until they are
Fig. 12Fig. 9
41 1st sound i-f grid1 (pin, 1, VII5)
21.00 1st sound i-f gridre- (pin I, V115)
ducedoutput
21.00reducedoutput
Terminal A ofT110 in serieswith 33K
' Sweep output re-duced to provide0.3 volt p -to -p onscope
1110 (top and bot.)for max. gain andsymmetry of 21.00mc.
Fig. 13Fig. 10Fig. B
PICTURE 1-F AND TRAP ADJUSTMENT
5 7Not used t Not used - I Not used Junction of R1026 R103
Connect bias box toJunction of R102 68103 and to ground
Adjust potentiom-titer for -3.0 voltson meter
Fig. 10
6 Terminal D of I 21.001101
.. - " Pin 2 of V106 andto ground
Meter on 3 v. scale.Rec. between 2 5. 13
T103 (top) for min.on meter
Fig. 10Fig. 8
7.1
..I 21.00 - " " " T105 (top) for min. Fig. 8
8 " I 27.00 - T102 (top) for min.
94-
! 27.00 " - " T104 (top) for min. .,
10 I 19.50 .. - " TIO1 (top) for min.
11..
1 24.35 " - " " L102 (top) for max.
12Of 22.5 " - " " " T104 (bat.) for max. Fig. 9
13 " 21.75 " - 1
" " T103 (bot.) for max. .,
14 " 25.3 - 1 " " " T102 (bot.) for max. "
11-F UNIT ALIGNMENT
STEP.No.
CONNECTSIGNAL
GENERATORTO
SIGNALGEN.FREQ.MC.
CONNECTI SWEEP
GENERATORTO
SWEEPGEN.FREQ.
MC.
CONNECTHETERODYNEFREQ. METER
TO
HET.METERFREQ.
MC.
CONNECT"VOLTOHMYST"
TO
MISCELLANEOUSCONNECTIONS
ANDINSTRUCTIONS
ADJUSTREFER
TO
15 Disconnect the co -ax I-nk from terminal 2 of the r -f unit terminal board and connect a 39 ohm composition resistor between lugs 1 and 2. If thereceiver osci lator is adjusted by feeding in the r -f sound carrier signal, couple the link loosely to lug 2 of the r -f unit terminal board so as topermit measurement at sound discriminator. In early production units in which L44 is adjustable, back the L44 core all the way out. Detune
T1 by backing the core all the way out of the coil. In order to al'qn the r- tuner, it will first be necessary to set the channel 13 oscillator to
frequency. The shield over the bottom of the r -f unit must be in place whey, snaking any adjustments.
16 Antennaterminals
215.75MC.
Not used Loosely coupledto r -f oscillator
236.75MC.
Junction of RI926 5103 for signalgen. method only
Fine tuning con-tered. Receiver onchannel 13. Het.freq. meter coupledto osc. if used.
Cl for zero onmeter or beat onhet. freq. meter
Fig. 10Fig. 8
17.. C o n n e c t "Volt-
Ohmyst" to ter.minal 3 of theIA unit terminalboard
Turn AGC controlcounter -clockwise.Connect bias boxto terminal 3 ofr -f unit term. board
Adjust the biasbox potentiometerfor -3.5 volts.
Fig. 10
II Antennaterminal(loosely)
181.25185.75
Antennaterminals(see text forprecaution)
Sweep-inq
channel8
Not used - Not used Rec. on chan. 8. Connect oscilloscopeto test connection at R5 on top the r -funit. Adjust C9, CI 1, C16 and C22.Correct curve shape, frequency, andband width. C22 is adjusted to givemax. amplitude between markers. C9primarily affects tilt and C16 primarilyaffects the frequency of response. CIIaffects the response band width.
Fig. 16(B)
19 87.75 Notused
Loosely coupledto r -f oscillator
108.75 Junction of R1926 5103 for signalgen. method only
Rec. on channel 6 I L5 for zero onor beat on
het. freq. meter
Fig. 8Fig. 10Fig. 11
20 83.2587.75
" Channel8
Not used - Rec. on chan. 6. Adjust L42. L45 and149 for proper response. L42 is adjustedto give max. amplitude between markers.L45 primarily affects tilt and L49 pr it
marily affects freq. of response. Itnecessary, retouch CII for proper width.
Fig. 16(6)
5
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
12
RCA Victor ALIGNMENT TABLE ( Cont in ue d ) 4T101
STEPNo.
CONNECTSIGNAL
GENERATORTO
SIGNALGEN.
FREQ.MC.
CONNECTSWEEP
GENERATORTO
SWEEPGEN.
FREQ.MC.
CONNECTHETERODYNEFREQ. METER
HET.FREQ.METER
MC.
I
CONNECT"VOLTOHMYST"
TO
MISCELLLANEOUSCONNECTIONS
ANDINSTRUCTIONS
ADJUST
---REFER
TO
21 Not used - Not used_- Not used - C o n n e c t "Volt-
Ohmyst" to r.funit test point R5
Rec. on channel 6 Adjust C7 for -3.0volts at the testpoint
Fig. 8Fig. 9
22 Repeat steps 19, 20 and 21 until the specified conditions are obtained.23
--Antennaterminal(loosely)
185.75_Not used - Loosely coupled
to r -f oscillator206.75 Junction of R192
6 5103 for sig.gen. method only
Bee. on ehan. 8--
CI for zero onmeter or beat onhet. freq. meter
Fig. 8Fig. 10
24 Antennaterminal(loosely)
181.25185.75
Antennaterminals(see text forprecaution)
Sweepingchannel
8
Not used - Not used ! Rec. on chan. 8. Readjust C9, C16 andC22 for correct curve shape, frequencyand band width. Readjust C11 only ifnecessary.
Fig. 8Fig. 9Fig. 16
(9)211.25215.75
Sweepingchannel
13
Not used - Not used Rec. on chan. 13. Adjust L52 for max.amplitude between markers and thenovershoot a little more than the amountof turning required to reach max. re-sponse. Adjust C22 to regain max.amplitude of response.
-- -Fig. 9Fig. 16
(13)
26 " 215.75 Not used -'
Loosely coupledto r -f oscillator
236.75 Junction of RI926 9103 for signalgen. method only
Fine tuning centered. Receiver on chan.13. Adjust L43 for correct channel 13osc. freq. then overshoot. Reset the ose.to proper freq. by adjustment of Cl.
Fig. 10Fig. 11
27 " 205.25209.75
Antennaterminals(see text forprecaution)
channel12
-Not used - Connect "Volt-
Ohmyst" to r -funit test point atR5
Roc. on chan. 12 Check to see that Fig. 8response is correct FM. 16and -3.0 volts ofosc. injection ispresent
VI " 199.25203.75
channel11
.. Rec. on chan. 11 Fig. 16(11)
29 193.25197.75
channel10
Her. on chan. 10 Fig. 16(10)
30 " 187.25191.75
" channel9
Rec. on chan. 9 Fig. 16(9)
31 181.25185.75
channels
Rec. on chats. B Fig. 16(9)
32 " 175.25179.75
channel7
--- --
Rec. on chan. 7 Fig. 14(7)
33 It the response of any channel (steps 27 through 32) is below 80% at either marker, repeat step 24 and adjust C9, C I, C16 and C22 as necessaryto pull response up on the low, channel yet maintain correct response on channel 8. If C22 required adjustment, the adjustment should be overshota small amount and corrected by adjustment of L52 to give maximum amplitude of response between the sound and picture carrier markers.
34 Repeat step 23. If the oscillator is off frequency overshoot the adjustment of Cl and correct by adjusting L43.35 Repeat steps 27 through 34 until all requirements are obtained.36 Antenna
terminals(loosely)
87.75 Not used - Loosely coupledto r -f oscillator
108.75 Junction of RI926 S103 for sig.gen. method only
Roc. on chan. 6 L5 for zero onmeter or beat onhet. treq. meter
Fig. 10Fig. 11
37 " 83.2587.75
Ant. terminals(see text forprecaution)
Sweepingchannel
s
Not used - Not used Observe response. If necessary read-just L42, L45 and L49. It should not benecessary to touch Cll.
Fig. 8Fig. 9Fig. 16
39 Not used - Not used - Not used - Co nnect "Volt-Ohmyst" to ther -f unit test point
i at R5
Check ose. injection. If necessary ad-just C7 to give -3 volts. If C7 is ad-lusted, switch to channel B. and read-Just C9 for proper response then repeatstep. 37.
Fig. 9Fig. 10
39 Antennaterminals(loosely)
77.2581.75
Ant. terminals(see text forprecaution)
channelS
. Rec. on chan. 5 Check to see thatresponse is correctand -3.0 volts ofose i ispresent
Fig. 16(5)
40 " 67.2571.75
" channel4
Rec. on chan. 4 Fig. 16(9)
41.,
61.2585.75
channel3
- Rec. on chart. 3 Fla. 16(3)
42 55.2559.75
" channel2
" - Rec. on chan. 2 Fig. 16(2)
43 Likewise check channels 7 through 13, as outlined in steps 32 back through 27, stopping on channel 13 for next step.44 Antenna
terminals215.75 Not used - Loosely coupled
to r -f oscillator236.73 Junction of R192
d, 5103 for sig.gen. method only
Fine tuning con-hued. Receiver onchannel 13
Cl for zero onmeter or beat onhet. freq. meter
Fig. B
Fig. 10
45 209.75 - 230.75 . Rec. on ehan. 12 LII as above Fig. 1146 203.75 - " 224.75 Rec. on chan. 11 LIO as above Fig. 1147 " 197.75 . - " 218.75 Rem on chem. 10 L9 as above Fig. 1145 191.75 . - " 212.75 Rec. on ehan. 9 L8 as above Fig. II49 165.75 " - " 206.75 " Rim. on chan. I L7 as above Fig. 1150 179.75 ' " 200.75 " Rec. on chan. 7 1.6 as above Fig. 11_51 " B7.75 4 - 108.75- Rec. on chum. 6 LS as above__ Fig. 1152 61.75 " 102.75 Rec. on chem. 5 L4 as above Fig. 1153 71.75 " 92.75 " Rea. on chan. 4 L3 as above Fig. 1154 " 85.75 - 86.75 Rec. on ehan. 3 L2 as above Fig. 1155 " 59.75 80.75 Rec. on chan. 2 LI as above Fig. 11__ .--
Repeat steps 44 through 55 as a chock.ntennagerminal' 181.25 Antenna 1
185.75 terminalsSweepingchannel
8
Not used - Rec. on chan. B. Oscilloscope at R5test point.
Fig. 16(II)
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCA Victor ALIGNMENT TABLE (Continued) 4T101
STEPNo.
CONNECTSIGNAL
GENERATORTO
SIGNALGEN.
FREQ.MC.
CONNECTSWEEP
GENERATORTO
SWEEPGEN. CONNECTFREQ. OSCILLOSCOPEMC. TO
CONNECT"VOLTOHMYST"
TO
MISCELLANEOUSCONNECTIONS
ANDINSTRUCTIONS
ADJUSTREFER
TO
I 58 Switch through all channels and ob response, oscillator injection and r -t oscillator frequency. Minor touch-ups of adjustments may be madeat this time. However, if C7 or C9 are changed appreciably, then a recheck of the oscillator frequency on all channels should be made.
59 Remove 39 ohrn resistor and reconnect link from TIO1 to terminal 2 of r -f unit terminal board. Proceed with sweep alignment of Pie I -F.
SWEEP ALIGNMENT OF PICTURE I -F AMPLIFIER
60 Looselycoupled toi-t amplifier
22.325.4
Antennaterminals
Sweeping Terminal 2 ofselected V106 socketchannel
junction of R102and R103
Select channelknown to havegood r -f response.Clip 330 ohm re-sistors across R107,8110. R115, R119.Connect bias boxto junction 5102,R103.
Adjust bias box for-1.0 v. Set sweepto give 0.5 v. p -pon oscilloscope. Ad-just TI and T101for correct response.
Fig. II
Fig. 9Fig. 10Fig. 14
61 21.8524.7525.5026.25
ft Remove 330 ohmresistors. Set biasbox for -4.5 v.
Set sweep to give3.0 v. p -p on oscil-loscope. Adjust T1,T101 bot., 1102 bat..1103 bet., 7104 bot.and L102 for de-sired response
Fig. 15
L4Sji.c0.4t149
TII0 T10 TIOZ TrOI L44Zi OOMS ITT SLID ZIOOM< 2P-SIPPI TTOOMC IS? PIA IDSOFIC L203SNO I.F i AMP .MPIT I F AMP 26PPIT T F AMP I MPIX TM
ells v102 [0S'TRANS
VII66AUS
TI I I
021000.1C
2FSSNO.4- AMP
3EPPIA.F AMP.
4TEPlyI -F
TRANS.
v IOA6C66
S AUDIO
DAMP.
I T AUDIOAMP. ErBIAS
CLArAP
-F TRANS
Figure 8 Top Chassis Adjustments
C7OSCILLATOR INJECTION
E D 0
violS C
TO TERM3 ON1Z-F
UN,TERM. BD
E'
Figure 9 - Bottom Chassis Adjustments
CONNECT BIASBOA AND
DJUST AAyOLTONPANDMySYEASNEURREE TO
1-F BIAS
CONNECT BIBOXN AND `VOLTAS OPINTST.MERE TO ADJUST ANDMEASURE R -F BIAS
CONNECTSWEEP OSC. MERE TO
o oALIGN SOUND
o o
T104o 0
CONNECT
Igen7TLIGN
SOUNDDISCR.
0
TIII0
CONNECT"VOLTONMVST
?14YOTPOE
CSHORTD TO ATERDJNUMIASTLS
AHORIZONTAL 05C.FREQUENCY
Figure 10-Test Connection Points
Figure
SNOMSGR.
RESPONSE
APPROX.400 KCBETWEENMARKERS
RESPONSE
Figure 12 Figure 13Discriminator Sound I -F
Response Response
S
11- R -F Oscillator Adjustments
21.00 22.3 25.4 21.35 24.75MC 90% BO, MC
TO
00.4 25.50MC
45%
26.25MC
5-10%
Figure 14 Figure 1.5T1 and TIO1 Overall I -F
Response R -F Response
7\
Figure 16 12-F Response
<T17INCORRECT INCORRECT CORRECT
Figure 17-Horizontal Oscillator Waveforms
127
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION IANT T.B.
300A.BALANCED
P3004-14REARVIEW
J200 -F T200 C202 C200FRONT ANT 100 18VIEW TRANS.
TOANT. 72 tt
COAX.
P30013 -MREARVIEW
MODEL 41101Chassis No. 61
ANT. MATCHIN-GlUNIT .
7200 L2., `43
AA 7201 7203 11 c.z---.-----"AA'-r5+197 v. C21,:t 18 39
I 7-3°J _J --... I
2K7 15000
-.3V2 -
L37
L36SI-4 L35FRONT
133
51-3FRONT
Cl2 11,
no
100
9°8°
270
RS100 K
TESTCONN.
FRONT
L II
LIE
SI-1 L9FRONT
LB \I
1.7
SI- REAR
o I1
51 -3 REAR(.27
L28 L26
L29 125
L30 L24L3I L23
a
L49 L22
R4n0100K 1% °
110
RI2 Ieo
8200 9.a°,
LI
L2
L
,.1.4 C23T 0.58
R -F UNITVS
C20 6C B 6 RII RIO270 R -F AMPL 3900 150 3
rrrL$2
1.014V.IC174 I714
138
C241. REL39
12 I27L41 =
L42
S1-2REAR
LIE
LI.L20
L2I
C3IS
L47
C IS0.8-3.8
_ c rts11500
6J 605C. f mixER
a +130 V.
3 4 LSO(ON WI)
=C1815001
L43"FP
CHANNEL sELECTORSWITCH (St) VIEWED C5FROM FRONT AND j9SHOWN IN CHANNEL2 (54-Got..c.) POSITION.
All resistance values in ohms. K =1000.
All capacitance values less than 1 inMF and above 1 in MMF unless other-wise noted.
In some receivers. R213 was 4.7 megand was connected from R -F unit ter-minal 3 to junction of 8207 and C104.R103 was 33K, C217 was omitted, R229and R230 were omitted and pin 1 ofV105 was connected to ground. C130was .0015 mid, R135 was 6800. L117(500 muh) and R225 (10K) were removedand replaced by R143. C218 wasomitted.
128
C70.8-1.4
R10I 0K
1.1500 1 1500
C19i1500
JCSr 0.13-3.8
171511500
T I -1CONY. WITRAN. 754
COAX0;)Tr -
All voltages measured with "Volt-Ohmyst" and with no signal input.Voltages should hold within ±20% with117 v. a -c supply.
Direction of arrows at controls indi-cates clockwise rotation.
In some receivers, R142 was 47K,R144 was 100K. 8150 was 27K, R155was 12K, R202 was 39K, R227 was 3300,C140 was .001 and C179 was .0047 mid.11231 and C219 were omitted. R220. 100Kconnected between V107-1 and R142was removed.
In some receivers, 8179, 1 meg wasemployed as high voltage filter andwas connected between V113.2 and thekinescope.
In some receivers, C220 was omittedand 1104-2 was connected to V106-8.
In some receivers, R151, 2.2 meg wasconnected between 11149-3 and ground.
In some receivers, R182, 100K wasconnected from 9101 to ground.
7194.01
R2I310 NEE.'1R206100
VIIS
6A U6!ST SOUNDI- F AMPL.
0 V.
3C166
- 1500
C165 RIBS1500 T
C191T 1500
TI10SOUND I -F
TRANS.
RIBS1000
+ 270 V.
C199
V6'I-F 11q UPI
1100R187.56K:
T 1011ST PIK I -FTRANS.
C10241500
'C1031500
R10312015
C10152
A 0.6V
RI<VB
5,4024
V101
6A U 61ST FIX 1- FAMPL.
4
V102
6C B 62ND. P1X. 1-F
C107270
5 1125.2
R10533 K
C1025-1500
AMPL.
57102
2ND. PIX. 1.FTRANS. -0.65
11108(2 5
IR 1016 4"-I- C10513 R216;1-C1--.118*-1C1081-1-410004 I.01 1000i 11500 1500
+270V. LIO t
47...Ta C106
8i2070
C 1054 2,!e0 2,Y
4713213R205 15 "F100 -
_C184R207 C104 C124 C185 T 15006800 1500T 11500 .11500
t 270V.
Cm270
8109 S 811047K 12KI22v.
CI104 C11013.01 1.01
4
+270V
5600
C211
7135.0022
39
R2268200
813933K
109 A
65N7- GTSYNC. AMPL.
270V.
R1452215
pm, +6.1V6
RIAI2200
R 158SOK
NOR. HOLDR 167 CONTROL RIGE100K 22 K
vI09 B65147-GTVERT. SWEEP
8146 R147 C140 R200 050.8200 8200 .0027 63K
0137 CI38 C13910022 T.0047 T.0047
C 1360.47
.Tev...\7WAAC145
+270v.
+ is, V..047
C144 R162 C14675 330K 0.1
C 143 A10-160NM/
LOCKINGRANGE
-2.9V. I
16.3 V.
CI480.47
8163 RI65 C147 RI66'
15015820K 82K .022 T 3900
R146560K
R149I MEG.
VERTICAL140W CONTR.
VIII65N7- GTNORIZ. NORIZSWEEP SWEEPoSC oSc.CONTR.
3
2
7
3V
R2031-MEG2.2
T 107N01211 OSC
TRANS
C149220 I
s 8170220 K
RI64330 K
-SI--c 150.01
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
TillSOUND DISCR.
TR. ANSf- Di 7I Es
R1813 016956K
-0168 -0190
T150011500C197 .1"
'I I
6 'Ali 63RD. PIE. I -F
Tio33ROPm
I F
^c S 13>et - 47 42
ft2135 21.0 8111fMC. Mc. 61113
2.
0112.131 R112.-71500 T 47030
AMPL.
GA LSSOUNDMSGR.
C 172.
C117VO
11104
U
R11433 K
01725.1
4 Y
-L C1139T
;Ft -
R 19222 K
ATH. PINI -F TRANS.
FA Z.
C18I 22.s iiz tie0.1 c__T 36,,
RI I5 11'1 - f1,
1800 MC. +
az- , 0116 qa_C 195 C1161.5000 1000 7. 1.01 15001
+270 V. ' L 115
0173 C175.0022 .01 2
R 194I MEG.
SOUNDVOL.
CONTR
+270 V.
V
0g6 64TH FIX. I -F
AMPL.
15195to 5156
J102PHONOINPUT
6AV61ST AUDIO
AMPL.
7
C116.00,5
V119
SAGSAUDIOOUTPUT
C1771.01
R197470K
0190 R199 C1600330K 330 T 20 MF
+270 V.
VIOS
GALS2ND. DRY It
C122 C125 A -G.0 RECT0.52 V.
+166v ttTIO5 36
-2.45y
LilE
SOUND MUMr 301 C
1.1:17.P 21i!Sek:
C 183
22K
M0. 6a0120o C151201013
5000
1 1500R1181000
C 186 -15001
CI A1500
+270V. 9K
C127 11-1 R123 .LCIB7 0129 -2 mF IB K 0.47 1500
R22968K 82301 C217
2700 .01
6
1.10336 MU. N.
ORN-WHY
ST. ,r,
7 10126:
4
+5.5v
-.3avR1265600
L104500 MU m0GRN -WitT
R 221001K
C tGoc10 MF..f --h A
5127220
3
V106
12 AU71ST 4. 2NDVIDEO AMPL.
4191v.
P101- FREARVIEW
48v.
4.05 R128220
C220 C130.04.7 .0033
1 0213 3
0015 -
3 104
J 101-NPIN
VIEW
+ 270 V.
TI 12AUDIOOUTPUTTRANS.
PM_SPEAKER
(See next pagefor service hints).
C RESTORER(2 SYNC. SEP.
12A U 7
120 mu
LAS C 1 33
019214
13Lu- RED .047
47STRAP
MC .047 -T C212
470 .+1-11,TRAP. Fziyi
R130 131 GRNyEL5601 0.1
s :7200324
RI314700
L106.500 MU -H.
GRN,441
R1432700 7.c
270
15135HI
4700 7.
+270v.
R2121841
C2I4 3 R129100 3500
tpi .
CoNTR. R217
5144 R227 4/41B2 K 4700
R21018 K
R2111BK
+ 270 V.
15142100K
R125ISO K
3.4
R214 IC19356K 10022
R22I3.100K
5105 R218A G C CONTR Sw. 390 K
( 3- POSIT ION)
vtio6A0.5
VERT. SWEEPOUTPUT
CUM390 C 142 8231
1
0-2 2 2.2 mE6 II: T k 3 9 K1
52 t 0C141
47 1127:005155 .1
I 3 KMEG.
tO 2
)Y
,VVVvAr-2
R 153 -.11 R1572.5 MEG. C inC.- 5000 R158 R202HEIGHT 150 mF.I VERT. LIN 470 56KCONTR. _ CONTR. -r
1500
T %OEVERT. SWEEPOUTPUTTRANS.
0219 50.1 47413K
R150
C179 - -C1594 3 .0027 T T.022
3CI32 A20 MF.
C 160A t Rt5410 MF.I 11# 56 K
C152560
0 17547Mito.
V 112
6AU5-GTHORIZ SWEEP
OUTPUT
R215 C1436680K 0774< 10- IGO4700# H01212
DRIVECONTR.
-4-
C 5.00
117312K
.270V.
II
5
Y
0C153 1 15176.22
T 220
0203270 K.A..
F 101
ISLU jI
GR,.,,
I
I : I
RED 11 1 YEL_ J
5 159560
- -1
GRNI19
1
CisolYEL,J 2701
R204 C1231 MEG. .047 1
DEFL. YOKEVERT. COILS
htiR ISOI MEG.
C109.001I(
R13282K
+ 270 V.
R 13B R13400 K 50 K
BRIGHTNESS2 CONTROL
1 C1340.1
22KR133
S0.5
II
8222 15223220K 220K
2R13620K
V
KINESCOPE
S
2
GLASS
COATING
/4 AMR
7108 Lit,- -1N -V TRANS.' R228
I :I m
8177+ 1135v. 68008 I -.1
0154
1
C 215 !
I 7 2
V 113
IB3-GTH -V RECT.
+ 10.1 K V
10 -r\
+270V.
L114FILTERCHOKE
C15$250 I29 V.
C21633
I cDEFL YOKE1r.
RORIE' I
COILS
R178250
WIDTHCONTR. 2
3
C15556
C 156.0 18
114
6W4-GTDAMPER
CI57 R180 01.027 2200
CIRCUIT SCHEMATIC DIAGRAM
LII3HoRM.LINEARITYCONTROL
),11k 6.3 V.
1I4'41
+ 280 V
55101RECT.
4T101
C102 C101 +150 MF 150 MF
140 v.
trE
SR 102RECT.
T
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
13
TELEVISION SERVICE SUGGESTIONS
Following is a list of symptoms of possible failures and an (3) TI12 or C178 defective.indication of some of the possible faults:
NO RASTER ON KINESCOPE:
(1) Incorrect adjustment of ion trap magnet. Magnet reversedeither front to back or top to bottom.
(2) V112 or V113 inoperative. Check waveforms on grids andplates.
(3) No high voltage - if horizontal deflection is operating asevidenced by the correct waveform on terminal 1 of highvoltage transformer, the trouble can be isolated to the1B3GT circuit. Either the T108 high voltage winding is open,the 1B3GT tube is defective, its filament circuit is open,C158 is shorted, or 11179 is open.
(4) Viii circuit inoperative-refer to schematic and wave-form chart.
(5) Damper tube (V114) inoperative.
(6) Defective kinescope.
(7) 11134 open.
(8) No receiver plate voltage-filter capacitor shorted --or filterchoke open.
NO VERTICAL DEFLECTION:
(1) V109 or V110 inoperative. Check voltage and waveforms ongrids and plates.
(2) T106 open.
(3) Vertical deflection coils open.
SMALL RASTER:
(1) Low Plus B or low line voltage.(2) V112 defective.
POOR VERTICAL LINEARITY:
(1) If adjustments cannot correct, change V110.(2) Vertical output transformer T106 defective.
(3) V109 defective-check voltage and waveforms on grid andplate.
(4) C141, 11155, C132A or C132C defective.
(5) Low plate voltage-check rectifiers and capacitors in supplycircuits.
(6) If height is insufficient, try changing V109.
POOR HORIZONTAL LINEARITY:
(1) If adjustments do not correct, change V112 or V114.(2) T108 or L113 defective.
(3) C156 or C157 defective.
WRINKLES ON LEFT SIDE OF RASTER:
(1) C155, 11160 or C123 defective.
(2) Defective yoke.
PICTURE OUT OF SYNC HORIZONTALLY:
(1) T107 incorrectly tuned.
(2) R167, R168 or 11169 defective.
TRAPEZOIDAL OR NON SYMMETRICAL RASTER:
(1) Improper adjustment of focus magnet or ion trap magnet.(2) Defective yoke.
RASTER AND SIGNAL ON KINESCOPE BUT NO SOUND:
(1) II -F oscillator off frequency.
0 Sound i-f, discriminator or audio amplifier inoperativecheck V115, V116, V117 and their socket voltages.
(4) Speaker defective.
4T101
SIGNAL AT KINESCOPE GRID BUT NO SYNC:
(1) AGC control switch S105 misadjusted.
(2) V107B inoperative. Check voltage and waveforms at itsgrid and plate.
SIGNAL ON KINESCOPE GRID BUT NO VERTICAL SYNC:
(1) Check V109 and associated circuit --C140, R200, etc.(2) Integrating network inoperative- check.(3) 11148, R149, R150, R151, R152, R153, R154, 11201, 11202.
