RCA Victor TRK-9 User manual

PAGE 2 51 -C
MODELS TRK-9, TRK-12, TRK-90 and TRK-120
AC, Superheterodyne, High-Picture- efinition, Five-Television-Channel, Receiver
and
' Three-Band, Electric Tuning, AC, Superheterodyne Broadcast Receiver
Models TRK-12, TRK-120 Models TRK-9, TRK-90
T R K -9 , TRK-90 General Specifications T R K -12, TR K -12 0
Height 47% in ; Depth 24%jin H e ig h t 40% in ; D epth * 1 9 % in
Width 31 Vi in ; Weight 200 lb W idth 34% in ; W eig ht 198 lb
Shipping Weight 2831b Shipping Weight 2751b
Chassis Numbers and Power Supply Ratings
Model TRK-12:
Chassis KC-4, KK-7, RC-427, RS-83E,
105*125 volts, 60 cycles 420 watts (total)
Chassis KC-4B, KK-7DV RC*427, RS*
83E, 105*125 volts, 50*60 cycles 420 watts (total)
Model TRK-120:
Chassis KC*4F, KK*7F, RC*427F, RS*
83E, 105*125 volts, 60 cycles 420 watts (total)
Chassis KC*4j, KK*7J, RC*427F, RS*
83E, 105*125 volts, 50*60 cycles 420watts (total)
General
Models TRK*12 and TRK*120 arc console-type, high*
picture-definition, mirror-viewing, five channel Television
Receivers and thrcc*band broadcast radio receivers enclosed
in handsomely styled modern cabinets Features of the Tele*
vision receiver include: Twelvc*inch Kinescope; Styrol
(humidity-resisting) r*f and i*f transformer forms: black and
white pictures; single station selector switch: temperature com*
pensated condensers; iron core i-f and r*f tuning; double
Model TRK-9:
Chassis KC-4A, KK-7 A, RC-427A, RS*
83E, 105*125 volts, 60 cycles 420 watts (total)
Chassis KC-4C, KK-7E, RC*427A, RS*
83E, 105*125 volts, 50*60 cycles 420 watts (total)
Model TRK-90:
Chassis KC-4H, KK-7H, RC-427G, RS*
83E, 105*125 volts, 60 cycles 420 watts (total)
escription
safety switch protection; safety*glass viewing shield; and extra
large viewing mirror for wide angle viewing
Models TRK-9 and TRK-90 are direct viewing, high*
picture-definition, console-type, five channel, Television Re*
ccivers and three-band broadcast radio receivers in deluxe up*
right modern cabinets Television features of these receivers
arc the same as for the TRK-12 and TRK-120, except that a
nine-inch Kinescope is used
RCA M O R P pS IO M OF RADIO CORPORA TlOhaP^ AMERICA, CAfMŚIŃ N H , l ^ A

PAGE 2 5 2 -C
TRK9, TRK90, TRKI2, TRKI20
TELEVISION RECEIVER
Electrical Specifications
RCA TUBE COMPLEMENT
In KC-4,
( I) RCA
( 2) RCA
( 3) RCA
( 4) RCA
( H RCA
( 6) RCA-
( 7) RCA
( 8) RCA
Kfl 9) RCA
(10) RCA-
(11) RCA
(12) RCA
RCA
KC-4B (TRK-12) and KC-4A, KC-4C (TRK-9) Video Chassis:
6AC7/1852 1st Det
6J5 - Oscillator
6 A B 7 /1 8 5 3 : 1st Pix IF
6AB7/1853 2nd Pix I F
6AB7/1853 3rd Pix I F
6AB7/1853 4th Pix I F
6AC7/1852 5th Pix I F
6H6 Pix 2nd Dct
6F8-G AVC or Limiter
6AC7/1852 Video Amp
6H6 D C Restorer
12AP4/1803-P4 (TRK-12) or
9AP4/1804-P4 (TRK-9) Kinescope
(13) RCA-6SK7 1st Sound I F
(14) RCA-6AB7/1853 ’ 2nd Sound I F
(15) RCA-6H6 Sound 2nd Det 'AVC
(16) RCA-6N7 jV , 1st Sync Sep -Amp
(17) RCA'6Y6'G 2nd Sync Sep
(18) RCA-6N7 i f Sync Amp
(19) RCA'6N7 Hor Osc -Discharge
(20) RCA-6L6 Hor Output
(21) RCA-5V4G (60 cycles) or
RCA'25Z6 (50 c y cle s ) Hor Damping
(22) RCA-6N7 Vert Osc -Discharge
(23) RCA'6J5 Vert Output
In KK-7, KK'7D (TRK-12) and KK-7A, KK-7E (TRK-9) Television Socket Power Units:
(24) RCA-5T4 Low Voltage Rectifier (25) RCA-2V3-G
In KC-4F, KC-4J (TRK-120) and KC-4H (TRK-90) Video Chassis:
High Voltage Rectifier
( 1) RCA-6AC7/1852 1st Det
( 2) RCA-6J5 Oscillator
( 3) RCA-6AB7/1853 1st Pix I F
( 4) RCA-6AB7/1853 2nd Pix I F
( 5) RCA-6AB7/1853 3rd Pix I F
-( 6) RCA-6AB7/1853 4th Pix I F
( 7) RCA-6AC7/1852 ------- 5th Pix I F
( 8) RCA-6H6 Pix 2nd Det
( 9) RCA-6SQ7 Limiter
(10) RCA-6AC7/1 8 5 2 Video Amp
(11) RCA-12AP4/1803-P4 (TRK-120) or
RCA-9AP4/1804-P4 (TRK-90) Kinescope
Note: An RCA-6H6 D C Restorer is added in some TRK-
(12) RCA-6SK7 1st Sound I F;
(13) RCA-6AB7/1853 2nd Sound I F
(14) RCA-6H6 Sound 2nd Det -AVC
(15) RCA-6N7 1st Sync Sep -Amp
(16) RCA-6Y6-G ; 2nd Sync Sep
(17) RCA-6N7 Sync Amp
(18) RCA-6N7 Hor Osc -Discharge
(19) RCA-6L6 Hor Output
(20) RCA-5V4-G (60 cycles) or
RCA-25Z6 (50 cycles) Hor Damping
(21) RCA-6N7 Vert; Osc -Discharge
(22) RCA-6J5 Vert Output
120, TRK-90
In KK-7F, KK-7J (TRK-120) and KK-7H (TRK-90) Television Socket Power Units:
(23) RCA-5U4G (60 cycles, without D C Restorer),
RCA-5T4 (60 cycles, with D C Restorer), or
RCA-5T4 (50 cycles)
Low Voltage Rectifier
TELEVISION CHANNELS (Selector Switch Positions)
1 50 to 56 me 3 66 to 72 me
2 60 to 66 me 4 78 to 84 me
5 84 to 90 me
PICTURE SIZE (Approximate Mask Dimensions)
TRK-9, TRK-90 I p x 7>/4 in
TRK-12, TRK-120 7% x m in
(24) RCA-2V3-G High Voltage Rectifier
Overall Video Band W idth 4 me
Scanning Interlaced, 525 line
Horizontal (Line) Scanning Frequency
(Sawtooth Wave) 15,750 cps
Vertical (Field) Scanning Frequency
(Sawtooth Wave) 60 cps
Frame Frequency (Picture Repetition R ate) 30 cps
Note: 7his sayięc- note includes all chant/cs that have been incorporated since initial production, including deletion of
the 44-50 in.c. channel and addition of the 0- m.c. channel.
IM PO RTA N T PRECAUTIONS
A good ground should be connected to the re
ceiver at all times
Always wear gloves and shatter-proof goggles
when handling Kinescope tubes
Do not eliminate the protection afforded by the
interlock switches
ALWAYS replace the shield can over the 2V3-G
high voltage rectifier The most dangerous portion
of the H V supply is the plate lead of the 2V3-G
tube
Do not measure any voltages on the video chassis
unless the primary leads of the high voltage trans
former have been unsoldered from the supply line,
and taped
Use -only one hand when working on the video
or high voltage SPU chassis, and always connect a
shorting lead to ground (first)* then to the high
side of both high voltage filter capacitors
Make no voltage measurements on the high volt-
age (7,300 volts) SPU chassis
Work on a television receiver should not be at
tempted by anyone who is not thoroughly familiar
with the precautions necessary when working on
high voltage equipment

