RCAVICTOR 721TS Service Data

^

TELEVISION RECEIVER

rcaVictor

Model 721TSisa

Television Receiver

receiver is

seven

PICTURE

complete in one

front-panel controls.

Model 7

Mahogany

having

or

10"

a

unit and is

Features

Walnut

twenty-one tube,

ELECTRICAL

2 ITS

direct-viewing,

picture

operated by

of the

GENERAL

(kinescope). The

tube

receiver

AND

table-model

of

the use

include:

MECHANICAL

Chassis No. KCS

Service

RADIO

DESCRIPTION

Full thirteen

brilliance:

picture

horizontal hold,

fier and

separator;

SPECIFICATIONS

MODEL

26-1

(60 cycles)

Mfr. No. 274

—

1947 No. T4

CORPORATION OF

VICTOR

channel

stabilized

RCA

CAMDEN,

coverage;

two

and

N.)., U.S.A.

stages

vertical hold;

reduced-hazard

721TS

,

Data

DIVISION

sound

f-m

of video

amplification;

improved

high-voltage

26-2

KCS

AMERICA

system:

improved

sync

(50

A-F-C

ampli-

supply.

cycles)

r

72 ITS

ELECTRICAL AND

MECHANICAL SPECIFICATIONS

(Continued)

PICTURE

Picture Carrier Frequency

Accompanying Sound Traps

SOUND INTERMEDIATE

Sound Carrier Frequency
Sound

VIDEO

FOCUS

SWEEP DEFLECTION Magnetic

SCANNING Interlaced, 525 line

HORIZONTAL SCANNING FREQUENCY

VERTICAL SCANNING FREQUENCY 60 cps

FRAME FREQUENCY (Picture Repetition Rate) 30 cps

OPERATING CONTROLS (front panel)

Station

Fine

Sound

INTERMEDIATE FREQUENCIES

21.25 Mc

FREQUENCIES

21.25 Mc

Discriminator Band

RESPONSE To 3 Mc

Selector

Tuning

Volume and On-Off S'witch Single

)

L

J

Width

(between

peaks)

^^ .

t^ i

Control Knobs

Dual

Magnetic

15,750

Control

25.75 Mc

350 Kc

cps

i t^ i_

Knob

HIGH VOLTAGE WARNING

Horizontal (Picture Horizontal

Vertical (Picture Vertical

Picture

(Contrast)

Brightness

NON-OPERATING CONTROLS (not including r-f

justments)

Horizontal Centering

Vertical

Width rear chassis

Height

Horizontal Linearity top chassis screwdriver adjustment

Vertical

Horizontal Drive rear chassis screwdriver adjustment

Horizontal Frequency

Horizontal Oscillator Frequency

Horizontal Locking Range....rear chassis screwdriver adjustment

Focus

Focus Coil

Ion Trup Magnet

Deflection Coil

(Brilliance)

Centering rear chassis adjustment

Linearity rear chassis adjustment

(Fine) rear chassis screwdriver

Hold) -i

'

Hold)

(coarse) bottom

top chassis wing screw^

chassis

top

chassis wing

top

.Dual Control Knobs

J

..Dual

rear chassis adjustment

screwdriver adjustment

rear chassis adjustment

screwdriver adjustment

chassis

rear

thumb

Control

Knobs

and i-f ad-

adjustment

screw adjustment

nut

chassis

adjustment
adjustment

adjustment

J

OPERATION OF THIS

COVERS REMOVED

POWER

BY

TIONS

NOT

SHIELD

SUPPLIES. WORK ON THE

ANYONE WHO IS

NECESSARY

OPERATE THE

REMOVED.

WHEN

RECEIVER

KINESCOPE

KINESCOPE

NOT OPEN

DO

HANDLE

THE

GOGGLES

SHOULD

KINESCOPE

kinescope bulb

The

considerable

to

ordinary

than

large

The

struck, scratched,

the tube

the cause

detailed
tons and

carton for

BE

end

sticks or

of the

instructions

should

possible future use.

THE

KINESCOPE

AND

HEAVY GLOVES

KEPT

AWAY WHILE

AWAY FROM

encloses

air pressure.

receiving tubes.

kinescope bulb

the

ol

or subjected to

fails

to

trouble. Do not

kinescope

on

left in the

be

RECEIVER

OUTSIDE

INVOLVES A SHOCK

RECEIVER SHOULD

NOT

THOROUGHLY

WORKING ON

WITH THE

HANDLING

SHIPPING

IN ANY

THE

vacuum

high

a

For these reasons,

—

more than

smoothly through

slip

force the

installation. All RCA

cartons until

BODY

particularly

MANNER

ARE WORN.

HANDLING

WHILE

and, due

kinescopes

moderate

the

tube.

Refer to

ready

THE CABINET OR

HAZARD FROM THE

NOT BE

WITH

RECEIVER

ATTEMPTED

FAMILIAR WITH THE PRECAU-

HIGH-VOLTAGE

HIGH-VOLTAGE

EQUIPMENT. DO

COMPARTMENT

PRECAUTIONS

CARTON,

HANDLING.

lo its

rim of the

the

pressure

deflecting

kinescopes

installation in

for

INSTALL,

UNLESS

PEOPLE NOT

KINESCOPES.

surface

large

viewing

any time.

at

yoke,

are

handled with

investigate

the

must be

Receiver

the

REMOVE,

SHATTERPROOF

EQUIPPED

SO

KEEP

area, is

surface

Installation

shipped

—must not

installation,

In

in

receiver.

and

subjected

more

remove

section

special

Keep

THE

OR

THE

care

be

if

for

car-

the

J

RECEIVER

OPERATING

INSTRUCTIONS

72 ITS

following

The

receiver on ior the

1. Turn the

adjustments are necessary when

volume control to

the STATION

2. Set

3. Turn the

control

clockwise.

NESS

terclockwise,

wise until

just

screen.

control

three-fourths

TUNING

sound

SOUND

able

CAL

the

fully counter-

Turn the

4.

control fully coun-

then clock-

faint glow

a

appears on the

Turn the

5.

approximately

clockwise.

Adjust the

6.

control for

fidelity

control for

volume.

Adjust the

7.

pattern

hold

control

stops

movement.

first time:

receiver "ON" and

approximately mid-position.

SELECTOR to the desired channel.

PICTURE

BRIGHT-

PICTURE

FINE

best

and the

suit-

VERTI-

until

vertical

PICTURE

BRIGHTNESS

IN SOME

turning the

advance the

SOUND

.^^=^

\==J^

RECEIVERS "BRIGHTNESS" IS

—

Fig/iie I

Receiver

8.

appears on the

9.

10. After

necessary to

SOUND'

ON-OFF

THE OUTER

KNOB AND

Operating

Adjust the

Adjust the

the receiver

readjust the

I

STATION

'PICTURE'

Controls

HORIZONTAL

screen.

PICTURE control

has been on

FINE TUNING

SELECTOR

THE INNER

FINE

hold control

for suitable

TUNING

until

for some time,

control slightly for

improved sound

11. In

station to

one

it may be

repeat steps

and 9.

When the set

12.

turned on again

period, it

idle

necessary to

be

adjustments if the

the

positions of the

not been

have

any

If

necessary, step

generally

6 is

13. If the

controls have

the

changed, it may be

essary to

number 1 through 9.

picture

the

contrast.

picture

it

may

fidelity.

switching from

another,

necessary

number 6

after an

should not

repeat

controls

changed.

adjustment is

number

sufficient.

positions of

repeat

be

to

is

been

nec-

steps

c

general design

The

conventional.

are

new

and

will be

Fundamentally

oscillator

ing

superimposed

plied to the

proper

the

plies a

portion

A

to the grid

control

the slope

on

If the

slope, the

the

Figure

control tube

freguency

bias to

of the

of the

tube cut

oscillator

2-B. If the

conduction time

control

cathode

plate

to

and

The

are

tube

circuit

conduction

oscillator

the

pulling it

effect of the

as follows.

adjustments

adjustments

fine

effect

control is

hold

CI 36

of

A is

variation

age.

features

However, the

described

horizontal

the

discharge

and

horizontal

on the

and

oscillator to

the

from the

bias

control

off except

grid

of the

changes

conduction

plate

pulse

increases as

conducts

chargetoa

time.

grid thus

phase with

into

various

is tuned

LI2I

oscillator

in

provided on the

frequency by

variable

a

of the

briefly.

oscillator is

circuit.

If the two

grid.

phase

bring it

tube

when the

waveform

phase so

slides up

shown in

capacitors

d-c

potential is

This

shifting

controls

frequency.

frequency.

in

varying the

portion of a

721TS

horizontal

a-f-c

a

The

oscillator

relations, the

blocking

and is

waveform

voltages

into

oscillator

sufficient

sync

shown in

as

that the

decreases as

time

slope, then

the

Figure 2-C.

C16I and

potential

applied

oscillator

the

the sync

with a

pulses.

associated

slug to

C136C

RI56 the

panel to

front

control tube

CIRCUIT

television

hold

running block-

free

incoming

are not

control

sync.

is

to keep

pulse is

Figure 2-A.

slides down

pulse

When the

CI67

proportional

as

with the

effect

provided

is

permit

plate

capacity

receiver

circuit

sync

and ap-

in

tube ap-

applied

the

high

shown in

plate

the

its

in

the

to

bias

a

frequency

circuit

coarse

horizontal

5%

a

volt-

voltage

DESCRIPTION

divider

is

is

to

the

on
on the

control

vided to

and hence

grid

Several

have

failure,

is a

R191

warm up

power

dress of

Strains or

bodies

control

and

changes

page

NORMAL CONTROL

SHADED

is

and

grid of the

positive

C136B is

vary the

components

special

should be

special

high

is a

drift.

transformer

this

excessive

of the

resistance

of

18.

AREA IS

OSCILLATOR

Figure 2

provided to set

control lube

of the

peaks

part of a

amount of

control

is a

of the

coefficients

replaced

resistor

capable

negative

mounted

It is

and

component

heat

VIOBA

associated

Such

with age.

GRID CUTOFF

resistors

circuits.

PORTION OF

—

Horizontal

the

waveform.

capacity

sawtooth

for

oscillator

characteristics

or

only by

coefficient

chassis

should

should

conditions

TOO LATE

SYNC

W/AVEFORM

CONTROL

amplitude

conduction

so that

voltage

voltage on

linearity.

picture

exact

stability

of

resistor

within about

good

for

disturbed.

not be

applied to

not be

with the

may

"Critical

See

EFFECTIVE

VOLTAGE,

Control

of the

occurs only

horizontal

The

divider and

control

and

and in

replacement.

of

1%

compensate

to

inch of

Vi

transfer. The

heat

the

horizontal

cause

Lead

SYNC TOO

PRODUCING

IN

Waveforms

waveform

drive

pro-

is

VI 09

the

circuits

case

RI73

better.

or

for

the

leads

oscillator

excessive

Dress"

EARLY

of

or

on

—

721TS

Model 72 ITS television receiver

The

one carton except

shipped in

for

special carton and should not

a

the

10BP4

kinescope. The kinescope

INSTALLATION

is shipped

be unpacked until

ready ior installation.