C159 or C,79 defective.(4) Gas current, grid emission or grid cathode leakage in
V 109-replace.(5) If C188 is small or missing, interlace will be poor.
SIGNAL ON KINESCOPE GRID BUT NO HORIZONTAL SYNC:
(1) T107 misadjusted-readjust as instructed on page 11.(2) VIII inoperative-check socket voltages and waveforms.(3) T107 defective.
(4) C144, C143A, C145, C146, C147, C148 or C150 defective.(5) If horizontal speed is completely off and cannot be adjusted
check R167, 11168, R169, R170, R171, R173 and 11215.
SOUND AND RASTER BUT NO PICTURE OR SYNC:
(1) Picture i-f. detector or video amplifier inoperative-checkV10'3, V104, V105 and VI06-check socket voltages.
(2) Bad contact to kinescope grid.
PICTURE STABLE BUT POOR RESOLUTION:
(1) V105 or V106, defective.
(2) Peaking coils defective --check for specified resistance.
(3) Make sure that the focus control operates on both sides ofproper focus.
(4) R -F and I -F circuits misaligned.
PICTURE SMEAR:
(1) R -F or I -F circuits misaligned.
(2) Open peaking coil.(3) This trouble can originate at the transmitter- check on
another station.
PICTURE JITTER:
(1) AGC control switch SIO5 misadjusted.(2) If regular sections at the left picture are displaced change
V112.
(3) Vertical instability may be due to loose connections or noise.
(4) Horizontal instability may be due to unstable transmittedsync.
RASTER BUT NO SOUND, PICTURE OR SYNC:
(1) Defective antenna or transmission line.
(2) R -F oscillator off frequency.
(3) R -F unit inoperative-check VI, V2.
DARK VERTICAL LINE ON LEFT OF PICTURE:
(1) Reduce horizontal drive and readjust width and horizontallinearity.
(2) Replace V112.
LIGHT VERTICAL LINE ON LEFT OF PICTURE:
(1) C155 defective.
(2) V114 defective.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCAVICTORMODELS 171153, 17T155,
171160, 17T174Chassis Nos. KCS66 of KCS66A
ALIGNMENT PROCEDURE
TEST EQUIPMENT. -To properly service the televisionchassis of this receiver, it is recommended that the followingtest equipment be available:
R -F Sweep Generator meeting the following requirements:
(a) Frequency Ranges35 to 90 mc., 1 mc. to 12 mc. sweep width170 to 225 mc., 12 mc. sweep width
(b) Output adjustable with at least .1 volt maximum.
(c) Output constant on all ranges.
(d) "Flat" output on all attenuator positions.
Cathode -Ray Oscilloscope. -For alignment purposes, theoscilloscope employed must have excellent low frequency andphase response, and should be capable of passing a60 -cycle square wave without appreciable distortion.
Signal Generator to provide the following frequencies withcrystal accuracy.
(a) Intermediate frequencies4.5 mc. sound i-f transformer39.75 mc. adjacent channel picture trap41.25 mc. sound trap45.75 mc. picture carrier47.25 mc. adjacent channel sound trap
(b) Radio frequencies
ChannelNumber
PictureCarrier
Freq. Mc.
Sound ReceiverCarrier R -F Osc.
Freq. Mc. Freq. Mc.2 55.25 59.75 1013 61.25 65.75 1074 67.25 71.75 1135 77.25 81.75 1236 83.25 87.75 1297 175.25 179.75 2218 181.25 185.75 2279 187.25 191.75 233
10 193.25 197.75 ' 23911 199.25 ' 203.75 24512 205.25 209.75 25113 211.25 215.75 257
(c) Output of these ranges should be adjustable and atleast .1 volt maximum.
Heterodyne Frequency Meter with crystal calibrator ifthe signal generator is not crystal controlled.
Electronic Voltmeter of Junior or Senior "VoltOhmyst"type and a 'high voltage multiplier probe for use with this meterto permit measurements up to 20 kv.
CAUTION: Do not short the kinescope second anode lead.Its short circuit current presents a considerable overload onthe high voltage rectifier V119.
ORDER OF ALIGNMENT. -When a complete receiveralignment is necessary, it can be most conveniently performedin the following order:
(1) Ant. Matching Unit (6) Picture I -F Traps(2) R -F Unit (7) Picture I -F Trans.(3) Ratio Detector (8) Sweep Alignment of I -F(4) Sound I -F Trans. (9) Horizontal Oscillator(5) Sound Take -Off Trans. (10) Sensitivity Check
ANTENNA MATCHING UNIT ALIGNMENT. -Theantenna matching unit is accurately aligned at the factory.Adjustment of this unit should not be attempted in the cus-tomer's home since even slight misalignment may cause seriousattenuation of the signal especially on channel 2. The r -f unitis aligned with a particular antenna matching transformerin place. If for any reason, a new antenna matching trans-former is installed, the r -f unit should be realigned.The F -M Trap which is mounted in the antenna matching unitmay be adjusted without adversely affecting the alignmentof the unit.
To align the antenna matching unit disconnect the leadfrom the F -M trap L58 to the channel selector switch S5.Connect an oscilloscope low capacity crystal probe from L58to ground. The sensitivity of the oscilloscope should be at least0.02 volts per inch. Set the oscilloscope gain to maximum.
Connect a signal generator to the antenna input terminalsof the matching unit. Modulate the signal generator 30%with a 400 cycle sine wave. Adjust for maximum r -f output ofat least 1..0 volt.
Tune the signal generator to 45.75 mc. and adjust L59 in theantenna matching unit for minimum 400 cycle indication onthe oscilloscope.
Tune the signal generator to 41.25 mc. and adjust L60 forminimum 400 cycle indication on the oscilloscope.
Connect the r -f sweep oscillator to the matching unitantenna input terminals. In order to prevent coupling react-ance from the sweep generator into the matching unit, it isadvisable to employ a resistance pad at the matching unitterminals. Figure 10 shows three different resistance pads foruse with sweep generators with 50 ohm coax output, 72 ohmcoax output or 300 ohm balanced output. Choose the pad tomatch the output impedance of the particular sweep employed.
Connect the signal generator loosely to the matching unitantenna terminals.
Connect a 300 ohm 1/2 watt composition resistor from L58to ground keeping the leads as short as possible. Leave theoscilloscope diode probe connected from L58 to ground.
Set the sweep generator to sweep from 45 mc. to 55 mc.
Adjust L61 and L62 to obtain the response shown in Figure11. L61 is most effective in locating the position of the shoulderof the curve at 52 mc. and L62 should be adjusted to givemaximum amplitude at 53 mc. and above consistent with thespecified shape of the response curve.
The adjustments in the matching unit interact to someextent. Repeat the above procedure until no further adjust.ments are necessary.
It is very important that the unit be aligned to the responseas shown in Figure 11 if maximum sensitivity and good r -ftracking of the r -f unit is to be obtained.
Remove the 300 ohm resistor and diode probe connections.Restore the connection between L58 and S5.
R -F UNIT ALIGNMENT. -An r -f unit which is operativeand requires only touch up adjustments, requires no pre-setting of adjustments. For such units, skip the remainder ofthis paragraph. For units which are completely out of adjust-ment, preset all adjustments to the approximate center oftheir range with the following exceptions: Set C18 so that thescrew head is approximately three -eighths of an inch abovechassis. Set the T1 core for maximum inductance (core turnedcounter -clockwise). Set C11 .near maximum capacity (one -quarter turn from tight). Do not change any of the adjust-ments in the antenna matching unit.
Disconnect the link from terminals "A" and "B" of T104and terminate the link with a 39 ohm composition resistor.
The r -f unit is aligned with zero AGC biat. To insure thatthe bias will remain constant, take a clip lead and short 131circuit the r -f unit power terminal board terminal 3 to ground.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCA Victor ALIGNMENT PROCEDURE(Continued)
Connect the oscilloscope to the test point TP1 on top of ther -f unit. Set the oscilloscope gain to maximum.
Turn the receiver channel selector switch to channel 2.Connect the output of the signal generator to the grid of the
r -f amplifier, V2. To do this, remove the tube from the socketand fashion a clip by twisting one end of a small piece ofwire around pin number 7. Replace the- tube in the socketleaving the end of the wire protruding from under the tube.Connect the signal generator to this wire through a 1,500mmf capacitor.
Tune the signal generator to 43.5 mc. and modulate it 30%with a 400 cycle sine wave. Adjust the signal generator formaximum output.
Adjust L65 on top of the r -f unit for minimum 400 cycleindication on the oscilloscope. If necessary, this adjustmentcan be retouched in the field to provide additional rejectionto one specific frequency in the i-f band pass. However, insuch cases, care should be taken not to adjust it so as toreduce sensitivity on channel 2.
Remove the wire clip from pin 7 of V2 and replace the tubeand tube shield.
Set the channel selector switch to channel 8.Turn the fine tuning control 30 degrees clockwise from the
center of its mechanical range now and at all times whenadjusting the oscillator frequency.
Adjust Cl for proper oscillator frequency, 227 mc. This maybe done in several ways. The easiest way and the way whichwill be recommended in this procedure will be to use thesignal generator as a heterodyne frequency meter and beat theoscillator against the signal generator. To do this, tune thesignal generator to 227 mc. with crystal accuracy. Insert oneend of a piece of insulated wire into the r -f unit through thehole provided for the adjustment for C11. Be careful that thewire does not touch any of the tuned circuits as it may causethe frequency of the r -f unit oscillator to shift. Connect theother end of the wire to the "r -f in" terminal of the signalgenerator. Adjust Cl to obtain an audio beat with the signalgenerator.
Connect the sweep generator through a suitable attenuatoras shown in Figure 10 to the input terminals of the antennamatching unit.
Connect the signal generator loosely to the antennaterminals.
Set the sweep oscillator to cover channel 8.Set the oscilloscope to maximum gain and use the minimum
input signal which will produce a useable pattern on theoscilloscope. Excessive input can change oscillator inductionduring alignment and produce consequent misalignment eventhough the response as seen on the oscilloscope may looknormal.
Insert markers of channel 8 picture carrier and soundcarrier, 181.25 mc. and 185.75 mc.
Adjust C9, C11, C15 and C18 for approximately correctcurve shape, frequency, and band width as shown in Figure12.
The correct adjustment of C18 is indicated by maximumamplitude of the curve midway between the markers. C15tunes the r -f amplifier plate circuit and affects the frequelityof the pass band most noticeably. C9 tunes the mixer gridcircuit and affects the tilt of the curve most noticetc.ably (assuming that C22 has been properly adjusted). C11is the coupling adjustment and hence primarily affects theresponse band width.
Set the receiver channel switch to channel 6.Adjust the signal generator to the channel 6 oscillator fre-
quency 129 mc.Turn the fine tuning control 30 degrees clockwise from the
center of its mechanical range.Adjust L5 for on audible beat with the signal generator
as before.Set the sweep generator to channel 6.From the signal generator, insert channel 6 sound and pic-
ture carrier markers, 83.25 mc. and 87.75 mc.Adjust L48, L50 and L53 for proper response as shown in
Figure 12.L50 tunes the r -f amplifier plate circuit and primarily
affects the frequency of the pass band. L53 tunes the r -famplifier grid and is adjusted to give maximum amplitude of
13 2the curve between the markers. L48 affects the tilt of the curvebut not quite the same as C9 adjustment. When the circuits
17T153, 17T155,17T160, 17T174
are correctly adjusted and L48 is rocked on either side of itsproper setting, the high frequency (sound carrier) end of thecurve appears to remain nearly fixed in amplitude while thepicture carrier end tilts above or below this point.
Turn off the sweep and signal generators.Connect the "VoltOhmyst" to the r -f unit test point TP1.Adjust the oscillator injection trimmer C8 for -3.5 volts or
at maximum if -3.5 volts cannot be reached. This voltageshould fall between -2.5 and -5.5 volts on all channels whenthe alignment of all circuits is completed.
Turn the sweep oscillator and signal generator back onand recheck channel 6 response. Readjust L48, L50 and L53if necessary.
Set the receiver channel selector switch to channel 8 andreadjust Cl for proper oscillator frequency, 227 mc.
Set the sweep oscillator and signal generator to channel 8.Readjust C9, C11, C15 and C18 for correct curve shape,
frequency and band width.Turn off the sweep and signal generators, switch back to
channel 6 and check the oscillator injection voltage at TP1if C9 was adjusted in the recheck of channel 8 response.
If the initial setting of oscillator injection trimmer C8 wasfar off, it may be necessary to adjust the oscillator frequencyand response on channel 8, adjust the oscillator injection onchannel 6 and repeat the procedure several times before theproper setting is obtained.
Turn off the sweep generator and switch the receiver tochannel 13.
Adjust the signal generator to the channel 13 oscillatorfrequency 257 mc.
Set the fine tuning control 30 degrees clockwise from thecenter of its mechanical range.
Adjust L46 to obtain an audible beat. Slightly overshootthe adjustment of L46 by turning the slug a little more in thesame direction from the original setting, then reset the oscil-lator to proper frequency by adjusting Cl to again obtainthe beat.
Check the response of channels 7 through 13 by switchingthe receiver channel switch, sweep oscillator and markeroscillator to each of these channels and observing the responseand oscillator injection obtained. See Figure 12 for typicalresponse curves. It should be found that all these channelshave the proper shaped response with the markers above80% response.
If the markers do not fall within this requirement, switch tochannel 8 and readjust C9, C11, C15 and C18 as necessary.
Turn off the sweep generator and check the channel' 8oscillator frequency. If Cl has to be readjusted for channel 8,the principle of overshooting the adjustment and then cor-recting by adjusting L46 should be followed in order toestablish the L/C ratio for the desired oscillator tracking.
Turn the receiver channel selector switch to channel 6.Adjust L5 for correct oscillator frequency, 129 mc.
Turn the sweep oscillator on and to channel 6 and observethe response curve. If necessary readjust L48, L50 and L53.
Switch the receiver through channel 6 down through chan-nel 2 and check for normal response curve shapes and oscil-lator injection voltage.
If excessive tilt in the same direction occurs on channels 2,.3 and 4, adjust C18 on channel 2 to overshoot the correctionof this tilt, then switch to channel 6 and adjust L53 for maxi-mum amplitude of curve between markers. This adjustmentshould produce "flat" response on the low channels if theother adjustments especially L48 are correct.
Likewise check channels 7 through 13, stopping on 13 forthe next step.
With the receiver on channel 13, check the receiver oscil-lator frequency. Correct by adjustment of Cl if necessary.
Adjust the oscillator to frequency on all channels by switch-ing the receiver and the frequency standard to each channeland adjusting the appropriate oscillator trimmer to obtain theaudible beat. It should be possible to adjust the oscillator tothe correct frequency on all channels with the fine tuningcontrol in the middle third of its range.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION17T153, 17T155,17T160, 17T174 ALIGNMENT PROCEDURE RCA Victor
(Continued)
ChannelNumber
PictureCarrier
Freq. Mc.
SoundCarrier
Freq. Mc.
ReceiverR -F Osc.Freq. Mc.
ChannelOscillator
Adjustment2 55.25 59.75 101 LI
61.25 65.75 107 L24 . 67.25 71.75 113 L35 77.25 81.75. 123 L46 83.25 87.75. 129 L57 175.25 179.75 221 L68 . 181.25.. .185.75 227 L79 187.25 191.75 .233 L8
10 193.25 197.75 239 L911 199.25 203.75 245 . L1012 205.25 209.75 251 L1113 211.25 215.75 257 Cl
Remove the 39 ohm resistor from the link and reconnectthe link to terminals "A" and "B" of T104.
RATIO DETECTOR ALIGNMENT.-- Set the signal gen-erator at 4.5 mc. and connect it to the second sound i-f grid,pin 1 of V102. Set the generator for 30% 400 cycle modulation.As an alternate source of signal, the RCA WR39B or WR39Ccalibrator may be employed. If used, connect its output cableto the grid of the 4th pix i-f amplifier, pin 1 of V109.
Set the frequency of the calibrator to 45.75 (pix carrier)and modulate with 4.5 mc. crystal. The 4.5 mc. signal willbe picked off at T110A and amplified through the soundi-f amplifier.
Connect the "VoltOhmyst" to the junction of 5110 and R114.Connect the oscilloscope across the speaker voice coil and
turn the volume control for maximum output.Set the trimmer C226 (on the bottom of the V103 socket) for
minimum capacity.Tune the ratio detector primary, T102 top core for maximum
DC output on the "VoltOhmyst." Adjust the signal level fromthe signal generator for 10 volts on the "VoltOhmyst" whenfinally peaked. This is approximately the operating level ofthe ratio detector for average signals.
Tune the ratio detector secondary T102 bottom core forminimum AM output on the oscilloscope.
Repeat adjustments of T102 top for maximum DC and T102bottom for minimum output on the oscilloscope making finaladjustment with the 4.5 mc. input level adjusted to produce10 volts d -c on the "VoltOhmyst."
Connect the "VoltOhmyst" to the junction of R112 and C113and note the amount of d -c present. If this voltage exceeds+1.5 volts, adjust C226 by turning the core in until zero d -cis obtained. Readjust the T102 bottom core for minimum out-put on the oscilloscope. Repeat the adjustments of C226 andT102 bottom core until the voltage at R112 and C113 is lessthan +1.5 volts when T102 bottom core is set for minimumindication on the oscilloscope.
Connect the "VoltOhmyst" to the junction of R110 and R114and repeat the T102 top core for maximum d -c on the meterand again reset the generator output so that the meter readsminus 10 volts.
Repeat the adjustments in the above two paragraphs untilthe voltage at RI12 and C113 is less than ±1.5 volts when theT102 top core is set for maximum d -c at the junction of R110and R114 and the T102 bottom core is set for minimum indi-cation on the oscilloscope.
SOUND I -F ALIGNMENT. - Connect the sweep gen-erator to the first sound i-f amplifier grid, pin 1 of V101. Adjustthe generator for a sweep width of 1 mc. at a center frequencyof 4.5 mc.
Insert a 4.5 mc. marker signal from the signal generatorinto the first sound i-f grid.
Connect the oscilloscope in series with a 10,000 ohmresistor to terminal A of T101.
Adjust T101 top and bottom cores for maximum gain andsymmetry about the 4.5 mc. marker on the i-f response. Thepattern obtained should be similar to that shown in Figure 13.
The output level from the sweep should be set to produceapproximately 2.0 volt peak -to -peak at terminal A of TIO1when the final touches on the above adjustment are made.It is necessary that the sweep output voltage should not exceedthe specified values otherwise the response curve will bebroadened, permitting slight misadjustment to pass unnoticedand possibly causing distortion on weak signals.
Connect the oscilloscope to the Junction of 8112 and C113and check the linearity of the response. The pattern obtainedshould be similar to that shown in Figure 14.
SOUND TAKE -OFF ALIGNMENT. -Connect the 4.5mc. generator in series with a 1000 ohm resistor to terminal"C" of T110. The input signal should be approximately0.5 volts.
Short the fourth pix i-f grid to ground, pin 1 V109, to preventnoise from masking the output indication.
As an alternate source of signal the RCA WR39B or WR39Ccalibrator may be used. In such a case, disregard the abovetwo paragraphs. Connect calibrator across link circuit, T104A, B, and modulate 45.75 carrier with 4.5 mc. crystal.
Connect the crystal diode probe of a "VoltOhmyst" to theplate of the video amplifier, pin 8 of V110.
Adjust the core of T110 for minimum output on the meter.Remove the short from pin 1 V109 to ground, if used.PICTURE I -F TRAP ADJUSTMENT. -Connect the i-f
signal generator across the link circuit on terminals A and Bof T104.
Connect the "VoltOhmyst" to test point TP101.Obtain a 7.5 volt battery capable of withstanding appre-
ciable current drain and connect the ends of a 1,000 ohmpotentiometer across it. Connect the battery positive terminalto chassis and the potentiometer arm to the junction of 5143and 5144.
Set the bias pot to produce approximately -1.0 volt of biasat test point TP101.
Connect the "VoltOhmyst" to test point TP102 at the picturedetector.
Set the signal generator to each of the following frequenciesand adjust the corresponding circuit for minimum d -c outputat TP102. Use sufficient signal input to produce 1.0 volt of d -con the meter when the final adjustment is made.
39.75 mc. . . .. . T104 top core41.25 mc. T105 bottom core47.25 mc. TI06 bottom core
PICTURE I -F TRANSFORMER ADJUSTMENTS.---Set the signal generator to each of the following frequenciesand peak the specified adjustment for maximum indicationon the "VoltOhmyst." During alignment, reduce the inputsignal if necessary in order to produce 1.0 volt of d -c at testpoint TP102 with -1.0 volt of i-f bias at test point TPT10110.9
43.7 mc.45.5 mc. T10841.8 mc. T107
To align T105 and T106, connect the sweep generator tothe first picture i-f grid, pin 1 of V106. Shunt 5141, 5149 andterminals "A" and "F" of T109 with 330 ohm compositionresistors. Set the i-f bias to -1.0 volt at test terminal TP101.
Adjust T105 and T106 top cores for maximum gain andcurve shape as shown in Figure 15. For final adjustments setthe output of the sweep generator to produce 0.5 volts peak -to -peak at the oscilloscope terminals.
To align T1 and T104, connect the sweep generator to themixer grid test point TP2. Use the shortest leads possible, withnot more than one inch of unshielded lead at the end of thesweep cable.
Set the channel selector switch to channel 4.Connect a 180 ohm composition resistor from terminal B of
TIOS to the junction of R135 and C132. Connect the oscillo-scope diode probe to terminal B of T105 and to ground.
Couple the signal generator loosely to the diode probe inorder to obtain markers.
Adjust the T1 (top)' and T104 (bottom) core for maximumgain and the response as shown in Figure 16.
Disconnect the diode probe, the 180 ohm and three 330ohm resistors.
SWEEP ALIGNMENT OF PIX I -F. -Connect the oscil-loscope to the test point TP102.
Adjust the bias potentiometer to obtain -6.0 volts of biasas measured by a "VoltOhmyst" at test point TP101.
Leave the sweep generator connected to the mixer gridtest point TP2 with the shortest leads possible and with notmore than one inch of unshielded lead at the end of the sweepcable. If these precautions are not observed, the receivermay be unstable and the response curves obtained maybe unreliable.
Adjust the output of the sweep generator to obtainvolts peak -to -peak on the oscilloscope.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCA Victor ALIGNMENT PROCEDURE(Continued)
Couple the signal generator loosely to the grid of the firstpix i-f amplifier. Adjust the output of the signal generator toproduce small markers on the response curve.
Retouch 1108 and 1109 to obtain the response shown inFigure 17. Do not adjust T107 unless absolutely necessary.If T107 is adjusted too low in frequency it will raise the levelof the 41.25 mc. sound i-f carrier and may create interferencein the picture. It will also cause poor adjacent channelpicture rejection. If T107 is tuned too high in frequency, thelevel of the 41.25 mc. sound i-f carrier will be too low and mayproduce noisy sound in weak signal areas.
Remove the oscilloscope, sweep and signal generator con-nections.
Remove the bias box employed to provide bias for alignment.
HORIZONTAL OSCILLATOR ADJUSTMENT.-Nor-many the adjustment of the horizontal oscillator is not con-sidered to be a part of the alignment procedure, but since theoscillator waveform adjustment may require the use of an oscil-loscope, it can not be done conveniently in the field. Thewaveform adjustment is made at the factory and normallyshould not require readjustment in the field. However, thewaveform adjustment should be checked whenever thereceiver is aligned or whenever the horizontal oscillatoroperation is improper.
Horizontal Frequency Adjustment.-Tune in a stationand sync the picture. If the picture cannot be synchronizedwith the horizontal hold control 8201B, then adjust the T113frequency core on the rear apron until the picture willsynchronize. If the picture still will not sync, turn the T113waveform adjustment core (under the chassis) out of the coilseveral turns from its original position and readjust the T113frequency core until the picture is synchronized.
Examine the width and linearity of the picture. If picturewidth or linearity is incorrect, adjust the horizontal drive con-trol C181B, the width control L106 and the linearity controlL107 until the picture is correct.
Horizontal Oscillator Waveform Adjustment. - Thehorizontal oscillator waveform may be adjusted by either oftwo methods. The method outlined in paragraph A below maybe employed in the field when an oscilloscope is not available.The service shop method outlined in paragraph B belowrequires the use of an oscilloscope.
A.-Turn the horizontal hold control completely clockwise.Place adjustment tools on both cores of T113 and be preparedto make simultaneous adjustments while watching the pictureon the screen. First, turn the T113 frequency core (on the rearapron) until the picture falls out of sync and one diagonalblack bar sloping down to the right appears on the screen.Then, turn the waveform adjustment core (under the chassis)into the coil while at the same time adjusting the frequencycore so as to maintain one diagonal black bar on the screen.Continue this procedure until the oscillator begins to motor-boat, then turn the wavefrom adjustment core out until themotorboating just stops. As a check, turn the T113 frequencycore until the picture is synchronized then reverse the directionof rotation of the core until the picture begins to fall out ofsync with the diagonal bar sloping down to the right. Continueto turn the frequency core in the same direction. Additional-bars should not appear on the screen. Instead, the hori-zontal oscillator should begin to motorboat. Retouch theadjustment of the 1113 waveform adjustment core if necessaryuntil this condition is obtained.
B.-Connect the low capacity probe of an oscilloscope toterminal C of T113. Turn the horizontal hold control one -quarter turn from the clockwise position so that the picture isin sync. The pattern on the oscilloscope should be as shownin Figure 18. Adjust the waveform adjustment core of T113until the two peaks are at the same height. During thisadjustment, the picture must be kept in sync by readjustingthe hold control if necessary.
This adjustment is very important for correct operation ofthe. circuit. If the broad peak of the wave on the oscilloscopeis lower than the sharp peak, the noise immunity becomespoorer, the stabilizing effect of the tuned circuit is reducedand drift of the oscillator becomes more serious. On the otherhand, if the broad peak is higher than the sharp peak, the
134scillator is overstabilized, the pull -in range becomes inade-uate and the broad peak can cause double triggering of the
17T153, 17T155,17T160, 17T174
oscillator when the hold control approaches the clockwiseposition.
Remove the oscilloscope upon completion of this adjustment.
Horizontal Locking Range Adjustment. - Set the hori-zontal hold control to the full counter -clockwise position.Momentarily remove the signal by switching off channel thenback. The picture may remain in sync. If so turn the T113frequency core slightly and momentarily switch off channel.Repeat until the picture falls out of sync with the diagonal linessloping down to the left. Slowly turn the horizontal hold controlclockwise and note the least number of diagonal barsobtained just before the picture pulls into sync.
If more than 3 bars are present just before the picture pullsinto sync, adjust the horizontal locking range trimmer C181Aslightly clockwise. If less than 2 bars are present, adjustC181A slightly counter -clockwise. Turn the horizontal holdcontrol counter -clockwise, momentarily remove the signal andrecheck the number of bars present at the pull -in point.Repeat this procedure until 2 or 3 bars are present.
Turn the horizontal hold control to the maximum clockwiseposition. Adjust the 1113 frequency core so that the diagonalbar sloping down to the right appears on the screen and thenreverse the direction of adjustment so that bar just moves offthe screen leaving the picture in synchronization.
SENSITIVITY CHECK. A comparative sensitivity checkcan be made by operating the receiver on a weak signalfrom a television station and comparing the picture andsound obtained to that obtained on other receivers under thesame conditions.