PAGE 2 S 3-C
TRK9, TRK90, TRKI2, TRKI20
Precautions in Handling Kinescopes
The Kinescope bulb encloses a high vacuum and, due to
its large surface area, is subjected to considerable air pres-
sure For these reasons, Kinescopes must be handled with
more care than ordinary receiving tubes
The large end of the Kinescope bulb — particularly that
part at the rim of the viewing surface—must not be struck,
scratched or subjected to more than moderate pressure at any
time If the tube sticks, or fails to slip into its socket or de-
fleeting yoke smoothly, investigate and remove the cause of
trouble Do not force the tube
All RCA Kinescopes arc shipped in special cartons and
should always be left in the cartons-until ready for installa-
tion in the receiver Keep the carton for future use
The RCA-12AP4/1803-P4 (12-inch) Kinescope is equipped
with a protective lid and shield Do not at any time remove
the close-fitting cone-shaped section of the protective shield
from the Kinescope This section should be installed with the
tube in the cabinet and is designed to protect the user while
handling the glass bulb
CAUTION: Do not open the shipping carton, install, re
move, or handle the Kinescope in any manner, unless shatter
proof goggles and heavy gloves are worn People not so
equipped should be kept away while handling Kinescopes
Keep Kinescope away from the body while handling
Operation
mm
M l
j c StCCCTOO
Ss&ss!
LtCTOO O
m
BRIGHTNESS O
CONTRAST I
Figure 1—Operating Controls, TliK-9, TRK-90
The “Power-Volume** control on the radio receiver turns
on the power for the complete receiver The “Victrola,
Radio, Television" control selects the type of operation de
sired There are three Victrola fidelity positions, four radio
fidelity positions and three Television sound fidelity posi
tions on this switch The furthermost, clockwise position be
ing the highest fidelity position for Television sound
Television Operation:
Station Selector and Fine Tuning —The outer ring “O ”
section of the central dual control knob on the Television
panel selects the station from which it is desired to receive
Television transmissions
Five Television channels arc covered as follows:
(R A D IO C O N T R O L S ) (T E L EV IS IO N C O N T R O L S )
Figure 2—Operating" Controls, TRK-12, TRK-120
nation of the spot which appears on the Kinescope before the
sweep circuits have started functioning
Contrast and Brightness Controls —The inner “I — section
of the “Contrast”-“Brightness” controls is the “Contrast”
control and varies the black and white tones of the picture
being received Too much contrast gives blurred details and
a lack of half-tones, while too little contrast makes it all half
tones or grays Turning clockwise increases contrast from
grays, to black and white Sec Operating Instructions for this
The outer ring “ O ” is the Brightness Control and affects
the average illumination of the picture Turning clockwise
increases the brightness See Operating Instructions for this
receiver
- An approximate adjustment for proper contrast'is to turn
the ‘‘Contrast** control fully counter-clockwise, then turn the
“Brightness" control until the screen is slightly illuminated
Then reduce the Brightness control just sufficient to make the
screen dark, then bring ur> the Contrast Control until the
picture appears A slight further adjustment of the Bright
ness or Contrast control may he necessary in some cases A a
slight readjustment of the contrast control may aid synchroni
zation of* the picture
(1) 50 to 56 me |
(2) 60 to 66 me
(3) 66 to 72 me
(4) 78 to 84 me
(5) 84 to 90 me
Set the station selector to the number corresponding to the
frequency of the station from which it is desired to receive
Television broadcasts
The inner section *,l” of this knob is used for fine tuning
and may eliminate moving ripples or distortion if due to
interfering radio signals
Before the Television portion of the receiver is turned
“ON" it is advisable to turn the Brightness and Contrast
controls completely counter-clockwise to reduce the illumi-
Hold Controls —The dual knobs on the Television panel
marked ‘‘Horizontal” and “Vertical" Hold, control the pic
ture stability The inner section designated by a “ I” is the
Horizontal Hold Control and when, being set should be
turned slowly to the point at which the picture “locks in”
horizontally!>Scc Operating Instructions for this receiver
The outer ring section designated b y“ 0 ” is the Vertical
Hold Control and when being set should be turned to the
point where the picture “locks in" vertically
These two controls, on this dual knob should not ordinarily
require readjustment after good picture reception has once
been obtained An occasional resetting maybe necessary due
to changing to a different station, and to the gradual aging
of the tubes