UNPACKING—To unpack the receiver,

pick the receiver

flaps,

inet and

lift

it

out of

Take the metal grill off the back of the

front panel from the cabinet as indicated in Figure

TO

TAKE

LOOSEN WING NUTS

TURN PLATES

from under

up

the shipping carton.

REMOVE CABINET

OUT

SCREWS UNDER

AND

tear open the carton

the bottom of the cab-

cabinet.

FRONT

CABINET

INSIDE

CABINET

REMOVE

FRONT

complete in

Remove

the

3.

INSTRUCTIONS

is

are worn.

handling the

body while

use in

INSTALLATION

contact

tube

lop.

the

gun

the

metal

installed

flags

Insert

focus

protrudes

If the

gate

tube.

People not so

handling.

case

of future

is

recessed

a

must

be installed

The

final

position

of the

structure,

base inside

flags,

as shown

so

that

will

be seen

the

neck

coils

as

approximately

tube

sticks,

and

remove

kinescope.

OF

KINESCOPE—

orientation

ion trap

it will

be observed

the

glass

when looking

as shown

Figure

of

the

shown

or

fails

the

equipped

Keep

The

moves.

metal

so that

in

—

5

kinescope

in

Figure

two

to

cause

the kinescope

shipping

well in

this

of

the tube

flags.

neck

Figure

down

in

Figure

FLAGS

Ion

Trap

6

inches

slip

of the

should

be kept

carton

should

The kinescope

the side

contact

is

will

be determined

Looking

that

the

second

is provided

5. The

kinescope

on the

4.

T

Flags

through

until

into

the

beyond

place

trouble.

the

away

away from the

be kept

second

of

the bulb.

approximately

at the

kinescope

cylinder

with

two

must

chassis,

base

smoothly,

Do

"S'3^

deflection

of

the

focus

not

force

the

the

investi-

while

for

anode

The

on

by

from

small

be

two

and

tube

coil.

the

3

Cabinet, Front View

are packed in

bracket inside the cabinet.

paper bag which

a

The operating

is tied to the

Figure

control knobs

focus coil mounting

Remove the bag.
Remove

fier. Make sure

their sockets.

in

Loosen the

slide the

deflection yoke

of the

cushion and yoke

the

protective

the

two kinescope

cushion toward the rear

chassis and tighten.

Figure

From

front of the cabinet, look through

the

4

cardboard shield from the

all tubes are in place

and are firmly seated

cushion adjustment wing

of

chassis. Loosen the

adjustment, slide the yoke

adjustments.

—

Yoke and Focus Coil Adjustments

See

the

Figure

4

FRONT

ON THIS SIDE AND

WITH REAR

and check the alignment of the focus coil

the focus

coil

is not in line, loosen the three focus coil

ment wingnuts and raise, lower, or rotate the

ment

position.

obtained. Tighten the

is

wingnuts with the coil in

Loosen the two lower kinescope face centering slides, and

them at approximately mid position.

tion of the slides and their adjustment

ion trap magnet adjustment

KINESCOPE HANDLING

scope

shipping carton, install, remove, or handle

in

any manner, unless shatterproof goggles

thumb screws.

PRECAUTION—

See

screws. Loosen

Do not open the kine-

5U4G recti-

screws and

toward the rear

for the location

FLAGS

/

Ml

MACNET

GAP

EVEN

MAGNET

GA»

the deflection

with the yoke. If

coil until align-

Figure

and heavy

adjust-

3 for loca-

the kinescope

gloves

yoke

this

set

the

of

Early

production

magnet

like

receivers

If

the neck

coil

justment

free

If

of

the

Figure

correct

side (from

the

Connect

kinescope

one-eighth

the four
the

securely.

safety glass

moistened

agent. Install
ing process

on the

employed

an EM

type

of

towards

thumbscrews

enough

the

PM type

the kinescope

tube

and

4. The front

position

the

rear

magnet.

the kinescope

until

of an

centering

center of

Wipe

with the

proper

Figure

receivers

that in

the model

a PM type

of magnet

the

kinescope

the

base of

to

permit

is

employed,

with

with the

magnet

of the front

rear of

the face

inch outside

slides

the

cabinet

the kinescope

clean

of all

Drackett

the

cabinet front

as

shown

control shafts.

—

6

Kinescope

employed

630TS

is

applied,

with

the

sufficiently

adjustment.

slip

the large

arrow

on the

is

movable

magnet

the

cabinet)

socket

of

the tube

the front

until

the face

opening.

dust

and finger

Co.'s "Windex"

in Figure

magnet

the

tube.

to hold

the

magnet

is with

and even

to the

screen

panel

3. Install

Insertion

an

EM type

receiver.

as shown

slip

the

coils

down

Tighten

it in

assembly

towards

assembly

on the

the

tube

base. Insert

protrudes

of

the cabinet.

of the

Tighten

surface

marks

or similar cleaning

by reversal

the

of

ion

Late

production

in

Figure

assembly

and the

the

magnet

position

up

over

the neck

the

as shown

but still

base of

assembly.

gap on the

with

the

gap

approximately

kinescope

the four

and front

with

soft cloth

a

of

the remov-

control knobs

trap

over

large

ad-

The

left

the

Adjust

is in

slides

panel

3-

4.

in

of

C

c

c

INSTALLATION

forward as

lar

Slip the

kinescope

tighten the

yoke as

lead to

kinescope

cushion

far forward as

kinescope second anode

the

The antenna

Turn the power

fully clockwise, and

control

TRAP MAGNET ADJUSTMENT—The ion

ION

should

poles

as

firmly up

adjustment

and

placed over

be

wing

power connections

switch to the "on"

against the

screws. Slide

possible.

picture

the ion

Figure 4. Starting from this position

moving it lorward or

slightly around

it

raster on

until the raster is slightly above average brilliance. Adjust

the focus control (R129

line structure of the raster

trap magnet for maximum raster brilliance. The final touches

screen. Reduce

the

backward

neck of the kinescope for the brightest

the

the

on the chassis rear apron) until the

clearly visible. Readjust the

is

on this adjustment should be made with

at the maximum position with which good line focus

possible. Slide

flare of the tube

the

Connect the

socket.

high voltage

should now be

position,

control

trap

adjust

at the same time

brightness control setting

the

counter-clockwise.

trap rear magnet

as shown in

flags

the

brightness control

the

INSTRUCTIONS (Continued)

and

deflection

made.

brightness

magnet

rotating

can be

maintained.

FOCUS COIL ADJUSTMENTS—

and R166 to

rear apron controls.

If

a

electron beam is

focus coil

vertical

approximately

focus coil adjustment wing nuts

the

position.

DEFLECTION

are not

the deflection
the yoke

PICTURE ADJUSTMENTS—It

test pattern

steps 2 through

mid position. See Figure

corner of

raster is

the

striking the neck of the tube.

adjustment wing nuts

and horizontal axes

centered and with no shadowed

VERT.

LINEARITY

—

Rear Chassis

7

LINEARITY

RI48

Figure

YOKE ADJUSTMENT—If the

horizontal or squared with

yoke until

adjustment wing screw.

picture in order to make further adjustments. See

9.

this

of the receiver

Turn the

shadowed, it

until the entire raster is

HOR.

(OX (CIX

*il>/VERT.

CENTERING CENTERING

condition is obtained.

will

centering controls R152

7 for location

indicates that the

and rotate the coil

corners. Tighten

with the

CONTROL

a.

FOCUS

q;^

HOR. LOCKING^

^CjpHOR.

Adjustments

the picture mask, rotate

necessary to obtain

now be

operating instructions

HOR. DRIVE

HOR.FREa.''

lines of the raster

of these

Loosen the

about its

visible,

coil

in

WIDTH a

Ct36A

CI36C e

Tighten

this

«

page 3.

CHECK OF

the horizontal hold control to the extreme counter-clockwise

position. The picture should remain in

mentarily remove the signal

then back. Normally

the control clockwise slowly.

will be gradually reduced and

sloping downward

into sync

trol. Pull in

90 degrees from the

picture

of additional

clockwise

HORIZONTAL OSCILLATOR ALIGNMENT—Turn

horizontal

switching

picture will

the

to the left are obtained, the picture will pull

slight

upon

additional clockwise rotation of

should occur when the control

extreme counterclockwise position.

should remain

clockwise

position,

in sync for approximately

rotation of the control.

the picture should

by

The number of diagonal bars

when only

off channel and

of

be out

3'/2

is approximately

At the

out of sync and

be

sync. Mo-

Turn

sync.

iVi

to

bars

the con-

90 degrees

extreme

The

the

by

ion

on

4'/2

should show from

right.

If the receiver passes the above checks and the picture is

3'/2

normal and stable, the

Skip "Alignment of Horizontal Oscillator" and proceed

"Focus"

adjustment.

ALIGNMENT OF HORIZONTAL

check the receiver failed to

the extreme counterclockwise

at

sync at least 60 degrees

from

pull in point, it

the

bars sloping

to

horizontal oscillator is properly aligned.

OSCILLATOR—

hold

of clockwise rotation of the

will

be

with the hold control

sync

position or failed to hold

necessary to make the fol-

lowing adjustments.

Horizontal Frequency

control

station

mer C136C

41/2

bars sloping

insufficient range, set the

extreme clockwise

to the

and adjust the rear

until the picture is out

from max. capacity) and adjust the L121

adjustment

the location of L121.

Horizontal Locking Range

hold control to the

until

remove the signal

Slowly turn the

least

the

picture

If more than

into sync,

slightly clockwise. If less

C136A

control counterclockwise,

number

pulls

into sync.

4'/2

adjust

slightly counterclockwise. Turn the

recheck the number of bars present at the

procedure until 3V2 to

adjustments under

the

"Horizontal

specified

operates

Alignment"

AND

control (R141

height

mask

the

compromise

horizontal

see

7

removing

Adjustments

in all

detail,

rear

bottom.

with the

DRIVE

width

the

Vary the

of the

just fills

picture

Adjust

vertical

to see

thumb

Make

high

R-F

OF

test

if the

made by

page

through

available

for

antennas

on

apron),

sure

receiver

all

the

or

a

peat this

Repeat

ment" and

conditions

zontal hold

Oscillator

HEIGHT

the

fills

(R148 on

top to

justment of the

picture

WIDTH.

—Turn

tion.

best

the

right half

picture

align the

FOCUS—

of the

Check

magnet

grille.

rattle at

CHECK

calibrated

to

frequency on

should be

cedure on

and

by

8.

Tune

for

interference

section

Adiustment—Turn the

apron horizontal

downward to the right.

trimmer to

condition is

this

full counter-clockwise

by

horizontal

of diagonal bars

bars are present just

the

under

VERTICAL

vertically (6%

Adjustment

other.

mask.

HORIZONTAL

AND

control

horizontal

between

linearity

picture.

the

with the

focus

the

wedge

all

that

screws

that the

volume.

OSCILLATOR

oscillator

channels.

the

10. The

are

12

station

channels

for

proper

reflections.

on

Adjustment

switching off

hold

horizontal locking

than

momentarily remove the

"Horizontal

Locking

each are

as outlined

oscillator

the

LINEARITY

chassis

on

inches).

either

of

Adjust

LI 12 to

drive

brightness and

control

Readjust

mask.

control

test

of the

cushion,

light.

are

back is

test

vertical

LI 13

Adjust

yoke,

until the

mask.