This weak signal can be obtained by connecting the shopantenna to the receiver through a ladder type attenuator pad.The number of stages in the pad depends upon the signalstrength available at the antenna. A sufficient number ofstages should be inserted so that a somewhat less than normalcontrast picture is obtained when the picture control is at themaximum clockwise position. Only carbon type resistorsshould be used to construct the pad.
RESPONSE CURVES. --The response curves shown onpage 12 and referred to throughout the alignment procedurewere taken from a production set. Although these curves aretypical, some variations can be expected.
The response curves are shown in the classical manner ofpresentation, that is with "response up" and low frequencyto the left. The manner in which they will be seen in a giventest set-up will depend upon the characteristics of the oscillo-scope and the sweep generator. The curves may be seeninverted and/or switched from left to right depending on thedeflection polarity of the oscilloscope and the phasing of thesweep generator.
NOTES ON R -F UNIT ALIGNMENT.-Because of thefrequency spectrum involved and the nature of the device,many of the r -f unit leads and components are critical in somerespects. Even the power supply leads form loops which coupleto the tuned circuits, and if resonant at any of the frequenciesinvolved in the performance of the tuner, may cause seriousdepartures from the desired characteristics. In the design ofthe receiver these undesirable resonant loops have beenshifted far enough away in frequency to allow reasonablelatitude in their components and physical arrangement with-out being troublesome. When the r -f unit is aligned in thereceiver, no trouble from resonant loops should be experienced.However, if the unit is aligned in a jig separate from thereceiver, attention should be paid to insure that unwantedresonances do not exist which might present a faulty repre-sentation of r -f unit alignment.
A resonant circuit exists between the r -f tuner chassis andthe outer shield box, which couples into the antenna and r -fplate circuits. The frequency of this resonance depends on thephysical structure of the shield box, and the capacitancebetween the tuner chassis and the front plate. In the KRK11units, this resonance should fall above channel 13 and iscontrolled in the design by using insulating washers of properthickness in the front plate to tuner chassis mounting. Theperformance of the tuner will be impaired if the properwashers are not used. Obviously then, if the r -f unit is removedfor service, the washers should be replaced in the correctorder when the unit is replaced.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCA Victor
C I TI C9 TP2 C-5
FRE& TRANS GRID POINT PLATE
C) tv il 6W1 .:-'04440)OSC. TEAM MIXER TEST R -F
TUNINGFINE VeljLr
41.25 MC.LEO
C2
I -F TRAP
L5945.75 MC.I -F TRAP
ALIGNMENT DATA ( Continued )
L46
L1 INMAN L11INOWIDUAL CPANNEOSC. ADJUSTMENTS
CIO L511 1.41 L62R -FGEC TRAP
E6 05C. INJECT L 46ADJUSTMENT ON CRAM 6OTHER SIDE OF UNIT MIXER GRID
Figure 6 -R -F Unit Adjustments
Figure 7 -R -F Oscillator Adjustments
4,VT 71015- T io7Gtoralt 4TH PSI 3RD. pm.
- RATIO - Sat?. STN 61* - I -F TR.- TR.CET TR. f.T.X. i-F TR. 45.5 5C. 41.5 MC.
Le_ 1:14 AT TO
2GTOPuTir
a'111.)G.
131fOCLA.
131 PIE. I -F
laticGRID TR.
Figure 8-Top Chassis Adjustments
Figure 9 - Bo t to m Chassis Adjustments
CuGAMOW MTH
L 53CMAN.SR -F GRID
L50CNA.. 6R -F PLATE
SEPACTO!SMiTC11
TONE'''COMTAPUMA SW
1103 Irl0A-01.1 TAY
COMMA.
PAD FOR PAO FOR501E COAX 724 COAX.
1300.1300
3000_BALANCED
OUTPUT
SHOULDERAT 52 MC
3004BALANCED
OUTPUT
17T153, 17T155,17T160, 17T174
PAD FOR3000. BAL
INPUT
Figure 10-Sweep Attenuator Pads
60 MC.
53 MC. 100% RESPONSE
50 ME AT 50% * 15% RESPONSE POINT
Figure 11- Antenna Matching Unit Response
0\Figure 12-R -F Response
4.5 MG
Figure 13 Figure 14Sound I -F Ratio Det.Response Response
42.25 MC 42.25 MC
44.5MC
.4tit5 41.575MC AT00 %
AM 5MCAT20%
41 25 MC47 Z5MC
Figure 15T105 and T106
Response
45 MC85 %
45.75 MC.50%
46 5 MC5 Y.
api
43g-1
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vi
43
0Figure 16 Figure 17 0
T1 and TI04 Over-all I -FResponse Response
T17INCORRECT INCORRECT CORRECT
Figure 18-Horizontal Oscillator Wavejorms 13s
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONRCA Victor Models 17T153, 17T155, 17T160, 17T174, Chassis KCS-66 or KCS-66A
TO ANT
P18- MREARVIEW
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KANT TB
300 isGAL.
PIA- ni1REARVIEW
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9°8° ;
ANT MATCHING UNIT
0 L60 159 1;18I.F TRAP 45I-F7TsliTRAP TFR-AeM
41.2514C
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VIEW TRANS
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In a few early production receivers the VI13sync separator circuit was wired as shown inthe above partial schematic diagram. R265,8268, 8269, R270 and C223 were omitted andR153 was connected to the +145 volt bus.
136
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R103 011000 ,
+265V.FUNCTION SWITCHES VIEWED
FROM FRONT. AND SHOWN IN Po5.1( MAX. COUNTER -CLOCKWISE)
P05.1 _TV MIN.Hi6NS2 -TV NORMAL3 -TV 5010 LOWS4-PNONO. MIN. HIGHS.5-PHONO. NORMAL.6- PHONO. MIN. LOWS.
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C126 1212947001 100K
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C 220112 Tf52021(
In some receivers, focus bleeder resistorsR238 was 12 meg and 8240 was 15 meg. In somereceivers, R238 and R240 are combined intoone 18 meg resistor.
In some receivers, R264 (in video amp at synctake -off) was 220 k.
In some receivers, r -f unit terminal 7 by-passcapacitor C224 was omitted.
In some receivers, terminal C of I -F trans.
C1434 C1234700 1 14700
VIII6CS6A- G -CAMPL.
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T105 was connected to ground and C225 wasomitted.
In some receivers ratio detector trimmerC226 was omitted.
In some receivers, C193 was connected fromV118.5 to ground.
In some receivers a 22 k resistor, RI42 wasconnected from V110-8 to junction of L105, L114.
In some receivers, C227 (at video amp) wasomitted.
RISCLOMB
82001320K
C189 R233680 47
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C19082082002015 ME.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONRCA Victor Models 17T153, 17T155, 17T160, 17T174, Chassis RCS -66 or RCS -66A
V103TIO2
RATIO DET 6AL5TRANS. RATIO45_14C DETECTOR
6 8v./Th112;6?
-4 -IR10756 K
C1070 010713
101 T.01
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R1081000
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18 K5101-2 'A',
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RI I5MEG.6800 250E
1 611927K
C1161 R1M.015 1)
t22K
REAR. rE YE J103P HON 0,2,02INPUT
C21510
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A St6600
Dcmscs4700
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5
T 1084TH. POE I -F
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C140 # R147 51454700 74700 1000
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11
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122128200
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560 5C0 I yEL
PI02-PIN VIEW
Coil resistance values less than 1 ohm arenot shown.
Direction of arrows at controls indicatesclockwise rotation.
BLK-RED
0205A100 MET
J 102-FREARVIEW
qaDsL108
FILTERCHOKE
+265YSUPPLY
3000 v ( ARPRox
0203ISO MF
eLU-YEL
All voltages measured with "VoltOhmyst"and with no signal input. Voltages should holdwithin ±20% with 117 v. a -c supply.
All resistance values in ohms.K =1000.
All capacitance values less than 1 in MEand above 1 in WAY unless otherwise noted.
6.30
1 JUL
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iR
194.
10
R19
61
ME
G27
KT
.
_C18
81.
0082
RI9
72.
5 M
EG
.T
ON
E
V11
8
6AV
61S
T A
UD
IOA
MP
L.
Cl2
SC
126
270
100
C12
41.
RIZ
' IC
127
C12
912
NW
T+
IBK
10.4
7 15
00T
BA
V.
C15
2_1_
.01
RI9
947
0K01
81
V10
5
P10
0 -F
RE
AR
VIE
W
V11
9
6K6-
GT
AU
DIO
OU
TP
UT 34
8 V
BU
J
360
VB
RIJ
08 G
RN
)."
C21
3CC
2 1
2C
T2O
MF
10 M
F
+12
0 V
.+
250V
1114
SO
UN
D T
AK
E -
OF
FT
RA
NS
.R
283
70K
6A L
. 528
0.0E
1 a
A-G
C R
EC
T
Y
0224
14
.011
.
FOC
US
MA
GN
ET
AD
JUST
ME
NT
. -T
he f
ocus
mag
net s
houl
dbe
adj
uste
d so
that
ther
e is
app
roxi
mat
ely
thre
e -e
ight
hs in
chof
spa
ce b
etw
een
the
rear
car
dboa
rd s
hell
of th
e yo
ke a
nd th
efl
at o
f th
e fr
ont f
ace
of th
e fo
cus
mag
net.
Thi
s sp
acin
g gi
ves
best
ave
rage
foc
us o
ver
the
face
of
the
tube
.T
he a
xis
of th
e ho
le th
roug
h th
e m
agne
t sho
uld
be p
aral
lel
with
the
axis
of
the
kine
scop
e ne
ck w
ith th
e ki
nesc
ope
neck
thro
ugh
the
cent
er o
f th
e op
enin
g.
CE
NT
ER
ING
AD
JUST
ME
NT
. --N
oel
ectr
ical
cent
erin
gco
n-tr
ols
are
prov
ided
. Cen
teri
ng is
acc
ompl
ishe
d by
mea
ns o
f a
sepa
rate
pla
te o
n th
e fo
cus
mag
net.
Som
e ce
nter
ing
plat
esin
clud
e a
lock
ing
scre
w w
hich
mus
t be
loos
ened
bef
ore
cen-
teri
ng, a
nd o
ther
s ar
e he
ld in
adj
ustm
ent b
y fr
ictio
n. U
p an
ddo
wn
adju
stm
ent o
f th
e pl
ate
mov
es th
e pi
ctur
esi
deto
sid
ean
d si
dew
ise
adju
stm
ent m
oves
the
pict
ure
up a
nd d
own.
If a
cor
ner
of th
e ra
ster
is s
hado
wed
, che
ck th
e po
sitio
n of
the
ion
trap
mag
net.
Rep
ositi
on th
e m
agne
t with
in th
e ra
nge
of m
axim
um r
aste
r br
ight
ness
to e
limin
ate
the
shad
ow a
ndre
cent
er th
e pi
ctur
e by
adj
ustm
ent o
f th
e fo
cus
mag
net p
late
.In
no
case
sho
uld
the
mag
net b
e ad
just
ed to
cau
se a
ny lo
ssof
bri
ghtn
ess
sinc
e su
ch o
pera
tion
may
cau
se im
med
iate
or
even
tual
dam
age
to th
e tu
be.
In s
ome
case
s it
may
be
nece
s-sa
ry to
shif
tth
e po
sitio
nof
the
focu
s m
agne
t in
orde
r to
elim
inat
e a
corn
er s
hado
w.
0.5
2C
125
I'°=
5125
5600
3
LID
S50
0 m
u 9
,841
A'4
R12
6C
l9m
,22
0.0
0 5
.0,7
0130
0220
1.0
022
100
2R
224
0
7.37
11.1
.10
0KR
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+5.
5V35
00P
19 C
ON
T
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001
1500
,-4.
----
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-4.
DR
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C28
610
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---
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6L1
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064.
3 M
C T
RA
P
Llos
12A
U7
YE
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LN00
000
C27
547
34 M
LL M
.15
1 4
2N0
OR
t4,4
441
VID
EO
AM
PL. 5v
RI4
212
0 K
Vvv
?R
179
8190
-I-
C21
2068
0015
KI 5
MF
054
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I311
7 *I
IOV
47
+12
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J105
R23
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3300
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IEW
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OA
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R23
310
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t41
56K
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422
014
A
5232
R23
1S 2
20K
220
K
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCAVICTORMODELS 21T176,
21T177, 21T178,Chassis Nos. KCS68C
The following measurements representthe picture synchronized and thecircuiting the receiver antenna terminals.chassis ground and with the receiver
Alignment information given forChassis KCS-66, preceding thissection, can be used as a guidein carrying out alignment onthe models described. Voltagechart which begins on this page,continues on the page after thedouble -page circuit diagram.
VOLTAGE CHARTconditions. In the first condition, a 5000 microvolt test pattern signal was fed into the receiver,
adjusted. The second condition was obtained by removing the antenna leads and shortshown are read with a type WV97A senior "VoltOhmyst" between the indicated terminal and117 volts. 60 cycles, a -c.
21T179
two sets ofAGC control properly
Voltagesoperating on
TubeNo.
TubeType Function
OperatingCondition
E. Plate E. Screen E. Cathode E. GridI
Plate(ma.)
IScreen(ma.)
Notes onMeasurementsPin
No. VoltsPinNo. Volts
PinNo. Volts
PinNo. Volts
VI 6X8 Mixer5000 Mu. V.
Signal 9 - 8 - 6 0 7 - - -No
Signal 9145 to
150 8145 to
150 6 0 7-2.8 to-3.5 - - Depending
on channel
VI 6X8R -FOscillator
5000 Mu. V.Signal 3 - - - 6 0 2 - -
NoSignal 3
88 to108 - - 6 0 2
-3.0 to-5.1 - Depending
on channel
V2 6BQ7R -FAmplifier
5000 Mu. V.Signal 6 - - - 8 - 7 - -
NoSignal 6
133 to138 - - 8 1.1 7 - - - Depending
on channel
V2 6BQ7R -FAmplifier
5000 Mu. V.Signal 1 - - - 3 - 2 - - -
NoSignal 1 260 - - 3
133 to138 2 - - - Depending
on channel
V101 6AU61st SoundI -F Amp.
5000 Mu. V.Signal 5 127 6 124 7 0.7 1 -0.4 6.0 3.0
NoSignal 5 126 6 123 7 0.5 1 -1.2 5.0 3.0
V102 6AU62d SoundI -F Amp.
5000 Mu. V.Signal 5 132 6 60 7 0.14 1 -10 2.8 1.2
NoSignal 5 131 6 65 7 0.14 1 -5 2.0 1.0
V103 6ALSRatioDetector
5000 Mu. V.Signal 7 1.0 - - 1 9.2 - - -
NoSignal 7 0 - - 1 8.0 - - -
V104 6AV61st AudioAmplifier
5000 Mu. V.Signal 7 90 - - 2 0 1 -0.7 0.45 At min.
volumeNo
Signal 7 86 - - 2 0 1 -0.7 0.45
V105 6AQ5AudioOutput
5000 Mu. V.Signal 5 350 6 360 2 150 7 116 30.0 2.0 At min.
volumeNoSignal 5 346 6 356 2 145 7 114 30.0 2.0
V106 6AU6lst Pix. I -FAmplifier
5000 Mu. V.Signal 5 180 6 230 7 0.15 1 -6.5 1.5 0.3
NoSignal 5 97 6 129 7 1.0 1 0 7.0 3.0
V107 6CB62nd Pix. I -FAmplifier
5000 Mu. V.Signal 5 236 6 233 2 0.1 1 -6.5 1.5 0.14
NoSignal 5 226 6 138 2 0.85 I 0 12.0 3.0
V108 6CB63d Pix. I -FAmplifier
5000 Mu. V.Signal 5 149 6 144 2 ' 0.9 1 0 11.0 3.0
139NoSignal 5 129 6 ,133 2 0.8 1 0 10.0 2.0
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
1110
MODELS 21T176, 21T177, 21T178, 21T179TO *HT MT T5.
300 .r1-BAL
ANT MATCHING UNIT
L60 1.59 L58-F 1-F F -MTRAP TRAP TRAP
015 - M PIA- MREAR REARVIEW VIEW RONT ANT. 18 111 2
VIEW TRANS
R- FUNIT
no10.
1000AA.
11500
3300 150
55 55I FRONT REAR 9
HZ 1713
03 o
155
3154 157
L42 L36 LOB 11500
143 105 59
144 L34 0330054145 Ls, L33 141 FRONT
132L53
53 -FRONT SO -REAR L49
270 -1.05*e
L2B L2629 L7S
L30 124
100K 100KV 52 -FRONT
1-4 6B0.7R -F AMPL 410K 1000
MA.I021.0V.
1511500.T 15001
L22 270,- 15001 82 1500T
.1145VI
330 rS5-80 6X 8To
52 -REAR OSC. AND MIXER
L10
LSI
186
LS LS
LI
1 L2
13
+1018.+To 5
- To- 2
2.1
L TX64 162
FINETUNING
100 K
CTHANO"YS. .
I027K LI
C
1_! 4
T1500
CHANNEL SELECTOR SWITCHES VIEWEDFROM FRONT A50 SHOWN IN CHANNELNO. 2 (54 - GO MC.) POSITION.
COLOR CODES MOULDED PAPER CAPACITORSMULTIPLIER MULTIAGE*
DIGITS TOLERANCE DIGITS TOLERANCE
VOLTA GE VOLTAGERATING RATING
11111111OUTER EOM END OUTER FOIL END
(MAY SE ON EITHER END) (MAY BE ON EITHER END
DIGITS MULTIPLIER
VOLTAGE.4O,
TOLERANCE
ARROWPOINTSTO OUTERFOIL ENO
RMA COLOR CODE. FIXED MICA CAPACITORS
WHITE INDICATES AMA STDSLACK INDICATES JAN STD
A
WHITE INDICATES RNA IITOSLACK INDICATES JAN STD
DIGITS
DUALITY (:?----SMULTIPLIER TOLERANCE MULT'PUUTOLERANCEQUALITY
RNA FIXED MICA C.AOACITORS RATED AT SOOV. UNLESS MARKED OTNIERWISE
1
ti
IRA
rl27
33 K .0047.31113Y.
4700
4700 10004700 c-1
w.I4
4700T-11SW
01 1. 220K
50KA.G-C
CONTR
10 - 18 0HO R12.1
LOCKiN6r1 'so KRANGECONTR.
*13SV.
3.3 MEG
+373 V.
=
Chassis Nos. KCS68C
V101 V102
6AU61ST SOL/NO
F AMPL.
5 1260
SOUND I- FTRANS.
ru ' _Log Iv.
1000 15 T a 1147 z
- 1
Lc_ _ A
T°I "t4
2
?1000
.3134V
6 A U 62ND. SOUNDI- F PL
.01 T 68
FUNCTION SWITCHES VIEWEDFROM FRONT, AND SHOWN IN P05.I(MAK COUNTER -CLOCKWISE)
POS 1 -TO miN.NIGHS2 -TV NORMAL3 -TV MIN LOWS4 -1380NO. MIN. HIGHS3-P31000 NORMAL.6-PH0N0 MIN. LOWS.
V107
15= PIX 1-F 6AU6V106
1ST PIX 2ND. PIE. I -F 6 CB 6GRID TRANS 1,-5FT
AMPL.PLATE TRANS. GRID TRANS. 22ND.mFIXL.
E5 4.37
33KB
1001
4700 15 - 244
14100
47001
A JluL g_
too. r\ 10005-11-4- $2
4700
100 T4.700 4154V.
FAGC
V 111
6CB6A- G. CAMPL.
MEG.El 22 520 Y
+2 8V 82 = 150
V 112
6SN7-GTHOR. SYNC. AMPL.
,/50 K +373
NOR. HOLD
02K 68K
82 .047
0,1665N7- GTNOR.SwEEP 05c
AND CONTR.
+3738.
4 Nu
100 KTP101
v113
6SN7-GTSYNC
SEPARATOR
+ 720 + 00.5
220K El 22
NOR. OSC.TRANS.
14
14700
150K
1 MEG
.001
Geo K
5.6.022 T mEG
_ +3730
.001000
R-1- 1-4
.01
19
All resistance values in ohms.K = 1000.
+373V J.
56
10-160HORiZ
MEG DRIVECONTR.
_ _11-
.0015OK
Coil resistance values less than 1 ohmare not shown.
All capacitance values less than 1 in Direction of arrows at controls indi-MF and above 1 in MMF unless other- cates clockwise rotation.wise noted.
1/4 AMP
crLo--
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
RCAVICTORRATIO DET
TRANS.
1000
+138V
3RD. PIX. I -FTRANS.
s
6800D
rt1700I %loc.:,
L101
+2160.
V 1144
65N7-GTvEKT SYNC
AMPL °,
0103
GALSR AT 0
DETECTOR
47
5101-2FRONT
V108
6CB63RD. P1X.I -F AMPL.
1.5MEG
+1350
VII,6CD6-6NOR. SWEEPOUTPUT
1200
1000 39 K
SRIEC;',Lut"firilII
4TH. MX. I -FTRANS
4700 4700
10K 2200
.0047
1.5 MEG.MEGVOL
CONTR. 250K
6600 25oK
27 K
:0022 .015 I 22K
I008l
V109
6CB6Arm PiX.I -F AMPL
+154V +2160.
PHONOINPUT
v104 0105
6AV61ST. AUDIOAMPL.
470K
T .0027
11H270 T 7330K 330
SOUNDTAKE -OFFTRANS.
100
(-10114 IS 0115
+DEN.
6A0.5AUDIOOUTPUT
120 MF
+134V
TP102VII0
1.103
06AG7
72.411.11000 VIDEOORK RED AMPL.
a +130v
3300 -20V+107
ZOOKBRIGHTMSCONTR.
REARVIEW
10
PINVIEW
AUDIOOUTPUT TR1
21T176, 21T17721T178, 21T179
P -
SPEAKER
CHANNELINDIC. LAMP
SHELL® BRN
O JEWEL LAMPBRN® 13LK
S101-1+373 V.
FRONT
1.11645 MC
TRAPBLU-YEL
j000II
18 K +2100 +1350
ER
g J1Z
6SN7-GT- 39 6A0.5VERT SWEEPVERTICAL 0.1
OSC 4 DISCHVESTOLITSPWUTE"
OTURT,,PNUST
Z2K 0200 .01 YEL BLU+1760 , 41571/ i Bltr L -'ye, .2.72,°
tooI MEG. GRix: 68Kli ! .11
22 K 100210047-27V.
0.22I .0022 : " T.021
_i_
VERT. OSC 27 .022 ; RED eaK
22K TRANS. C'' r_W105-3.3MEG
R205 4I._ _ _ J
2 1 MEG.0003.1 10K 000 y a. 1 350., 10K
820K 10K .047 100 MEI 1500.../.VW
VERTICAL VERTICAL10 MEG, I PEAKING LINEARITY
2.5MEG CONTR.+3730 220 K5m,iE 150K
ONTRT2CI
I MEGVERT.HOLD
cc....4rR
L1154.7 MU -NVio-YEL
500110512.
LINEARITYCONTROL
vI18153-GTH -V RECT.
7
1000MEG.
3100. PULSE0119
Lu71.514111*1,04.6101
L118L5 NU -
MEW BEN-UI
YOKE- --t
V120 '..-: 150 r-,-: VERT. ColLSI REDA3-
7 6 I P -, 56 ' L110 I-109 100041
3 6W4 -6T 1 tz ..7.- =270 i1 YELDAMPERS L: 3 ii 10
_ 1 - -, ELK -RED
In some receivers, substitutions have All voltages measured with "Volt -
caused changes in component lead color Ohmyst" and with no signal input. Volt -codes, in electrolytic capacitor values ages should hold within ±20% withand their lug identification markings. 117 v. ac supply.
270 K
TERM.VIEW
740 GRN 2
+5300. RED m
Sic.- IREAR
L11400 mu.
T YE I.
GLASS
v121 METAL
21AP4K INESCOPE
373V +245V..218V +15461 +135V. +134V
10K 7000
25 pART mF.
35 MF
lin I2n0101
047 .0.11.LE-T--° lisv..
(J.
141
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONVOLTAGE CHART (Continued) 21T176, 21T177RCA Victor
21T178. 21T179
Tube Tube OperatingE. Plate E. Screen E. Cathode E. Grid
I I Notes onNo.
---Type Function Condition Pin
No. VoltsPinNo. Volts
PinNo.
PinVolts No. Volts
Plate(ma.)
Screen Measurements(ma.)
V1094th Piz. I -F
6CB6 Amplifier5000 Mu. V.
Signal 5 178 6 163 2 2.2 1 0 8.9 2.1
NoSignal 5 165 6 150 2 2.0 1 0 7.9 2.1
V110Video
6AG7 Amplifier5000 Mu. V.
Signal 8 130 6 172 S. 1.2 4 -5.0 22.5 5.5No
Signal 8 130 6 107 5 0.8 4 -2.0 15.0 4.0
V111 6CB6AGCAmplifier
6600 Mu. V.Signal 5 -27 6 238 2 152 1 155 0.1 3.4
AGC controlset for
NoSignal 5 4.5 6 218 2 135 1 118 0 0
normaloperation
V112 6SN7GTHor. SyncAmplifier
5000 Mu. V.Signal 2 152 - - 3 0.9 1 -44 1.1
NoSignal 2 135 - - 3 0.4 1 -30 0.5 -
5000 Mu. V.Signal 5 86 - - 6 0 4 -2.0 5.5 -
NoSignal 5 80 - - 6 0 4 -1.8 4.6 -
V113 6SN7GTHor. SyncSeparator
5000 Mu. V.Signal 2 374 - - 3 216 1 155 1.2 -
NoSignal 2 372 - - 3 155 1 134 0.8 -
V113 6SN7GTVert. SyncSeparator
5000 Mu. V.Signal 5 345 - - 6 205 4 135 <0.1 -
NoSignal 5 340 - - 6 160 4 130 <0.1 -
V114A 6SN7GTVert. SyncAmplifier
5000 Mu. V.Signal 5 7.0 - - 6 0 4 -0.2 0.6 -
NoSignal 5 7.0 - - 6 0 4 0 0.5
V114B 6SN7GTVerticalOscillator
5000 Mu. V.Signal 2 176 - - 3 0 1 -27 0.2 -
NoSignal 2 176 - - 3 0 1 -27 0.2
V115 6AQ5VerticalOutput
5000 Mu. V.Signal 5 359 6 359 2 30 1 0 17.3 1.2
NoSignal 5 357 6 357 2 29 1 0 . 17.3 1.2
V116 6SN7GTHorizontalOsc. Control
NoSignal 2 188 - - 3 -24 1 -42 0.37 -
5000 Mu. V.Signal 2 145 - - 3 -18 1 -42 0.4 - Hor. hold coun-
ter -clockwise5000 Mu. V.
Signal 2 230 - - 3 -18 1 -42 0.4 - Hor. holdclockwise
V116 6SN7GTHorizontalOscillator
5000 Mu. V.Signals 5 258 - - 6 0 4 -91 2.0 -
V117 6CD6GHorizontalOutput
5000 Mu. V.Signal li- Cap * 8 165 3 12.5 5 -30 110 15.0 *High
Voltage
V1181B3GT/8016
H. V.Rectifier
5000 Mu. V.Signal * Cap " - - 2 & 7 16,000 - - 0.2 - Pulse
PresentV119V120
-6W4GT Dampers
5000 Mu. V.Signal 14
-5 355 - - 3 * - - 57 -
V121 21AP4 Kinescope5000 Mu. V.