PAGE 2 54 -C
TRK9, TRK90, TRKI2, TRKI20
SERVICE
Kinescope Installation (TRK-9, TRK-90)
1 Remove back cover of cabinet
2 Remove the two screws which secure the wooden block,
on which the yoke is mounted, to the upper shelf, and drop
this block and yoke away from the shelf
3 Loosen the thumb screw in the center of the slotted
block of wood on the tbp shelf, pull this block of wood to*
wards the rear of the cabinet and turn it so that the **V" slot
on the front end of the block is to your right
4 Wearing gloves and goggles, carefully slide the Kine*
scope on the “V” in the block, and turn both the block and
the Kinescope so that the Kinescope faces the viewing win'
dow Slide the Kinescope up to the mask in the window and
fasten loosely in place by sliding the “V*' block up to die
bottom of the Kinescope face, and fastening it with the
thumb screw
5 Place the yoke and the wooden block on which it is
mounted, on the Kinescope neck, rotate the block 90° from
its original mounting position in order to have it clear the
top of the cabinet and slide it into position on the Kinescope
neck DO NOT FORCE YOKE In some cases where the
yoke lead is too short it may be necessary to loosen the “V”
block and swing the Kinescope neck to the left in order to
be able to place the yoke on the Kinescope neck -without
forcing
6 Fit the upper part of the wooden yoke mounting block
into the slot on the underside of the cabinet top and fasten
the lower end of the block securely by means of the two
screws The Kinescope should be mounted loosely in place,
so that the yoke is not forced on the Kinescope neck at any
time
7 Loosen the wing nuts on the yoke mounting bracket,
and move the yoke forward on the neck of the Kinescope so
that it pushes the Kinescope against the mask Tighten the
wing nuts to hold the Kinescope and yoke securely in this
position
8 It may be necessary to rotate the Kinescope, within the
limits allowed by the high voltage second anode lead, with re'
spect to the mask in order to obtain proper masking of the
Figure 3A—Cabinet Wiring—Model TRK-9, TRK-90
A TA
edges on the Kinescope screen Before rotating the Kine'
scope, the screws holding the yoke mounting block should be
loosened, so that the Kinescope neck will not be forced
9 Move the “V" block forward so that it holds the bot'
tom of the Kinescope in place Tighten the thumb screw
10 Place the second anode lead on the second anode cap
at the side of the Kinescope '
11 After the receiver is operating, and if the picture is
not squared with the mask, using a screw driver loosen the
clamping screws on the band around the yoke and rotate the
yoke until the picture is squared with the mask, then tighten
these clamping screws securely
CAUTION: When removing the back cover of the cabi'
net, after the screws have been removed do not allow the
cover to slide down on the neck of the Kinescope, or the
neck of the Kinescope may be snapped off
Kinescope Installation (TRK-12, TRK-120) —Refer to fig'
ure 4
1 Remove back cabinet cover
2 Remove the top safety glass cover by removing the
three wing nuts “E” at the two front corners and right reąr
corner of the cover and loosening the wing nut “E*° at the
left rear corner of the cover
3 Lift the cover straight upwards, taking care not to
scratch the cabinet finish with tne protruding screws or the
cover itself
4? Loosen the two Wing nuts “F” on the yoke holding
frame, and allow the yoke to drop down as far as possible
5 Using gloves and goggles, open the Kinescope shipping
carton and remove the top cover on the Kinescope
6 Remove the Kinescope from the shipping carton (do
not remove the close fitting cardboard shield from the Kine'
scope), and insert the Kinescope into the cabinet, guiding
the neck of the Kinescope into the yoke! Do not force the
neck of the Kinescope into the yoke, or the tube may
break Let the Kinescope down slowly so that it finally rests
on the yoke

PAGE 2 5 S -C

PAGE 256-C
TRK9, TRK90, TRKI2, TRKI20
7 Rotate the Kinescope and cardboard container (but
not the yoke), so that the second anode cap at the side of
the tube is towards the front of the cabinet
8 Place the white rubber mask on the face of the Kine-
scope, with the ribs on the mask facing upwards toward the
mirror Line up the mask so that it masks the edges on the
Kinescope face Then, if necessary, lift the Kinescope and
rotate it so the mask is 'approximately squared up with the
cover opening! The second anode cap should be kept towards
the front of the cabinet
9 Replace the safety glass cover and wing nuts Tighten
wing nuts to hold the cover securely
10 Loosen the wing nuts “F” on the yoke mounting
bracket and push the two metal brackets, on which the bot-
tom of the yoke rests, upward, until the rubber mask rests
against the top cover If the mask and the cover opening do
not line up, rotate the cone-shaped Kinescope shield until
they do TighteA the wing nuts to hold the yoke and tube in
this position In some cases it may be necessary to loosen the
four screws holding the yoke support to the wooden frame
and shift the yoke support to make the mask and Kinescope
II W
OC MSTOX* WOIO *0??* S,M e'*
Figure 5A —Top View TRK-9, TRK-12 Video Chassis
Video
When it is desired to measure any voltages on (his chassis,
the primary leads of the high voltage transformer T6 (T9—
50 cycle models) should be disconnected and taped together
When any changes have to be made in the Video chassis,
the lead and part locations should be replaced as closely as
possible to the original positions
Because of the special equipment and procedure necessary
for the proper alignment of these receivers, the alignment
will not dc covered in this service note
Refer to the booklet: Practical Television by RCA, for de
tailed explanations of circuit operation in a Television re
ceiver
Service Hints:
1 Poor Horizontal Distribution of the picture elements
may be due to a 6L6 tube RCA-6L6 tubes of known recent
manufacture, are*the only tubes recommended for the Hori
zontal sweep output circuit By careful scrutiny, these tubes
can be identified by the three “rings" or sections welded to*
line up symmetrically with the cover opening
11 Place the second anode lead on the second anode cap
at the side of the Kinescope
12 After the receiver is operating, and if the picture is
not squared up with the cover opening, the two screws “H “
on the band around the yoke should be loosened, and the
yoke rotated to square up the picture, then these screws
should be tightened with a screw oriver
Focusing Control —This is,a screw driver adjustment lo
cated on the right side of the cabinet near the base On early
production receivers, a knob located at the bottom, rear of
the cabinet is the focus control
Adjustments —There are a series of screw driver slot ad
justments at the rear of the TRK-12 and TRK-120 (at the
side of the TRK-9 and TRK-90), used to obtain the proper
picture size, centering, and vertical distribution These ad
justments are explained fully in the receiver operating in
structions, and also in the booklet: “Practical Television by
RCA ”
When the receiver is moved from one location to another
some readjustment of these controls may be necessary
Figure 5B—Top Vino TRK-90, TRK-120 Video Chassis
Chassis
gether at* the base ring of the tube, as shown in Figure 6 If
any other 6L6 tube is used in this position it will break down
in a very short time
Figure A—Recommended Type L Identification

