Technical information
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SILVERTONE
16,t{r. Blurping
at
high volume
tevels
. . Reverse trang-
former secondary
leads to
grids
of
46's.
SILVERTONE
I640
Motorboating
check
.2 mfd
screen
bypass
for
open.
SILVERTONE
rOS2,
1654.
poor
selectivity
in
models
equipped
with .005
condenser
in
i.f.
stage
.
Remove
second
i.f.
untuned
transformer
under.
ncath
chassis
and
replace
with
part
R64l5A,
a
tuned,i.f.
iransformcr.
Re-
align
both
i.f.
stages.
If
set oscillatcs
reverse
'connections
on
plate
coil
in
r-econd
i.f.
stage,
being
careful
not
to
disturb
connections
to trimmer
from
plate
and
-B-plus.
Rotor
must
go
to
plus.
Any
good
tuned
i.f.
input
transfoinrcr
which
peaks
at
175
kc.
ian
be used
if a
Colonial
part
is
not
easily
obtainable.
SILVERTONE
l7ll.
When chang-
ing
to standard
tube
typcs
. .
. Replace
951's with
32's.
Replaii
950's
with-49's,
not
with
33's
as the
latter draw
exces-
sive
flament
current
and
will
blow bal-
last
tube.
SILVERTONE
(Scaru-Roebuck)
t7r2,
1713.
Distortion,
weak
signals
. .
,
With
batteries
disconnectcd
check
with
ohmmeter from
B minus
(red
and
black)
to
chassis.
It
should read
700
ohms. If
less
test
35 mike.
20 volt
condenser
rcross
700
ohm,
I
watt
carbon
resistor
for full
or
partial
short. It
is
found,
to-
gether
with
two 8 mfd.
capacitors,
in a
square cardboard
box bolted
to chassis.
Leads
are brown
and
black. Fading
..
.
Sandpaper
band
change
switch
contacts.
(I.f.
175
kc.)
SILVERTONE
1732.
To
increase
"pep"
.
. Install
a 10.0fi)
ohm resistor
in
the screen-grid
lead
instead
of
the
15,000
ohm unit
normally
used in
this
position.
Screen voltage
shoutd
increase
from
60
to 80 volts.
SILVERTONE
I75O
No reception
look
for
shorted
I mfd.
condenser
bypassing
second
i.f.
plate
supply.
Usually
the
1000
ohnr
resistor
in
same
circuit needs
replacir-rg.
srrvERToNt
ttot
Ac-Dc.
Undue
hum
pfter
regular
6lter
re-
placement
.
. .
Tie
the cathodes
of the
25ZS
together.
The
filter
arrangement
of this
set is identical
with
that
of a
Sparton
57
so that
a
filter
block
for this
latter
make
will
work
quite
satisfactory
if
the
original
replacement
is not
ob-
tainable.
Care
must
be
exercised
be-
cause
the
color coding
of the
leads
sup-
plied
with the
two
blocks
is not
iden[i-
cal.
Both
schematics
must he
on
hand.
to avoid
wiring
error.
SILVERTONE
t802A,
t803A.
t8o7
No receptiou
at high
flcquency
curl.
.
Opcn 2 ntkl.
tubular
concl. frorrr
oscillator
coil to
grprrnd.
Se; dead.
.
.
.
Check
open l7N{
and 321\I
ohnr section:
of
L.anrlolrrr voltiLgc
dividcr.
S|LVERTONE
t802, t803
Oscillation test
160
volt
I
mfd.
condenser
betwcen
chassis and
high
voltage
centertap
of
power
transfornrer
for
open.
SfLVERTONE t82t, t827
No reception
. .
.
short in
0.1
mfd.,
300 volt tubular condenser. bypassing
plate
supply of 78 tube in second i.f.
stage. Use
400
or 600
volt replace-
ment. 1,000
ohm
(j
watt) resistor in
same
circuit
likely
damaged
also by
overload
due
to condenser breakdown.
SILYERTONE
t824-r8t0
Weak or
dead
. . . clreck
,l
mfd,
cond.
from
78
screens
to
ground.
Also
clrecli
tuning
metcr for
open.
Wave
changc
switch
dirty;
clean with
alcohol
antl
srrrall
brrrsh.
SILVERTONE
I829
Weak,
tuning meter
becomes
hot
shorted
.l mfd
condenser
in
plate
of
6A7.