Signal Cone 16,000 10 555 11 140 2 82 0.2 - At averageNo
Signal Cone 16,400 10 550 11 132 2 76 0.2 - Brightness
V122V123 5U4G Rectifiers
5000 Mu. V.Signal 4 & 6 388 - - 2 & 8 389 - - '139 - Per
NoSignal. 4 & 6 386 - - 2.58 387 7, - '145 - Tube
142-is833113 voltage values are obtained under "No Signal" condition.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Chassis 20AY21, used in Models C -2001A, C-2002A, RC -2005A, and C -2006A,is covered by the circuit on the next two pages. Models M -2007A and
M -2008A use this chassis with the 12AT7 video amplifier tube changedto 6AB4, code numbered 124115 and up. Some of these sets have a dif-ferent type of L-19 and 1-26 coils.
The following changes went into effect in the process of production.
1. Resistor R79 was changed to 1000 ohms to increasevertical scan reserve. This change was incorporated inchassis stamped with RMA date code numbers 124106and up.
2. Resistor R87 was changed to 1 megohm to balancethe AFC output at no signal. This change was incor-porated in chassis stamped 124107 and up.
3. Resistor R47 was changed to 22K ohms to accom-modate picture tubes requiring greater cut-off bias.
ON OFFSWITCH
8
I2AT75T VIDEO AMP
23
6V6/GT2 HD VIDEO AMP
10
6AU6A G.0 AMP
11
6AU6SOUND F AMP
13
6V6/GTAUDIO OUTPUT
12
6AL5AUDIO DET
236AU6AUDIO AMP
21
IB3/GTHIGH VOLTAGE
RECTIFIERION TOP OF CHASSIS)
PICTURECONTROL
R 32
KOMI HOLDL23
Bottom View of Chassis
VOLUMER61
VIDEO TRAP
Tv - PHONOWITCH
pu050TiPu T
7
6AL5D C RESTORERAND DETECTOR
BRIGHTNESSR 46
6AU6
16
0 6AL5
20
6W4/GTDAMPER
This was incorporated in chassis stamped 124108 and up.
4. Resistors R73 and R76 were changed to 18K ohmsand 390K ohms to center the range of the vertical holdcontrol. This was incorporated in chassis stamped 124110and up.
5. Capacitor C142 (.05 mfd x 200 volts) was changedto .05 mfd x 400 volts, to prevent breakdown in the field.This change was incorporated in chassis stamped 124110and up.
TONE
p6
11300
5
6AU6
18
6E106
VENT HOLDR 74
46AU6
74vERT OUTPUT
TRANS
PULSE AMP
19
6606PULSE AMP
3
6AU6I ST I F
1.9vERT 05C
TRANS
FILTER CHOKE
ERJ SIZER70
vERT LINR80
TUNERCHASSIS
77POWERTRANS.
L25FILTERCHORE
225U4/GT
14
6SN7,,,, 05G
AND BUFFER
15
6V6/GTVERT OUTPUT
ANTENNAINPUT
LOH VOLTAGE RECT 143
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONRaytheon Television Chassis 2QAY21
TUNER WIRE TERMINALS
NOTES
vOLTAVE RE7845 742N WITH 20. 000 048 PER VOLTvOLTAICTER OCT=EN POINTS SHOWN AND CHASSIS
NORMAL OPE0471011, NO 387481. INPUT.LINE VOLTAGE 117 V AC
ra17.71411.7. 22001 OHM RES15200 IN SEMIS
CARAWOR VALUES SHOWN Mk0A° UNLESS02RERwil
SCHEMATIC DIAGRAM No. 2
130*Pow
037
144
CAS
TUNER CHASSIS
C 11
C16
1,2j CAS
.0 tTUMOR DRAAnR
MIN
C30241.
U-COO C/2
21
TUNER A. G.0 LINE
1.0
Rro
CPL
CES R M3
* I
R34ION
IN urVIDEO AMPLIFIER
80
116
4200
0352200
100
L33
1R1177700
0I2AT7
of VOCO AMP.
,6V
@6 /GT
PI 1DEO AMP
119
120Rile5600
R120150
C58 tR440
R 32
IPcTunT I
C122
C
- 1
L2I
L.e,2 /55
R 45
Ci03
P42
Ro
6SN7
LPTNE .1C71
51I-.
005
O
Inc ARP]
889
R44oa
C11'
aro°
0123
6A16CA7-ts1Pre1
050 1.
C70
0,01oo
P77'
C90
T
6SN7
Ro72o.
LR Be
2.6V6/GTLi2RT Ov7PLA
R52co.
CI47
III
0O
00
T9
>70
o
CIS iItt!
R 76&NA008
82
nNvn
7,7
C116
74 I00
R73ION
R78a,a.a
117;3
R 70MEGiiiv
.1. 350Y
1- 350r ArJ
8114
PTo
1531
R80
C152
PS356
AUTO.FREO.
CONTROL .82EAR]9C99
reo
: o 11 31:1 "I
6A5014 , aka I
II*
G R 4ME
057
0142
R141106
883 0125bro =
0
0012
084
P05"mck
HORIZONTALDEFLECTION
L23
C10220
R07
1011.
0CIOS
21
RS,91
0
00
II-
CO960- 460
OM
6SN7wwTI
V
C
C41
097580v
R99co,
C156
7
VERT/CALDEFLECTION
Alignment facts on the next page.
CE2L2On0o. ORESOCKET AND Pt=
0128
0157
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
riLIO II
C 6AU6C35SOCO
C34
46.0 LINE
t /55rt R IXr /5 ANO I/ MAY Of
Lrrl,r1 LrEirL NS P CNOKE
C 39
L12
10.0 6AU6
czq
C74WOO
IIC67
R107
rj174.:2-449
Rp6311
C 56
C155
11---11"
1153R 111,7g,
06W4r WM, 1
61306
0154RII2
1$ 11'.1ANN 1--1
0106 C104 73,4.4
Iso
L 26 .=1.
RIO5
1
0bz
0I B3
HIGH VOLTAGE
L2.
20AY21 SCHEMATIC DIAGRAM455
MOO
C43 CM
1103 1U, ,4.,_,.D
1." 6AU6 ic...--,,-..77 .
T
9.2 1
R27 i.4a>
/2 41426 C50...C47
T
T-V?1:131
/. F. AMPLIFIER
-T-
1 016
6AU6Is...wit .1.1
31
9
.510
C77
R60
1,4 al. MOO
rirClrf-Mrrrr094-B
430 -t41771
10
Choke coils are connected in series with the 155 volt B+ leadsin the I.F. Amplifier strip between R-15 and R-19 and be-tween R-19 and R -2a (Part No. A -16A-18676).
6AL5143,0
2Ss
6AU6
3000L 32
06V6/GT4YM10 94TINrr
62 C145I
I
Jr
+ 350 r
0. 6AI-5
SOUND STRIP
1094 G
Rya
+ 350 r
EARLY PRODUCTION RUNReferring to the schematic, the following componentsdiffer: Capacitor C-106 and resistors R-105 and R-124are not incorporated. Capacitor C-104 is .03 mfd andis wired across the entire linearity coil (L-26), C-110 is68 mmf, C-111 is 680 mmf and C-157 is 1000 mmf. TheH. V. Deflection transformer (T-6) is C-201-19874 andthe H. Linearity coil (L-26) is B-1 3M-1 9499 with the 10ohm resistor shorted out and a A -51A-16945 iron coreused.
L IS
22
5U4R
C61 A
M TUBE FILAMENTS
ANS MO'C'ATPE"111:
y
sxxxl,R104 IN470ff
145
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
14
Raytheon Television Chassis 20AY21 Alignment (Continued)
PRE -ALIGNMENT PRECAUTIONS ohm resistor in series with hot scope lead.1. If sweep generator does not have a balanced output, connect a 150 3. Connect signal generator thru a 1000 mmf capacitor.
ohm resistor in series with the ground lead and 150 ohms minus the 4. Set Picture control to maximum.internal resistance of the generator in series with the hot lead. 5. When aligning the I.F. Amplifier be sure the tuner is tuned to a
2. Connect a 1000 mmf capacitor across scope terminals and a 10K high band channel (any channel).
VIDEO I -F ALIGNMENT
StepNo.
SignalGenerator
Freq. (mc.)
SweepGenerator
Freq. (mc.)
SignalInputPoint
OutputPoint
Adjust Remarks Response
1 26.25Converter
GridVTVM at pin7 of tube 8
L-111-13
Adjust generatorfor output ofapprox. 1 volt
MaximumReading
2 23.9Converter
GridVTVM at pin7 of tube 8
L-12L-14
Adjust generatorfor output ofapprox. 1 volt
MaximumReading
3 25.1Converter
GridVTVM at pin7 of tube 8 T-1
Adjust generatorfor output ofapprox. 1 volt
MaximumReading
4 25.5Converter
GridVTVM at pin7 of tube 8
SENSITIVITYGenerator output should beless than 150 microvolts
(If not, repeat alignment)
1 volt VTVMReading
(above noise)
26.7523.65
25.0 ConverterGrid
Scope at pin7 of tube 8
Ti for properratio as in #6
below
SELECTIVITYMarker should be as
in responsecolumn. (If not, repeat
alignment).
I
. - nr,
6
Connect scope and sweep generator as in step 5 and VTVM as in step 4. Adjust marker generator until markerreaches shoulder. Record marker frequency (F-1) and VTVM reading (V-1). Keeping generator output constant,adjust marker generator until marker reaches other shoulder. Record marker frequency (F-2) and VTVM reading(V-2). The response curve should be flat from shoulder to shoulder and V-1 should equal V-2. The difference be-tween F-1 and F-2 should be 1.9 Mc. If not repeat steps 1 to 5.
7 Channels 2-46-7-10-12
AntennaTerminals
Scope at pin7 of tube 8
Check channelsfor band width
(2.9 mc to 3.3 mc)- -
Picture I.F. frequency 26.75 mc - Sound I.F. frequency 22.25 mc.
SOUND I -F ALIGNMENTShort antenna to ground and connect generator thru a 1000 mmf capacitor.
1 4.5Pin 1 ofTube 11
VTVM junc-tion of R-58
and C-88
T-8 andT-2 primary
(bottom of can)
MaximumReading
2 4.5Pin 1 ofTube 11
Scope junc-lion of R-58
and C-88
T-2secondary(top of can)
Sweep approx.±100 kc. Adjustfor max. linearity
3 4.5 Pin 1 ofTube 11
Scope junc-tion of R-58
and C-88
T-2primary
(bottom of can)
Sweep approx.±-100 kc. Adjust
for symmetry of peaks
44.5 Pin 1 of
Tube 11
VTVM acrossspeaker voice
coil
Generator output shouldbe less than .025 volts withSweep of ± 25 KC andsweep freq. of 400 cycles
rox.Appvolts1.25
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Sentin
MODELS 438, 439, 440, 441, 443, 444, W-438, IU-439, IU-440, IU-441,IU-443, IU-444
WHEN REPLACING PICTURE TUBE ALWAYS HAVE FACE OF TUBE TIGHT AGAINST RUBBER STOPS
VERTICAL ANDHORIZONTAL CENTERING
IMPORTANT: THE HORIZONTAL HOLD CONTROL SHOULDNEVER BE USED TO CENTER PICTURE. THE HORIZONTALHOLD SHOULD BE SET PROPERLY BEFORE PROCEEDINGWITH THE FOLLOWING CENTERING ADJUSTMENTS. SEEPAGES 4 AND 5 FOR HORIZONTAL HOLD INSTRUCTIONS.IF pattern is too high or low and/or too far to right orleft on the screen and CANNOT be properly centeredwith the HORIZONTAL OR VERTICAL CENTERING CON-TROLS-
I. Adjust the HEX STUD on the FOCUS MAGNET with anon-magnetic tool or a special adjustment fool, P-1004, ina circular motion until centering is within range of the twocentering controls.
2. Additional centering can be obtained by moving the com-plete FOCUS MAGNET ASSEMBLY to bring the center-ing to within range of the two centering controls. Loosenthe two wing nuts "D'' and move the complete FOCUSMAGNET ASSEMBLY so that centering is within range ofthe two centering controls. Leave at least a 1/16 of aninch between neck of tube and Focus Magnet, otherwise,damage to the tube may occur
NOTE: Some models have a FOCUS MAGNET equippedwith a non-magnetic adjustment shaft for centering, andan extended non-magnetic shaft for focusing. The sameprocedure should be used as listed above, except for theuse of the magnetic tool.
ELIMINATING SEMI -CIRCULAR CORNERSHADOW OF PATTERN OR PICTUREI. Use same procedure as listed above on Horizontal and
Vertical Centering.
2. Adjust ION TRAP for MAXIMUM BRIGHTNESS.
CAUTION! DO NOT USE ION TRAP TO ELIMINATE COR-NER SHADOW OF PATTERN IF BY SO DOING THE IN-TENSITY OF RASTER IS DECREASED.
IF NECESSARY after completing the above procedures,recenfer pattern with the centering controls. DO NOTUSE THE HORIZONTAL HOLD CONTROL TO CENTERPICTURE.
PICTURE TUBE GROUNDSPRING MUST TOUCHOUTSIDE COATING OF
TUBE
REPOSITIONING LOOSEOR REPLACED PICTURE TUBE
This rubber gasket around edge of Deflection Yokemounting bracket supports the picture tube. It shouldalways be pressing very firmly against the bell of thetube, otherwise the picture tube may move andcause corner shadow or shifting of pattern on screen.
To position loosen the Deflection Yoke mountingscrew "A" and 2 wing nuts "V and the 4 Phillipsscrews "C". Pusf the complete Bracket Assemblyforward so that the rubber gasket fits snugly aroundbell of picture tube. Tighten the 4 Phillips screws ''C"firmly. IF the foregoing procedures have been fol-lowed correctly the picture tube should now be heldfirmly in place. Gently push the deflection yoke for-ward and tighten the 2 wing nuts "B". Before tighten.ing screw "A" make sure that pattern is not tilted.
STRAIGHTENINGTILTED PATTERN
If Pattern is tilted on screen, adjust De-flection Yoke position by-
I. Loosen yoke -locking screw (A).
2. Straighten pattern on screen by slid-ing locking screw to right or left.
3. Lock yoke in proper position by firm-ly tightening screw.
FOCUS CONTROLAdjust for sharpest definition witha brass, copper or non-magneticscrewdriver.
ION TRAP ASSEMBLYMaximum brightness will be determined by the position of the IONTRAP ASSEMBLY:
I. Advance BRIGHTNESS CONTROL on front of chassis to maximumbrightness position.
2. Adjust the ION TRAP ASSEMBLY for maximum brightness by slidingback and forth and rotating to right or left.
3. Reduce BRIGHTNESS with BRIGHTNESS CONTROL and repeat ad-justment of ION TRAP for best positioning.
147
Sentinel Models 438, 439, 440, 441, 443, 444 (and with prefix III-), continued.
SIG
NA
L G
EN
ER
AT
OR
sup
plyi
ng 4
.5M
.C.
(with
inS
WE
EP
GE
NE
RA
TO
R c
apab
le o
fco
verin
g 20
to 3
0.2
57 )
, 20
to 3
0 M
.C. a
nd 5
0 to
216
M.C
. (w
ithin
I%)
M.C
. and
50
to 2
16 M
.C. w
ith a
10
M.C
.sw
eep.
equi
pmen
t:si
gna°
Is.
MO
DU
LAT
OR
TU
BE
AD
AP
TE
R (
Par
t No.
AD
6AG
5)3
VO
LT "
A"
BA
TT
ER
Y to
pro
vide
fixe
d bi
as d
urin
gT
UB
E V
OLT
ME
TE
R h
avin
g a
5 vo
lt an
d a
10us
ing
11/2
vol
t bat
tery
as
show
n in
Fig
ure
7.vi
deo
I.F. a
lignm
ent.
DIS
CR
IMIN
AT
OR
AN
D S
OU
ND
I -F
ALI
GN
ME
NT
O Cl) q 0 1-3 Li Z s Z tri
tri el tri
ef INI
11)
in b) I LI Li °G NI
FA 12 ge...
.
gal
PS N 4 D
NS
es Iml
N Cli III N lis eh.
Cur A pill q 11.1 0 z
411
fri equ
ired
VA
CU
UM
volt
rang
e.
Ste
pN
o.C
onne
ct S
igna
lG
ener
ator
toS
igna
l Gen
.F
req.
MC
Con
nect
Sw
eep
Gen
erat
or to
Sw
eep
Gen
.F
req.
MC
Con
nect
Osc
illos
cope
toC
onne
ctV
oltm
eter
toM
isce
llC
onne
ctio
nsan
d In
stru
ctio
nsA
djus
tI
In s
erie
s w
ith .0
1 M
fd.
Con
d. to
Grid
, Pin
I
of V
ideo
Am
plifi
er.
See
Fig
. 2
4.5
Not
use
dN
ot u
sed
Not
use
dIn
ser
ies
with
47K
Ohm
Res
isto
r an
d A
cros
s th
e10
MF
D. C
ond.
C-2
8.S
ee F
ig. 2
Met
er o
n 5
volt
scal
e an
dm
aint
ain
3 vo
lt re
adin
gT
-7 (
top)
and
T-8
(bo
t-to
rn)
for
max
. on
met
er.
See
Fig
s.1
and
2
2In
ser
ies
with
.01
Mfd
.C
ond.
to G
rid, P
in1
of V
ideo
Am
plifi
er.
See
Fig
. 2
4.5
Not
use
dN
ot u
sed
Not
use
dIn
serie
s w
ith 4
7K O
hmR
esis
tor
Con
nect
to J
unc-
Lion
of39
Kan
d.0
02M
FD
. Con
d. C
-42.
See
Fig
. 2
Met
er o
n 10
vol
t sca
leT
-8 (
top)
for
zero
on
met
er. S
ee F
ig.
I
NO
TE
I:F
or m
inim
um b
uzz
alw
ays
adju
st 1
-8 a
djus
tmen
t scr
ew w
ith th
e so
und
carr
ier
of a
TV
sta
tion.
PIC
TU
RE
I -F
ALI
GN
ME
NT
Ste
pN
o.C
onne
ct S
igna
lG
ener
ator
toS
igna
l Gen
.F
req.
MC
Con
nect
Sw
eep
Gen
erat
or to
Sw
eep
Gen
.C
hann
elC
onne
ctO
scill
osco
pe to
Con
nect
Vol
tmet
er to
Mis
cell
s C
onne
ctio
nsan
d In
stru
ctio
nsA
djus
t3
Ada
pter
and
con
nect
adap
ter
to p
in #
1 on
Mod
. Tub
e. S
ee F
ig. 7
25.3
Not
use
dN
ot u
sed
Not
use
dIn
ser
ies
with
47K
Ohm
Res
isto
r an
d A
cros
s R
-57,
a56
00 O
hmR
esis
tor.
See
Fig
. 2.
Con
nect
a 3
vol
t bat
tery
. pos
i-tiv
e si
de to
gro
und,
acr
oss
C-5
6.M
eter
on
5 vo
lt sc
ale
and
mai
n -
tain
I vol
t rea
ding
.
T-6
for
max
imum
read
ing.
See
Fig
.1
4A
dapt
er a
nd c
onne
ctad
apte
r to
pin
#1
onM
od. T
ube.
See
Fig
. 7
22.9
Not
use
dN
ot u
sed
Not
use
dIn
serie
s w
ith 4
7K O
hmR
esis
tor
and
Acr
oss
R-5
7,a
5600
Ohm
Res
isto
r.S
ee F
ig. 2
.
Con
nect
a 3
vol
t bat
tery
, pos
i-tiv
e si
de to
gro
und,
acr
oss
C-5
6.M
eter
on
5 vo
lt sc
ale
and
mai
n-fa
inI
volt
read
ing.
T-5
for
max
imum
read
ing.
See
Fig
.I
5A
dapt
er a
ndco
nnec
tad
apte
r to
pin
#1
onM
od. T
ube.
See
Fig
. 7
25.5
Not
use
dN
ot u
sed
Not
use
dIn
ser
ies
with
47K
Ohm
Res
isto
r an
d A
cros
s R
-57,
a56
00 O
hmR
esis
tor.
See
Fig
. 2.
Con
nect
a 3
vol
t bat
tery
, pos
i-fiv
e si
de to
gro
und,
acr
oss
C-5
6.M
eter
on
5 vo
lt sc
ale
and
mai
n -
fain
Ivo
lt re
adin
g.
T-4
for
max
imum
read
ing.
See
Fig
.I
6A
dapt
er a
ndco
nnec
tad
apte
r to
pin
#1
onM
od. T
ube.
See
Fig
. 7
22.9
Not
use
dN
ot u
sed
Not
use
dIn
serie
s w
ith 4
7K O
hmR
esis
tor
and
Acr
oss
R-5
7,a
5600
Ohm
Res
isto
r.S
ee F
ig. 2
.
Con
nect
a 3
vol
t bat
tery
, pos
i-fiv
e si
de to
gro
und,
acr
oss
C-5
6.M
eter
on
5 vc
It sc
ale
and
mai
n -
tam
Ivo
lt re
adin
g.
T-3
for
max
imum
read
ing.
See
Fig
.I
7A
dapt
er a
nd c
onne
ctad
apte
r to
pin
#1
onM
od. T
ube.
See
Fig
. 7
24.1
Not
use
dN
ot u
sed
Not
use
dIn
ser
ies
with
47K
Ohm
Res
isto
r an
d A
cros
s R
-57,
a56
00 O
hmR
esis
tor.
See
Fig
. 2.
Con
nect
a 3
vol
t bat
tery
, pos
i-tiv
e si
de to
gro
und,
acr
oss
C-5
6.M
eter
on
5 vo
lt sc
ale
and
mai
n-ta
inI
volt
read
ing.
T-2
for
max
imum
read
ing.
See
Fig
.I
NO
TE
2:
For
vis
ual c
heck
of I
.F. c
urve
(se
e fig
. 6)
conn
ect S
wee
p G
ener
ator
to a
dapt
er a
nd O
sc
PIC
TU
RE
R -
F O
SC
ILLA
TO
R A
DJU
ST
ME
NT
Ilosc
ope
acro
ss R
-57.
- V
ISU
AL
Ste
pN
o.C
t Sig
nal
Gto
r to
Sig
nal G
en.
Fre
q. M
CC
onne
ct S
wee
pG
ener
ator
toS
wee
p G
en.
Cha
nnel
Con
nect
Osc
illos
cope
toC
tV
oltm
eter
toM
isca
lls
Con
nect
ions
and
Inst
ruct
ions
Adj
ust
8Lo
osel
y co
uple
toS
wee
p G
en. l
eads
55.2
5 se
efig
. 430
0 oh
m a
nt.
term
inal
s2
Acr
oss
R-5
7 di
ode
load
. See
Fig
. 2N
ot u
sed
Cha
nnel
sw
itch
on c
hann
el 2
Adj
ust S
ig. G
en. o
utpu
t for
min
. dis
tort
ion
of s
wee
pcu
rve
#2 tr
imm
er (
fig. 3
) so
that
mar
ker
pip
is 6
DB
(50%
)dow
n fr
om to
p of
curv
e. S
ee F
ig. 5
9Lo
osel
y co
uple
toS
wee
p G
en. l
eads
59.7
5 se
efig
. 430
0 oh
m a
nt.
term
inal
s2
Acr
oss
R-5
7 di
ode
load
. See
Fig
. 2N
ot u
sed
Che
ck p
ip. S
houl
d be
26D
B(9
5%)
dow
n on
opp
osite
side
of c
urve
. See
Fig
. 5
Rep
eat s
teps
4 a
nd 6
if pi
p po
sitio
n is
not
corr
ect.
10R
epea
t Ste
ps 8
and
9 to
Alig
n C
hann
els
3 to
13
Usi
ng C
orre
ct F
requ
ency
Fig
. 4)
and
Osc
illat
or T
rimm
er fo
r E
ach
Cha
nnel
Bei
ng A
ligne
d
NO
TE
3: T
his
trim
mer
(se
e fig
. 3)
is to
be
used
onl
y in
cas
e th
ere
is n
ot e
noug
h ra
nge
toos
cilla
tor
scre
w fr
om c
hann
els
7 to
13.
If th
is s
crew
is to
uche
d, th
en a
ll ch
anne
ls
7 to
13
will
hav
e to
be
rech
ecke
d.If
insu
ffici
ent r
ange
is s
till e
ncou
nter
ed, p
roce
ed a
s ou
tline
d in
Not
e 4.
NO
TE
4: O
scill
ator
Pad
der
adju
stm
ent s
crew
(se
e fig
. 3)
shou
ld b
e us
ed w
hen
ther
e is
not
eno
ugh
rang
eto
any
one
osc
illat
or tr
imm
er.
Adj
ustin
g th
e P
adde
r w
ill
nece
ssita
teth
e re
alig
nmen
t of a
ll th
e O
scill
ator
Trim
mer
s.
Ste
pN
o. II 12 w
PIC
TU
RE
R -
F O
SC
ILLA
TO
R A
DJU
ST
ME
NT
- A
LTE
RN
AT
E (
US
ING
T.V
. ST
AT
ION
TE
ST
PA
TT
ER
N)
Con
nect
Sig
nal
Gen
erat
or to
Not
use
d
Sig
nal G
en. C
onne
ct S
wee
pF
req.
MC
Gen
erat
or to
Not
use
d
Sw
eep
Gen
.F
req.
MC
Con
nect
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cope
toC
t
Vol
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er to
Mis
cell
s C
onne
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nsan
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stru
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djus
t
Not
use
dN
ot u
sed
RE
PE
AT
ST
EP
9 F
OR
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DIN
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FIG
:
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1110
11,
110,
WH
O
FIG
3
FR
ING
E A
RE
A A
DJU
ST
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4010
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01"
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41.4
ell
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rr:1
14;;,
T.4
',Pe
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elat
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at 1
00 4
40.0
1.41
1(0
4.14
FIG
2
TU
RN
Rec
eive
r C
hann
el S
elec
tor
Switc
h to
Cha
nnel
on
whi
chT
V s
tatio
n is
tran
smitt
ing.
AD
JUST
CO
NT
RA
ST C
ON
TR
OL
TO
MA
XIM
UM
con
tras
tpo
sitio
n.T
UR
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HE
PR
OPE
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TO
R T
RIM
ME
R A
DJU
STM
EN
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CR
EW
CO
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TE
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LO
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ER
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EST
PIC
TU
RE
IS
OB
TA
INE
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ITH
SA
TIS
FAC
TO
RY
SO
UN
D.
Tur
n ch
anne
l sw
itch
toch
anne
l nee
ding
alig
nmen
t
004
r0l0
414
44.4
.1 S
t f S
SSSS
'0 "
(.0
1004
./ rO
kr 4
41r
tter
405,
lrf
$104
."I
I 40
0.10
rot .
0 lio
cor
msc
,.
SO
UN
D P
IP30
DB
9D
OW
N
PIC
TU
RE
OV
ER
ALL
RE
SP
ON
SE
CU
RV
EW
ITH
PIC
TU
RE
AN
D S
OU
ND
CA
RR
IER
MA
RK
ER
PIP
S.
Pro
per
osc.
trim
mer
clo
ckw
ise
until
soun
dba
rs a
ppea
r on
patte
rn; t
hen
back
-of
f trim
mer
until
sou
nd b
ars
disa
ppea
r an
dbe
stre
solu
tion
isob
tain
ed.
See
Fig
. 3.