PAGE 2 57 -C
TRK9, TRK90, TRKI2, TRKI20
2 If the picture “tears out" when the receiver is jarred
it may be due to microphonic 6AB7/1853, 6AC7/1852 or
6J5 tubes
3 The 6J5 oscillator tube should be removed without
rocking it in its socket to loosen it, as the rocking motion
may cause the 80 5 mmf capacitor to break off
4 The coils in oscillator circuit should not be touched or
moved or the alignment of the receiver will be disturbed
5 The insulator on the filter capacitors may become dirty
and break down to short out the high voltage
6 The Video coupling capacitors C50, 53, 59 should be
kept clear of chassis
7 A gassy 2V3'G tube may cause resistor R'137 to burn
Replace 2V3'G tube, and resistor, if necessary
8 Changing the position of the oscillator shield plate will
disturb the alignment
Television Socket Power Units
The following precautions should be observed when any
work is being done on the SPU:
1 Remove power supply cord from the power supply
socket
2 No attempt should ever be made to measure the high
(7,500 volts) voltage because of the difficulties and dangers
involved Servicing should be done with an ohm meter
3 If, at any time it becames necessary to service the
SPU, the suspected parts should be replaced by parts known
to be in good operating condition
4 Use only one hand at a time It is advisable to keep
the other hand in one's pocket
5 Connect a shorting lead between ground (first) and
the high voltage side of O-113 and CM 14 (C-121 and CM 22
in 50 cycle models)
6 Whenever working with the oihfilled capacitors, keep
a constant short across the capacitor, as these capacitors do
not completely lose their charge after being discharged a
single or several subsequent times
7 Only one person at a time should work on the unit to
prevent any misunderstanding which may result in an accident
Antenna Installation
The finest television receiver built may be said to be only
as good as the antenna design and installation It is therefore
important to use a correctly designed antenna, and use care
in its installation
In most cases, the antenna should not be installed per'
manently on the apartment or residence roof until the quality
of the picture reception has been observed on a Television
receiver A temporary transmission line can be run between
receiver and the antenna allowing sufficient slack to permit
moving the antenna Then, with a telephone system cori'
necting an observer at the receiver and an assistant on the
roof to find an antenna location, the antenna can be posi'
tioned to give the most satisfactory results on the received
signal A shift of only* a few feet in antenna position or di'
rection may effect a tremendous difference in picture re'
ceptfon
Whenever possible, the antenna location should be chosen
or erected so the antenna is not only broadside to the trans'
mitter but removed as far as possible from highways, hos-
pitals and doctors' offices and similar sources of interference
Auto ignition and diathermy apparatus may cause noise in'
terference spoiling the picture
In mounting any antenna, care must be taken to keep the
antenna rods or pickup wires proper at least ł/» wave length
(at least 6 feet) away from other antennas, metal roofs and
gutters or metal objects Under certain extremely unusual
conditions, it may be possible to rotate or position the an'
tenna so it receives the cleanest picture over a reflected path
If such is the case, the antenna should be so positioned
However, such a position may give variable results as the
nature of reflecting surfaces may vary with weather condi'
tions, as a wet surface has been known to have different re'
fleeting characteristics than a dry surface
In short, a television receiving antenna and its installation
must conform to much higher standards than an antenna for
reception of International Short Wave and Standard Broad'
cast signals because:
(1) Intervening obstacles have a pronounced shielding
effect on the ultra'high frequency waves producing low
intensity signals Severe trouble with multi'path transmissions
may be experienced, especially in congested city areas
(2) The picture signal is comprised of a very wide band
or range of frequencies, all of which must be received with
good efficiency
(3) It must be continually remembered that the discern'
ment for the eye is much more critical than that of the ear
For further information on antennas and antenna installa'
tion see RCA Booklet entitled: “Practical Television by
RCA,” and also the specific instructions accompanying the
RCA Television Antenna
Figure 7—R.F.—Oscillator Unit Wiring and Adjustments

PAGE 2S8-C

PAGE 2 5 9 -C

Figure 10—Schematic Diagram TRK-90 and TRK-120 Without D C Restorer.

