Technical information

ManualsBrandsZenith ManualsTVs & monitorsC36C35

RADIO

RETAILING'S

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ehui@

SILVERTONE

field-coil

resistance

data:

Number

King-made Silvertone

100

111

lllB 75v750

SILVERTONE

I ]O

Unstable

tighten all

ground

screws throughout

chassis, also

those

gnng

condenser.

Pigtail

gang

rotor.

Replace

9000

ohm 5

watt carbon

re-

sistor

(black

and

red) and

10,000 ohm

3 watt

with

l0 watt. Also

connect

.002

condenser

from detector

plate

grid to

reduce

R.F.

component

audio;

reneutralize.

SILVERTONE

ll0,

1ll. Defective

volume

control.

Replace with

10,000-

ohm

unit and

ground

through

5 or 10

watt, 500-ohm

resistor in series with

the

cathode circuit

give

better

control on

locals.

SILVERTONE t72,36,

'11,

37. To

increase

pep

in thesc sets, volume

con-

trolled by

primary.coil

movement into

secondaries . . .

Loosen setscrcw on

volume control shaft on

rear

of con-

denser

gang

and

move

primaries

in. farther into

secondaries. Tighten

screw, align trimmcrs on

gang

to cut

out

oscillation end

insert

35 type tubes

r.f. sockets instead

l4's.

STLVERTONE

821,

t82r

ICOLONIAL

6561

Abnormal

hiss

on all stations

except

strong

locals . . .

poor

contact on

rotor

wiper springs.

Clean and

bend

for

better

tension

and

realign set.

(i.f.

480 k.c.

)

SILVERTONE

t3r0, t3r2, r330

coLoNlAL 37, 37P

Distorted,

unstable,

rveak or

dead

common fault of these receivers is

leaky

shorted bypass conclensers.

SILVERTONE

1390, l,+00,

1.t02, l,{04. 1406

Dead,

weak, distorted signals on

powerful

locals

. . . Check

bypass

block

mounted in

can

27 tube. De-

tector

plate

bypass section

(.1

mfd) is

usually at fault. Replace with higher

voltage

unit.

Check

1000

ohm

resistor

plate

cirguit of some tube

for

over-

load

caused by short.

SILVERTONE

f506.

No reception

. Look

first

for

a shorted .01 mfd.

bypass between the 47

plate

and

grid.

This is a common

ailment.

SILVERTONE 1570, 1574. Elec-

trolysis in outpqt

transformer Com-

monly

encountered due to use of

paper

winding

form

which evidently contained

some chemical heightening

this effect.

Use

a bakelite form when repairing

place

Empire

cloth between winding and

paper

form. Pre-heating

and

sealing in

some

moisture-proof compound also

recommended.

SILVERTONE

1570. Troublc due

to electrolysis..

To completely cure

this for all time use

a dpst switch

re-

place

the spst

switch in order that the

B minus lead

well

as the A

positive

may be broken. Change oscillator

coil

to one

usirig bakelite

form

lay Em-

pire

cloth

betr,r'een form and winding.

SILYERTONE

I57O

Weak...

Look

for

corrosion

around control

giid

of second

detector

where

goes

through

hole

ir.r chassis;

slip spaghetti

over lead

to insulate

from

chassis. May be

further

pepped

up by

substituting

almost any

175 k.c.

lead

l.F. transformer

for resistance

first

and

second I.F.

network.

Leave 20M resis-

tor

previously

used as

a filter with the

addition of a .l

mfd.

paper

tubular to

bypass this

resistor or the increased

gain

will

cause motorboating.

SILVERTONE

1580. Improving

sensitivity Use 200 ohm resistor iu

place

400 ohms found in series with

volume

control.

SILVERTONE

15E4. Continual

btowing of .003,

600 volt condenser con-

nected across

primary

power

trans-

former . . .

Due

surge built up

primary

winding when line switch ir

opened. use an 800 volt

condenser

a replacement,

connecting

it between

the

line side of the

on-off switch and

the

chassis.