ADJUSTMENTS—

heterodyne

or

oscillator

r-f

adjustments

If

method

adjustments

available

Television

selector

6

interlacing

these

If

6.

page

escutcheon

and

position.

obtained. See

Tune in

of sync and

mid-position

horizontal frequency

Set the

—

position.

channel and, then

control clockwise

obtained just before the

before the picture

range trimmer C136A

3'/2

bars are

4'.^

bars are present.

Adjustment"

Range

fulfilled.

"Check of

under

properly

is

ADJUSTMENTS—

rear apron)

Adjust

is

pattern

control will

centering

LINEARITY

maximum

the

trimmer

R129

pattern.

outlined

from

Stations,

for

width

the

horizontal

for

focus

Replace

tight,

on

frequency

adjusted

is

for

the

are

13

and

are

C136B

best

maximum

are

in

channels

front of

as

Observe

for

encountered,

downward

in

If

the

horizontal hold

television

a

frequency

shows 3Vi to

trimmer has

If the

turn

(1

figure 22

horizontal

Momentarily

back.

and note

present, adjust

horizontal hold

signal and

pull in point.

Frequency

When

adjusted.

until the

vertical

until the

the

Horizontal

linearity

symmetrical

require a

align the

to

ADJUSTMENTS

clockwise

yield

to

linearity.

linearity

until the

control

centering

definition

ion trap

and

coil

cabinet

the

otherwise

With a

meter,

the

to

required,

alignment

the

under

shown

the

through 5

1

the

in

the

the

presence

721TS

to the

with

above

control

trim-

out

pulls

Re-

Adjust-

hori-

Adjust

picture

from

read-

posi-

the

Adjust

the

of

back

it may

crystal

check

proper

these

pro-

cabinet

Figure

chassis.

picture

the

see

for

to

of

—

72 ITS

Oscillator

Figure 8

PEAKING

VIDEO

changing the video

permit

factory with

the

produced

taken out by

the chassis

the

on high

connection

ANTENNA TRAP

r-f amplifier

the

from FM

on

channel

trap is

ever, in the

ments

interference.

To

the

minimum

location of the

by

original position

tion.

In severe

reorient the antenna to

RECEIVER

the

in

stations on the

channel 6 from a

5 from

adjusted to

or to readjust

adjust the trap

interference is

interference in

visual inspection.

Repeat this process

cases of such

LOCATION—The owner should be

importance of placing the

room.

the

The location

—Away

from bright windows and so

will fall directly on the screen. {Some

room is

desirable, however.)

—To give easy

permit

—To

Convenient to an

—

allow adequate

—To

VENTILATION

adequate

cabinet. Care

be

ANTENNAS—The

to be

is

and

RCA

signed

antennas

transmission line.

make

of transmission

tory

ventilation holes in the

covered or

only as

therefore

to use care

Television Antennas,

reception on all thirteen

for

use the

any changes in

reproduction.

picture

—R-F

LINK—A video

the

removing

near the

and location

—

grid circuit is

a

field, it may be

trap. Keep both

and repeak the

shjDuld be chosen

access for operation

convenient connection to

CAUTION—

should be taken not to

ventilation to be

finest television

good as the

important to use a

in its installation.

Installation personnel are

line as

response.

peaking in.

contrast

pictures the

link on the

the

VI04 socket. See

of the link.

In some

sets, a

provided to

image of

station on

station on

reject the

the trap

in the

observed. Tune

Then, turn

eliminate this

electrical outlet.

ventilation.

channel 10 or

channel 7. In

channel

necessary to

for channel

field, tune in the

the picture. See

cores

until the best

interference, it may be

receiver in the proper

receiver is

The

impeded in any way.

antenna design

stock No. 225 and

300-ohm RCA

the antenna or to

such changes may

receiver built

correctly designed

INSTALLATION INSTRUCTIONS

The stock

through six

maximum

side

The

channels

maximum

side toward

ment between the

When

216 Mc), both

channels,

Adjustments

peaking

channel

link is provided

This link

However,

series resonant trap across

6-10'

both cores

is connected

transients are

if

peaking should be

terminal board

Figures 49

eliminate

2,

interference. How-

retouch the adjust-

and 51

interference

interference

from

interference on

production, this

5-7

FM image

or

station on which

of the trap for

Figure 21 for the

under

for

approximately the same

one core V2 turn from the

second for maximum rejec-

rejection

difficulty.

obtained.

is

necessary to

advised

location

that no bright light

illumination in the

and comfortable viewing.

the antenna.

provided with

and back of the

bottom

allow these

and installation. It

No. 226, are de-

television channels.

"Bright Picture" television

cautioned not to

substitute other types

result in unsatisfac-

may

holes to

be said

antenna,

These

to

at

of

antenna

tion from its broadside

tenna.

In general,

flections

the receiving location

countered, the

tory.

In

until the quality

a

run

slack

system connecting

at the antenna,

most satisfactory

direction

mendous

REFLECTIONS

or ghosts, are

by two or more routes.

curs when a signal arrives

flected off

of reflections,

cases, reflections

flections but that will

picture.

Depending upon the circumstances,

inate the

to a new location. In

eliminate

Under

to rotate

picture over a reflected path. If such

should be so positioned. However,

variable

with weather conditions.

have

INTERFERENCE

chinery and

which spoils the picture. Whenever

location should

hospitals, doctors' offices, and similar sources

In mounting

antenna rods at least Vi wave length

from

Short-wave radio

cause interference in the picture

In some instances

ference

However, if

the

WEAK PICTURE

area

speckled,

the screen. This

from the transmitter.

(Continued)

antenna is

#226

to 88 Mc). When

(44

signal is obtained

toward the transmitting

stock

#225

antenna

one through six.

signal is obtained

the transmitting antenna,

reflector and the

operated on channels

of

types

the maximum

is rotated approximately

the stock

are encountered,

some cases, the

television

receiver.

is noisy. If

stock

#226

antenna should not

the

of

between receiver and

to permit moving the

an observer

the antenna

or a few feet

difference in picture reception.

results on the received

—Multiple

caused

building,

a

a hill or other object.

even the sound

may occur that

instead cause

reflections

the reflection.

certain extremely unusual

position

or

results as the nature of reflecting

different reflecting characteristics

by

extreme cases, it

the antenna so that it

—Auto ignition, street cars,

diathermy apparatus

bi-directional on

used on these

when the antenna

antenna.

reflector

with

rods are broad-

is unidirectional

When used on these

when the antenna rods

with the antenna

transmitting

seven through thirteen,

antennas have

signal will be obtained

position toward

antenna

#225

if the signal strength

side lobes.

35 degrees in

these conditions are not

the

should

transmitting

be

antenna will probably

installed

picture reception has been

temporary

A

the antenna, allowing sufficient

antenna. Then,

be

transmission line

with a telephone

at the receiver and

can be positioned to give

in antenna position

signal. A shift of

may effect a tre-

images sometimes known

the signal arriving

by

The second or

at the antenna after

at the antenna

subsequent image

In severe cases

may be distorted. In less

are not noticeable

loss

of definition in

a

rotating

the

it may

antenna

possible

be

or by moving it

may be impossible to

conditions, it may

surfaces

Wet

receives the cleanest

is the case, the antenna

such

position

a

surfaces may vary

have

been

dry surfaces.

than

electrical ma-

may cause

possible, the antenna

be removed as far as possible from

the antenna, care must

other antennas, metal roofs, gutters, or other metal

by the use of

television

transmitting and receiving equipment

it may be possible to eliminate the inter-

trap in the antenna transmission line.

a

Interfering signal

the

station,

trap will provide no improvement.

a

the

in

form of moving ripples.

is on the same frequency as

of interference.

taken

be

(at least 6 feet) away

—When the installation is near the limit of the

served by the transmitting station, the picture

having

"snow" effect, and

a

condition is due to lack

may

not hold

of

signal strength

channels

channels, the

channels, the

antenna.

one

are broad-

ele-

(174 to

these

On

when the

either direc-

used

is weak, or if

be satisfac-

permanently

observed on

an-

if re-

en-

can be

an assistant

the

as echoes

oc-

being re-

severe

as re-

the

to elim-

possible

be

may give

known

interference

highways,

keep the

to

objects.

may

may be

steady on

on

3

to

SERVICE SUGGESTIONS

72 ITS

C

C

Some of the

their effects and causes,

with

RASTER ON KINESCOPE—The

NO

be caused by

Incorrect

(1)

No

(2)

(8016) tubes and

are operating, as

terminal 4 of horizontal output

on

can be

Either the high-voltage

the 8016 tube is defective; its filament

high-voltage filter capacitor C142 is

Damper tube (VI 11, 5V4-G)

(3)

possible

the following:

adjustment of ion trap

high voltage.

isolated to the high-voltage

troubles that may be

are listed

effect

magnet.

Check V109 (6BG6-G) and

circuits. If the horizontal-deflection

evidenced

the correct

by

transformer

rectifier (VllO) circuit.

winding (points 2 to 3 on T105) is open;

circuit is open; or the

shorted.

inoperative. Plate voltage

supply for 6BG6-G horizontal output tube is obtained

the damper tube. Check tube, and

If tube is O.K.,

tinuity, and capacitors C139 and

Defective

(4)

circuit open.

No plate voltage. Shorted electrolytic capacitor; open

(5)

check

LI 13 (horizontal

kinescope. Heater open; cathode "return"

heater winding on T106.

linearity coil) for con-

for short

C140

encountered,

below:

of

raster can

no

VI

circuits

waveform measured

the trouble

T105,

through

circuit.

speaker field coil. All -j-B measurements are accessible for

measurement

Horizontal

(6)

operative. Check

tube (V109. 6BG6-G). If not present, check waveforms,

ages, and components in V108 circuits.

HORIZONTAL

only

is obtained, evidenced by

face of the kinescope, it

Vertical oscillator

(1)

inoperative. Check waveforms

Vertical output transformer

(2)

Yoke vertical coils

(3)

POOR VERTICAL LINEARITY—

height

any of the following

Vertical output transformer

(1)

Capacitors

(2)

V107 (6SN7-GT)

(3)

ages.

Excess leakage

(4)

Low plate and bias

(5)

capacitors in

Capacitor CI

(6)

POOR HORIZONTAL

does not correct this

Check or replace

(1)

Check or

(2)

(3) Check waveform

Check linearity

(4)

Check capacitors

(5)

TRAPEZOIDAL

lion

can

Defective

by removing cover from bleeder box.

osc. and control tube (V108, 6SN7-GT) in-

for sawtooth on

grid of horizontal

DEFLECTION ONLY—If horizontal deflection

"straight line" across the

a

can be caused by the following:

and output tube (V107, 8SN7-GT)

voltages

and

(T103) open.

open.

If

and linearity controls

may be

C128-C or

defective.

or incorrect

-|-B supply circuits.

29 defective.

LINEARITY

condition,

horizontal output tube

replace damper tube (VI

on grid

coil L113 for

C139

OR

NON-SYMMETRICAL

be caused by:

yoke.

adjustment of the vertical

will not correct this condition,

the

cause:

(T103) defective.

defective.