PAGE 2 6 4 -C
TRK9, TRK90, TRKI2, TRKI20 —
Television Service Suggestions
Some of the possible troubles that may become evident
during air-check of Models TRK'9, '12, '90, '120 are listed
below, together with the most likely causes of each trouble,
based on field experience w
1 Connect the receiver for operation, being certain that
all cables are plugged in correctly, and that all tubes are
seated down in their correct sockets
2 Blown fuse; shorted High-voltage rectifier Turn the
set on Look to see that the high'voltage rectifier lights If it
does not, check the fuse A r'iorted rectifier will cause the
•'A ampere fuse to blow
3 Intensely bright round spot; no deflection If ah in'
tensely bright round spot appears on the Kinescope, and can'
not be dimmed with the brightness control, turn the set off
immediately This indicates lack of deflection and lack of
voltage across the brightness control Check for—
(a) Defective low-voltage rectifier (5T4 or 5U4'G)
(b) Bent'over pins on the octal plug on cable from the
video chassis to the SPU
(Note that a bright spot may appear for several seconds
if the receiver is turned on again too soon after it has been
shut off Avoid doing this )
4 Thin vertical line; no horizontal deflection If only a
thin vertical line appears on the Kinescope when the bright'
ness control is advanced, it indicates lack of horizontal de'
flection Check the 6N7 horizontal oscillator and the 6L6
horizontal output tube
5 Thin horizontal line; no vertical deflection If only a
thin horizontal line* appears, it indicates failure of vertical
deflection Check the 6N7 vertical oscillator and the 6J5
vertical output tube
6 Excessive hum; defective high-voltage filter Turn con'
trast control fully counterclockwise and adjust the brightness
control to secure faint illumination of the raster ‘‘Lock in”
any residual hum by adjusting the vertical hold control
Normally the hum should be scarcely discernible Excessive
hum may be caused by a defective (low value) filter resistor
R137 in the SPU, which in turn may be caused by a shorted
2V3'G high-voltage rectifier Observe necessary precautions
before checking the filter
7 No focus; off-value high-voltage resistors Adjust the
focus control to secure sharpest lines on the raster The indi'
vidual lines can be seen most readily by turning the hori'
zontal hold control to the lowest frequency (counter'dock'
wise) The lines should be in sharpest focus at one setting of
the focus control Inability to pass through a definite point
of focus indicates incorrect voltages, which may be caused by
off'value resistors in the SPU Inability to focus may also be
due to a defective Kinescope
8 Failure to lock-in;* sync trouble Turn band switch to a
channel that is in operation Adjust the fine'tuning control
for clearest sound, which should be at approximately half'
capacity position Turn contrast control full counter'dock'
wise Turn brightness control until the Kinescope is faintly
illuminated Turn contrast control clockwise until the picture
signal is evident Lock in the picture horizontally and verti'
cally! Adjust the contrast and brightness controls for best
contrast
If the picture will not lock'in horizontally or vertically,
change the 6N7 and/or 6Y6rG sync tubes: Interchanging
6N7's may correct the trouble Otherwise check the resistors,
capacitors and voltages in the sync circuits The capacitors
should be checked for opens and leakage Do not forget that
advancing the contrast control too far on a strong signal will
cause the picture to “tear” out of horizontal sync
9 “Smeared” picture or insufficient contrast There should
be a jumper in the Kinescope socket between the cathode and
one side of the heater Omission of this jumper may cause
‘‘smearing” of the picture when the contrast control is ad'
vanced for good contrast
Check for presence of the jumper with an ohmmeter, and
insert, one if necessary Diagonals may be used to cut out a
artition for the jumper, which should be solid wire Avoid
realringth crocket wafer _________________ _ _______
10 Picture folded back at left-hand side If the picture is
lapped'over, or folded back on the left'hand side, change the
horizontal damper tube
11 No picture; weak picture If the station's sound is re'
ceived, it is an indication that the oscillator and first detector
are functioning Run an RF sweep into the antenna and check
with a CRO for overall response at the picture 2nd'detector
load resistor If there is no response, check the picture'IF
tube's and circuits If response at the load resistor is normal,
remove the sweep and feed a 10 me, 400'Cyde modulated
signal into the lst'detector grid Note the amplitude of the
400'cycle signal at the load resistor, and then shift the CRO
back through the video stage to localize the point ‘at which
the signal disappears
12 Picture signal too strong; contrast control ineffective
In sets where the contrast control is a manual bias control
for the picture'IF amplifier (TRK'9 and TRK'12 without
AVC; all TRK'90 and TRK'120), a grid short in one of the
picture'IF tubes will cause the tubes to operate near full gain
regardless of the setting of the contrast control The defective
tube can be found by using the VoltOhmyst to check grid
voltages throughput the picture'IF amplifier First turn the
contrast control counterclockwise and measure the voltage
from the arm of the contrast control to the chassis This
should be approximately -17 volts for TRK'90 and TRK'120,
or ~23 volts for TRK'9 and TRK'12 without A VC No x*
mally, this same voltage should then exist at each picture'IF
grid and at the lst'detector grid (The last picture'IF tube
has fixed bias )
The same trouble can exist in TRK'9 and TRK'12 re-
ceivers with AVC on the picture'IF amplifier, but in this case
the contrast control is the picture 2ndrdetector load resistor
and the amount of picture signal into the video amplifier can
be controlled In both types of receivers, in normal signal
areas, the absence of bias on the picture'IF amplifier will
cause, overloading of the last picture'IF tube with resultant
grid current and distortion in this tube, which will produce
a voltage across the grid resistor of this tube In normal
operation, there should be no grid current and therefore no
voltage across this resistor The VoltOhmyst can be used to
check for presence of voltage
Grid shorts can usually be located by tapping each tube
very gently, or by changing one tube at a time Shorts in ’52
or ’53 tubes can sometime's be cleared, by tapping the base of
the tube on a table, holding the tube in an upright position
13 Weak picture; insensitive receiver A simple sensitivity
check can be made by removing the antenna from the re'
ceiver and turning the contrast control full clockwise with
brightness control at normal position This should produce
some evidence of tube noise which will appear as speckles oh
the Kinescope raster When the antenna is connected to the
receiver, there should be more pronounced speckles due to
random noise, streaks dtfe to ignition interference from pass'
ing cars, and possibly hum lines that can be locked in verti'
cally, due to sparking in 60'cycle circuits, diathermy, etc
Check each band for sensitivity Noise conditions vary from
band to band Certain types of interference, such as diathermy,
may exist in only one band and may be seen but not heard,
or vice versa Sensitivity can be estimated in this way, just as
with an ordinary radio receiver, bv observing the amount of
noise and the strength of the weaker stations
If the receiver is insensitive, check all tubes in the picture'
IF amplifier and the lst'detector by substituting a good tube
in each socket If the trouble is not due to tubes, it may be
necessary to check the gain of each picture stage
14 Small picture size Adjust picture size, centering, and
vertical linearity Inability to secure a full-sized picture may
be due to low'voltage on the 315'volt bus Check the low'
voltage rectifier (On an improvised Kinescope mounting in
a service shop, another cause for small picture size is due to
placing the deflection yoke too far back on the neck of the
Kinescope )
15 Insufficient width In case of insufficient width on
9'inch and 12'inch receivers, check voltage on the 315'volt
bus that feeds the 6L6 horizontal output tube If the voltage
is low, change the low'voltage rectifier (5IJ4G or 5T4) and,
check heater voltage of this rectifier Also check the 6L6
With low line voltage, if the picture width is not sufficient,
( Continued) ________________________ ■