ALI
GN
ME
NT
CU
RV
ES
PIC
TU
RE
PIP
5DB
44%
DO
WN F
IG. 5
PIC
TU
RE
PIP
25.7
5 M
C
SO
UN
D P
IP21
.25
MC
PIC
TU
RE
I. F
. RE
SP
ON
SE
CU
RV
EW
ITH
PIC
TU
RE
AN
D S
OU
ND
CA
RR
IER
MA
RK
ER
PIP
S. FIG
. 6
AD
JUS
TM
EN
T F
OR
ST
AT
ION
BU
ZZ
IF S
TA
TIO
N B
UZ
Zis
exc
essi
ve a
nd is
NO
T D
UE
to "
Con
-tr
ast"
con
trol
bei
ng to
o fa
r ad
vanc
ed in
clo
ckw
ise
dire
ctio
n,ad
just
Dis
crim
inat
or S
econ
dary
adj
ustm
ent s
crew
for
MIN
I-M
UM
buz
z. M
AK
E S
UR
E T
HA
TT
HIS
PO
SIT
ION
IS B
E-
TW
EE
Nth
e tw
o M
AX
IMU
M b
uzz
peak
s th
at w
ill b
e no
ticed
whe
n ad
just
ing
scre
w is
turn
ed to
the
righ
t and
left
of
the
MIN
IMU
M b
uzz
posi
tion.
Thi
s sc
rew
is lo
cate
d on
top
of th
eD
iscr
imin
ator
Coi
l Shi
eld
Can
whi
ch is
mou
nted
bet
wee
n 6A
L5
Soun
d D
etec
tcr
tube
and
6A
U6
Soun
d I.
F. A
mpl
ifie
r tu
be.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
SENTINEL RADIO CORPORATION EVANSTON, ILLINOIS
1O
4,
I
N.60
3
00 worr
L <
6AU61ST I T 11.0. .00 NNr
r
ij
8
G18
6AU6180 r 6.6
6AU6100 our .0 r or.
.3
t65 V
6AU641, I IPP
6A150E7 cc
4
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4
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1:
3344
CD
12AU7v..0 SE
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418711_
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R-66 t.
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6SN7GTKR.z osc ddd
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KATT NOLODOD00-8-
T.'
047 Pr
39400075
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0.7 Nr
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s
6W4GT
.47 or,
Ct8
2k0.00p.r. 56004
Sentin150
6BL7e-.00
- -
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
6GB6910e0
av1_
MODELS 438, 439, 440, 441, 443, 444, IU-438, IU-439, IU-440, IU-441,IU-443, IU-444
64U690040 if
64L5A07101.4.,
.19.00C, Ou "-MAW.2
r------10 Yr I i0
n-s
O 00000
TO Gfolf..1DNifff
6W4GT
6AV6AUDIO DRIVER
6W4GTkccT
6K6GTAUDIO OUTPUT
POR[01 TRANS
-
SOCKET FOR COLOR ADAPTERROSTON viS
Please note that Models 111-438, IS -439. ru-440,IU-444, marked with "SERIES XD" ink stamped on
the chassis are similar to, but different in many res-pects to the models here described. Those marked 2101Dmay use a 17" electrostatic picture tube, 17HP4k. 151
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONSentinel Models 438, 439, 440, 441, 443, 444 (and with prefix continued.
NOTE:
A 6CB6 or 6AG5 or 6BC5is used in the R.F. amplifierand modulator tube sockets.Always use the same typetube for replacement. Intermixing these tubes mayrasult in loss in sensitivitycaused by the differencesin tube capacities detuningthe circuits and making itnecessary to realign the R.F.amplifier and modulatorstages by spreading orsqueezing turns on the coils.
r
6CB6 6AG5 ON 6305R r 6.3.1.01
6112.
ELEC...05,0T.0SNIEL0
6CB6 Or 6AG5 01 6305 604MODULADA 06C 433,7A
25 V. 37:. yur
63
5 NM
C-15
e.ea
POdr
I CRONE1.11
I
it
660 Nurl
IT CHOKE0001.--
el
0 043 r4
43
44 0
OU
6BL7VERTICALAMPLIFIER
0 250
6J505613361011
1B 3GT3.163. 03.4E
117,30ER
DO NOT MEAS.( VOLTAGES ON THIS TUBE
AcreA.fit
NC
AGO
61 xC61306GTHORIZONTAL
OUTUT
6SN7GTHORIZONTALOSGI33 ATOA .GS
DETERMINED ST SETTING OFBRIGHTNESS NO CONTRAST.
NC
155
2I3 0
235
6AU6iar I I ANP
360
6AU6F A.
xco
6AU6F
6AU63
6AL5SYNC SEP
01.0020" 0 c AESTORER
G it 105 " 7
6W4GTRECT0.101
0.95
6AL 5OE FECTOR
ACC
I2AU7
A
6
360
61
6 5
srNE--1TACI
A
A
230
.60
60136VIDEO
70
50:.,5.T5
2E0'
VI:110.9
55
6AU6S03.60
6 5 .00
AC.
25
.AOOn
6CB6 ON 6BC5_ F APJP3rF.EN
604OSCILLATOR
6AG5
6a36 6BC5A100,3 TOR
GAGS
265 6K6GT111/0.0
00, VF
6 A V6ubio
DRIVEN
6A L 51.13
DE T EC FC
A 'AGES PALL vART 71.731 5E61.2 STRENGTHVO,AGE MILE VARY 5.100 CONTRAST SETTINGALWAYS ADJUST DRIVE CONTROL TO OBTAIN THISREADINGAC VOL LTTAGE 6
(01 290 DOS DC AROVE GROUND
.1. PT AD.NGS UN3ESS SPEC.E.E0 ME A3.73WITH NO SIGNAL INPUTmi6H FOLIAGE READING TO BE TAKEN ON,AT SECOND ANODE Of PICTUREL.A. 01.15...C5 NADI 31111.1 A VACUUMTUBEV VOLTMETER
152
-
RADIO FREQUENCY RANGESChannel Channel Picture Carrier Sound CarrierNumber Freq. (Mc) Freq. (Mc) FrItO. ( Mc)
1 44-50 45.25 49.752 54-60 55.25 59.753 60-66 61.25 65.754 66-72 67.25 71.755 76-82 77.25 81.756 82-88 83.25 87.757 174-180 175.25 179.758 180-186 181.25 185.759 186-192 187.25 191.75
10 192-198 193.25 197.7511 198-204 199.25 203.7512 204-210 205.25 209.7513 210-216 211.25 215.75
TO SIGNAL OEN.,0*
FIG. 4
005 NT TO Pm2.0Of 0.100210.
TWEE
T TTO CHASSISCONVERTER511151.0 CUD
...00uuTORTVIE
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONTHE SPARKS - WITHINGTON COMPANY - JACKSON MICHIGAN
SPARTON TELEVISION RECEIVERS
CHASSIS TYPE 2655171 & 26SS17IA
MODELS 5107X, 5I62X & 5163X.
The material below and on the next five pages is almost exactin all respects for the following additional recent Sparton models:
Chassis 25S172, Model 5207AChassis 25SD201A (power supply 2SD201), Models 5191, 5192
Chassis 26SS170D, Models 5107, 5108Chassis 26SD171, Models 5165X, 5166X, 5175X, 5178X
Chassis 26SD172, 26SD172A, Models 5265, 5267, 5268
Chassis 26SS172, 26SS172A, Models 5207, 5208, 5262, 5263.
Some of the differences are in the use of a 12AT7 (V16) inplace of 12AU7, a horizontal width coil instead of a control,additional linearity coil, dual damper tubes in sets with largersize picture tubes, and a built-in dipole. In general, all thismaterial can be used as an aid in repairing these additional sets.
6AL5
14C
B
6AU6
i4S-
SS
-2 6AU6.,...,.7
0
0
L145AVC
6AL5 .-..
32
ITPdc
5Y3OT 0 5U40V25 V26
6A H6 6AU6 V2330.C .4S 0 ° 65N701
6AT66A35
APT & 10"g,riu°47.SEE G)
13,0c6J6
R. F TUNER
IZAU7
140
l0400
4.0-4 S
V 2 2613060T
5 s
VISO
6W4OT0
VI?65N7OT
.A .C. 5
140
-45
VOLTAGE CRUST AND ALIGNSLENT TEST POINTS
FIG. 2
.40
V2168060TC en,
v lb6V66T
6AL5 IA=
143
340
0 30
ZS
1174 C
U.
Co4-).4-4
- pi a) o)of
crI0 PI 2 ultio
4.3C 00,H,-1 4c0
,d_O o 0 I -I
o"-4 R.+3o.0F.4 F4 OP 4-1
43) 0 t> 4.30 4-1 4-3 0
0 F -I
03 4)W00 0
4-) F-4 d riO 0 r -I 03
CO cH O r21 43
rol 0CD 0 4-) -1-) -P 0
;-4 r -s
430 4T)t r-ira 03°
o 000O. 0
4 ,0 4-3t04.) r-i
r-1 CS rd 0 0H C.) E -I
It It-P 0 0 0G6 r-1 F4 0 co GO
r-4 fr 0 00 0004-4
1:0 4-3 0 biD4e4sTi
Ho 4.34 d-) O 00
alt 4-1 0 b0
Po) 4-F1 rAcci
N-1,4° 4i 1400 4)24rIg cul?tZ 153
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
SPARTON TELEVISION SCHEMATIC DIAGRAM
DIPOLE ANT.
/ /
A CSWITCH
CHASSIS TYPE 2655171 & 2655171A STANDARD
USED IN MODELS 5107X, 5162X & 5163X.
TuRRET SWITCH SETTINGSELECTS COILS FOR CHANNEL
VI6AG5-t
F AMP
1
T-12.POWERTRANS
7
100C5
R. F. TUNER
I 116K
]-9 I 20
I I -I
I 12
2R21,
20C
CT5-3
V26J6
05C a m.KER
RED
C.,
IX22 5MC.
C.3 L23
WHITE
15ARE
VII6A U6
1ST SOUND I F
V3loo 6CB6R'5 1ST I F. AMP
C
415
V255Y3 GT
L V RECT.
ISO
L-29
POWER SUPPLY
V1.4000(75
VC). -PVC2540. 2300
V28SR5U4G 8135
MEDV. RECT.
L- 31
250 -5w
L-542 Sil0l
C.I20e CI20, Cele40e/D - 40.6 -T40..004750 4750 A750
130VAMP
T)VCTTTS: V I9 )BANS
NTERLOC K
c',41, -a
NITS
154
120 IAA
1105*330 VOLTS
331. 14'
I I-I I
II
II
II
II
III
I A024 7M
VIDEO 1.FL_
Rea220
ISOVOLT5
330N3LTS
I VI7B16 SN7G
PHT
ASE'SPUTTER ago MICA
VERT. DEFLECTIO
V246AL 5
HORIZ. PHASE DET.SNC4
113
IVI Ve VIO VII 012 013 014 VII VII $.7 Vie V t $ 022 v2 024 I
:(\ r :-. 3p4 n re r vr , n .t.N. r\' 4.( \ ' '.n. ..n./7 7 . . T rGin .5K -
HEATER HOOKUP DIAGRAM calVOLT
C 2
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
7-6
T60
"1459non
SOUND 1 FVI 2
6AU62ND SOUND I F
1
I 3
63
2ND I.AMP6BA6V4
3RD I. F. AMPF.
6 BA 6
623
V5
622100 2 Do
C3µSK
31 4
62400
2424 25Mc
654
V136 AL 5
RATIO DET.
ROO 4000476
Ca6036,1 61OR
V66C B 6
4TH I.F.AMP
zo
.1. So,
C4056
6623106VOLUME
RI
L-,152565.
VI46A T6
AUDIO AMP
V7 ?-a-o,.I6AL5 _L
VIDEO Mt
C 4.02NA6000
VI56V6GT
66C74 PWR. AMP.
R70Ctsp 340
20Na 625v.
T-6OUTPUT TRANS.
GREEN
III r L LOw
SPEAKERPC61000-12 10
PC63000-33 3
667 Roe cl A R7
6.6 M2 706
4505.0so.a 21-5
4 51.K
11 _IL-2) 1
1107C4;
14645
1W1
R!k54 L-20220 < ,,Y3.5,5
2001/47I 600v
V96AU6 ( -
A G C , --
:gi 441334476
--VT15I 2 AU7SYNC STRIPPER, AMPI CLIPPER
9
1406 47.1-
SYSTEM
MICA5 16,2±4
-las
7004 C1090460
666 - 166
411 1a %I: 4"-Tcav
Tx,c,R9
VENT ,67L0
EL LOW
VILAGSN 7GT
KED VERT 05,: & DISC.TUBE
T-.0FIELD
OSC TRANS
V2365 N7GT
HoRiz.osc. i DISCHARGE
1312466
c ot390 I
6123 f 1006
TANK501462.05EL-24
1W226111127
C1103 965.c6
6122SOKnoRaHOLD
- 1 4505
0400vCI
V 2 26 BQ6GT
HORIZ. OUTPUT
HORIZ. DEFL. SYSTEM
RuaOoIw
611310w0a
6931306 C54
r551456
NERD.SIZE
V216 BQ 63 I"
MORO. OUTPUT
R 112100IW
TOP CAP
5 C1r,
V96AH6
VIDEO AMP
4005.
C90
L-22
1134 R312711 256
CONTRAST
VIB6V6GT
VERT OUTPUT
111001.06IW
Riot
v 13.
MORI OUTPUTTRANS
+330V 0
RIOSPAW.3.3A.WIRE
1M -1W4106
WOUND ..--6,5W44- .4.....CIO° 4.1410.- 500 TO 2.0 4/4302
/OK
A400
4204
VIOI7BP4A
PICTURE TUBE
Se
R475.IK
VERT. OUTPUT TRANS.
71-
- 1102
9
540
+14010011.73
12 KV2440 AMOS('
R411lOOK
511110247.1.115
0+:40,41.1s
GREEN io
OS L -20A
vs, YOKECOIL
YELLOW RITE C)
V20IB 3 GTN.V. RECT.
TOP CAP
2065
193112 CENTERING
15609.6
CD
CD
L-268NOR I Z.YOKECOIL
0
155
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONSPARTON TELEVISION RECEIVERS CHASSIS TYPE 2655171 & 26SSI71A, Continued
156
0I B3GT
6B06GT
T-13
6110607"
411106W4GT
0
6V6GT
FILT.C75
CO ND
CO6V6GT
6AL 5 65N7GT
5U 40
65N7GT
FILT091
COND
O
O
O
O
V25
5Y3GT
® L-22
V6 V9
SAWS 6AH6
I2 AU 7
FILTC 120CO ND
FILTCI 19
COND
CRAM= DIAGRAM troy VISA)
FIG 3
T-12
6AU6
01-6
411D
L-27
6AU6
T-7
(1)PRI.
0&ALS
064115
&ALS
L-17
6CB6
OL -I5
6BA6 VS
OL -I4
6BA6
0L-13
6C Be
L -I20
L-622.5MC
6A0 5R F AMP
0 i6J6
osc a Mix(
®
ALIGNMENT PROCEDURETEST EQUIPMENT SET UP: A certain amount of experimentation must be employed to securea stable test set up before alignment or service of the receiver is attempted. It isrecommended that the top of the test bench be covered with a sheet of aluminum toinsure good grounds between the various pieces of test equipment and the receiverchassis. In general all test signal input leads should be kept away from output leadsas much as possible.
SOUND TRAP ALIGNMENT: FIRST, Connect the R.F. signal generator to the grid of V-2by means of the I.F. inpa7gapter as shown in Figure 6.
R.F. Generator 50'1 Coax.
Output40
500 UMF
100K
1
To grid of V2Point (A) Fig. 2
To chassis ground
3 Volt biasbattery
Figure 6 I.F. Input Adapter
SECOND: Set the R.F. tuner to Channel #13.
THIRD: Connect a 4.5 volt bias battery between the A.G.C. buss (Point F. Fig. 2) andchassis ground so that the voltage on the A.G.C. buss is -4.5 volts in respect tothe chassis.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
SPARTON TELEVISION RECEIVERS CHASSIS TYPE 26S S. I 7 I & 26 SS17IA
ALIGNMENT PROCEDURE (CONT'D)
FOURTH: Connect the electronic voltmeter across the picture detector load resistorR37, Point B, Fig. 2 and set the voltmeter on the low D.C. volt scale.
FIFTH: Set the R.F. signal generator to the frequency shown below and tune thespecified adjustment for minimum indication on the voltmeter. It isadvisable to check the output off'the generator with the crystal calibratorto make certain that it is exactly on frequency.
21.75 Mc. L12 (Top of chassis as shown inFigure 3)
PICTURE I.F. ALIGNMENT: FIRST: Connect the R.F. Signal generator, voltmeter andbias battery to the receiver as described in steps 1, 2, 3 and 4 of the sound trap
alignment instructions.
SECOND: Set the signal generator to each of the following frequencies and peak thespecified adjustments for maximum indication of the voltmeter.
tuner as shown in Fig. 3)chassis as shown in Fig. 3)chassis as shown in Fig. 3)chassis as shown in Fig. 3)Chassis as shown in Fig. 3)
SOUND I.F. ALIGNMENT: FIRST: Connect the R.F. signal generator to Point B, Fig. 2
SECOND: Set the signal generator accurately to 4.5 Mc. This is very importantbecause the picture and sound carriers sent out from the television stations are
exactly 4.5 Mc. apart.
THIRD: Connect the electronic voltmeter across C71 from Point D to ground as
shown in Fig. 2Set the voltmeter on the 10 volt scale.
FOURTH: Peak the following coils for maximum reading on the voltmeter.
L 27 Top of chassis as shown in Fig. 3.T 6 Top of chassis as shown in Fig. 3.T 7 (Pri. Ratio Det)Top of chassis as shown in Fig. 3.
RATIO DETECTOR TRANSFORMER ALIGNMENT: FIRST: Connect the R.F. signal generator
to the receiver as described in Step 1 of the Sound I.F. Alignment instructions.
SECOND: Connect the electronic voltmeter from Point E, Fig. 2 to ground.
Set the voltmeter on the lowest DC scale.
22.5 Mc. L6 (Top of25.25 Mc. L13 (Top of24.25 Mc. L14 (Top of23.25 Mc. L15 (Top of26.0 Mc. L17 (Top of
THIRD: Set the signal generator output to 4.5 Mc. Adjust the secondary of T7.Notice that it is possible to
produce a positive or negative voltage indication on the meter by varying this
adjustment. As the voltage swings from positive to negative, adjust T7 for
zero output as indicated by the voltmeter. This point is called zero ratio
detector output and indicates correct alignment of T7 transformer. If the secondary
of T7 is found to be way out of alignment it will be necessary to re -peak the
primary as described in the proceeding section on sound I.F. alignment.
4.5 MC. TRAP ALIGNMENT FIRST: Connect the R.F. signal generator as described
in Step 1 of the sound I.F. alignment.
SECOND: Connect the electronic voltmeter from the cathode of the picture tube
to ground (Point C Fig. 2)The voltmeter must be capable of giving a reading at 4.5 Mc. at approximately
1 to 2 volts.
THIRD: Peak L22 (Top of chassis as shown in Fig. 3) for minimum output
on
PICTURE I.F. TOUCH UP: Connect the R.F. Sweep generator output to the grid of
7-2 by means of the I.F. input adapter shown in Figure 6.
SECOND: Apply bias to A.G.C. line as described in Step 3 of sound trap alignment.
Set R.F. selector to Channel #13. 157
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONSP ART ON TELEVISION RE C IVE RS CHASSIS TYPE 2 6 :5 :3 I 7 1 & 2 6 S :3 I 7 A
ALIGNMENT PROCEDURE (CONT'D)THIRD: Connect the oscilloscope across the picture detector load resistor R37(Point B Fig. 2) by means of the shielded cable and the filter system shownin Figure 7.
158
Oscilloscope 47K
I r - - - - - -Shielded Cable
I
I
50 uuf.
To Junction orR37 and L19
To ground
Figure 7 FILTER SYSTEM FOR SCOPE CONNECTION
FOURTH: Set the R.F. sweep generator so that it sweeps from approximately 20 to 30 Mc.
FIFTH: Adjust the oscilloscope so that the swept I.F. response is visible on thecathode-ray tube screen.
SIXTH: Loosely couple the output of the R.F. signal generator to the grid of V-2so that the marker signals of proper frequency can be mixed in with the R.F.sweep signal.
SEVENTH: Observe the band width, relative position of the picture carrier, and flatnessof the overall I.F. response curve. If necessary slightly vary the tuning ofthe picture I.F. coils L6, L13, L14, L15, L17 until the picture I.F.response shown in Figure 8 is obtained. The solid curve in Figure 8 depictsthe ideal I.F. response while the dotted curves shown permissable variations.
Figure 8 IDEAL I.F. RESPONSE WITH PERMISSABLE VARIATIONS
The picture I.F. carrier should appear approximately half way down the I.F. responsecurve as shown in Figure 8. Variation in the pix carrier position should not exceed10% from the half way point.
PICTURE I.F. SENSITIVITY CHECK: FIRST: Connect the R.F. signal generator to thereceiver as specified in Steps 1 Tu77-7-of the sound trap alignment instructions.(Whenmaking sensitivity checks no bias battery is connected to the A.G.C. buss.)
SECOND: Connect the electronic voltmeter across the picture detector load resistorR37 Point A, Fig. 2 and set the meter on the low D.C. volts scale.
THIRD: Set the generator output frequency at approximately 23 Mc. Adjust thegenerator output until the voltmeter reads approximately 1.0 volt.Record the R.F. signal input in microvolts. Repeat the procedure withthe generator output frequency set at 24.2 and 25.4 Mc. In all casesthe T.F. input voltage should be 100 Microvolts or less. The sensitivityat the I.F. picture carrier 26.25 Mc. should be approximately half of theI.F. Sensitivity between 24.2 Mc. (Maximum of 100 microvolts.)If the generator output is not calibrated in microvolts, comparativesensitivity measurements can be made by using another receiver that isknown to be in good operating condition as a standard. This applies toall sensitivity measurements and good results can be obtained ifsufficient care is used.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
STEWART-ET-WARDER
MODELS 9202-C, 9202 -DA, 9202-DB,9202-DD,9202-E & 9202-F
The service material below and on the next seven pages is exact forthe Stewart -Warner models listed above. Models 9200-A and 9200 -FA arebasically the same as these models and represent early versions of this
series. Model 9203-A is a combination model, but the TV section isalmost identical to the sets covered in this manual. Model 9204-A is
a straight TV set using a 20" picture tube, with its circuit practicallyidentical to the models covered in these notes. This set has an addi-tional 500 mmfd. condenser in the HV supply and use an electro-magnetic
instead of PM focus assembly.
Information on alignment of the sound and I.F. channels is presented
on pages 160-162. For convenience of printing, the circuit diagram andrelated information are divided into sections and are printed on pages
163 to 166. Such separation is not to be taken to mean that the actual
circuits are divided physically in this manner.
TUBE LOCATIONS
Model 9202-C(Mahogany)
Mod el 9202-F(Blonde)
Model 9202-E
Model 9202 -DA(Mahogany Base-Green Top)
Model 9202-DB(Blonde Base-Beige Top)
Model 9202 -DD
(Mahogany)
CHANNELSELECTOR
ATELEVISION
FINETUNING
111U1 -1a
54
61G5 on6105 et 6CI6
..f SLIP
VERT.HOLD
VERTICALLINEARITY
611
tin6166 SERI 11.001.0 (SC.
RFT`KINK OUTFIT
VI
6AU6EN !UR/.
66
FUSEI AMP. 250 VOLT
LOCATED ONUNDERSIDEOF CHASSIS
Ma
EIGHT HOLD BRIGHTNESS
VT1
MIN*MEM TM
CENTERINOCONTROL ARM
VII
VOLUMEOFF -ON
*A -CONTRAST
'IA$}mu LI. r. nLKIIEE
(1114)MMTUA
RCTRII
FUSEW I/ AMP. 250 VOLT
LOCATED ON--.DAU UNDERSIDE
NOW. oi.C. OF CHASSISTIME DETECTOR m
(I") ()MINIM .2120111TEL
SCUSIIKMI
MM 1 WMSYNC CLIPPERMUSPLITTE IIYPMI
1.104qDRIVE
WIDTHLOCATED IN
H. V. COMPARTMENT
REAR OF CHASSIS 199
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONStewart -Warner Models 9202-C, 9202 -DA, etc., continued
SOUND CHANNEL ALIGNMENT PROCEDURE1. Short antenna terminals together with a jumper wire.
2. Set receiver Channel Selector to any inactive television channel andcontrast control to its maximum counter -clockwise position; othercontrols may be left at any desired setting.
3. Na special aligning tool is required to adjust the cores in the SoundIF and discriminator transformers. The blade of a small screwdriverwill fit the slot in these cores, however, the screwdriver should beof a non-metallic or insulated type to prevent detuning when insertedin the transformer con.
STANDARD SIGNALGENERATOR
VTVMCONNECTIONS
MISCELLANEOUSINSTRUCTIONS
TRIMMEROR SLUG
TYPE OF ADJUSTMENTAND OUTPUT INDICATIONCONNEC..
TIONS FREQUENCY
Connect asshown in Fig. 1.
4.5 MC.unmodulated
IMPORTANTThis signal mustbe accurate with-in 1/4 of 1% of4 . 5 Mc. Ch ac kgenerator calibre-tion against acrystal controlledsignal source by"zero beating''(heterodyning)with harmonicsof the crystal fre-quency.
Connect as shown in.Fig 2.
I Set Contrast control to its maximumclockwise position.
2. A special detector must be utilized whenaligning the 4.5 Mc. Sound Trap Coil.This unit can be constructed in ac-cordance with the information con-tained in the circuit shown below. Ifa VTVM containing a high frequencyA.C. probe is avaitable, this probe canbe utilized in place of the crystal de-lector shoWn in Fig. 2.
3. During this adjustment only, removeone of the three 6AU6 IF amplifiertubes (V6, V7 or VIP. This will preventnoise in the RF stages from effectingthe voltage reading while adjusting thesound trap.
1
4.5 MC SoundTrap
Adjust for minimum readin aon VTVM.
Connect as shown inFig. 3.
A "swishing" sound may be heard in thespeaker during Sound Channel Alignment.This spurious oscillation is caused by hori-zontal sweep voltage being picked up inthe audio system thru stray coupling ofinstrument leads; it should be disregardedas it will have no effect on alignment ofthe sound channel.
#2DisSeconcrimindaryator
Adjust for maximum readingon VTVM.
.
#3Discriminator
Primary
Adjust for maximum readingon VTVM.
#4Sound IF
Transformer
Adjust for maximum readingon VTVM.
Same asabove.
Same asabove.
Connect as shown inFig. 4.
To obtain zero balance of the discriminatorcircuit, two 68,000 ohm resistors will berequired. These resistors must be matchedso that their respective resistances donot differ by more than 1%-the accu-racy of the total resistance is not critical.Connect the two resistors in series frompin 2 of the 6T8 tube to chassis groundas shown in Fig. 4.
#2Discriminator
Secondary
Note that as slug #2 is rotated,a point will be found where thevoltmeter will swing rather sharp -ly from a positive to a negativeieacling or vice versa. The cor-reel setting of slug #2 is obtainedwhen the meter reads zero asthe slug is moved thru this point.
REDUCTION OF INTERCARRIER BUZZSlight "dynamic" unbalance of the discriminator secondary con em-phasize intercarrier buzz due to incomplete amplitude modulation rejec-tion. Therefore it is vitally important to obtain an accurate setting ofthe discriminator secondary slug under actual reception conditions.Disconnect all instruments (be sure that I.F. tube removed for the adjust.ment of Sound Trap has been replaced) and then connect an antenna tothe receiver to obtain program reception from a local station. If inter -carrier buzz is prominent, a slight readjustment of the discriminatorsecondary slug (#2) should be made to obtain the "dip" point for thebuzzing sound. Note that program sound will be clear and free fromdistortion at this point. Buzz should now be at an acceptable minimumif station transmission is not at fault.