C127-B

Check

value in capacitor

voltages. Check

If adjustment

check the following:

V109.

of

short circuit.

and C140 for defects.

on grid and plate.

waveforms

rectifier tube

of controls

(V109,

11, 5V4-G).

RASTER

This

output

volt-

and volt-

C130.

and

6BG6-G).

condi

WRINKLES

ON LEFT SIDE

OF RASTER

-This condition

can be

caused by;

Defective

assembly) being

yoke due to RlOl, H151.

wrong value or open. These

or C141 (internal in yoke

components are

mounted in rear of yoke assembly.

SMALL RASTER

Low +B or line voltage.

10

(1)

Insufficient

(2)

(6BG6-G).

RASTER—

condition

No signal

(1)

tubes VlOl (6AG5), V102 (6AG5). V103 (6AG5), second de-

tector V104 (6AL5), and' video amplifier V105 (12AU7).

Bad contact to kinescope grid. (Lead to

(2)

SIGNAL APPEARS ON KINESCOPE

SYNCHRONIZE

ZONTALLY—

Defective sync amplifier and

(1)

If tube is O.K., check

(2)

circuits.

SIGNAL ON KINESCOPE GRID

—

If this condition is

ONLY

Vertical integrating

and

C125,

PICTURE STABLE BUT

ture resolution

following:

of the

Defective

(1)

(V105, 12AU7).

Open video

(2)

L105, L106,

(L104,

LI 06 have

Leakage

(3)

If above

following:

effective on either

circuits.

PICTURE

low-frequency

caused by

Check for

the

PICTURE

replace the

"noise"

sync, or

components are

Check all potentials

(1)

Check kinescope

(2)

Check adjustment

(3)

Check and

(4)

Normally,

(1)

This trouble

(2)

receiver.

regular

1!

(1)

Vertical

(2)

received

Horizontal

(3)

to "noise."

This condition

output from horizontal output tube

can be caused by:

Vi09

Replace tube.

NO IMAGE, BUT ACCOMPANYING SOUND—This

can be caused by:

kinescope grid. Check picture if amplifier

on

socket broken.)

GRID BUT IMPOSSIBLE TO

PICTURE VERTICALLY

THE

condition of this nature can be caused by:

A

separator (V106, 6SN7-GT).

voltages, waveforms and

AND

encountered, check:

network capacitors C164,

resistors R13B, R137, R138.

WITH POOR

is

picture detector (V104,

shunting

in V105

to standard,

not up

peaking coil. Check

for continuity.

L107)

resistors.

grid capacitor CI 15.

not found to

in video

grid circuit

of focus

side of proper

realign, if

necessary,

RESOLUTION—If the

it may be

6AL5) or

be

circuits.

for poor

control

focus.

the picture

AND HORI-

associated

HORIZONTAL SYNC

C123, C124,

pic-

by any

caused

video amplifier

peaking

all

Note that L105

defective, check the

or dirty

(R129). It

coils

and

contact.

should be

if and

SMEAR—

shift at the

in the

another

picture

6BG6-G).

loose

to

phase

V105.

the

station.

connections

unstable

This can be

circuits.

video

transmitter

displaced,

are

transmitted

smear can be

end of the

improper

current on

grid

Check

JITTER—

sections at

horizontal

instability may

with the

instability may

attributed to

video

of

values

video

originate

can

reception

the left

output tube (V109,

be

signal.

characteristic.

and C

R

amplifier tube

in either

from

of the

due to

due

be

r-f

or

or

721TS

TEST

EQUIPMENT

recommended

R-F Sweep Generator

Frequency

(a)

18 to 30 mc,

40

170 to 225

(b) Output

(c) Output constant on all

(d) "Flat" output

Cathode-ray Oscilloscope,

vertical deflection

Signal

Generator to provide

(Output on these ranges should

volt maximum.)

(a)

Intennediate

21.25 mc

22.8

23.9 mc first

24.5

26.0

27.25

Radio

(b)

Channel

Number

1 45.25

2

3

4 67.25

5 77.25

6

7

8 181.25

9 187.25

10

11 199.25

12

13

Heterodyne Frequency

signal generator is not crystal controlled.

Electronic

Voltmeter of

voltage probe for

up to 10 kr.

—To service this

that

the following test

meeting

ranges:

to 90 mc, 10 mc sweep width

mc, 10 mc sweep width

adjustable with

in all attenuator positions.

and an input calibrating

frequencies:

sound M

mc converter

mc third picture

mc second

mc second

frequencies:

,

use with this meter to permit measurements

the following

1 mc sweep width

at least .1 volt maximum.

ranges.

preferably

the following frequencies:

be adjustable

and sound

transformer

picture i-f

Meter with crystal calibrator

"Junior VoltOhmyst

coil

i-f coil

picture i-f

picture i-f

Picture

Carrier

Freq. Mc Freq.

55.25 59.75

61.25

83.25 87.75

175.25

193.25

205.25

211.25

primary

secondary

ALIGNMENT

receiver properly,

equipment

one with

source.

traps

type" and a high

available:

be

requirements:

wide

a

and at least

Sound

Carrier

49.75

65.75

71.75

81.75

179.75

185.75

191.75

197.75

203.75

209.75

215.75

it is

band

Mc

if the

PROCEDURE

SERVICE

make

without

the

when it

In manufacture,

every effort

If

must first

the chassis

However, if

the

turned

support

should

By

"up," all

Since

.1

rest

drawings

CAUTION:

to become

considerable overload

ADJUSTMENTS REQUIRED

line

other circuits

seldom require

Due to the high frequencies

the r-f oscillator-line

by a

quency on channel

socket. However, it

line to frequency on all of channels

For an

to adjust the line to proper frequency

control in the middle of its range. It

sary to select

the old tube can be matched for frequency

new ones,

it

completely after changing the tube.

Tubes which cannot be used

factorily as an r-f amplifier or

The detailed alignment procedure which follows is intended

primarily as

be taken, and the reasons

more

the

ment is given in the tables; however, alignment

should not be attempted before reading the detailed instruc-

tions.

PRECAUTIONS—

it

possible to

removing

cabinet,

necessary to

kinescope

turning

and

will require the

a soft pad

is inverted,

should

be removed.

should

it is necessary

on end. The

its weight

be used to

the

adjustments

this

is the only

still

leave

are oriented

Do not permit

"shorted" to the

the

remove

should

by resting in

chassis

are either broad

Cutouts in

do some

the

chassis.

should

in

order to

cabinet

be made

the chassis

See Figures

then

be serviced

to

be inserted

kinescope

support

the tube

on end with

will be

safe position

adjustments

similarly

on the high-

attention of

the

bottom of

of the

servicing

If the receiver

be placed

avoid scratching

receives

to preserve

from

a

3, 4

Class

that

cabinet,

without

view

the raster

only

after the

should

never

the deflecting

at its viewing

the power

made conveniently

in which

accessible,

for ease

the kinescope

chassis. To

voltage filter

Normally,

only the

the service technician.

or very stable

and

the trimmer

of use.

second-anode

do so will

readjustment.

at which

adjustment is critical

tube

change. The line can be adjusted

with

oscillator

13

may

tube to be satisfactory, it should

practically any

not then

the receiver

and may be

be possible

7, 8, 9, 10,

with the fine-tuning

therefore

may

tube for the oscillator socket.

a

this practice

will probably

a

discussion of the method used, precautions

is recommended. At best,

necessary

be

to realign the oscillator line

an oscillator may work satis-

as

converter.

a

for

these precautions. Then, for

convenient reference during alignment,

method is given. All the information necessary for align-

the cabinet

of the

receiver

is serviced

under

the

cabinet

the surface.

1 rub

finish

and

finish.

the kinescope

6. If possible,

the

kinescope.

during

servicing,

chassis

be allowed

yoke.

A

bracket

screen.

transformer

available.

the

chassis will

location

lead

cause

resistor

HI 87.

r-f oscillator

All

and hence

to the proper

6J6

to adjust the

will

operates,

affected

fre-

tube in the

11, and 12.

be possible

be neces-

In replacing, if

by trying several

however,

tabulation of

a

tables

by the

in

is

to

a

to

3

ALIGNMENT PROCEDURE (Continued) 721TS

ORDER

OF ALIGNMENT—When

is necessary, it

following order:

can be most conveniently periormed in

complete receiver

a

alignment

Sound discriminator
Sound i-f transformers

Picture i-f traps

Picture i-f coils

R-F and converter lines

oscillator

R-F

line

Retouch picture i-f transformers

Sensitivity check

SOUND DISCRIMINATOR

the signal generator

Set

21.25 mc. and connect it to the second sound i-f grid.

Detune

Set the "VoltOhmyst"

Connect the

junction

Adjust the primary of

meter.

Connect the "VoltOhmyst" to pin 1 of V118 and

volt scale.

3

secondary (bottom).

T108

meter

of diode resistors R181 and R182.

ALIGNMENT—

for

the

on

10 volt scale.

in series with

(top) for maximum output

T108

approximately .1 volt

megohm resistor

a one

output at

to the

on the

set on the

Adjust T108 secondary (bottom). It will be found that it is pos-

sible

produce

to

pendent upon this adjustment. Obviously to pass from

tive to

negative voltage, the voltage must go through zero.

a

T108 (bottom) should be adjusted so that the meter

zero

output as the voltage

This point will

positive or negative voltage on the meter

a

swings from positive

called discriminator zero output.

be

to

de-

posi-

a

indicates

negative.

Connect the sweep oscillator to the grid of the second sound

i-f amplifier.

Adjust the sweep

the center frequency at approximately 21.25

output of

Connect

The pattern

Figvure 13A. If

is

The peak to

opproximotely

to

SOUND

Connect

trap winding of T3 (on top of the chassis).

approximately .1 volt.

oscilloscope

the

obtained should be similar to that shown in

it U not, adjust T108 (top) until the wave iorm

symmetricaL

peak bandwidth

350 ke. and should be linear from 21.175

21.325

mc.

IF ALIGNMENT—

the sweep and signal

Connect the oscilloscope

(terminal A T107) in series with

Connect

Insert

into the first sound if grid.

5600

a

ohm

21.25

a

mc.

Adjust T107 (top and bottom)

metry about

similar

be

21.25

the

that

to

80% response from the first sound i-i

should

be approximately 250 kc.

The output level from the sweep should be set to

approximately .3 volt peak-to-peak

return when

made.

the

It is necessary that the sweep

band

width

approximately

to

1 mc. with

and with

to pin 1 of V116.

of

the discriminator should be

generator to the

to the second sound

33,000 ohm isolating resistor.

a

resistor from terminal A,

top end

if grid

T107 to

ground.

marker signal from the signal generator

for maximum gain and sym-

marker. The pattern obtained should

mc.

in Figure 13B. The band width at

shown

grid to

second i-f grid

the

produce

at

second sound i-f grid

the

final touches on the above

adjustment are

output voltage should

mc.

of

the

return

the

an

specified values

not exceed

will be

unnoticed and

PICTURE

Connect the

and adjust the

Set the

Connect the

load

Connect

C14 and

the

broadened,

possibly

TRAP ADJUSTMENT—

IF

"VoltOhmyst" to the

picture

channel switch to

"VoltOhmyst" across the

RI18 and set it on the

resistor

output of the

the

R8.

connection is

This

through a hole in the side

unit.