PAGE 2 6 5 -C
TRK9, TRK90, TRKI2, TRKI20
Figure 12—Partial Video Chassis Wiring TRK-9 and TRK-12 W ith Picture AVC Otherwise same as Figure 13.
Television Service Suggestions
the 5V4-G damper tube can be replaced by a 5Z4 This may
cause a slight spreading of the picture on the left-hand side
16 Picture compressed on left-hand side Shrinking of
the picture on the left-hand side may be caused by a defec-
tive 6L6 horizontal output tube Also check 6L6 cathode
resistor
17 Inability to center picture This may be due to low
voltage across the centering control caused by a defective
low-voltage rectifier or low line voltage Another possibility
is that the elements in the Kinescope may be tilted This can
be checked as follows:
With the brightness control at normal setting, turn the
receiver on and observe the position of the illuminated spot
during the few seconds before the horizontal and vertical de
flection voltages start operating The illuminated spot should
be in the center of the Kinescope (its position during these
few seconds is not affected by the centering controls) If the
spot is off center, it is a definite indication that the Kinescope
“gun” is tilted
18 Distorted sound or sound in picture An open in one
side of the antenna transmission line can cause distorted
sound Other possibilities include:
(a) If the sound-IF response curve is not linear for 75
kilocycles on each side of 8 25 me , distortion will result
(b) Inaccurate adjustment of the oscillator frequency bn
any channel may result in no sound or distorted sound, due
to the fact that the sound-IF beat frequency will not be 8 25
me If the oscillator frequency is too low, the beat note, in
stead of falling on the high-frequency slope of the sound-IF
response curve, may fall on the low-trequency slope In this
case, the sound may be satisfactory, but operation on this
side of the curve should be avoided In some localities, it
results in sound image interference from other channels
A quick and definite method to check the oscillator fre
quency is as follows:
(a) Tune in a television station
(b) Turn the fine-tuning trimmer to minimum capacity
This should prpduce some evidence of sound in the picture
The sound usually appears as horizontal bars o f varying
density, and these vary in step with the speech or music The
bars disappear when the voice or music stops
(Continued)
(c) Turn the trimmer for best sound quality This should
correspond to approximately half-capacity of tnie trimmer
(d) Turn the trimmer toward maximum capacity If the
slope of the sound-IF response curve is narrow, this will move
the beat on to the_ peak of the response curve, producing
low volume and severe distortion
On service work in the home or where test equipment is
not available, if one or more of the oscillator frequencies re
quire re-adjustment, the recommended procedure is as
follows:
(a) Tune in the television station on the channel which re
quires re-adjustment of the oscillator frequency
(b) Turn the fine-tuning trimmer to minimum capacity
(c) Turn the magnedte-ebre for the particular oscillator
coil toward the highest frequency position (core moved away
from the coil) This will definitely put sound in the picture
Turn the core in the opposite direction, to lower the oscil
lator frequency, until the sound is barely perceptible in the
picture Leave the core in this position
(d) Now, by turning the fine-tuning trimmer to half-
capacity, it should be possible to secure good tone quality
with no trace of* sound in the picture
If the sound-IF is deliberately moved into the picture-IF
by adjusting the oscillator core to produce the highest fre
quency, the effect of the sound-IF interference will produce
a “reversed" image, somewhat like a film negative
The customer should be instructed to adjust the fine-tuning
control for-best sound quality, at which point there is no
sound in the picture If the set is turned on in a cold room,
it may be necessary for the customer to readjust the fine-
tuning trimmer to compensate for the slight' drift in oscillator
frequency during the warm-up period
On all converted receivers, the fine-tuning trimmer is per
manently fastened to the fine-tuning control, so that it is not
necessary to press in on the control knob ( “C" washers are-
slipped between the end of the shaft and the rubber drive
and cement is used between the rubber drive cone and the
cup on the fine-tuning trimmer )
19 Insufficient sound In locations remote from the trans
mitter, additional sound volume can be obtained in the 9-inch
and 12-inch receivers by eliminating the irtverse feedback in
the audio 'amplifier of the radio chassis
( Continued)

PAGE Z 66-C PAGE 267-C
TRK9, TRK90, TRKI2, TRKI20 1 TRK9» TRK90, TRKI2, TRKI20
Figure 13— Video Chassis Wiring TRK-9and TRK-12 Without Picture AVC.

Figure 14— Video Chassis Wiring TRK-90 and TRK-120 Without D.C. Restorer.