SOUNDDISCRIMINATOR
SECONDARYAdjust this slug
for minimumintercarrier buzz
LOCATION OFDISCRIMINATOR
SECONDARYSLUG
160 AFAR OF CHASSIS
ON -OFF a VOLUME
CONTRAST
100MMF.
CIRCUIT DIAGRAM FORCRYSTAL DETECTOR
47K
INSTRUMENT CONNECTIONSFOR
SOUND CHANNEL ALIGNMENT
STANDARD
SIGNAL GEN. iAC7
SET TO 4.5 MC. 811E0 AMP.
NO MODULATION. ;25
(PURE R.F.)0.1
Gore
'26
no.GROUND TO
RECEIVER CHASSIS
27B7110,.
FIG. 1CONTRAST
Generator Connectionsfor Sound Channel and 4.5 Mc. Sound Trap
Alignment
USE 10,000 OHMISOLATING
RESISTOR INSERIES WITH
METER PROBE.
GROUND TORECEIVER CHASSIS
FIG. 3VTVM Connections
for Sound IF Alignment
STI$011111 DISCIIM -500 AMP
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Stewart -Warner Models 9202-C, etc.(Continued)
136
135
INSTRUMENT CONNECTIONSFOR
SOUND CHANNEL ALIGNMENT
'36
CRYSTALDETECTOR
GROUND TO
nI RECEIVER
PICTURE THECHASSIS
EL
V. T.V. M.
IGROUND TO
RECEIVER CHASSIS
FIG. 2Crystal Detector and VTVM Connections
for 4.5 Mc. Sound TrapAlignment
It
iTI10111 NUM.-SOWN MAP.
20
FIG. 4VTVM Connections
for Sound DiscriminatorAlignment
71 68K
USE 10,000 OHMISOLATING
RESISTOR INSERIES WITH
METER PROBE.
V.T.V.M.
STANDARD INSTRUMENT CONNECTIONSSIGNAL GEN. FOR
(SUPPLIES
MARKER SIGNAL(T IF CHANNEL ALIGNMENTGROUND TO
TUNER FRAME
SWEEP
GENERATOR
GROUND TOTUNER FRAME TERMINAL FOR I.? SWITCH CONTACT
THIS CORRESPONDS TO POINT .0. ON
CIRCUIT DIAGRAM.
FIG. 5Generator Connections
for IF Channel Alignment
MIXER GRIDTRIMMER
R.F. AMP.GRID TRIMMER
25.9MC.
USE 10,000 OHM ISOLATINGRESISTOR IN SERIES WITH
METER AND OSCILLOSCOPE PROBES.
116
6
23
PLACE 1000 MMFD. CONDENSERACROSS 'SCOPE TERMINALS
AS AN R.F. FILTER.
V.T.V.M.
GROUND TORECEIVER CHASSIS
GROUND TORECEIVER CHASSIS
FIG. 6VTVM and Oscilloscope Connections
for IF Channel Alignment
11
OSCILLATORTRIMMER
R.F. AMP.PLATE TRIMMER
23.5MC.
(i) (i)23.5 25.9MC. MC.
4.5MC.
SOUNDTRAP
4.5MC.
SOUNDDISCRIMINATOR
SECONDARY4.5 MC.
OO
WIDTH CONTROLlocatod In hien vol-tate compartment.
FIG. 14TOP VIEW OF CHASSIS 161
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Stewart -Warner Models 9202-C, 9202 -DA, etc., continued
IF CHANNEL ALIGNMENT PROCEDURE1. A special aligning tool designed to fit the sterns on adjustable cores of
the IF and Trap coils (see points 5, 6, 7 and 8 in Fig. 14) is availableand may be obtained front Stewart -Warner by requesting IF AlignmentTool r.:-507479.
2. Turn receiver Channel Selector to television channel #12 and shortantenna terminals together with a jumper wire.
3 Connect a 3 volt battery to the receiver AGC system so that negativeterminal of battery connects to the AGC line and positive terminal ofbattery connects to receiver chassis
4. If the IF channel is badly misaligned and two or more immediately ad-joining IF stages are tuned to the same frequency, oscillation may occur.
Such oscillation shows up as on excessive voltage across the video de-tector load, symbol 122, and is indicated by the VTVM that is connectedto this point during alignment. It should be noted that voltage due to IFoscillation is unaffected by strength of signal from the generator.
Where IF oscillation is encountered, it is generally possible to correctthe condition by detuning the IF coils in different directions. If thatdoes not have the desired effect, increase fixed bias on AGC line by usinga 41/2 volt battery instead of the 3 volt battery referred to in instruction#3 After stopping the oscillation in this manner it will then be possibleto align all IF stages using the following procedure, however, the AGCbias battery must be changed back to 3 volts when using the oscillo-scope to observe bond pass characteristics. Once all stages have beenaligned using the 41/2 volt bias, the IF channel should be stable withreduced bias.
STANDAGEN
RD SIGNALERATOR SWEEP GENERATOR
CONNEC-TIONS FREQUENCY
CON NEC-TIONS FREQ.
VTVMCONNECTIONS
OSCILLOSCOPECONNECTIONS
MISCELLANEOUSINSTRUCTIONS
TRIMMEROR SLUG
TYPE OF ADJUST-MENT AND OUTPUT
INDICATION
Connect asshown inFig. 5.
23.5 MC.
Use a 330Mmf. isolat-ing conden-
r and c onec t as
shown inFig. 5 butkeep powerswitchturned offduring thisstep.
Connect as shownin Fig. 6. Not used.
#5Converter
platecoil
Adjust for maximumreading on VTVM.
#62nd I.F.
Adjust for maximumreading on VTVM.
Same asabove. 25.9 MC. Same as
above.Same asabove. Not used.
#71st I.F.
Adjust for maximumreading on VTVM.
#83rd I.F.
Adjust for maximumreading on VTVM.
Same asabove. 26.75 MC.
With connec-tions madeas shown inFig. 5, turnon this gen-erator andset controlsfor operationas specifiedin next col -
25 MC.Sweeping
5 Mc.
Same asabove.
Connect asshown in Fig. 6
IMPORTANT:
1 Adjust outputattenuator onsweep generatorso that readingon.VTVM is ap-proximately one-half volt.
2. Set attenuatoron standard sig-nal generator sothat marker sig-nal does not dis-tort the patternon the oscillo-scope.
3. Be sure that a3 volt batteryis connected toAGC line asspecified in in-struction #3 atthe head of thischart. Do not usea battery of anyother voltage.
The IF band pass characteristic nowdisplayed o the 'scope should becompared with the curve shown inFig. 7. If top of curve is not prop-erly shaped, make a slight readjust-ment of slug #6. Should that adjust-ment fail to yield the desired result,then note whether the curve has apeak on the high or low frequencyside. Slugs #7 and #8 control highfrequency response (25.9 Mc.) andslugs #5 and #6 affect the low fre-quency response (23.5 Mc.); by mak-ing a small change in the settings ofthe high or low frequency slugs, itwill be possible to obtain correct bandpo-s curve.
FREQUENCY242 24 26 28
20S-22.25
40
60
BO-
100-X FIG. 7
35%
PIX26.75
I.F.RESPONSE
CURVE
The 26.75 Mc. picture IF carrier mark-er should now appear at the 35%amplitude position on side of thebond pass characteristic (see Fig. 7).If position of the marker appears toohigh or too low, slight readjustmentof slugs #7 and/or 8 is required.
Some as 22.25 MC.so-,above. above.s
162Same asabove.
Same asabove.
Same asabove.
Same asabove.
Adjust the vertical gain control onthe 'scope in order to magnify thesound portion of the response curve.The 22,25 Mc. sound IF carrier mark-er should appear at the position indi-cated in Fig. 7. If the position of thesound marker is incorrect, readjust-ment of slugs #5 and'or 6 is required.
Receivers incorporating productionchanges explained at right, areidentified by coding stamped onrear surface of chassis. Codingconsists of the word SERIES andletter A or B.
The tuner assembly diagram isshown on this pagei and it con-nects -to the main circuit shownon the double page spread 164-165, and continued on page 166.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONStewart -Warner Models 9202-C, etc. LETTER INCLUDED
(Continued) IN DESIGNATIONFOLLOWING THEWORD "SERIES"
CHANGE INCORPORATEDIN CHASSIS
WHITE
0
GREEN-WHITE
A\RED-WHITE
BBLACK-WHITE
D
BOTTOM VIEW OF CHASSIS SHOWINGCONNECTIONS TO RF TUNER UNIT
Lettered terminals in illustrations correspond tosimilarly lettered terminals on the circuit diagram.
42OUR,- IN ANTENNA
UNCODED INITIAL PRODUCTION
"A" The following changes were incorporated to provide for anew TV sound discriminator transformer which improves AMrejection.
I. Sound Discriminator Transformer 20 was changed from507321 to 509706. Terminal connections ore the samefor both transformers.
2. Condenser 18 (8 Mmfd.) was removed. It formerly waswired externally from pin 1 to pin 2 of Sound Dis.criminator Transformer 20, part 507321.
3. Condenser 208 (10 Mmfd.) was added. It is an integralpart of Sound Discriminator Transformer 20, part509706 and replaces Condenser B, removed in step 2.
4. Condenser 20A across secondary of Sound Discrimina-tor Transformer 20 was changed from 110 Mmfd. to95 Mmfd.
5. Condenser 35 in plate circuit of tube V2 (Sound Dis-criminator) was changed from 4 Mfd. to 10 Mfd.
"B"
44Ir 1
cunisann," LLLL ..,
05-051 00001.(000010cail
508890 R.F. TUNER ASSEMBLY
62
1'44Z6CHHNFLSn. V S 44; 4:NVE R
3 TO 12 ARE 4414/ HU SAME MANNER
AS SHOWN HERE. S SHOW HERE
55 73r00000000
ANTTERMINALS
6A85 011 61105
oA 6C86A.F. AMP.
rmese rusts coma IN some cilssss,
00004
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The following changes were incorporated to improve opera.tion of horizontal multivibrator and to reduce the possibilityof fuse 191 blowing out during the worm -up period.
1. Condenser 174 in plate circuit of tube V14 (HorizontalScanning Multivibrotor) was changed from 470 Mmfd.to 390 Mmfd.
2. Resistor 177 in plate circuit of tube V14 (HorizontalScanning Multivibrotor) was changed from 330,000Ohms to 680,000 Ohms.
3. Resistor 235 in plate circuit of tube V14 (HorizontalScanning Multivibrator) was changed from 3900 Ohmsto 3300 Ohms.
4. Resistor 248 (270,000 Ohms) was added between pin5 of tube V14 (Horizontal scanning Multivibrator) and315 volt supply.
The following change was incorporated to allow vertical holdcontrol to operate in the center of -its range..
1. Resistor 223 in grid circuit of V19A (Vertical BlockingOscillator) was changed from 1.8 Meg. to 2 Meg.
The following changes were incorporated to reduce illumina-tion of picture tube with minimum setting of the BrightnessControl.
1. Resistor 140 (15,000 Ohms) was removed from end ofBrightness Control and chassis ground.
2. Resistor 137 in brightness circuit was changed from47,000 Ohms to 15,000 Ohms.
85
97
MME.
186Ar.
aR
90ISOmi47.
(--0 A
B
C_J
THESE POINTSCONNECT TO
IDENTICALLYLABELLEDPOINTS ATINPUT TO
Ist I.F. STAGE
163
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
E \X T,\ R T -fir, R N R lit If. IR.IANA AN
21S11. AMP.SASS
3411.1111.
Stewart -Warner
Models 9202-C, etc.2391.2
hemri
For printing convenienceparts of this circuitare shown on page 163and page 166. Wiresmarked A, B, and C,connect to tuner onpage 163; while wiresV, X, Y, and Z, con-nect to sound sectionand power supply shownon page 166.
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All oscillograms taken with'scopeground to chassis; normal stationreception. Number below * or **specifies 'scope HOR. FREQ. setting.*-observed with 'scope of limitedfrequency response. **-observedwith 'scope with vert. frequencyresponse flat 120% up to 2 MC.
MOST -OFTEN -NEEDED 1952
I
12040
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100
1250.1
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YTo page 166.2
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SERVICING INFORMATIONo CoC 6s6E.IB
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166
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41
Pu
BLU
E
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208A
2055
V - Connects to V of
qcircuit on page 164.
511
121)
1,1.
40.
The separation of schematic circuit sections
from pages 164-165 to this page, is for printing
convenience only, and does not imply that the
actual circuits are so separated in the physical
sense.
Letter reference V, X, Y, and Z, connect
to corresponding letter -points shown in the
schematic on pages 164-165.
5214
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
STROMBERG-CARLSON 321 SERIESAlignment on sets of Series 321 is given below. The schematic diagramappears on the next two pages. The page after that has additional ser-vice material including illustrations of the trimmer positions. Shouldyou be called upon to service sets of the 317 Series, you will findconsiderable similarity to the 321, and this material will prove ofaid. The 317 Series use 17BP4 Kinescope, V-10 video amplifier is atype 6AG7, and V-20 horizontal amplifier is a type 6AU5-GT. There areother differences as well. The 317 -RPM is a combination and includesAM radio and phono with additional circuits and selector switch.
Signal Generator Oscilloscope or VTVMConnection Connection Adjustments and Notes
1 Output of sweep Input of scope to grid of 1. Adjust the bottom slug of 1-3,Quadruple generator to grid of video amplifier, pin 2 of 1st IF Transformer for low in -Alignment 1st IF tube, pin 1 of V-9, 12AU7 thru 47K termediate frequency. (23.7
V-5, 6BA6 thru 100 ohm isolating resistor. mc. appox).MMF isolating re- 2. Adjust the bottom slug of T-4,sistor. 2nd IF Transformer for low fre-
quency. (23.0 mc. approx).3. Adjust the bottom slug of 1-5, --1
The output from the sweep generator should besuch 3rd IF transformer for high fre- 26.4 / 2 2.7
that with a DC bias of approximately -3.0 volts quency. (26.0 mc. appox). 1
I
applied to the AGC line (across C-160) the output 4. Adjust the bottom slug of T-6,high iforn- _...on the oscilloscope will be 2 volts peak to peak. 4th IF transformer f
This level of output 2 volts peak to peak from thetermediate frequency. (25.3 279 Z..9mc. appox).
video detector should be maintained throughout the 5. Maintaining the above relativealignment procedure by readjusting the bias and/or frequency positions of the in -
the input from the sweep generator, and leaving the dividual stages, adjust the slugs
gain of the oscilloscope fixed. The contrast control to produce a curve as shownwith the 22.7 mc. and 26.4 mc.
should be set at maximum contrast position, markers at 70% response.
2 Same as Step l(1 Same as Step !;t1 1. Adjust the top slug of T-4 forSound Using 21.9 mc. minimum response at 21.9 mc.Traps marker. 2. Adjust the top slug of T-3 for
curve shown. RJR
971 REA,:TAN'TRAP
3 Same as Step 1;1 Same as Step #1. 1. Adjust the top slug of 1-5 forAdjacent using 27.9 mc. minimum response at 27.9 mc.'Sound marker. 2. Repeat Step 1 (QuadrupleTrap alignment) to reproduce the ,,, i
curve as shown.27.9
4 Couple the output of Same as Step $1. 1. Adjust L-8 on tuner assemblyDouble- the sweep generator and 1-2 for curve as shown in
26.4 22 7Tuned into the converter Fig. 6 for maximum gain, main- d
Stage plate by means of taining the 22.7 mc. and 26.4 / \\._
Alignment the split tube shield. mc. markers at 50% response.
5 Connect an unmodu- Connect 2-100K resistors 1. Adjust 1-10, 1-11, and bottomSound IF lated 4.5 mc. signal in series from plate of slug of T-8 for maximum re -Alignment to the grid of the ratio detector pin 2 of sponse.
1st sound IF amp. V-13, 618 to ground.pin 4 of V-9, 12AU7. Connect VTVM from junc-
tion of the 2-100K re-sistors to ground.
6 Same as Step $(5. Reconnect the VTVM from 1. Adjust the secondary (topRatio the junction of the 2- slug) of 1-8 for zero volts be -Detector 100K resistors (see S tween the positive and nega-Balance above) to the junction tive excursions.
of C-134 and R-131. 167
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION!
DEFLECTION YOKE A15111§tkOT
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
V.I46V6 -G'
AUDIO OUTPUTSTROMBERG-CARLSON
321 SERIES
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169
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONVOLTAGE CHART
1. Measurements are made at 117V. line using vacuum tube volt-meter. All voltages are D.C. and are positive with respect tochassis ground except where noted.
2. All voltages shown in telev. section measured with rangeswitch in TV position.1"23. Contrast control set maximum, brightness control set at mini-
mum, antenna disconnected.4. Voltages shown with asterisk (*) vary considerably with con-
trot settings. DEFL. YOKE a V -I9FOCUS COIL SOCKET 6SN7 -GT
TUNER UNIT
V -I6BC5 OR 6AG5
GNO.
200 2,-_16 v 102ND.
' G1(..' 484761,,''.. V-2 6:C6 r..eiral 6J6GNO "Gar
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Stromberg -Carlson Co.Series 321, continued
- 000, 20v. 2006 .0 0. 600 0 0sso 0 0 on, -10 00
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MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
SYLVAN IA Chassis 1-502-1Models 71M-1, 72B-1, 72M-1
The service material on the next six pages is exact for SylvaniaChassis 1-502-1 used in Models 71M-1, 72B-1, and 72M-1. Chassis1-502-2 used in Models 73M-1 and 73M-2, is the same except that adifferent tuner, using tubes 6CB6 and 6J6, is employed.
There are many other Sylvania television receivers which are verysimilar in circuit to the chassis covered on these pages. Besidesminor circuit differences, some of these sets may use other tuners,different tubes in some of the stages, other stagger I.F. frequencies,20" picture tubes, and some sets are combinations. The material pre-sented on these pages will be helpful in servicing these additionalreceivers:
Chassis 1-356 Models 74B and 74M." 1-366 " 71M, 72B, 72M, 73B, 73M." 1-387 " 22Mi 22M-1, 23B, 23M, 23M-1, 24M-1, 24M-3, 25M.
1-437-1 74B-1, 74M-1, 75B, and 75M.1-441 71M (similar to 1-366 but different tuner).
!I 1-462-1 24M.
Horizontal Hold Adjustment
A. Tune in a station and adjust the ChannelSelector for best picture quality. Adjustthe Picture Contrast and Brightness con-trols for normal picture.
B. Remove V15 - 6AL5 - Horizontal Dis-criminator tube.
C. Turn the Horizontal Hold Control untilthe picture moves back and forth across
the screen with blanking bars vertical.
D. Replace the Horizontal Discriminator tubeand repeat "A," "B," and "C" under "Checkof Operation" above.
E. If the receiver will not pass these checks,it will be necessary to proceed with "PhaseAdjustment".
ALIGNMENT PROCEDURE
VIDEO IF ALIGNMENT
1. Connect signal generator to the jig shieldson the Oscillator -Mixer tube. Allowgenerator and set to warm-up for fifteenminutes.
2. Connect the negative lead of a 3 voltbattery to the AGC Line, positive lead toground.
3. Connect an ungrounded D. C. VTVM acrossthe diode load resistor R145 - 3,900 Ohm.
4. Tune generator to 27.9 Mc. and adjust trapcoil L55 for minimum output. Keep volt-meter reading under 2 volts by reducinggenerator output as required.
'kfig Tube Shield - made by cutting off orinsulating a tube shield such as used or V2the 12AT7Oscillator-Mixer tube on the tunerso that the shield does not ground whenin place on the tube.
5. Adjust the cores of the Video IF Trans-formers in the following order. Reducegenerator output to keep voltmeter readingbetween 1 and 2 volts.
Set SignalGenerator At: Adjust:
26.2 Mc.
24.1 Mc.
25.3 Mc.
Core on 2nd VideolF TransformerT57 for maximum outputCore on 1st Video IF TransformerT56 for maximum outputCore on Mixer Coil L8 for max-imum output
Repeat adjustment of trap coil L55 as instep 4 above.
6. Disconnect signal generator and VTVM.
7. Connect sweep generator (frequency 25Mc. , sweeping 10 Mc.) using a . 005 Mfd.capacitor to pin 1 of 3rd Video IF Amp-lifier - 6BC5. 171
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONSylvania Chassis 1-502-1, Models
8. Connect oscilloscope to junction of diodeload resistor R145 - 3,900 Ohm and coilL58.
9. Adjust primary (top core) and then secon-dary (bottom core) of IF Bandpass T58to obtain curve shown in Figure 8.
FIGURE 8 - IF BANDPASS RESPONSE
172
71M-1, 72B-1, 72M-1, continued.
10. Disconnect Sweep Generator from 3rd IFGrid and connect it to the Jig Shield on V2,the Oscillator -Mixer tube. Loosely couplesignal generator at this point for markers.
11. Observe IF response curve and, if neces-sary, adjust Video IF transformer coresslightly to obtain the response curve shownin Figure 9. Use low signal input and highenough scope gain so that the IF amplifierdoes not overload, resulting in distortionof the IF response curve.
24.0 MGMARKER
70%
f---- 26.4 MCMARKER
FIGURE 9 - OVERALL IF RESPONSE
SOUND TAKE - OFF &4.5 MC. TRAP ALIGNMENT
1. Connect a 4.5 Mc. sweep generator havinga 250 Kc. sweep through . 005 Mfd. to pin7 of video detector 6AL5. Loosely couplesignal generator for use as markers.
2. Connect oscilloscope to limiter grid resis-tor R104 - 47M through a 270M isolatingresistor. Adjust trap core L56 until 4.5Mc. marker is centered at the peak of theresponse curve. See Figure 10.
1.
FIGURE 10 - SOUND IF RESPONSE
SOUND DISCRIMINATORALIGNMENT
Connect oscilloscope across the VolumeControl.
2. Adjust the cores of the discriminatortransformers T52 and T53 until the dis-criminator curve corresponds to that inFigure 11. Note especially that:
(a) 4. 5 Mc. marker is exactly in thecenter of the curve.
(b) The curve is linear between the out-side two markers.
(c) The amplitude is the greatest obtain-able.
FIGURE 11 - SOUND DISCRIMINATOR
RESPONSE
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
SYLVAN IA
Note 1: The terms "Hori-zontal," "Vertical," or "60 cpssine wave" refer to the oscil-loscope sweep employed.Note 2: All waveforms aretaken with the oscilloscope hor-izontal sweep direction fromleft to right and with upwarddeflection corresponding to pos-itive polarity.Note 3: In some instances thewaveforms obtained will not beidentical with those shown, dueto the electrical characteristicsof the oscilloscope used.Note 4: All waveforms aremeasured with respect to chas-sis unless otherwise indicated.Note 5: Have Picture Contrastcontrol at maximum.
*The peak to peak (PP) vol-tages of these waveforms aredependent on the depth of mod-ulation of the transmitted sig-nal; voltages shown are ob-tained when modulation is ap-proximately 90 percent.
P
WAVEFORMS
Chassis 1-502-1, continued,Models 71M-1, 72B-1, 72M-1.
311"11P"."'Irgill9.1.
*6BF5 (V7) Video Amplifier *6BF5. (V7) Video AmplifierControl Grid (Pins 1 and 7) Control Grid (Pins 1 and 7)
3. 5 Volts PP Vertical 3. 5 Volts PP Horizontal
*6BF5 (V7) Video Amplifier *6BF5 (V7) Video AmplifierPlate (Pin 5) 55 Volts PP Plate (Pin 5) 55 Volts PPVertical Horizontal
12AX7 (V13) Hor. Sync. Sep. 12AX7 (V13) Hor. Sync. Sep. 12AX7 (V13) Hor. Sync. Sep.and AGC Rectifier Cathode and AGC Rectifier Cathode Plate (Pin 6) 37 Volts PP(Pin 8)2. 6 Volts PP Horizontal (Pin 8) 2. 6 Volts PP Vertical Horizontal
12AX7 (V13) Hor. Sync. Sep.Plate (Pin 6) 37 Volts PPVertical
12AX7 (V13) Sync. Separator 12AX7 (V13) Sync. SeparatorPlate (Pin 1) 25 Volts PP Plate (Pin 1) 25 Volts PP 60Vertical cps sine wave
173
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Sylvania Chassis 1-502-1, Models 71M-1, 72B-1, 72M-1, continued.
6SN7GT (V12) Sync. Amp. &Clipper Plate (Pin 2) 110 VoltsPP Vertical
6SN7GT (V12) Sync. Amp. &Clipper Plate (Pin 2) 110 VoltsPP 60 cps sine wave
6BL7GT (V14) Vertical Oscil- 6BL7GT (V14) Vertical Oscil-lator Control Grid (Pin 1) 600 lator Plate (Pin 2) 235 VoltsVolts PP Vertical PP Vertical
6SN7GT (V12) Sync. Amp. &Clipper Plate (Pin 2) 100 VoltsPP Horizontal
6BL7GT (V 14) Vertical OutputControl Grid (Pin 4) 95 VoltsPP Vertical
6BL7GT (V14) Vertical Output Vertical Deflection Coils (Test 6AL5 (V15) Hor. DiscriminatorPlate (Pin 5) 830 Volts PP Point 1) 55 Volts PP Vertical Plate (Pin 7) 70 Volts PPVertical Horizontal
6AL5 (V15) Hur. DiscriminatorPlate to Plate (Pin 2 to Pin 7)Scope ground to pin 7 -23 VoltsPP Horizontn1
174
6AU6 (V16) Hor. Control Plate 6SN7GT (V17) Hor. Oscillator(Pin 5) 68 Volts PP Horizontal Plate (Pin 5) 95 Volts PP
Horizontal
6SN7GT (V17) Hor. DischargePlate (Pin 2) 105 Volts PPHorizontal
6W4GT (V19) Damper Cathode(Pin 3) 1000 Volts PP Hori-zontal downwini
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONCHANNEL SELECTOR
SYLVAN IATOP LAYOUT FOR 1-502-1 TV CHASSIS
O
V8
6AU6
SOUNDI F AMP
V3 V4 v5 V6 V7
6C B6,.._.,
6GB6..._,
611a._., 6AL55_.,
68F5\_....,
"Th ITN I-", f",I! !'AIDED 2.2 VIDEO 352 VIDEO VIDEO VIDEOIA AMP E A AMP IF AMP DETECTOR il AMP
A 5 C LINE CLAMPER
FUSE
TJiw AMP
P
NORUN SII
VI9 " VI7V21
61306GT 6SN7GT 56426W4GT H V RECT
How C.6OUTPUT NOR DrAGNARIXDAMPER
NORRCMT3
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SYNC MP
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6SN7GTSYNG AMPa CLIPPER
V15
F.T-TS
6AL5NOR. DISCRIN.
V16
6AU6NOR
CONTROL
ON -OFF 5VOLUME
BRIGHTNESS
JUMPER
V9
6AU6
SOUNDIF LIMITER
VIORATIO DET IU A F
VI4
68L7GT
PERT osc aVERT OUTPUT
AUDIOSOCKET
TOO
TOO
GC
C27.000002
VI V26086 12,477
44 3
CI.001
VI60E16
R. f.
UHF POWER SOCKET HORIZONTAL117V 60 CYCLES SOW DRIVE
HORIZONTALHOLD
VERTICAL HEIGHT VERTICALCONTRAST L./REMIT HOLD
G6 CO
FM- C7
.0005.0005
QC CS
PICTURE
C19
107 eteLt
'L00KER-F.0191
V27-7 12 AT 7,/ MIXER
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C21
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C231.00001
C26- .0011
C25T.000005
V2I2AT 7
Osc.