Set the generator to 21.25 mc.

calibrator

Adjust T3 (top) and TlOl for minimum

r

Ohmyst."

Set

the

tom)

insure that the generator is

to

generator

for

minimum indication on the "VoltOhmyst" {this adjust-

to

ment is omitted on some chassis).

PICTURE I-F COIL ADJUSTMENTS—

signal generator to each

Set the

peak the specified

and

"VoltOhmyst."

the

mc—T3 (bottom)

22.8

23.9 mc.—

26.0 mc.

24.5 mc.—L103 (top

Picture I-F

more of the i-f coils are tuned to the

two or

receiver may fall into i-f

the

up

as a

load resistor.

LlOl (top of chassis)

—

^T104 primary (top

Oscillation

voltage in excess of 3

This voltage is unaffected by

and sometimes is independent

If such a condition is

stop oscillation by

quency by

LlOl, T104 and LI03 to be

another

setting

receiver known to be in

does not have the desired

to stop oscillation by

then be possible to

aligned in this manner, the

Once

reduced bias.

If the os<dllation cannot be

shunt the

mmf.

1000

of the first two i-f

grids

capacitors.

Connect the signal generator to the third

L103 to frequency.

Remove

the signal generator to this grid

shunting capacitor from the second i-f grid,

the

Remove the shunting capacitor from the

the signal generator

Coimect the signal generator to the junction of C14 and R6

(in

the r-i tuning luit) and align T3 to

B this does not stop the osdllation, the difficulty is not due

to i-f misaligiunent

erly aligned. Check all

resistors,

tubes, socket voltages, ete.

otherwise the

misadjustment

permitting

control

slight

causing

distortion on

junction

-3

for

channel

13.

signal generator to the

of R106 and

volts on the

picture

3 volt scale.

available on

apron of the chassis,

and check it against a

exactly on frequency.

indication on the

27.25

mc and adjust T104 secondary (bot-

following frequencies

of the

adjustment for

of

chassis)

If

—

receiver is badly misaligned

the

maximum

of chassis)

same frequency,

oscillation. I-F oscnllation

volts at the picture

of picture control

encountered, it is

adjusting the coils

adjustment stud

the

approximately

effect, it may now be

increasing the grid bias.

align the coils by the

sometimes

approximately to

extensions of T3.

equal to those

-

proper

alignment.

i-f should be

stopped in the above

amplifiers

i-f grid and adjust

and align T104.

first i-f

align

and

as the

i-f

section is

by-pass

i-f

LlOl.

frequency.

very stable when prop-

condensers, coil

response

weak

curve

to pass

signals.

R107

meter.

second detector

junction of

terminal

a

lug

beside the r-f

crystal

"Volt-

indication

and

shows

detector

r-f signal

If so, it should

input

setting.

possible

fre-

If this

possible

usual method.

stable with

matmer,

ground with

to

connect

connect

grid,

loading

on

to

of

—

721TS

H-F AND

Connect the

minals. If the

output, it

connecting

Connect

r-f tuning

By-pass the

capacitor.

If

and cause an

Connect the

and

Connect the

terminals.

Since

high

Set

for switch

Set

Insert markers

175.25 mc.

Adjust

mately

tween the

overcoupled or

ley

sponse. See

ments, the

mately

Check the

the

oscillator to each

obtained. See

be found

sponse

do

quency

justments, it

L52, and

to

no

higher frequency

the

Channel

Set

Set the sweep

Set the marker

rier frequencies.

CONVERTER LINE

r-f sweep

will be

as shown in

BO OUM

UNBALANCED

SWEEP OUTPUT

CABLE

MSa2T

figure 9

this is not

adjust the

the

the sweep

excursion and

receiver

not fall

get the

difficulty of this type

markers

the receiver to

—

oscilloscope to the

the

unit)

first

Keep

done, lead

"VoltOhmyst" to

signal

channel 7

frequency

receiver

shaft

and

L25, L26,

flat topped

markers.

Figure 17,

stud

equal.

response

channel

that all

with the

within this

channels,

will

possibly

markers up on

easily fall

6 is next

through

incorrect

oscillator to

of channel

Figure

oscillator to cover

ADJUSTMENT—

oscillator

oscillator has a 50

sweep

necessary to

Figure 9.

to the

obtain balanced

D

Unbalanced Sweep

junction

resistor.

ohm

10,000

a

picture if grid to

the leads to

picture of the

control for

picture

generator

has the

channels,

channel switch

location versus

flat

179.75 mc.

L51 and L52

response

Normally

double humped

the markers

channel 7.

extension of all cores

of channels 8

switch, sweep

of these

17 for typical

these channels

markers above

requirement on one

since there are no

necessary to

be

^compromise some channel

channels become

within

aligned

channel 6.

oscillator

ground through a

this by-pass as

resonance may

junction of R170

the

-1

loosely

narrowest

it should be

to channel 7

channel).

cover channel 7.

7 picture

carrier and sound

(see Figure

curve located

this curve appears

with

a

occur at

In making these

through 13

channels and

response curves. It

have the proper shaped re-

70% response.

readjust L25, L26, LSI and

other channels. Normally however,

should

be

comparatively broad and

required range.

the

the same manner.

in

channel 6.

channel 6 picture and

to

ALIGNMENT PROCEDURE (Continued)

receiver antenna

single-ended

ohm

output by

IZO

A.

—

(/VA/"

RECEIVER

ANTENNA

TERMINALS

<S)

db

Termination

Cable

of

C14

fall in the

r-f response.

volt on

to the receiver

response of any

adjusted first.

16)

10 or 15%

approximately

should be

oscillator and marker

observe the response

individual channel ad-

experienced since the

R6 (in the

and

mmfd.

1000

short as

possible.

r-f range

and R171

the meter.

antenna

of

(see Figure 18

carrier

for an approxi-

symmetrically be-

somewhat

peak to val-

90%

adjust-

kept approxi-

switching

by

should

If

markers

the

or more high fre-

slightly in order

sound car-

ter-

the

re-

Adjust Lll,

response curve

Check

receiver,

nel and observing

markers should

not

final adjustment,

ification.

Coupling

link

a

factory and should

channel 6 with the link in

response is slightly

excursion from peak-to-valley.

the response is somewhat broader

cursion is approximately

missible is

not be greater

Remove the

R-F OSCILLATOR LINE

The

with

feeding

quency and

sound discriminator. In this latter

must first have been aligned to exact frequency.

of adjustment will produce

will depend upon the

Regardless of which method of oscillator alignment

the frequency standard must

If the receiver oscillator is to be adjusted

frequency meter

Osc.

If the

sound

Carrier" must be available.

If the

meter probe

If the

Ohmyst" to

LI2, L37 and

channels

sweep oscillator

the case, Lll, L12,

between r-f and

between L12 and L37. This

limited by the peak-to-valley

1000

r-f oscillator line

crystal calibrated

a

signal into the receiver

a

Freq." in the table must be available.

receiver oscillator is adjusted by feeding in the r-f

carrier signal, the frequencies

Channel R-F

Number Freq. Mc.

1

2

3

4

5

6

7

8

9

10

II

12

13

heterodyne

r-f sound

pin 1 of

L38, for

located symmetrically

5 down through

an approximately

channel 1

and marker oscillator

the response

be above the 70%

L37 and L38

all channels

not require adjustment

overcoupled with

obtained. In

response

should

must be within

converter lines is

the minimum coupling

With the

and the

40%. The amount

than 30 °o on any

mmf capacitor

channel.

from the first

ADJUSTMENT—

may be aligned by adjusting

heterodyne frequency meter,

adjusting

the oscillator for zero output

type

method, the frequencies listed

Receiver R-F Sound

frequency

carrier

the

method

loosely to

V116.

at the r-f sound carrier

case

the same results. The method

of

equipment

test

crystal controlled

be

Osc. Carrier

71

81

87

93

103

109

201

207

213
219
225

231

237

method

meter

receiver

oscillator.

is used,

between

flat-topped

the

markers.

by switching

to

each chan-

all cases,

point. If

retouched.

be

the 70%

augmented

link is

adjusted in

in the field.

position,

approximately

coupling at maximum,

peak-to-valley

of coupling

excursion

which

picture i-f

it to beat

from

the

sound discriminator

Either method

available.

is used,

calibrated.

or

the heterodyne

by

under "R-F

listed

under "R-F Sound

Freq. Mc.

49.75

59.75

65.75

71.75

81.75

87.75

179.75

185.75

191.75

197.75

203.75

209.75

215.75

is used,

connect

couple the

the

this is

spec-

10%

a

per-

should

grid.

or by

used

"Volt-

the

the

On

by

the

On

the

ex-

fre-

the

3

10

ALIGNMENT

PROCEDURE

(Continued)

72 ITS

c

c

generator to the

Connect the

The

method

Since lower

inductance,

tinue in

Set the

Adjust the frequency
mc. for

generator).

Set the fine

ing

Adjust

frequency meter or

core stud

inspection.

Switch the receiver to

Set the

in

the

Adjust L76

Adjust the oscillator to frequency on all

ing the receiver and the

and

fied indication. It should be

to the correct

control in

After

signal

order of

alignment

is used.

frequencies

it is

reverse numerical

receiver

remains

are obtained by

necessary to align

channel switch to

standard to

heterodyne frequency

tuning control to the

the adjustment.

and L78 for an

L77

extensions should be

zero voltage from sound

channel 12.

frequency standard to the

alignment table.

for indications as above.

frequency standard to each

adjusting the appropriate

frequency on all channels with the fine

middle third of its range.

the

the oscillator has been set on all channels, start back

channel 13 and recheck to make sure that

correct.

RETOUCHING

OF

PICTURE

The picture i-f response curve

of bias and for this reason it should be

mately the same

If the receiver is located at the edge of the

should be aligned

signal input as it will receive in

with approximately

receiver antenna

regardless of

same

the

channel 13

order.

channel 13.

the correct

meter or 215.75 mc.

middle of its range

audible beat on the

discriminator. The

maintained equal by

proper frequency as

channels by switch-

oscillator trimmer for the

possible to adjust the

all adjustments are

ADJUSTMENTS—

I-F

varies

somewhat

aligned with approxi-

—1

However, for normal conditions, (signals of 1000

or greater), it is recommended that the picture i-f be aligned

with

grid bias of

a

junction of R106 and R107.

at the

Connect the

minals.

—3

volts. Set

r-f sweep generator to the receiver antenna ter-

the picture control for

terminals.

which

adding

steps of

first and con-

frequency (237

signal

for the

while mak-

heterodyne

visual

listed

channel

speci-

oscillator

tuning

with change

operation.

service area, it

volt i-f grid bias.

microvolts

—3

volts

Connect the signal generator to the antenna terminals and

feed in the 25.75 mc. if picture carrier marker and

marker.

a

23 mc.

Connect the oscilloscope across the picture detector load re-

sistor, R118.

the channel switch to channel (between 1 and

Set

to have the best response during the r-f and converter

justment.

Set the sweep output to produce

approximately .3 volt peak-to-

found

6)

line ad-

peak across the picture detector load resistor.