PAGE 2 7 0 -C
TRK9, TRK0O, TRKI2, TRKI20
NOTE: Brightness Control, R6I, is connected as follows: Terminal 1 Red) to SC of'Tobe 12 100V.) : Terminal 2 Yellow) to C127 ■
Terminal 3 Bus) to Chassis, K144 being omitted.
Figure 15—Partial Video Chassis Wiring TRK-90 and TRK-120 W ith D.C. Restorer. Otherwise same as Figure 14.
Television Service Suggestions (Continued)
To do'this, strip away a section of the insulation on the
two leads from the radio chassis to the two-prong feedback
plug Twist the leads together, solder and tape Remove the
feedback plflg from the speaker- socket and tape it out of
the way
In Models TRK'9 and TRK'12, leave the feedback switch
on radio chassis in the “with feedback” position (counter'
clockwise)
20 Interference on picture If the interference can not
be definitely identified as coming from an external source
such as diathermy, ignition, etc , check to see if it is present
On the remaining channels and then remove the antenna
from the television receiver to see if the interference continues
The various forms of interference may be classified as
follows:
(a) Microphonic streaks Tap the video chassis If this
produces severe streaking or affects picture brightness, check
for microphonic tubes and intermittent tubular capacitors and
connections in the picture'IF and video stages If the picture
smears completely, check for intermittent grid shorts in the
pictureJF tubes If the tapping produces noise in the sound
channel, as well as picture streaking, check for a microphonic
oscillator or lst'detector tube
If tapping does not affect picture strength or sound, but
does upset horizontal or vertical sync, check the sync and
deflection tubes
(b) Electrical interferences This is caused by sparking or
arcing contacts in electrical equipment If the equipment is
a'C operated, there may be horizontal bars or lines that can
he locked in vertically Turn on and off the lights, motors,
etc , in the building to determine if the interference is com'
ing from these sources Occasionally a defective light bulb
will arc and radiate interference in a definite frequency band
(c) Diathermy This varies in intensity (depending on
proximity) from a faint horizontal herringbone streak to a
solid black bar If the diathermy equipment is on the same
power supply as the television transmitter, the interference
will be stationary Otherwise it will travel up or down on the
picture In the latter case, if the interference is severe, the
vertical oscillator, may lock in occasionally on the diathermy,
and the picture will then move up or down •
On remote pickup or chain telecasts, diathermy or other
interference may be picked up on one of the remote links, and
of course in this case nothing can be done at the receiver to
reduce this interference
(d) RF Interference This can be produced by:
(1) Harmonics of a local short'wave station falling in the
television channel
(2) A station operating in the image'frequency band
(which is approximately 8 to 14 me higher than the
oscillator frequency for any band)
(3) Strong signals in the picture'IF band (8 75 to 14
me) leaking through to the grid of the 1st picture'IF
tube
RF interference patterns will alter in step with the modu'
lation of the transmitter (dots and dashes or speech and
music)
Orientation of the antenna and use of standard antenna
reflectors are helpful in reducing the effects of RF inter'
ference If the transmission line is a spaced type, a matching
section at the receiver end may reduce interference due to
(2) and (3) above
The nature or source of RF interference can sometimes
be determined by listening in on the output of the picture'IF
channel To do this, connect the input lead of an audio am'
plifier to the cathode of the picture 2nd'detector load resistor
through an 01 mfd capacitor Connect the ground of the
amplifier to the television chassis This connection will spoil
the picture but permits listening to the audio component in
the picture channel The sound will be a composite of pic'
ture, blanking, and sync signals, together with any audio
modulation on the interfering station, making it somewhat
difficult to pick out and identify the interference A better
method is to use the RCA Chanalyst UHF Converter: Place
the input probe on the picture 2nd'detector load resistor
and tune the converter through the picture'IF band width

r ^ ^ / U A r — V
KINESCOPE
(1 8 0 3 * 4 )
YOKE CLANSP
( S t o c k * s a a © ? )
gStH .M A O L!
* © - 3 2 X I
DEFLECTING YOKE
PROTECTIVE
SLEEVE
(DO NOT REMOVE
FROM TUBE)
CONICAL
METALLIC
SHIEL .
SLOT FOR WING NUT
O UTE R SHIEL
(WING NUT *1 0-3 2
INNER SHIEL
EFLECTING YOKE
SHIEL ASSEMBLY
M-91126
Figure 18—Assembly Details, Showing Kinescope and
De lecting Yoke Shielding

(8 75 to approximately 14 mc) The RF interference can
thus be picked out and identified
(To gain experience in recognising the visual aspect of
various forms of interference, it is possible to produce the
interference locally and study the results Sparking motors
and similar devices can be operated near the television re*
ceiver A test oscillator can be coupled to the receiver input
while a television program is being received Tune the oscil'
lator to the pictur e carrier frequency and then shift it up
several megacycles to produce a range of beat frequencies
with the picture carrier The oscillator output can be in*
creased and decreased, and modulation can be turned on and
off to note the effects )
21 Failure to operate when installed in cabinet-
fa) Check for grid shorts in '52 and 'S3 tubes
(b) Check for bent'over pins on the octal plug from video
chassis to SPU
_________________ PAGE 2 7 1 -C
TRK9, TRK90, TRKI2, TRKI20
22 Interference from harmonics of horizontal deflecting
circuits In lst'production 9'inch and 12'inch receivers,
harmonics of the horizontal deflecting frequency (15 75 kc)
may cause interference on nearby radio receivers In this
case, install the following:
(1) A shielded yoke (RCA Stock No 9857N) This has
a metal pigtail at plug end of cable for grounding
under one of the mounting screws on the horizontal
output transformer Unshielded yokes / do not have
this pigtail
(2) A tube shield (RCA Stock No 12181) on the 5V4G
horizontal damper tube Ground the tube shield to
chassis with a pigtail
(3) Remove the external ground connection from the
television receiver
TRK-9, TRK-12, TRK-120 for 105-125 Volts—50-60 Cycle Power Supply
General differences are as follows:
Chassis KC-4B, KC-4C, KC-4J
1 Horizontal Damping tube, formerly RCA'5V4G,
changed to RCA'25Z6 and socket* wiring revised
2 TRK'9, TRK'12 only: Capacitor 0 6 1 not connected
Its function is performed by an added capacitor Cl 17 (4 mfd
—450 volts)
Chassis KK-7D, KK-7E, KK-7J
1 Capacitors CM 18 (80 mfd ) and (M19 (10 mfd ) added
in parallel with (M10
2 Capacitor 0128—'TRK'l 20 or (>120—TRK'9, TRK'
12 (Q 2'5 mfd ) added in parallel 'with resistor R'166—
TRK'120 without D C Restorer, or R'126—TRK'9, TRK'
12, TRK* 120 with D C Restorer
3 Capacitors CM 13 (0 03 mfd ) and (M14 (0 03 mfd )
changed to (M21 (0 1 mfd ) and 0122 (0 1 mfd )
4 Power transformer (T'5) changed to (T'8) having a
25v heater winding to supply the RCA'25Z6 horizontal
damping tube
5 High voltage power transformer (T '6) changed to
(T '9)
6 Resistor R'165 is added (TRK'120 only)
7 Inductance' L'50 is 100 ohms in these models
8 An RCA'5T4 is used in these models as low voltage
rectifier
In addition Kinescope shielding is provided as follows:
1 A metallic conical section is installed in the cabinet to
shield the Kinescope bulb
2 A double metallic cylindrical section is installed with the
deflecting yoke' mounting assembly to shield the deflecting
yoke proper The accompanying illustration shows its as'
sembly
CAUTION: The conical shield is of the proper size to
permit installing the 12AP4/1803'P4 Kinescope, with its pro'
tective cardboard, sleeve The latter should never-be removed
To prevent Kinescope breakage, when installing a Kine'
scope, the deflecting yoke and shield, assembly must be in
place To prevent breakage of Kinescope when removing the
deflecting yoke and shield assembly the Kinescope must be
removed first
Replacing or orienting deflecting yoke:
1 Remove Kinescope
2 Loosen yoke support bracket wing nuts and remove
complete yoke and shield assembly
3 Remove outer shield Loosen yoke damp screws ta
permit removal or orientation of -yoke If it is necessary to
orient yoke, pull yoke out so it extends about one inch
Tighten screws just enough to hold yoke but not too tight
as it may be necessary to turn it in this extended position
Replace the inner shield and yoke in the yoke mounting
brackets
4 Replace Kinescope and protective glass cover
5 Move the inner shield and yoke assembly vertically
until yoke is gently touching Kinescope bulb Tighten yoke
bracket wing nuts
6 Rotate yoke carefully with one hand to orient raster or
picture
7 Remove Kinescope
8 Remove carefully (so as not to disturb yoke adjust'
ment) the inner shield and yoke assembly Place the latter on
a flat surface with the extended yoke end flush to surface
Press inner shield gently down until yoke edge is flush with
inner shield edge Tighten yoke clamp screws evenly by first
pulling one up and then the other
9 Assemble outer shield to inner shield and yoke assent'
bly so bottoms of shields are flush
10 Replace complete shield and yoke assembly in the yoke
support bracket
11 Replace Kinescope and tighten protective glass cover
12 Push gently complete assembly up flush against the
Kinescope bulb Tighten wing nuts
IMPORTANT: 1 The hole in the conical metallic shield
must line up with the hole in the protective sleeve to permit
connection of the second anode cable
2 Do not jar or drop the shields and keep away from the
loudspeaker field coil to prevent magnetization