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RF TUNER SCHEMATICFOR 1-502-1 TV
L6
I.F.OUTPUT
175
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
SYLVAN IA
LO -BANDANTENNA
HI - BANDANTENNA
Chassis 1-502-1Models 71M-1, 72B-1, 72M-1
MODELS 728 -1,72M -IHI -LO ANTENNA
0-
0ANTENNASWITCH
ON -OFFSWITCH
ION VOLUMEc.09740L)
176
DIPOLEMODEL 71 M -I
0 USE HIGH VOLTAGE MULTIPLIER PROBEWITH SYLVANIA POLYMETER TYPE 22I2FOR ALL HIGH VOLTAGE MEASUREMENTS
0 CAUTION. VOLUME CONTROL SHIELDSARE AT -135V DO NOT CONNECT TOGROUND
R FTUNER
L8125.3mcl
UHF POWERSOCKET
117V 60 CYCLES50W.
T50 V22 V23r i 5U4G 5U4G
L.V RECT. L.V. RECT +14ov.
I SV.A.C.-11---4. 4 o v
oCI
011-0 I0
I
WO VII VIZ V13 V14 V15 V16 V17 VI86T8 6V6GT 6SN7GT 12AX7 6BL7GT 6AL5 64116 6SN7GT 61306GT
48
4A5 2 7 7 8 9 5 13A7 3
R1714
31131 I
7
* CONTRAST CONTROLAT MINIMUM
BRIGHTNESS CONTROLAT MAXIMUM
AA- -135V
0
P
A HIGH PEAK VOLTAGE OF SHORT DURATION(APPROX. 2,000V)MAY DAMAGE METERUSED FOR THIS MEASUREMENT
el SOURCE OF VOLTAGECONNECTED TO INDICATED VOLTAGE SOURCE
VOLTAGES ARE MEASURED TO CHASSIS UNLESS OTHERWISE INDICATED, DC TAKEN AT 20,000 OHMS PER VOLT, A C AT1,000 OHMS PER VOLT MEASUREMENT CoNDIT:ONS, UNLESS OTHERWISE NOTED SOURCE 117 VOLT 60 CYCLE, ANTENNADISCONNECTED WITH NO SIGNAL INPUT, PICTURE CONTRAST AT MAXIMUM, BRIGHTNESS AT MINIMUM -OTHER CONTROLSAT NORMAL POSITIONS.AVERAGE VOLTAGES AND COIL RESISTANCES ARE INDICATED. RESISTANCE OF TAFPED COILS S FOR EN TIRERESISTANCE IS NOT SHOWN WHERE READINGS ARE TOO SMALL OR WIDELY VARIABLE.
AC LINE
I.F. OUTPUT
A.G.C. -0v
8+ +125v
FIL
300V A.C/T
6 3V AC0
INTERLOCK
6.131. XAC
6.3v, AC
V3 V46C86 6CB6
C155_..4014F0
350V.
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0
6.1 V.A.C.
0126 -005
0127.0051
L50
6.8M
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015860MFD200v
VS V6 V86BC5 6AL5 64U6
413-I
0160 CI61 CI62.001 .001 .001
L52 L53
V19
R132W.6.8 MEG
6129
100M
C1291.005
RI433.3M
61643.6MRI691190D.
6w4GT
V36CB6
C130 IST VIDEO I.F.
0001
V611/21
Ro.evtR1355611
6AL5A G C. LINE CLAMPER
+125v.
R166I275.11
-105v8167 PICTURE
250A CONTRAST-t32V.
R16818011
It 7.0 NCI
T56
WINDING. COIL
The thirdfrom typethe socket
C134.0000047
V4-6C136
2M0. VIDEO I.F .000001+,00v 1575
R13747m
+0.0)42R13956110133
.005
6138IM
V1311/21I2AX7
SYNC. SEP. EtA.G.C.RECT.
V12 0/2)6SN7GT 8I77
A.G.0 AMP 10M
-0v -75v5 7
IC1611IOMF
Om 25v.
.003 8178
A.G.C. 111711
CONTROL 1.0MEG
R180mom
CI36
3t
27M® 81
9.004 T
R1402.2 M
+125V.
RI84
0171-.047 0172
-1.7 .01v
1.2MEG.
V13I2AX7
SYNC. SE
C170
3
61831.0
MEG.
t 6182). 55m
+125V. -135V.
46181S2.2 MEG.
VI66AU6
R2I9 HOR. CONTROL
R18512M
470M c195 8.281
C194 PHASING 1.0001 80T m CORE)
TS2
1.0 MEG.
HORIZONTAL HOLD(TOP CORE) -135V
V17I0197.0001 6SN 71
HOR.C198
+
.002
#22I470M.Z
-132v.
-135V.
SCHEMATIC DIAGRAM FOR 1-502--I TV CHASSIS
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONV8
6AU6SOUND I.F. 0102
V96AU6
SOUND I.F. LIM.
0100 8101 0101
.004 10011 .004
.00004RI044781
L54
deo IF tube V5, is changedIC 5 to type 6CB6, Observe[ring change for this tube
5C5IIDEO I.F.
III111
0140
.004
[SANG10 MGSWEEP
RI431M
V6 0/21D°T 6AL5
V DEO DET. L57-1"100.
7 11.2n
4.6 MC850 KCSWEEP
01370000lI
6.711
(Th L58
- 6141.00001
RI453.9M
RI47V7
613F5VIDEO Amp
S3.30
-1050.* 132V
CI4 4.005
CI43
.005
V12 (1/2)6SN7GTIC AMP. 8.IPPER -6.4VV
C176.00075
ii1189 8I510 RI91
2
I2 M
8.2 M 6.2MC174
1:1 73 '005 C175
3 1.002T .005
R18733M
ISV. +125V. -135V.
!22!ZIA
19IS
C200
+125V.
V17 (1/2)6SN7GT
HOR. DISCHARGE-1600. -ISV
2
V14 (I/2)6BL7GT
VERT. °SC....,20 V +70V. ""
C17? RI95
HOLD °
MEG.
I 5MEVERT.
P19323
RI93
1.2
07B
-135V.
R2264.7M
C.0006112021
R225
-I35V. 25081
C201HOR. DRIVE
.0051
474REo
470M
+125 V.
15 MG290sCSWEEP
0138
VIO6T8
RATIO DET.
.0000047
RI508.2M
-142 VT53-
1 13.00
1.0 MEG.
* - 11 V.-43 V.
YELLOW it
LGO
RISI7.581
CI51.0051
C(15
11
.01
RII222031
-C1121.0001
CI20Ip IF -
C109 80. .25
.010'
CIII 8111
.011 I5MEG
VOLUMECONTROL
CII91.005
V24.1 1 PICTURE TUBE
17BP4A
JUMPER
R113
Tan.
-0V. 10+2204-121V.
RI52470M
C1521 LC146.003- T.o,
RI532.0MEG.
- BRIGHTNESSTEST CONTROL
VI4 (1/21 POINT6BL7GT (I) VERTICAL
Csio VERT. OUTPUT a DEFLECTIONO COILS1 + V. A c.,
.1
HEIGHT
R198
C179.1"-
M197Vv 4.781
10111FI:i 196450V. 100M
C203 f.001
470MR227
+275 V.14)
R228 -145V.
10013
-1154.C204
IOMF450V
822915011
1.0
R1991.0
MEG
VERT.LIN.
i-10611
8200
II
4 7612
R201 m%181
TIOOMFO50V.
M
-135V.
R202510
R2035600
L61
YELLOW 478
+275V. (A)
VI86B06GT
NOR OUTPUT+350V A
8230loon.
+125V. 047 8.2M
-135V.+12511.
VI96W4GTDAMPER
HORIZONTALDEFLECTION
COILS
FUSE/4 AMP
-135V.r
VI 1
6V6GTA F OU T
-1230 4711S '4.65V.
13,000 V. 0
DO NOT AT TEMPTTO MEASURE THIS
VOLTAGE
t.8M1
LT63
J 6511
HOR.LIN.
C2I1
-4(.0007
R232 W.C2O)M
t.033C206
I T® SLUE
cL64 ;911 I'00RANGE
L6519n I
6C116
60MFO350 v.
RII747011.
+125 V.
0. 135 V.
V20 V2I5642 5642
H.V. RECT. H.V. RECT
HOR.SIZE
L6767n
C212
)I----,.0005
R235
1.5ME
012361.5MEG.
j_C213
.0006
A B C J K L
7818DE FGHI 0 0 0
TERMINAL LOCATIONS ON HIGHVOLTAGE SCANNING ASSEMBLYREFER TO CIRCLED LETTERSON SCHEMATIC
C209.22
-135 V
R233
IM0
0210TiOMFD
450V.
+275V. (A) -135V. 177
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Western Auto Supply Co. *** Television Receiver Model 2D1185B.
See below for list of similar models.
R -F UNIT
OATEN-vellIr
OH-131.14 150
WHITEH.RED
V -9A 6SN7-GTv. eVERT. PHASEOSC. SPLITTER
6
1 Foy H
ALL RESISTANCE VALUESIN OHMS.
K.1000
ALL CAPACITANCEVALUES LESS THAN 1.0IN MI AND ABOVE 1.0IN MME, UNLESSOTHERWISE NOTED.
COIL RESISTANCEVALUES LESS THAN 1.0OHM ARE NOT SHOWN.
178
1000
3.3 K
T.100,
3.3 K
150
v -I
6CB61ST P/X. I -F
5
V -I
6CBC4A3
T- 81ST P/X.I -F COIL
47
1K 22K
V-2 T-9CCB6 ND PIX.
2ND PIX. I -F 1-E COIL
1000 150
I 1000V-2
T 6CB6J 4
1000
2 2 MEGI MEG.
VERT. HOLD
.005
4.7 MEG.
Tion4/50V
L-13
1.5 MEG.
V36 C -B 6
3 RD FIX. I -F
1000TJ.
180 Tw° I.5 K
T 1000
471,
12 K.-
T-103 RD PIZ.I -F COIL
V -4A
6AL:P/X. DE
V-3 V -4A I. V-4 B6CB6 6AL5 1.5 -JA. 4
L-14
V -I0
6S4VERT. OUTPUT
TAKE -OFF I
700V
1420 s1 -01/511 -
COIL0 Tv rOUTPUTrroo NN .600; PA iy I____
12.5 MEG.
V-16
6SN7-GTHORIZONTAL
OSC.
10.25 1 47
100 K
100 K
HORIZONTALDRIVE
T 0.25
3390 v 330
820 0 1
05 K
PERT REDLIN.
330470 1301
101,
I MEG.,
82
V-17
6AL5HORIZONTAL PHASE DET.
5
1T'i
25 K
HORIZONTALMOLD
27
.0515 K
560
560
TO PIN.7 or
1.7t7ILVJO V_!
20 MF4501,,
L-16VERT.
DEFLECTION,C0/1.
T-5HORIZONTAL
N. V. TRANSFC
v-18 6BG6-GHORIZONTAL 01/
11T.0
5 MF.
6,8 K
0-1
1000
10 K
Tv
1.140t4003-18
rV9140NOSWITCH
450V II
BOTTOM VIEW OCTAL SOCKETON CHASSIS TO RECEIVE PLUGFOR YOKE AND FOCUS COILCABLE.
H1000
Model 2D1185k differs from 2D1185B mainly in a few minor mechanicalChanges. The circuit of this set is very similar to Models 2D2052,2D1190 (with a 20" picture tube),and 2D1194 combination. Use thismaterial as an aid in servicing all of these models.
V -5A 12AT7 V -5B
1ST VIDEO SYNC. AMP.AMP.
11.05
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Western Auto Supply Co MODEL 2D1185B
.-5MU Ht Dor
5.66 22K
--74N0OT9 NUM
?ED,OT5 MOH
2.7'a
2.2 K
5 MF.25V T
360
L-9 TRAP
4 MOO
0.275 V
II 6AU6T-2
SOUND I -F TRANS.7 SOUND I -F
1 MEG
V -6A 12AU7 V -6BSEPSYN. VIDEOARATOR OUTPUT
`MF.
47 K 470 K
390 K 0.5
0.251 100 K
-PUT
UT
471
.005
5.1
L-18HORIZ. LIN.
CONTROL
6
4
47 K100
'CONTRASTCONTROL
3.9 MEG
I /05L. MUoH-1 ,
BROWN DOT
1 III SE1 In II
L-11190 MUN
WH/TEDO7
0275 V
(FACTORY MODEL 229T26M-166-1)V -4B
6AL5D.C. RESTORER
I MEG.ft
ILA100 K 2 2 K
a
500 KBRIGHTNESSCONTROL
0 I 5 0 V
T-3souNo RATIOV -I3
6AL56AU6 v-12SOUND I -F r -osr.
TRANS. RAT/0 DET.
.5.6 K
T1"Tr
2
5_MF
15.6K
V -I9
183-GTN. V RECT
2MEG.
iirYv
V-20
6W4-GTDAMPER
1
O 3.n. 61 L-19 TO PIN 91 OF P1
I WIDTH CONTROL ro PIN .1 OF
.03 .110 vO 0.25
10 K
TOP VIEW PLUGFOR YOKE ANDFOCUS COIL CABLE.
4150 V
i100 K
K
56
470 K PHONO5-14
r V-PHONOswIrcre
PHONO/NPLIT
C-99-- R-115
.005T I MEG. J. .005
I MEG.
V-7P1X. TUBE
T -IIAUDIO OUTPUT
TRANS
1 6 TID MF.4175V
V146AQ5 500 KAUDIO
OUTPUT 01
io2.
MEG.?
v-Is6AV6VOLUMECONTROL AUDIO AMP.
68 K
L-20HORIZ.
DEFLECT/ON
V-21
5U4 -GL.V. RECTIFIER
WHEN P.M.FOCALIZER ISUSED L-21. R-96 & R-97ARE REMOVED.PIN2 &"8 OF X -I & P -IARE NOT USED.
A 500,, RESISTOR ISCONNECTED BETWEENR-95 & L-22
TO P/N -4 OF
TO PIN .1 Of N./ FUSE
/TO PIN .1 OF X-,.275 v 410 TO P/N "2 OF P -I
Cr\j)73,0,
11.
,TO PIN .11 Or P-1 \ IL_
47 K .os
..?75
T-6 ON -OFFPOWER TRANS. SWITCH
9
F ___40CUSCOILCHORE
FIT-7.2E21:-. "75R.95 L-21625"
1500 500
I 8405o.,I 30 kV.
ISO vR-96500 I "430V
R 4-9 K
FOCUS CONTROL
In some receivers C-99 and R-115 are not used.
I 80 ME450 V
Additional service material on the next page.
CAN.
INTERLOCK
179
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION23.5 25.25
23.0 26.2
50 %
21.7Overall Response Curve
T-345 sic
SOUND RATIODE r. rwANS.SECONDARY
aL-9145 MCTRAP
T-24.5 MC
7S071/NO IF TRANS.
L-15-4.5OUIA)RAEC OFF COIL
T -I021.7 MC
JRD P/A IF TRAP
T-925.9 MC
IND PIT I, COIL
T-823.'sr Pet IF COIL
25.1 MCCONVERTERPLATE COIL
Top Chassis Video andAudio I -F Adjustments
/ FRONT APRO
.100.1LEAD IN
180
r
8
AWN, A- CATHODE ._moot PL ATEDP,D I IL ATE Ts 'MODE 6PID
Western Auto Supply Co. (Continued).
MODEL 2D1185B(FACTORY MODEL 229T26M-166-1)
TRUETONE TELEVISION RECEIVER
ALIGNMENT PROCEDURE
F AAA Tue. OOOOO Lt
55147.0T
n NOOK I al ;7[XM:RE i1DAv
61106-13
(1'.4/5H PITEPHAL SHIELD Pi HEATED 0 -TAME GPO d HNu.
Bottom Socket Voltages
TURRET, SWITCH SETTINGSELECTS COILS. FORCHANNEL DESIRED.
6 AG 5R -F AMR 5
3-9 47K
WHITE
A.G.T C.
1000
1,5o:
H
10 K6 8
2.2 K
1
1
1
1
1
I 2H 041I ell 101
1j CMS 7
PIX I -F
6CB6
T-1024.1 MC.
3RD PIK I -F COIL
T-3 e) T-2SOUND RATIO 111°11FTOUND I -F TRANS.
4.5 MC 4.5 MC
DET. TRANS.RR/MARY
BACK APRON
Bottom Chassis Video andAudio I -F Adjustments
Tuner Schematic Diagram
6J6OSC.t MIXER
20
i1000'r L-51
..- r
0.5-3 3 -.4-ZrAf..L-52
1000
REDV11-1BP
120
MOST -OFTEN -NEEDED 1952 TELEVISION
Wedinythawe electricChassis V-2200-1 usedin Models H -649T17,H -650T17, H -651K17,H -655K17, H -656K17,H -657K17, H -664K17;
and
Chassis V-2204-1 usedin Models H -659T17,and H -663T17.
A list of chassisand models similarto thethe setsdescribed is mwREgiven on mmpage 182.
L401RINGING COIL
2AU7HOR
INKTIvIEOTATOR
SVNO AMP8 SEP
604PHASE DET.
TO SPKR
SU83L v
R CT
TIOI130
e]C3IR
4125w
IFAMP
T302
RATIO OCT151 AUDIO
65N7UvErIT
wolsolowoR
T 401VERT OUTPUT
TRANS
)6V6GT
VERT
T`01v
POWER TRANS.
1303
12001
7 304
5(Z4125VIDEO OET
NOISE CLIPPER
L 20i
AU6 L203 6AU6`,T950 e IiT SOUNO
AMP iF AMPGROUND
VIDEO TEST TERMINAL ORVIDEO Ou PUT TO COLORCONVERTER
HOR LIN.
BRIGHTNESS
HEIGHT
VERT HOLD
VERT LIN.
illvAC
DISCONNECT JUMPER_NNEN COLOR CON-VERTER IS INSTALLED
FIG. 4 TOP VIEW OF CHASSIS
42 25Mc 44.0Mc 45.75Mc41.25Mci43.0Mc 45.OMc
B
41 CMc 43 0Mc 450Mc 47 0Mc42 0Mc 44 0Mc 46 °Mc
FIG. 5 - RESPONSE CURVES ATVARIOUS STAGES OF ALIGNMENT
COMMON I -F SECTION
Remove the 6AK5 RF amplifier tube from its socket, and turn the chan-nel selector to channel 13.
Connect the oscilloscope to the video test terminal through the de -coupling network shown in Fig. 2.
Connect a 3 volt bias battery to the AGC line.Adjust the sweep generator for a center frequency of 44 mc. with a 10
mc. sweep deviation, and couple the marker generator to the sweep generator.
StepConnect Sweepand Marker
Generators to -Marker Use
ConnectDetuningClip to -
Adjust -
I. 3rd I -F amp.grid
Check for equal re-sponse at 42.25 mcand 45.75 mc usingweak signal. Also43 mc and 45 mc.
2nd I -F amp.plate
Pri. of T304 for max.response and sec. ofT304 for symmetricalcurve shown in Fig.5A.
2. 2nd I -F amp.grid
Same as step 1 1st I -F amp.plate
Pri. of T303 for max.response and sec. ofT303 for symmetricalcurve shown in Fig.5B.
3. 1st I -F amp.grid
Same as step 1 Not used Pri. of T302 for max.response and sec. ofT302 for symmetricalcurve shown in Fig.5C.
4. 6 3 6 mixerth r o u g hcoupling de-vice shown inFig. 3.
Check at 4 4 mcMarker pip must beat center of flatregion on curve.
Not used Turn C318 adj. corn-p I ete ly clockwiseand adjust T101 formax. response. Ad -just T301 for sym-metrical top.-
5. Same as pre-ceding step
Adjust to 41.25 mc.and increase outputuntil pip is readilyvisible.
Not used C)18 to minimize am -plitude of 41.25 mc.marker pip.
6. Same as pre-ceding step
Check curve at Ire-quencies shown onFig. 5.
Not used Re -adjust TIO1 andT301 to obtain curveshown in Fig. 5D.
1 a
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
There are many other Westinghousetelevision chassis which are verysimilar in circuit to the setsdescribed on these pages. Eachof these chassis may be used inseveral models, and at times thesame model may have been issuedwith either of two chassis. Forexample, Model H -650T17 describedhere as using Chassis V-2200-1,also used Chassis V-2192-4 at anearlier date.
Some of the differences betweenthese various chassis are out-lined below, but in the main thedifferences are in minor circuitparts, picture tubes, high voltagetransformers and yokes, and tuners.
Chassis V-2175-3, V-2175-4 usedin Models H -646K17, H -647K17,H -654T17, differ from the setsdescribed in tuner yokes used.
Chassis V-2178-1, V-2178-3 usedin Model 642K20, differ in tuner,and in Horizontal sweep and AGOcircuits.
Chassis Assemblies V-2192, andthe sane with suffix -1, -2, -3,-4, -5, and -6, have been usedinterchangeably to a degree inthe following models and differmainly in the type of tuner em-ployed:H -639T17, H -640T17, H -641K17,H -646K17, H -647K17, H -649T17,H -650T17, H -651K17, H -654T17,H -657K17, H -658T17, H -663T17.
Chassis V-2194, V-2194-1,V-2194-2, V-2194-3, are usedin Models H-642K20A, H -652K20.
Chassis V-2201-1 used in ModelsH -648T20, H -652K20, H -662K20,uses a 20" picture tube and hasminor circuit differences fromthe chassis described here.
Chassis V-2202-2 (with ChassisV-2210-1) used in Model H -653K24has a 24" picture tube and adifferent high voltage circuit.
Chassis V-2203-1 is used in com-bination Models H -660C17, H -661C17
Chassis V-2206-1, Model H -665T16,
182 is identical except thata 16KP4 tube is used.
WestinghouseRADIO TELEVISION
CHASSIS V-2200-1 V-2204-1Models H -649T17, H -650T17, H -651K17,
H -655K17, H -656K17, H-65710.7,H -659T17, H -663T17, H -664K17.
T C
6.3y
111,-
[-7
!-I-
j
I -ALE 9
ft
SECTION I RF
ti; ti
"
. TroiCo SECTIONS Of. AEr.. Of wafERSA" . Of ma,.Toff". riumats, 'MONT TO 11000
6V6GT 651.1761- 6 AH 6YEW vaO WONTErl71/%! r)._
14,11 .rEfSGT :W=T
YO1
C)! riti_.2
MOMI. ALL CAPACJTANG /ALOES tH WC, .6M ALL MUNCIE VALUES HI 0.11S
/81WASS OTHEIHNISE 10/2
2,1 "ALT PACOUCTIOM CHASSIS A FEW CCUPOWENTS RAW OE SANTO' DEFERENTVALVE THAN SHOFFM. ACK CENEW/ PANTS SHOULD t OF MUMS LOWS.vOL TAM WILAYAIEC MOW CHASM MOWS USW/ 1opoo /VOLT METES.LAW MOO. of FA C. 1/EAweSS 90.6.0 SW AS IMMO WI.
WISTALL TWO 100s WES/STOWS IS SOUP 1101E .1.0.I. 01 OLS / 10ISTOISISH TEST PONT5.60 C,AS. FEKTITNIN FATE.
IFITA OFT. PULSE REPETt110111 RATE.
T. SOOOT COMECTIOw5 FDA 111111/111.1TE ME, AM 990 MOW S.F. ODOMHOEHN T SWISWITUTE TAWS MI 000tEET ASPS AGESSEYT.
GAC7 GA06 GAT6 1111016
11916 12AV6 68411
GOO
I ITT
Tr
T.
a
.SO
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
1TO [R
I.IM
' Nu,
0322
6.0
113011002
Weilinghouse electric Corporation6T8
GAL5 §j2t 303 0323
VIDEO OC T VIDEO 014P L 3091.0,11 10012
IC303tVf
-L
WIDTH
0327 50KBOGRTHESS 43200
4-'111C/4,VVIVN R526IT ASK
1.6.1 IF MN#306100
v-17:05 2 66 II AMP.
102 I 800
#3322.212
TC 45COITTP01. I4
NEW AGC DISTRIBUTION SYSTEM
T 304
010E0TEST
TERMINAL
330?11)T1un
R333220
L305
R316$6
eSYNC AMP
304'Dun
03223.6
rOv
0324100K
NEW VIDEO AMPLIFIER CIRCUIT
SECTION 2 SOUND IR AND AUDIO-- - ---. CHASSIS V -2205-I 4 - - - -
TRIT5NA
WIO
T202
Aug S ja 1.41,:u1 526 62 OUAUDIO
6
M OAT. 15T 2110
III BIROAu.,.
21111 =AO i f WI RAI
TRAM&
_T 202 109 /OTI 4 9 c airteAMIIIIII5
-CC ,- Ci..3 R.K.
, 4 100
,, .± 50,1I.
201
111,11 2*.Ooa
=c..2..s.
11
100211,_
C.
-a 5 0.00
_ _
AtIO I AtIMAI
212 0jp :V
C .202IR
. C2..02 MOP
I C21230
2084./
CU.
142990? Aeb 5030I ' o" =:Ala..,.
I
.. -04.M.,L.5- 1:0C^ET
6CB6411SON
I I M 4' ' so-,T 500
TAW 1,41.44.___GOMELE:r -II- 1 OIA,,,
= L ait-LW. i LOM610.
5:6: ,..6A.LIE,
0.11 MINNA
5
GANG
06120 AIN
T 302
Lat 1
I m F
5 :II
N515,00I
R3:1 5012
61112020255
I it 05.WA MN
' 4 T303 T2°i. -In .`!7mg
rL
I- 3 1 1E-4111,------ ,
... I al ItC" 5 i! . MT
C310
- 'Or30T
L. -J . 2 1--
...1.
L.30,.am
73:Nur
m11
,..T1TTF
309
ri3OT
'R512
50 0315 I. - -'ATO -
= 11315im
'11103aB :::
C .a.4.T, ,,,..
rue 2.2a
4-, W,504 gal r
1 II I2.3 24 -ET ...I CNA
Gos
2301
.14. /C
I
NOOK 0310t. 1E322
.E209319 i .
NETeL
Eel, I y \I
LIGOWAN.- --- - - - .- -- - -
01000NINCT Minn ---e 0 0 TEM TERM1.1.
SECTION 3 VIDEO rer.....455431=1112A PrWOW corPuT TOr03.011 com.1211
IQ
UDC 3a xoTE 5
111
- .1 0,.91, .T
E 5 TiC,TE 5
4 v. T 011.01 .04 ,
/1. :6:'11405EU F;TA. MN ....7 " ___ a "iiiir TO.
1
2401
e 00 it aII.MIM.. : ...r ANI L.002 T .0011 .005 Li ANT J -
,,,K.
250
I.
111)K
1.5K 2 V203
5A
P.1400 MkAVIT 'Er
to-CONTROL
1E11M.A
Mr'HE .25
LIsN ."T..T
; C2!NICOATAM
07541,L ,.7. .N--- MN
HT
Ix. c.23.
....."4.4r!,_ es
T''''' ,;:t..°0. 2.0.-ji . SECTION 5 POWER.4" .r. Int
+0lee
c025I '
=2012
3 Il
1.25I
L.R.N. III.1 It Mt MillithF171 POTTERMAIO
.,90-4----705:e.,9c%
30TKa..
99 9503 i. " TOP. . ...C. I- .0 I- 4.
T NW, A
011.0:74:01 1
C" 6414 Mara T40T-.05 i 0.5315
....:. C. 1..1.0.3900
NM,10111. OUTIVII
Mil8 44714:Y
Mil.111/{11
C11
A . 1
50i
1.40t Ifio ..Mk
BBirU TOTIa
C44
,_-."
T CHASSIS No. V -2200-I 8i V-2204-1wow NMIeft NNWcame..