Meter
may
be
re-
placed
with 1,000
ohm
resistor,
con-
nect
same
as ltleter.
SILVERTONE
t85O
Poor
control
of
volume
.
. .
over-
sensitive
951
tube. This
condition
can
be eliminated
in
most
cases
bv
increasing
the normal
lj
volt
bias
to
3
volts.
SILVERTONE
I85O
Intermittent,
weak
.
,
check
4%
volt
"C"
battery.
If
the voltage
is
not
up to
full
value
operation
will
be
erratic.
SILVERTONT
t926
Code
llttertercnce.
Repeak
at
445
k.c.
(
originally
480
r.
Retrinr
rhe trvo
pad-
ding
condensers
nrounted
on
gang
at
1500
kc.,
also
repad
600
k.c.
irimmer
s'hile
rocking
selector knob.
Sf LVERTONE
1426,
4427,
44/.6,
1447,
4526.
4546
No
gain
in
r.f.
section
.
,
. . look
for
high
resistance
leak
in
wave
bancl
switch
which
disturbs
a.r,.c.
on
this
stage.
SILVERTONE
4589
Cuts out
on
frcquencies
lrigher
than
770 kc
check
00-11
nrf<l
con-
rlenset'
byp:rssing
oscillator
coil
trr
grourrcl.
Replace
with
.(X)5 nrfd
rrnit.
SILVERTONE
46I5
Blows fuses.
Insulate
shickl at
bottonr
of
vibrator
section of chassis.
Also, insulate
filar-r-rent
chokes f ronr
carrdohn.
resistor.
SILVERTONE
.1720
Dead
. .
remove
control
grid
lead
Irom ICTG
mixer; grasp lead
clip
in
one hand
and
place
index
finger
on
grid
cap
of tube. If
set
plays
look
for short
between
primary
and secondary
of an-
tenna
coil.
SILVERTONE
4786
Large 140
ohm flexible resistor lo-
cated
at
6V6G socket
gets
hot
to
smok-
ing
point
.
look
for trouble in the
.003
mfd condensers
from
plate
to cath-
od6
of
6VZG
tubes.
SILVERTONE
6.{03,
6,10.t, 6,105,
6,106,
6,t92,
6,f96
Hum, low
volume
check the
antenna
loop
for
opens
at
the corners.
This
also may
cause internrittent
howl.
SIMPLEX
SIMPLEX
sDA
Static,
noisy
.
check
oscillator:
coil.
Replace
coil
to
eliminate
trouble.
SIMPLEX
P
Dead
replace
.00008
nrfd
con-
denser
from negative
filan-rent
of first
detector
to chassis.
SONORA
SONORA.
Avoiding
high
price
of
replacing
speciet
tuber
. .
Rewire for
27's
in
thc
r.f.
dctector and
first a.f. end
a
45
in
the output. Place five-prong
wafer sockets
ovcr regular four-prong
types
in
r.f.
sections. Fasten
*ith small
bolts.
Bring up
connections.
Carry
cathode
leads from
chassis
through holes
in rivets
holding
coils.
.Make
cathode
return
to
powerpack
through one side
of
unused filament wiring.
Install new
transformer
with following
specifica-
tions:
700-vott c.t.
secondary,
2.S-volt
c.t.
filament
secondary and
S-volt sec-
ondary.
Change bias for
27's to 500
ohms
and
place
grid
return
to
45
in
filament
center
tap. Discard
batlast
tube.
Job
costs less
than
half
the
price
of new
speciat
tubcs.
SONORA.
Mushy
tone,
poor
audio
quality
in
this and
other
sets using
Peer-
less
dynamic
speakers
. Burnish
con-
tacts
of voice
coil
bands to
heavy coppcr
strip
(secondary)
of output
transfoim-
er.
Rd-assembte
and tighten
well.
SONORA
2E. Frailty
of chassis
pcr-
mits
plate
coil in
first-r.f.
transformer
to
twist
out
of line.
Symptom
is
or-
cillation
with
volume
control
full
on.
Twist
coil
back
into line.
soNoRA
705
Hunr,
poor
volume
control
action
.
look
for
open
8 nrfd
electrolytic
under
resistor-condenser
bank.
Re-
place
with
300
volt unit.
OD