Observe and analyze the response curve

sponse will not

retouched in order to obtain

these adjustments, care should

formers are tuned to the same frequency as i-f

result.

ideal and the i-f

be

desired curve. In

the

be

obtained. The re-

adjustments must

taken that no two

oscillation

making

trans-

may

On final adjustment

the picture carrier

approximately 45% response. The curve must be

mately flat topped and with

the 23 mc. marker at approxi-

marker

must be at

approxi-

mately 90% response.

most important consideration in

The

ments is to get the picture

If the picture carrier

loss of low

blanking, and of sync may occur.

ates too high on the

impaired by

frequency video response,

loss of

SENSITIVITY CHECK—A

made

television station and

tained to that obtained on

conditions.

This weak signal can be

antenna to the

shown

pends upon the

sufficient number of

what less

picture

operating the

by

receiver through

in Figure 10. The

signal strength

than normal contrast

control is at the

1ZO

-vww-

at

-vww-

Vigure

type

carbon

Only

attenuator

generally

sistors

advisable to

it is

used in

sistor

RESPONSE

14 and

12,

were

cedure

are

curves

2 r-f

nel

response

The

presentation, that

left. The

the

set-up

test

and the

scope

and /or

verted

polarity of the

flection

generator.

sweep

be

ALIGNMENT

presented in

thereby

is

can be

choose the

found that the

easily

Since

pad.

available

break

order to

CURVES

and

15

taken

typical, some

response (not

curves are

is

manner

depend

will

sweep

switched

TABLE—Both

alignment

the

dual

erased.

carrier at the 45% response

operates too low on the

response curve, the picture

frequency video

high

comparative sensitivity

receiver on a

comparing

other receivers under the

obtained by

number of stages

stages should be

maximum

.^vvvvv-

-WWAr-

—

Attenuator

10

many

and

determine its

response

from a

variations

shown)

shown

"response up"

with

which they

in

upon the

generator.

from

oscilloscope

methods of

method

listing

should be

of the

are

examine one

production

left to right

table. The

to

is

resistors

—The

referred to

making the i-f adjust-

point.

response curve,

of picture brilliance,

If the picture carrier

definition is

response.

check can be

weak signal from

picture and sound ob-

the

same

connecting the shop

in the

I20

of

the type

pad de-

a

some-

an attenuator pad

available at the antenna. A

inserted so that

picture is obtained when the

clockwise position.

^

RECEIVER

I

ANTENNA

I

TERMINALS

-JWSA/V-

Pad

construct the

to

used

low value

of wire

construction.

curves

throughout

set.

can be

to that

similar

is

in the

and

will be

characteristics

curves may

The

depending

and

oscillator

service

suit his

confusing, the

test

moulded

construction,

wound

each type

of

shown on

alignment

the

Although

expected. Chan-

channel 3.

of

low

manner

frequency

classical

seen in a

the

of

be

on the de-

phasing

the

alignment

technician may

equipment.

unwanted

of re-

pages

given

oscillo-

seen in-

of the

listing

of

oper-

a

re-

pro-

these

of

to

are

If it

11

721TS

THE DETAILED ALIGNMENT

STEP

No.

PROCEDURE

BEGINNING

DISCRIMINATOR

ALIGNMENT

ON PAGE

SHOULD BE

8

AND

TABLE

READ

SOUND IF

BEFORE

ALIGNMENT

ALIGNMENT

BY

USE

OF THE

TABLES

IS

ATTEMPTED.

ALIGNMENT

TABLE (Continued)

72 ITS

THE DETAILED ALIGNMENT

STEP

No.

PROCEDURE

BEGINNING

ON PAGE 8 SHOULD BE READ BEFORE ALIGNMENT BY

PICTURE

IF AND TRAP ADJUSTMENT

USE OF THE TABLES

IS ATTEMPTED.

721TS

THE DETAILED

STEP

No.

ALIGNMENT

PROCEDURE

BEGINNING

ALIGNMENT

ON PAGE

R-F

AND

8

CONVERTER

TABLE

SHOULD BE

(Continued)

READ

LINE

ALIGNMENT

BEFORE

ALIGNMENT

BY

USE

OF THE

TABLES

IS

ATTEMPTED.

c

STEP

No.

ALIGNMENT TABLE (Continued)

R-F OSCILLATOR ALIGNMENT

72

ITS

721TS

CHASSIS

VIEWS

T106

POWER

TRANSFORMER

I

Figure 21

—

Chassis

Top

View (Showing

Location

of

Major

Components)

NOTE: IN SOME

Figure 22

—

Chassis

Bottom

RECEIVERS.

View

(Showing

LI02 IS

16

USED IN

Location

PLACE OF TI04

Major

of

3

Components)

c

Peak to

peak voltages

shown

are nominal

WAVEFORM

when

1 volt peak

Video

Signal

Amplifier (At Pin 2

PHOTOGRAPHS

to peak video

Input to

signal

1st Video

of V105)

is

applied

ma >

to Isl

video amplifier

(V105).

72

1 TS

c

Figure

25

(1.0 Volts, P

'

S=

Figure

25

(5.0 Volts,

Figure

21

Volts, P

(32

—

Vertical

.

—

Vertical

P to P)

—

Vertical

to P)

'P-

to P)

Figure

'

'

i

Output

Input to Kinescope

(]unction

1st

of

(Pin 1

L106

of

to Kinescope

Video Amplifier

of V105)

Figure 26

Grid

and Green head

Socket)

Figure 28

—

Horizontal

24

(1.0 Volts, P

—

Horizontal

Volts,

(5.0

—

Volts,

(32

to P)

P to P)

Horizontal

to P)

P

c

i^^WMIK

29

Volts,

31

—

Vertical

P to P)

—

Vertical

P)

Figure

(8

Figure

(90 Volts, P to

Input

Input

Output

to Grid

(Pin

to Sync

(Pin 2

of

(Pin

6

Sync

1

of V106)

of

Sync

of V106)

Amplifier

Separator

VI

06)

Separator

ffl

Figure

Volts, P to P)

(8

Figure

Volts,

(90

ffl

—

30

—

Horizontal

32

I

Horizontal

P to P)

33

—

Vertical

to P)

Figure

(10 Volts, P

17

Figure

—

Horizontal

34

(10 Volts, P to P)

72 ITS

WAVEFORM

PHOTOGRAPHS

(Continued)

Figure

PtoP)

Output

(Junction

Figure 38

—

35

Integrating Network

of

of

—

Output Tube

Volts,

(750

(Pin

5

V107)

of

Figure

tor Control

(Junction

—

41

R158 and R164)

Vertical

(25

Volts,

R138 and C125)

Plate

P to

Horizontal Oscilla-

(45

Vertical

of

P)

Volts, P to

P)

Figure

Oscillator Tube

(175

(Pin 1

Figure

tical

L109)

Green Lead

—

36

Volts,

P

VI

of

—

Voltage Across

39

Deflection

Volts, P to

(90

of

Grid

^Y

Figure

Oscillator

(Pin

—

Grid

42

(400 Volts, P to

4

VI 08)

of

of

to P)

07)

Coils (L108,

to

T103

of

Vertical

Ver-

(At

P)

Ground)

Horizontal

P)

Figure 37

—

Output Tube

Volts,

(65

(Junction

Figure

tor

(20

(Junction

Figure

lator Output

(Junction

P to P)

of

—

40

Waveforms and

Volts,

P to P)

of

—

43

of

Input to Vertical

CI 29 and CI

Horizontal Oscilla-

C122

Horizontal

Volts, P to P)

(60

30)

Pulse

Sync

and C133)

Oscil-

C135 and C163)

Figure

Output

(40

(Pin

Figure

ing Out

When Horizontal Hold Control

Is

tion

Sync

—

Grid

44

Volts, P to P)

5

of V109)

—

Test Pattern Show-

47

of

in a Counterclockwise Posi-

—

Just

Before

Horizontal

of

Sync Condition

Pulling Into

Figure

Output

P

Capacity

from

Figure
ing

When

Is

Position.

—

Plate

45

(Approx. 5000 Volts,

(Measured Through

to P)

Divider

Plate

to

—

48

Test

Out

Of

Horizontal Hold Control

Maximum Clockwise

at the

18

Horizontal

of

Connected

Ground)

Pattern Show-

Sync Condition

Figure 46

a

Horizontal Deflection Coils

(Approx. 1100 Volts, P to

(Pin 4 or 6

Ground)

CRITICAL LEAD DRESS

1. Do not

placed on the leads of R126, R157,

R158, R164, R165,

R191.

sistors

of a

than is absolutely

2. Dress

sating

mately

the

chassis.

3. Dress

tors and

aivay

Contact

4.

tor

and

nel

avoided.

i^Db.

—

Voltage Across

permit any

Do not

be exposed to

to

soldering iron

temperature compen-

the

resistor R191

one-quarter

transformer and

power

all video

peaking

from the

between

oscillator

switch

adjustment

eyelets

frequency

the

Vlll to

of

strains

to

R173, R188

these re-

permit

the

more

any

necessary.

approxi-

inch

coupling capaci-

coils up

chassis.

oscilla-

the r-f

screws

chan-

coils or

must

P)

and

heat

from

the

and

be

be

--11

" I

:^hzJ

n iT^

SE7J

'S'

MOTE

CHASSIS

J

'

;

t

WIRINQ

DIAGRAM

(^

o

Li-:^

Early

ness and
the

brightness

ture,

the

shown

control

outer

knob and

production

picture

center

in

the above

#73193 in

sets employed

control

is the

outer knob

knob.

wiring diagram

which

brightness

#71784 in which

production,

Late

picture is

center.

the

bright-

end pic-

employs

the

The

front

fected

#72805

#73194 is for

The operating instruction

fected by the

Book #49050-1

trol

#71784.

panel

by the control

is

for control

control

control change.

is

19

control

#73193.

for sets

decals

changes.

1 784. Decal

#7

book is

Instruction

employing

are

also

af-

Decal

af-

con-

Figure

Supplementary

been issued to convert

with

sets

sequent

struct ion books will

iJ49050-2.

—

Chassis Wiring

49

employing

printings of

Diagram

sheet #49050-15 h

-

1 books for l

control #73193.

production i

late

designated

be

Su

CHASSIS WmiNQ

«E»-;i(eS--.»N.-_^

^

to ion

trap UlMiNEJ?-"^^

^~Jb1I9

*«vJl

f

DIAGRAM

72

—

-

f'o^l

The front

fected

#72805 is for

#73194 is for control

The

fected

Book #49050-1

trol

#71784.

panel control

by

the control

control

operating instruction

by the control

is for sets

decats are af-

changes. Decal

1

#7

784.

#73193.

book is

change.

Instruction

employing con-

oiso

Decol

af-

Supplementary

been issued to convert

with

sets employing control

sequent printings

struction

£r49050-2.

sheet #49050-

of late production in-

books will

-1

books for use

#73193.

designated

be

In early

has

S

1

Sub-

as

type of ion

was

lines.

R

ing

R

with

trap

connected

was

1 96

on EM

type magnet.