-.- .30eNe I15A ..--ON gOBBC SETS, ,6431To
TE Arli NA L 8"7INSTEAD Or 600110e-.e wll. .1
415N 4 qFFP=C -rin VVFIG. 7 - SCHEMATIC DIAGRAM 11 3
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Westinghouse Electric Chassis V-2200-1 and V-2204-1, continued.
SOUND I -F SECTION
Connect the signal generator to the video test terminal (point "D" on Fig. 41 through a .001 mfd capacitor.
Step Signal Gets .Frequency VTVM Connections Remarks Adjust-
1. 4.5 mc.unmodulated
Common lead to point "C"and high lead to point "A"as shown in Fig. 6.
Use 5 v. (-DC) scale onmeter. Set sig. gen. outputaccordingly.
L201, L202 and pri. of T201for max. voltage.
2. 4.5 mc.unmodulated
Common lead to point "A"and high lead to point"B"as shown in Fig. 6.
Use same sig. gen. output asin step 1.
Sec. of T201 for zero voltage.
z 0a CONNECT V.T.V.M. WERE FOR SEE FIG. 7 NOTE 4
SCNEM CONNECT V T.V.M. HERE FORATS_.1AGRAML201,1 202 a T"'1 Pill. AIM
i.917] S1201 ZERO ADJ.
Or.: le, ,T, 5iZ o t
.1 ,I RATIOLT El. AV& --
I51 AUDIO 2 to SOUND IF I ZT SOUND IF UIii. a' 3,9
vio,,, co A.i
a
R - FTUNING UNIT
T20180 1 2567 125419
125?CO 4 3 2 4 3 2
VI:.E0 DET. GANGI, MP. 20A.
GALS
3litini4P. NOISE CLIPPER VIREO AMP
INERMIllswim
4.5 Z34505 5 3415120 i(1.345111.5 ,,i 315 34 .210
2 0165t 7 ,115 P. 7 ,. 120 i' 76.11.5,r 78 1 7j , eirt4 )_T r,- I;;:91 " ell L--- i'l
1302 1304 CONTROL SET AT MAX....1-4E17.. (T303--6WOOT-( 1i -1.
LIJ
202I OUTPUT ] AIM° OUTPUT
-) 40330
-k.:Tieguisi(---..jCD
'41-5'
C scO4)2 -_
/7',5 -1 I:0
7 Cd
0 XL%fr,!) Z ...4
5U4G\ RECT.
s..
(6°1 2 3.
52 !7A3
7501L . V.
POWER TRANS
& -5 E1 (.4
rz 0 ZPHASE1DET.
;) kI,-,' IP0.
11
f,0 k 000 U
I H 4')((t Z,,,., g Z
5i
3.31 CONTROL AT MAX RES......"'"--
rg--1.5(:( CI I ( (SET$
32 3 21
320
Filr091:1;wO.
44 0d u _GSN7G.T_
U T( SNT. WITIVIEK..Tt Is V E
12 Al I i0
8)0_i68
LT: WDK
0Ucr:
110h. 1.1..11V1H.ATOK_N
$5 i
.
1401
0 L401
L=
geli 2
1-.1
a -1:3Y(1.'
:11 -.4 OaNM ; z
(7, i Io ,,,>rP- CV
RINGING COIL
KE7ED6AU6A.G.C.
s(
12 6 29054
GotCI6AU5GTum
i 1 1:'''' HON. OUTPUT
x a00II
L501 1I FILTER CHOKE
18 I
78 r,) 3.
-,1 550
184 FIG. 6 - BOTTOM VIEW OF CHASSIS
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
ZENITH RADIO CORPORATIONCHASSIS 20J21 -20J22 -21J20-21.121
The 20121, 20J22, 21320 and 21121 chassis describedin this manual are basically alike. Alignment and ad-justment procedures are identical. The slight differ-ences that exist are in the size and types of picturetubes used. The 213 series receivers utilize the highvoltage electrostatically focused picture tubes whichobtain approximately 2200 volts from a 5642 rectifierfor the focusing anode, while the 201 series receiversuse the new low voltage focus picture tubes whichobtain the 0 to 400 focusing anode voltage from theregular power supply of the receiver and do not re-quire the 5642 rectifier.Zenith Chassis 20H20 also used inmodels marked with (*) and in ModelsH2041R, H2052R, H2053E, H3074R, issimilar to Chassis 20J21, but uses17BP4 picture tube.
T9 POWERTRANSFORMER
vie 1133
A C INTERLOCKBEAM BENDER
175M A SLOW BLOW FUSEL20 LINEARITY,L19 WIDTH_
0 0 0 0 0 0O o0:900o 01C 0,0 0O GO -0/.) 0O 0 0-0 0 0O 0 0 0 0 0
0. AFC TESTPOINT
VI9\U4
.---PCTURECENTERIADJUSTMENT
\ PROTECT -is/VI C0-
564 2cz)
000000000 00 0 0 0 0 00000000000000000C: 0 00 0 00O 0 00 0 00
PHONEVISIONSOCKET
R 38A G C DELAY
CONTROL
R 28ON -OFF SWITCH
a VOLUME CONTROL
VI76W4
GT
L18HORIZONTAL_
HOLD
Models using the above chassis.
32026R 12051E J2142R12027R 12053R 12143R12027E 12054R 12144E12029E 12055R 12144R12029R* 12126R 32151EJ2030E* 12127E 12153RJ2030R* 12127R 12154R12040E 12129E 12155R12042R 12129R J2868R12043R 12130E 12968R*12044E 12130R 13069E12044R 12140E 13169E
R27BUZZ
OUADFATURE COIL [CONTROL* AUDIO TEST
POINT
68F 5v10
V9 6B
MAGNE TiC L9slitE
RING ©C4ru-L/C
- V7VIDEO E 6036DETECTOR OUTPUT-,
DEFLECTIONYOKE ADJUSTMENT/ s's
aFP4AoR
20GP4on
20FP4V20
BRIGHTNESS-R 42R 46
CONTRASTR51 VERTICALHOLD RANGE
6
ERRIEPCTOR
T7ERCAR
01
CONNECTOR FOREXTERNAL BIRO
A
1 [ I C 1 R.F. GRID TUNING
tk"---- I....11---V I 6CB61---
LyELLOW ,t.-1 ---- R.F.WIRE
IIS--- ,---11-C2
PLATE TUNING
, 11 L2 CONV PLATE TUNINGL. -__r, C7 HIGH CHANNEL PEAKING TRIMMER
IER TEST
fi___. V2 6CB6
T* i':;,,..,CONV GRID CONNECTOR
C3 CONV GRID TUNING
toL-V3 6AB4" t ; 012 MASTER OSCILLATOR TRIMMER
CHANNEL OSC TRIMMER
1©10V4
6 6CB6
r -
VERTICALSIZE
FINE TUNING
VERTICAL LINEARITYR52VERTICAL HOLD
CHANNEL OSC. ADJ. WRENCH
T 3 3RD I F T RANS
T2 2ND I F TRANS
-T I 1ST I F TRANS.
L 4 47 25 MC TRAPL82 39.75 MC TRAP
-L3 41.25 MC TRAP
_CHANNELSELECTOR
TEST POINTS USEDIN PRODUCTION
Fig. 1 Chassis Layout
185
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONZenith Chassis 20J21, 20J22, 21J20, and 21J21, continued.
TOP VIEWCOUPLING ADJUSTMENTS (BOTTOM)
4TH I.F.
CONVERTER PLATE)L (ON R.F. SHELF)
1©]3RD I.F
Fig. 7 IF Alignment Guide
[©]2ND I.F
O1ST I.F
IAFC ADJUSTMENTS
The AFC adjustment can effectively be made by set-ting the horizontal hold control L18 to a positionwhere it is virtually impossible to "throw" the re-ceiver out of horizontal sync when switching fromchannel to channel.
AGC ADJUSTMENTSThe AGC delay control can be adjusted from the frontof the cabinet by removing the volume control knoband reaching through the opening with a screwdriver.Connect the calibrated oscilloscope through a 10Kisolation resistor to terminal "E" (Fig. 1 ). Selectthe strongest TV signal and observe the deflectionon the oscilloscope screen. Adjust the AGC delaycontrol for 2 volt peak output.Satisfactory adjustment can also be made by observingthe picture and slowly turning the AGC delay controlfrom its maximum clockwise position, counter-clockwise until a point is reached where the picturedistorts and buzz is heard in the sound. The controlshould then be turned slowly clockwise and set at apoint comfortably below this level of intercarrierbuzz, picture distortion and improper sync.
ALIGNMENTA suitable sweep generator in conjunction with anaccurate marker must be used for alignment work.When aligning the RF and IF stages of the receiver,it is necessary to measure detector peak output.This may be done with a calibrated oscilloscope.Any oscilloscope can be calibrated with a known DCvoltage. To make the calibration, connect the groundlead of the vertical input cable to the negative side ofa 3 volt battery supply. Turn the horizontal gaincontrol fully counter clockwise. With the "hot" lead,make a momentary contact to the positive connection
186
on the battery and observe the instantaneous spotdeflection on the screen. Discharge the scope inputcapacitor by shorting out the leads and repeat theprocedure, each time readjusting the scope verticalgain until the spot deflects 3 large divisions on thescreen. Each division then represents 1 volt peak.The position of the vertical gain control should bemarked for future reference.
VIDEO IF ALIGNMENT1. Connect the negative lead of a 6 volt battery supplyto terminal "A" (Fig. 1) and the positive lead tochassis. The bias supply can be made up from foursmall pen -light batteries. Keep the connecting leadsas short as possible.HOOKED ENDFOR CONNECTINGTO VARIOUS GRIDS
470 MMFDCERAMICCAPACITOR
56n1/2 W 5%CARBONRESISTOR
GROUND DIRECTLYTO CHASSIS. DO NOTUSE LEADS.
Fig. 6 IF Alignment FixtureFig. 8 4th IF Response
2. Connect the calibrated oscilloscope through a10,000 ohm isolation resistor between terminal "E"and chassis. The sweep generator input to the re-ceiver should be adjusted for 2 volts peak detectoroutput. Do not exceed this output level during any ofthe adjustments.
3. Feed the output from the sweep generator throughthe special termination unit shown in Fig.6 to point"D" (Pin 1 of 6CB6, 3rd IF). Adjust the generatoruntil a pattern similar to Fig. 8 is obtained.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Zenith Radio Corp. Chassis 20J21, 20J22, 21J20, and 21J21,continued.
Fig. 9 3rd IF Response Fig. 10 Exploded View of Traps
4. Set the Marker Generator to 43.75 Mc and alter-nately adjust the top and bottom slugs and the coup-ling adjustment of the 4th IF transformer for max-imum gain and symmetry with the 43.75 Mc Markerin the center of the response curve. The wire rodtype of coupling adjustment utilizes an insulatedsleeve by means of which coupling can be changedby turning the rod in or out.If the correct response curve cannot be obtained inthis step, check the position of the two slugs to seeif they are entering their respective coils from theopposite ends of the coil form. The position of theslugs near the center of the coils may change thecoefficient of coupling, making correct alignmentdifficult if not impossible.
5. Connect the sweep generator cable to point "C".Adjust the attenuator for a 2 volt peak detector output.
6. Alternately adjust the top and bottom slugs of the3rd IF transformer until a pattern somewhat similarto Fig. 9 is obtained. It will be noted that the topslug affects the high frequency side and the bottomslug the low frequency side of the response curve.If the correct response curve cannot be obtained,check the position of the slugs as in Step 4.
7. Connect the sweep generator cable to terminal"B" (Converter Grid). In this step it may be nec-essary to disconnect the bias battery and temporarilyground the AGC in order to see the highly attenuatedtrap slots with the oscilloscope vertical gain nearmaximum.
8. Adjust the 47.15 Mc, 41.25 Mc and 39.75 Mc trapsfor minimum marker amplitude (See Fig.10 ). It canbe seen that maximum oscilloscope gain has been usedand as a result the top of the response curve has been"run off" the oscilloscope screen in order to see a"blow-up" of the trap slot.
9. Re -connect the bias battery and readjust the oscil-loscope to the calibrated position. Adjust the sweepgenerator for a 2 volt peak output from the videodetector. Bear in mind that only one tuning slug isused in each of the following stages to be aligned.
10. Adjust the slug in the second IF transformeruntil the 41.75 Mc marker is halfway down the slopeof the response curve. Correct slug position isindicated when it is possible to move this markerabove and below this 50% point.
Fig. 11 Overall IF Response
11. With the test equipment set up as in Step 10,alternately adjust the 1st IF transformer and theconverter plate coil until an overall response curvesimilar to Fig.11 is obtained. If the proper responsecurve cannot be obtained, it may be necessary toretouch the 4th IF coupling adjustment or make aslight readjustment of the other stages to obtain thecorrect overall response curve.
SOUND ALIGNMENTProper alignment of the 4.5 Mc intercarrier soundchannel can only be obtained if the signal to the re-ceiver antenna terminals is reduced to a level belowthe limiting point of the 6BN6 Gated Beam Detector.This level can be easily identified by the "hiss" whichthen accompanies the sound.Various methods may be used to reduce the signallevel, however, it is recommended that a S-17203 stepattenuator be used for most satisfactory results. Toprevent leakage, certain precautions must be takenwhen connections are made. Use as short a lead aspossible between the attenuator and receiver antennaterminals and approximately 6 feet of 300 ohm shield-ed line between the antenna transmission line and theattenuator. The shield from the transmission lineshould be connected to the attenuator and the attenua-tor itself grounded to the TV chassis under test.
After the connections have been made, proceed asfollows:
1. Tune in a tone modulated TV signal and adjust thestep attenuator until the signal is reduced to a levelwhere "hiss" is heard with the sound.2. Adjust the sound take -off coil T13 (top and bottomslugs), input coil L9, quadratuxe coil L10 and buzzcontrol R27 for the cleanest sound and minimum buzz.It must be remembered that any of these adjustmentsmay cause the "hiss" to disappear and further re-duction of the signal will be necessary so that the"hiss" does not disappear during alignment.If intercarrier buzz is in evidence, after all normalsound adjustments have been made, the cause may beattributed to one or more of the following:
1. Improper adjustment of the AGC delay control.2. Defective 12AT7 intercarrier sound amplifier.3. Extremely high signal levels which require atten-uation in the antenna circuit.4. Transmitter over modulation. 187
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
188
ZENITH Chassis 20J21, 20J22, 21J20, and 21J21
C.6BuRiP
6806
s 565
60E6
6C06
V4
6CB6
68N6
6;i!,v Soof,v
0 0
III
-04VVirRRECE.VER
I.4.°.1;"'
VI V2
6CB6 6CB6R.F. CONY.
0 nF.TtR3,1,
VI4 BV2 6SN7GT
A.G.C.
pYf
.
R 63
y o0
R40
V36AB4
osc.
r.
L_
L3
yip1/2 teAT7VIDEO OUTPUT
30
Jiip
V46CBE
1ST I. F.
C30
210,
00
:"CO'4)"'CIKSON
T9
ro
TIO
VI9 "
5U4GRECT.
NOTES:ALL VOLTAGES MEASURED FROM CHASSISTO POINTS INDICATED.ALL VOLTAGES ARE D.C. UNLESS OTHERWISESPECIFIED.ALL D.C. VOLTAGES TO BE MEASURED WITH AVACUUM TUBE VOLTMETER HAVING II MEGOHMINPUT RESISTANCE.ALL VOLTAGE MEASUREMENTS TO BE MADEWITH NO SIGNAL PRESENT, AND WITH CHANNELSELECTOR SET TO 2 UNLESS OTHERWISESPECIFIED.
MOVF (,,RTR
MU:
ALL CONDENSER VALUES IN MICROFARADSUNLESS OTHERWISE SPECIFIED.ALL RESISTORS 4 20% TOLERANCE UNLESSOTHERWISE SPECIFIED.RESISTANCE MEASUREMENTS SHOWN WITHCOILS DISCONNECTED FROM CIRCUIT.ALL CONDENSER CAPACITY TOLERANCE 120%UNLESS OTHERWISE SPECIFIED.CATHODE RAY TUBE 2ND ANODE VOLTAGE TOBE MEASURED WITH ELECTROSTATIC.OR 201<MIN. OHM PER VOLT,HIGH VOLTAGE METER.
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
ZENITH Chassis 20J21, 20J22, 21J20, and 21J21
VS 8 NOPOINTS
,TPO
V6
6CB6 6CB62ND I.F. 3RD I.F.
COUPLING40STmEN1
V76CB6
1ST VIDEOV 8A V9
I/2 I2AT7 6BN6INTERCARRIER AUDIO DET
SOUND
100
AMP.
C. 294 7
M 0
pot
AElfSOOK
:MA
\no
6BF5SOUND OUTPUT
V207HP4
'IX TUBE ^
OHOPR4
T6
.cmfurp
!DEUS EON, nog
4AI VISAN7GT V2 6SN7GT.CONT. HOR. OSC.
Ply
ES
V1513 V16
1/2HOR DIP T 1-10ERVUT
icc'.
0
TIE
V126BL7GT
VERT.SWEEP
CSI
V16IB3GT
IOU VOLT. RECT.
4 ft
MOTEOM SOME MD L.S. THE TWO TIETCOEE TIIE 44.101 <MUT AREINTERCIMECEll
LOMIEWEV
Mg.
T14
14
()ALIGNMENTPOINTS
CIRCLED ALPHABETS INDICATE ALIGNMENTAND TEST POINTS,
DENOTES CHASSIS
1
V176W4GT
DAMPERL19
r TM 440m
Cx
Schematic Diagram 20J21 and 20J22 Chassis
The 21J20 and 21J21 series receiversemploy high voltage electrostaticallyfocused tubes using the variation ofthe high voltage circuit as shown onpage 190, over. Outside of this dif-ference, the circuits are alike. 189
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATIONZenith Radio Corp.Chassis 20J21,20J22, 21J20,and 21J21.
a_
0
w
40
TERMINAL E__OUTPUT FROM CRYSTAL DET---11"
........
N// V3 N MI
i 6AB41
1 II
R F OSCILLATOR
/ V2 1
6CB6 11... ....
CONVERTER
/ VI \I 6CB6 I
R.F AMPLIFIER
V215642
C(2-17:SERIES ONLY4E-* *
*e_AFFECTS FOCUS)
V"*6BF5 I *
/ */
GRIDn 1 LOW VOLTAGEPIN 2
RECTIFIER
Signal Path Chart.
HORIZOUTPUT.
Vi8k 1B3\
H.V. RECTIFIER
VERTICAL CIRCUIT 00 00 00 410
HORIZONTAL CIRCUIT SOUND CIRCUIT COMPOSITE VIDEO ****
The signal path chart can be used forquickly isolating the particular sec-tion of the receiver where trouble issuspected. As an example, if the setunder test has video but no sound, thechart will indicate that the sound be-gins at V7, and continues through V8A,V9, and V10, so the trouble is in oneof these sections. The AGC tube (V14B)
190 a,'"fects both picture and sound. Hish
aVgIGT
HIGH VOLT. RECT.
7,i, V21
5642HIGH VOLT. RECT.
voltage circuit of 21J20, 21J21
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
IndexUnder each make, chassis or models are listed at left in
numerical order. The corresponding page number at the rightrefers to the first page of each section dealing with such
material. Under ADMIRAL only chassis not models are listed.
Admiral Corp.301 (radio) 5
21B1 5
21C121D121E121F121G121H121J121K121L121MY21N121P121Q121T121V121W121Y1
Air King700-100700-120700-140
Bendix, cont.3051 286001 28
5 6003 285 6100 285 7001 285
5 CBS -Columbia5 700-100 205 700-120 205 700-140 205
5 Coronado5 All on page 575 15TV1-43-8957A5 15TV1-43-8958A5 15TV1-43-9015A5 15TV1-43-9016A5 15TV1-43-9020A5 15TV1-43-9021A
202020
Airline -- seeMontgomery -W.
ArvinTE286TE300TE302TE31541265170-517352045206521052115212
Industries
2222222222222222222222
Belmontsee Raytheon
BendixT170 28T171 27C172 27T173 28C174 28C176 28C182 27T190 28C200 272051 282060 282070 28
CrosleyS11-442M1U 29511-444MU 29S11-447MU 29511-453MU 29511-459MU 29S11-472B1U 29S11-474BU 2917-CDC1 2917-CDC2 2917-CDC3 29
17-CDC4 2917-00C1 2917-00C2 2917-00C3 29DU-17CDM 29DU-17CHB 29DU-17CHM 29DU-17CHN 29DU-17COB 29DU-17COM 29DU-17PDB 29DU-17PDM 29DU-17PHB 29DU-17PHM 29DU -17E911,-1 29DU-17TOB 29DU-17TOL 29DU-17TOM 29S17-CDC1 29S17-CDC2 29S17-CDC3 29S17-CDC4 29S17 -00C1 29S17 -00C2 29517-0003 2920-CDC1 29
Crosley,20-CDC220-CDC3DU-20CDMDU-20CHBDU-20CHMDU -2000BDU -2000MDU-20PDMS20-CDC1S20-CDC2S20-CDC3DU-21CDM1DU-21CDNDU-21CHM1DU-21C0B1DU-21COLDU-21COLBDU-21COM1321-4323-3323-6331, -1, -2331-4356357, -1359363
Cont.292929292929292929292929292929292929292929292929292929
DeWald RadioET -140R 35ET -141R 35DT -162R 35DT -163RET -170ET -171ET -172DT -190D
3535353535
DuMont Labs.RA -111A 39RA -112A 39RA -113 39
Emerson686L687L696L700B, -D701B, -D120142B120153B120158B
FadaS6C55S6T65S7C20
4343434747434747
515151
Fada, continuedS7C30 51S7T65 51S20C10 51S20T20 5142.64 Tuner 5151055, -X 51S1060 51
Gamble-SkogmoAll on page 5715TV27-43-8957A15TV1-43-8958A15TV1-43-9015A15TV1-43-9016A15TV1-43-9020A15TV1-43-9021A
GarodSee Majestic
General -Elect.16C11716T517C10317C10417C10517C10717C10817C10917C112 -C11517C12017T1 tol7T620C15020C15124C101
6161616161616161616161676767
Hallicrafters14808, -A17804C17810C17810M, -MG17811-H178121781317815-H17 816178171781917824178251783817848178491785017860-H17861-H20823, -B20872
696973736969696969696969696969696969696973
Hoffman24B707 7724B708 77180 77183 77184 77185 77187 77636 77637 77638 77639 77880 77881 77882 77883 77884 77885 77886 77887 77893 77894 77895 77896 77897 77953 77954 77955 77963 77964 77965 77
Magnavox104 83CT -301 83CT -302 83CT -303 83CT -304 83CT -305 83CT -306 83CT -307 83CT -309 83CT -310 83CT -311 83CT -313 83
Majestic17C62 8517FA 8517JA 8517L, -72,-X 8520082 8520083 8520K, 20KA 8520L, 20LA 8520T82 8520T83 Pc
191
MOST -OFTEN -NEEDED 1952 TELEVISION SERVICING INFORMATION
Majestic, cont.20UAT 8520U0, 2OUT 8520X 8570 85A-70 8572 8573 85106, -A 85108, -A,-C 85700 85701 85712 85A-712 85715 85717 85718 85719 85800 to 804 85
Meck, JohnXSC614TTM -700717C, 717TTM -717CTM -717T720C, 720TTM -720C3M -720T90219022902390249026
8989898989898989898989898989
Montgomery Ward15WG-3046C 9315WG-3049A 9315WG-3050A 9315VIG-3051C 93
Motorola14B1B14T414T4B17K8, -A17K8B, -BA17K9A, -BA17K1017K1OE17K1OM
105105105979"9797
10597
17K11, -A 9717K11B, -BA 9717K11C 9717K11D 9717T3 9717T5A,-C,-D 9717T5E to -F 10517T6BD 9717T6BF 9717T6C, -D 9717T6F 9717T6G 10520K6, -B 9720T2A, -BA 9720T3, -B 97TS -196 97TS -214 97TS -216 105
192
Motorola, cont.TS -228 97TS -236 97TS -307 97TS -314, -A 105TS -315 105
Olympic Radio752, 752U 107753, 753U 107755, 755U 107764, 764U 107766, 766U 107769 107
PhilcoClCP1DlC2F2D43233353738414452-T161052-T161252-T180252-T1(30452-T180852-T131052-T181252-T183152-T183952-T184052-T184152-T184252-T184452-T188252-T210652-T210852-T211052-T214052-T214252-T214452-T214552-T218252-T224552-T2282
RCA Victor4T101 1254T1417T103,7T104,7T111B7T112,7T122,7T123,7T1247T125B7T1327T1439T1059T1269T128
-B-B
-B-B-B
125121121121121121121121121121121121121121
RCA (Continued)
9T14716T15217T15317T15517T16017T17421T17621T17721T17821T179KCS-47BKCS-47CKCS-47DKCS-47EKCS-47FKCS-47GKCS-47GF-2KCS-48AKCS-49B, -CKCS-60A61KCS-62KCS-66,KCS-66AKCS-68C
Eflytheon
2QAY21C -2001AC -2002AC -2005AC -2006AM -2007AM -2008A
Sentinel438IU-438439IU-439440IU-440441IU-441443IU-443444IU-444
121138131131131131139139139139121121121138121121121121121121125125131131139
143143143143143143143
147147147147147147147147147147147147
Sparton(SoMA.m-Wilailngton)
255172 15325SD201A 15326SD170D 15326SD171 15326SS171,-A 15326SD172,-A. 15326SS172,-A 1535107, -X51085162X5163X5165X5166X5175X5178X519151925207, -A
153153153153153153153153153153153
Sparton,520852625263526552665268
cont.153153153153153153
Stewart -Warner9200 1599202 1599203 1599204 159
Stromberg-Carlson
317317 -RPM321
167167167
Sylvania Elect.
1-356 1711-366 1711-387 1711-437-1 1711-441 1711-462-1 1711-502-1 17122M 17122M-1 17123B, 23M 17123M-1 17124M, -1 17124M3 17125M 17171M, -1 17172B, -1 17172M, -1 17173B, 73M 17174B, -1 17174M, -1 17175B, 75M 171
Western AutoTruetone2D1185A2D1185B2D11902D11942D2052
173178178178178
WestinghouseH -639T17 182H -640T17 182H -641K17H -642K20H-642K20AH -646K17H -647K17H -648T20H -649T17H -650T17H -651K17H -651T17H -652K20H -653K24H -654T17H -655K17
182182182182182182181181182181182182182181
Westinghouse(Continued)
H -656K17 181H -657K17 181H -658T17 182H -659T17 181H -660C17 182H -661C17 182H -662K20 182H -663T17 181H -664K17 181H -665T16 182V-2175-3 182V-2175-4 182V-2178-1 182V-2178-3 182V-2192-1 to
-6 182V-2194,-1 182V-2194-3 182V-2200-1 181V-2201-1 182V-2202-2 182V-2203-1 182V-2204-1 181V-2206-1 182
Zenith Radio20H2020J2120J2221J2021J21J2026RJ2027EJ2027RJ2029EJ2029RJ2030EJ2 03 OR
J2040EH2041RJ2042RJ2043RJ2044EJ2044RJ2051EH2052RH2053EJ2053RJ2054RJ2055RJ2126RJ2127EJ2127RJ2129E, -RJ2130E, -RJ2140EJ2142RJ2143RJ2144E, -RJ2151E
185185185185185185185185185185185185185185185185185185185185185185185185185185185185185185185185185185
J2153R 185J2154R 185J2155R 185J2968R 185J3069E 185H3074R 185J3169E 185
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