SILVERTONE

16,t().

Improving

tone

and reducing

hum

. . . Usc .fi)l

condenser

place

of original

.fl)3 tonc

control unit.

Replace

100,000 ohm

rc-

sistor and

,l mike

condenser

in lead to

midpoint of driver

tube's

gridleak

with

.5 mike

condenser

from

gridleak

mid-

point

ground.

Use

.003

condenser

instead

.02

from one leg of

power

transformer

primary

ground.

Use

grounded

electrostatic

shicld

betwecn

primary

and secondary

power

trang-

former

if set operates

25 cycles. Thc

60 cycle

jobs

do not need

such shields

and if shields are

provided

they

should

be disconnected.

Replace

8 mike,

475

volt electrolytic condensers

with a

mike, 4,|() volt unit.

In replacing

power

transformer use one

with a separate

fila-

ment

winding

having a

20 ohm adjust-

able center tap

resistor across

for

one

of the 46 driver tubes.

The adjustment

quite

critical. To impart

greatcr

bril.

liancy

tooe replace

auto-transformer

found mounted on 12 inch speaker

with

a new

auto-transformer having

fcwer

laminated

core sections.

Failure

volume control to

reduce volume

to zero

due to coupling

betwcen

second

i.f.

and detector

grid

leads,

under the

chassis.

The

i.f.

lead

connects

from

coupling choke and

detector

grid

lead

from tuning condenser.

Spread

these

leads

far

apart.

SILVERTONE

16,+0. Undesirable

time lag

a.v.c. system,

weak stations

interrupted during static

bursts

Replace the .l

mike fixed

condenser in

the a.v.c. circuit with .01.

Hiss

feed-

back in 283 tube

Insert

r,f.

choke

in red

plate

lead of tube.

If one

does

not cure trouble

put

another

the

other

plate

lead.

This noise

may affect

nearby sets as well

as the

receivlr

itself.

SILVERTONE

I640

Ilotorboating

replace the

screeu

ln'pass

on the i.f.

amplifier.

Ohms

2500

25W

2500

7s0-750

Colonial

No.

36......

4l ......

41C.....

38. .

. . ..

4l ......

42......

39.....

49...

...

41P.....

36P..

. . .

J/ . . . . . .

37......

47......

37P..

46. ... . .

44......

4l ......

42......

50.. .

. .

48... ...

l12

I150

rr52

I 154

lt70

tt74

1250

1252

750-250

9000

1450

9000

1450

2500

9000

l 450

1450

2500

2SN

2500

I 450

1450

zffi

260

310

312

320

322

324

326

330

370

390

400

402

404

406

408

420

420X

430

450

SILVERTONE

Often

these sets

rvill not

track

over

the entire tuning

range. \\'hen

this

trouble is encountered,

tr'_r' aligning

the i.f.'s

a ferv kc. higher

or'

l-rrver

than

the recordcc.l

peak.

SILVERTONE

Noise control on rear of chassis

burns up

look

for short

plate

circuit of

6A8G tube

near

plate

ter-

minal of socket. Replace

control

with

750 to ll00 ohm

pot.

SILVERTON

Weak,

oscillation

rePlace

filter

condenscr rvitl.r

450 volt

tvpe.

SITVERTONE

,t2.

Unsatisfactory

reception

from 950

540

kc., noise and

whistles accompanying

signals . . . Ground

one

side

of the

an-

tenna coil to

the chassis, Connect

ex-

ternal

ground

chassis

after

this

done

further

improve

cix

reception

and

re-

duce

hum.

SILVERTONE

I09

Lon'

sensitir.itv, especially orr 550

end.

I)rinr:irv

antenna

coil

rt'sistance

rvirc, very

brittle

and

us.ualll-

brcaks. Replace with

copper

\\'l r(].

SILVERTONE

Hum, weak check 8 mfd

wet

electrolltic

on.

top of chassis

for low

caoacity

and

leakage.