97 was

1

the 247-ohm

production

omitted

employed

receivers, an EM

mognet was employed

as shown by the

receivers employ-

in

only in

coil.

focus

and

dotted

receivers

19

Figure

—

Chassis Wiring

49

Diagram

-"-

< ^

72 ITS

49050-15 has

books for use

6^73193. Sub-

production

:iesignated

In early

type

was

in-

as

lines.

R196

ing

R197 was employed

with

of ion

connected

was omitted

an

EM

247

the

production

trap

tvpe

-ohm focus

receivers, an EM

magnet was employed and

as shown

magnet.

by the

in receivers employ-

only in

coil.

dotted

receivers

Figure

—

30

R-F Unit Wiring Diagram

20

Direction of arrows

clockwise rotation,

All voltages

and with picture coni

Voltages should hold

1 17 v. a-c supply.

Coil

are not shown.

caused changes in

codas, in

their lug

measure

resistance vqIl

receivers,

some

electrolytic

identificatioi

o

72 ITS

SCHEMATIC

DIAGRAM

Figure

—

50

jR-F Unit Wiring

Diagram

20

I n some receivers, substitutions have

caused changes

codas,

their lug identification

electrolytic

in

component

In

capacitor values and

markings.

lead

color

In early production receivers Qr\ EM

type of ion trap magnet was

was connected as shown by the dotted

ines.

L82, C21

omitted

and

R196 was

an EM type magnet.

ng

In some receivers, the

(LSI,

In some receivers, the bottom end of

CH2 is connected to pin 4 of Vlll

receivers employ-

in

C22)

21

employed

antenna trap

omitted.

may be

and

SCHEMATIC

VI

14

6bA6

SOUND 1-F

15T.

DIAGRAM

721TS

AM

resistance values

All

capacitance values

and

above 1 in

noted.

Direction

clockwise

All voltages measured

and with

Voltages

I

1 7 v. a-c supply.

Coil resistance values

ore not shown.

In some receivers,

caused changes

codes,

their

of arrows

rotation.

picture control counterclockwise.

should hold within

in electrolytic capacitor

lug identification

in ohms. K

less than

MMF unless otherwise

controls

at

with "VoltOhmyst"

less than 1 ohm

substitutions

in component

markings.

:

1000.

1 in MF

indicates

±20% with

hove

lead color

values and

21

In some

sets R108 is connected to ~!4V.

In some

omitted.

type of ion trap

was

lines.

ing

(L81, L82,

CI 42 is connected to

sets L122, R195 and R193 are

In early production

connected

R195 was omitted in receivers employ-

an EM type magnet.

In some

In

receivers,

and

C21

some receivers,

receivers an

magnet was employed and

as shown by the dotted

antenna

the

C22) may be omitted.

the bottom end of

pin 4 of VII

In some receivers,

used

in place of

26 mc.

EM

trap

1.

Figure 51

In early production

ance

of the focus coil was 247 ohms.

R197 was

with

the 247-ohm focus coil.

Optional

the video peaking

is connected

sients are produced

tures,

ure 49 for

In

—

Overall Circuit Schematic Diagram

video peaking Is provided

in place. However, if tran-

the link should be opened. See fig-

location

some receivers, R-149 is 3300 ohms.

single coil,

T104.

a

receivers

LI

02 is

L102, is

tuned to

the

resist-

employed only in receivers

link. Normally the link

contrast

on high

of the link.

pic-

by

721TS

STOCK

No.

75066

75067

71504
71500
71502
71520

45466

33101
65401

71540

71501

72122

71469

71479

71470

72597

72552
71480

72553

71481

71472

71471

71492

71491

71490

71489
71488
71506
71505
71493
71497

71498

71597

72743

71465

72744

71487

71462
30732

30880
34766

30494

3078
3252

30652

14343

71475

71476

71474

J

DESCRIPTION

RF UNIT ASSEMBLY

KRK2B1

Board

—

contact

2

terminal

Bracket—Vertical

tube shield

Capacitor—Ceramic, 0.68 mmf.

Capacitor—Ceramic, 1.5 mmf.

Capacitor—
Capacitor—Ceramic, 4.7

Capacitor—Ceramic, 10

Capacitor

Capacitor—Mica,

—

Capacitor—Ceramic, 270 mmf. (CI, C2)
Capacitor—Ceramic, 1500 mmf. (C5, C8, C9,

C17)

Coil

Channel

—

rear section or channel

front or rear section (LI, L2, L27, L28)

Channel

Coil—

tion

(L53,

Channel

Coil—

front or rear section

verter grid coil—front

LB, L29, L30, L33, L34)

Channel

Coil—

Coil—Channel
Coil—

Coil—

Coil—Channel

Coil—

Coil—
Coil—

Coil—
Coil—

Coil—
Coil—Channel #13

Coil—

Coil—

section

-front

(L31, L32)

section

Channel
Channel

section (L7,

rear

Channel

rear section

front or

Channel
Channel

channel

Channel

amplifier

L37, L38, L63,

Channel

coil—rear

plate

Channel #13

plate coil

Channel #13

Converter

Coil-Heater

Connector—

Channel

Core—

justable core

Channel

Core—

or front

coils

justable

converter

rear

plate

plifier

Channel

—

Core

adjustable core

Detent

Detent—

Rotor disc

Disc—

Fine tuning drive

Drive—

Form—Coil

coils—less

Oscillator to

Loop—

Resistor—

Resistor—150

Resistor—

Resistor—4700
Resistor—10,000
Resistor—

Resistor

Ring—

Screw

Screw

Segment—

47 ohms,

1000 ohms,

100,000

—1 megohm,

Retaining ring

#4-40

—

L56, L58,

L54,

#4-40

—

coils L66, L68,

ing

Converter grid

coils or

less coils (Part

terminal board

board)

on top of R-F

bracket ior holding

Ceramic,

Ceramic, 22 mmf.

L54)

rear section

#2

plate

—front

Segment

core and

2.2

mmf. (CI

270

rf amplifier plate coil

#1

oscillator coil

#1

and

#2

#2

#3
#3

#4

#4

#5

or channel

#5

#5

oscillator coil

#6

#13

choke

#6

and stud

and rear

coils adjustable

#13

#3

or Channel

and

L58, L60)

(L56,

converter

oscillator coil

amplifier plate

r-f

L8)

oscillator coil—

amplifier plate

r-f

(L9, LIO, L35,

oscillator

oscillator

oscillator,

coil—front or

L64)

converter

section {L25,

converter grid

section (L26, L52)

oscillator

oscillator

choke coil (L80)

grid i-f

coil (L79)

connector

front

front and fear

#6

stud or

coils or

grid

front

and stud

mechanism and

for fine

form only

winding

ohms, V2

for

converter grid

V2 watt (R8)

watt (R3,

V2 watt (R4,

ohms, V2

ohms, V2

ohms, V2

V2 watt

for drive

15/32" adjusting

x

L60, L62

binder

x W

L70, L72,

amplifier plate

r-f

of

S3)

S2,

(used

unit

(C13)

{C3,

mmf. (CIO)

mmf.

(C6, C7,

mmf.

(C19)

(C14)

8)

converter grid

#1

—front

amplifier plate

r-f

section (L3, L4, L5.

or rear

and

#3

#4

coil—front or

grid

—rear section

rear section

converter

#5

coil—rear

coil—front

—rear

converter

rear section

grid or

LSI)

coil—rear

coil—front

and rear

r-f

tuning control

watt (Rl, R2,

section

oscillator

amplifier

channel

front and

core

and rear

fiber

channels

coupling loop

Rll, R13)

R12, R14)

watt (R5)

watt (R9, RIO)

(R6)

head screw

L74,

rear

section

C4)

#2

L36)

section (L55,

or r-f

and

screw for

L76

—

—

—

REPLACEMENT

as antenna

R-F oscillator

CI

2)

Cll,

—

oi

front

coil

rear sec-

or

coil

#4

—

front

grid coil

section

grid or

(Lll, L12,

amplifier

amplifier

coils ad-

coils ad-

front

r-f am-

stud

and

adjust-

for

segment

con-

coil

rear

(L57)

or

(L59)

or

or

L82)

r-f

(L78)

grid

and

coils

#13

coils

less

and

oscillator

coil^front

coil

section (L61)

r-f

section (L77)
section

converter

plate

#13

rear

oscillator

shaft

(Part of C15)

#6

R7)

segment

rear

PARTS

STOCK

No.

71473

71467

71468

72951

71494

71461

75068
71466

71507
72811

73239

71894

72857

72809

72615

39620
39628
45469

39630
73102

73091

73094
71450

71501

39660

72524

72771

70602

70601

70622
70606

70627

71518

70610

71770

70611
70615

70638

73101

70618

72740
71780

71436

72736

71782

71781

71426
71529
71793

DESCRIPTION

Segment—Converter grid section

coils or r-f amplifier

less coils (Part

Segment^Oscillator section front

of

(Part

—Oscillator

(Part of

—

Oscillator

—

(Part of

Antenna trap

S4)

S4)

Snap spring to

C15)

—Antenna transformer

—Converter transformer

Segment

Shield—Lead tube shield for V3

Socket—Tube socket

Spring

Spring—Retaining spring for

Stator

Transformer
Transformer

Trap—

plate

of

S2, S3)

section

—miniature

hold fine tuning shaft

fine tuning

(L81, L82,

front segment

section

front segment

segment less coils

rear segment less

R-F oscillator tube shield

stator and bushing

(Tl)

(T3,

C21. C22)

C20)

TELEVISION CHASSIS

26-1, KCS

Bearing

—R-F shaft bearing assembly

—

Board

"Antenna"

i-f cable

Capacitor—Mica,

Capacitor—Mica,

Capacitor—Mica, 47 mmf. (C169)

Capacitor—Mica, 100 mmf. (C119)

Capacitor—Ceramic,

Capacitor—Mica,
Capacitor-

KCS

board—two

mmf.,

5

mmf.

10

100

mmf.

120

Mica, 180 mmf., 1000

26-2

contact—solders to

volts (C1B5)

1500

(CI 13)

mmf. (CllO)

(C122, C133)

volts

(C162)

Capacitor—Mica, 270 mmf., 1000 volts (C104,

C112, C156)

Capacitor—

Capacitor—High-voltage

Mica,

390

mmf.,

capacitor,

1000

volts

500

(C135,

mmf. (C142)

Capacitor—Ceramic, 1500 mmf. (C102, C105,

C107, cm,

Capacitor—Mica, 2200 mmf.

Capacitor
Capacitor

10-160

C136B, C136C)

Capacitor—Tubular, .0025

C155)

Capacitor—Tubular, .002 mfd.,

Capacitor

Capacitor—Tubular, .005

Mica, 4700 mmf.

—

—Mica

mmf. and 2

—Tubular, .002 mfd.,

Capacitor—Tubular, .005 mfd..