PAGE 27 2 -C
TRK9, TRK90, TRKI2, TRKI20
¥
DISCONNECT BOTH OF
■these L E AD S , ANO
CONNECT THe TERMINAL
OF C114 TO GROUND
BEFO R E' MAKIN6 ANY
VOLTAGE MEASUREMENTS
EITHER ON THIS
C H A S S IS , OR TH e
TELEVISION CHASSIS
CAUTION NOTe , FOCUS CONTROL POTENTIOMETER
AND ROD WILL BE TURNED 90* ON
LATER PRODUCTION MODELS
Figure 1 — Television SPU IViring TRK-9 and TRK-12 ( 0 cycle models)
r ukd m m-to-uo *
o e s[«To*ta
•mm a tOA M TOK-tQ-UO
WITH D c »t»Tp*ta
•WTC *t-LV BlCTintS It tu«-t IH TtK-HVlJO
WITHOUT OCBtSTOttt
tv ttcnnn it tT*
M0T* **• •• tlqOOOA M TOK-tQ-ilo
without tcm o m
out i» <to.oooa
M3TJ *«• BtłtłTOH It Mitt m
TtH-tQ-1 to ms
■cMiut a «i»»
with a c u i r o t n
C A U T IO N
DISCONNECT BOTH OF
"THESE LEADS ANO
CONNECT THe TERMINAL
OF C 114 TO GROUND
BEFORE MAKIN6ANY
Me a s u r e m e n t s
EITHER OH THIS
C H A S S I S OR THE
TELEVISION CHASSIS
TAPE THE ENDS QF THE
DISCONNECTED LEADS
„Figure 17— Television iP U IViring TRK-90 and TRK-120 ( 0 cycle models)

-----------------------— ____________________________________________________ PAGE 2 7 3 -C
TRK9, TRK90, TRKI2, TRK120
Radio Receiver Chassis No RC-427, RC-427A, RC-427F,
RC-427G and Socket Power Unit No RS-83E
Three-Band, Electric-Tuning, A -C , Superheterodyne Receiver
Electrical Specifications
Frequency R anges
Standard Broadcast (“A" band) 540-1,720 kc
Intermediate Frequency
Tube Co m pl em en t
( I ) RCA-6K7 R-F Amplifier
( 2 ) RGA-6A8 , 1st Detector
( 3 ) RCA-6J7 Oscillator
( 4 ) RCA-6K7 1st I-F Amplifier
( 5 ) RCA-6K7 2nd I'F Amplifier
( 6 ) RGA-6R7 2nd-Det , A F , A V C , and Muting
Medium Wave (“B” band) 2 3-7 0 me
Short Wave (“C” band) 7 0-22 me
455 kc
( 7 ) RCA-6J5 2nd A-F Amplifier
( 8 ) RCA-6J5 Phase Inverter
( 9 ) RCA'6F6 Power Output
(10) RCA'6F6 Power Output
R0427 and R 0427A only: RCA6U5 Magic Eye
(11) RCA'5U4G (In RS'83E S P U ) Full'Wave Rectifier
Dial Lamps
Power Supply Rating
J Two Mazda No 44, 6 3 volts, 25 amp
( One Mazda No 47, 6 3 volts, 1-5 amp
The Mazda No. 47 is the electric tuning set-up lamp, located at center of dial.)
• 105*125 volts, 50'60 cycles, 120 watts
Power O utput
Undistorted
Maximum
Loudspeaker (RL-70F-5)
10 watts Type 12-inch electrodynamic
12 watts Voice-Coil Impedance ' 2 2 ohms at 400 cycles
General
Radio receiver chassis No RC-427 is used in RCA Victor
Television Console Model TRK-12; RC-427A in TRK-9;
RC-427F in TRK-120; and RC-427G in TRK-90
The audio output of the television chassis is connected to
the audio input of the radio chassis by means of jack X-17
and section S7 of the fidelity switch The functions of this
switch are tabulated on a following page
A separate plug-in power unit, RS-83E, is used to supply
heater and plate voltages to the radio chassis Service data
and diagram for this power unit are shown below
escription
N M H iiu M rio eu T Y t u n in g r a n GC
CONTROL SELE CTO R CONTROL S EL EC T OR
Figure 19—Operating Controls (Radio)
Figure 20—Schematic Diagram Radio SPU, RS-83E M-86727 R S83?