Capacitor

Capacitor—Tubular, .01

Capacitor—Molded

Capacitor-

Capacitor—

Capacitor—Tubular, .05

Capacitor

Capacitor—Tubular, 0.25

Capacitor—

Capacitor—Electrolytic,
Capacitor—

Capacitor—Electrolytic, dry,

Capacitor—Electrolytic,

Capacitor—Electrolytic,

—Tubular, oil impregnated, .035

volts

(C139)

C158)

C144)

C118, C120)

Tubular, .02 mfd., 400
Tubular, .05 mfd., 400

—Tubular, oil

volts (C130,

C137, C161)

C129,

mfd., 450 volts, and 1

(C127A, C127B)

mfd., 10 volts, and 1

(C132A,

10 mfd., 400

and

C116C)

mfd., 450

(C131A, C131B)

mfd., 450

and 1

Electrolytic, dry, 24

Electrolytic, comprising 1

C132B)

1 section of 30 mfd.,

volts; and 1 section

section of 130 mfd., 50

C128C)

Coil—First or third pix

Coil—Peaking

Coil—Peaking

C145, C146, C150)

C114,

trimmer, consisting of 1

paper, .01 mfd.

C140)

volts; 1 section of 30

volts; 1 section

coil (L105, R119, L106,

coil

(L104, L107)

(C163)

(C126)

sections of

mfd.,

mfd..

mfd., 400

mfd., 600 volts (C138)

impregnated, 0.1 md.,

mfd., 400 volts

comprising 1

section of 10

section of 1000

comprising 1

250 volts

comprising 1

comprising 1

of 40 mfd., 150

i-f coils (LlOl, L103)

40-370

mmf.

volts (C154,

400

volts (C123)

400

600 volts (C134)

400 volts (C124, C125)

volts (C159)

600

volts

(C149, C157,

volts (C143,

400

volts (C167)

volts (C103,

(ClOl, C117,

mfd.,

of 10 mfd., 350

volts (C128A,

volts (C160)

300

section of 80

mfd., 450 volts

section of 250

mfd., 6

mfd., 350

(C116A, C116B,

section of 40

section of

R123)

less

coils

C108,

C164)

C106,

section of

(C136A,

mfd., 600

CI

15,

1000

volts

section of

volts;

volts

40

volts;

C128B,

22

REPLACEMENT PARTS

(Continued)

72

ITS

STOCK

No.

71528
71429
71449
73233

71789

71521

71784

73193

72735
71440
71443

72734

71441

71785

71457

71437

71783

72772

71510

71509

37396

73301

73600

71792

72737
71455

18469

71448

71513

72067

11956

32813

30732

31959

13961

30880

5164

19233

71916
34766

30731

30733
71986

30694

30494

71987
30734

14659
14250

3078

12876

30436
36714

70723
30492

72928

30650

8064
3252

72893
72892
30180

72891

30493

11959

19232

DESCRIPTION

Coil—Peaking coil

Coil—Width control

Coil

Horizontal linearity

—

Coil—Focus coil (L120)

Connector—
Connector—Hiah-voltage capacitor lead connector

Control

(use

Control

(use with

Control
Control
Control

(R152, R166)

Control

HI

Control

Control

SlOl)

Cord—

Cover—

#71780

Cover—

#71436 and

Cover—Insulating

Cushion

hood

Cushion

hood

Grommet

#73249

Magnet

Fuse—

Magnet

Nut

—

Nut

—

quired)

Plate

pacitor

Plug

—2-prong

Resistor
Resistor

Resistor—

Resistor

Resistor—

Resistor

Resistor

Resistor

Resistor—

Resistor—

Resistor—
Resistor—

R117,

Resistor—
Resistor—
Resistor—

Resistor
Resistor
Resistor

Resistor
Resistor
Resistor
Resistor
Resistor

Resistor—
Resistor—

Resistor

Resistor—

Resistor

Vi

Resistor—
Resistor—

Resistor—

R182)

Resistor—

Resistor—
Resistor—
Resistor—

Resistor—

Resistor—
Resistor—

Kinescope

—Brightness

with

decal

—

Brightness

decal

—Focus
—Height
—Horizontal

—Vertical

56)

—Vertical

—Volume

Power

Insulating

and

Insulating

—Rubber
—Rubber

—

Rubber

required)

(2

—

Ion trap

0.25 amp.,

—Ion trap

#8-32

speed

#8-32

wing

—Bakelite

—

3.3 ohms,

—5.1 ohms,

ohms,

39

—39

ohms, 1

47 ohms, V2

—82 ohms,
—82

ohms, V2

—

150 ohms,

560
680 ohms, 1

1000 ohms,
1000 ohms,

R125,

1200 ohms,

3300

3300

—3900
—4700
—4700
—5600

—

6800 ohms.

—8200

—

10,000 ohms

—Wire

12,000 ohms,
15,000

—

15,000 ohms,

22,000 ohms,

—

Temperature

watt (R191)

56,000

82,000 ohms,

100,000 ohms,

100,000
100,000 ohms,
120,000 ohms,

120,000

150,000
180,000 ohms,

270,000

#72805)

#73194)

control

control

and

linearity

control

cord complete

#71781

#71782

cover

cushion

cushion

magnet

250 volts

magnet

nut for

nut for

mounting

male plug

ohms,

R150,

ohms,

ohms, 1

ohms, V2

ohms.

ohms.

ohms,

ohms.

wound,

ohms.

ohms, Vz

ohms, V2

ohms, 1

ohms, Vi

ohms,

R195)

(1,122,

coil

(L112)

control coil (LI

anode connector

and

picture

and

picture

(R129)

(R141)

or

vertical

horizontal

control

and

with

cover

for

cover

for

for

electrolytic.

—lower

—upper—

grommet

%

'/2

V2

1 watt

V2
'A

R178)

to

(PM

(Fl)

(LI 10,

r-f

unit

mounting

plate

for

power

watt

(R187)

watt

(R190)

watt (R103,

watt (R196)

watt

(R120, R192)

(R162)

watt (R174)

watt (R115)
watt (R147)

watt

(R168,

1 watt

(R185)

V2

watt (R104,

V2

watt (R175)

V2

watt (R122, R193)

watt (R124)

watt

V2

V2 watt
V2
V2

(R149)

watt (R118)

1 watt (R163)

(Rill)

watt (R116,

watt (R137,

'/2

watt

10,000

ohms,

"^

watt (R107)

'/^

watt

1 watt

(R130)

V2 watt

compensating,

watt

V4

watt (R170)

V2

watt (R133,

watt

1 watt

'/i

watt (R135)

watt

watt (R155)

V2

watt {R158)

1 watt (R126)

13)

control

(R108,

control

(R1D8,

centering

hold

control (R144,

(R148)

power switch

plug

electrolytics,

electrolytics,

RCA

—for

deflection

for deflection

mount

socket

type)

LI

(EM

11)

shield

(2 required)

focus

for

electrolytic

cord

R112)

R169)

R109,

RllO, R113,

R132)

R138,

(R106,

R186, R188)

10 watts (Ri97)

(R102.

H114)

(R136,

R177)

30,000 ohms,

(R142)

R145, R18I,

(R173)

(R164)

(R1S9)

type)

coil

R172)

R128)

R128)

control

(R183,

RCA
RCA

#72736

yoke

yoke

RCA

(3 re-

ca-

STOCK

No.

14983

30648

30653

72738

72739

30652

71993
31449
30649
72632
70249

31071

30992
71456

71452

72741

72773

71508

9914

72516
72927

31251

73249
71453

71775
71774

71416

71772

73150

73708
71424

71427

71776
72770

71778
71777

71797

72786

X1648

72819

72805

73194

71984
71598
72113
72818
71539

71534
71533

71536
71537

71535

72817

14270

30330

4982

71538

DESCRIPTION

Resistor—
Resistor—

Resistor—

Resistor

Resistor—Voltage

Resistor—

Resistor—

Resistor
Resistor

Resistor—3.3
Resistor—3.9 megohms,
Resistor—
Resistor—

Screw

Sleeve—Rubber sleeve

Socket;

Socket

Socket—Tube socket for

Socket

Socket—Tube

Socket

Socket—
Socket—

Stud—Mounting

Transformer
Transformer
Transformer

Transformer—Power transformer,

Transformer

Transformer
Transformer

Transformer

Transformer—

Transformer

Trap—Sound trap

Yoke—

Speaker—

Back

Board—Baffle

Bracket

Decal

Decal

Decal—Trade

Escutcheon

Feet

Glass

Slide

Knob

Knob—Fine

Knob
Knob

Knob

Plate—

Spring

Spring—

Spring

Spring

330,000

ohms, Vi

470,000 ohms,

560,000

ohms, V2 watt

—Wire wound,

ohms,

20 watts, and 1 section

(R153A,

watts

8200 ohms,

and 1 section of

R154C)

R143, R160)

R153B)

watts; 1 section

5

megohm, V2 watt

1

megohm,

1

watt (R179)

'/4

watt

comprising

divider,

100 ohms, 2 watts

comprising 1 section of

watt

1

—1.5 megohms, V2 watt
—2.2 megohms, V2

megohms, 1 watt (R165)

megohms,

6.8

10 megohms, V2 watt (R180)

#8-32

—

quired)

—

wing

Kinescope

watt (R146)

V2 watt (R134)

V2 watt (R140, R171)

screw for deflection

for focus

socket

—Single contact female

—Tube socket,

socket, miniature (with

—Tube socket,

socket,

Tube

Tube socket, octal, ceramic, plate

stud for focus

8016 tube

miniature

noval wafer type

octal

—Vertical oscillator

transformer

(T106)

—Vertical
—Horizontal output

(T105)

output transformer

—Power transformer,

(T106)

C148,

—Second
—Sound i-f transformer

L116, L117)

pix

i-f (T104,

—Sound discriminator transformer

(C151,

C152, C153, L118. L119)

Audio output transformer

—Horizontal oscillator

Deflection yoke (L108,

RlOl, R151)

(TlOl. CI

SPEAKER

4"

6"

Cabinet

x

MISCELLANEOUS

back

board

with con.e and voice coil

—

—Decorative

Control

—

#71784)

—Control marker

marker

#73193)

mark

—Channel

—Rubber feet

Safety

—

—Kinescope

(4 required)

—
—Horizontal

—Volume

—

hold or

spring for

—Retaining

and

—Retaining
—Spring

glass

centering

Channel selector

tuning

hold

control

Volume

Retaining

control

brightness

plate

top

section

spring

#71534

Retaining

spring

spring

clip for

09)

ASSEMBLY

92565-lW

elliptical E.M. speaker

bracket for

decal (use with

decal

decal

marker

for cabinet

slide

knob

knob

or

picture

and

power

and

control knob

complete

of

cabinet front

for

for

for

escutcheon

(R176, R184)

(R157. R189)

1 section of 1125

of 610

of 35 ohms,

(R1S4A, R154B,

(R121, R127, R131,

(R167)

(R139)

yoke (3 re-

coil

socket for

shield attached)

coil

required)

(2

transformer (T102)

and high-voltage

115

volt, 60

115 volt, 50 cycle

C121)

T107

(T109)

transformer (L121)

LI

L109,

14, LI 15, C141,

front panel

(use with control

escutcheon

(4 required)

with rubber

control knob

switch knob

power switch,

with wing

knobs,

knob

knob

(2 required)

#71535,

#71536

#71533

ohms, 20

watt;

0.8

C142

mounted

(T103)

(C147,

T108,

complete

control

cushion

vertical

nut and

#71537

cycle

APPLY

TO YOUR

RCA

DISTRIBUTOR

FOR PRICES

23

OF REPLACEMENT

PARTS

. ^