Technical information
@
RADIO RETAILING'S
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ehui@
PHILCO
2Zt,
22t
A, 2t,
zt{
Dead;
sometimes
distorted,
tunes
sharply
. replace
Cathode bias
re-
sistor
of 24A
detector
with
200
ohm
2
watt
carbon.
PHILCO
511, Excessive
hum. Where
parts
check ok hum
can
be
removed
by
shielding the
detcctor,
grounding
the
shield.
PHILCO 5ll.
"Quivery"
reception
. . .
Check
for
partial
open in
voltage
divider
section feeding
the r.f.
plate.
PFTTLCO
600
Fading
.
.
. leaky
twin
.09
mfd. Bake-
lite housed
condenser
bypassing
screen
of 647
mixer
and 77
detector.
Re-
place
with
two .l
mfd. 400
volt
units.
PHTLCO
6t0
l)istortiorr
;rrrtl Ion'
r olt;rgt' orr
75
plate.
C'heck
.1
nrfd
contlenser
N,r.
-17
at intclsection
of
trvo
100,000
oltrrr rc-
sistors
irr
secontl
dct.
llatt:
cir-cui
t.
Rc-aligrr
all circuits.
PHTLCO
6t0
Oscillator
whenever
volume
control
is
touched
check
41
output plate
con-
denser
for
open.
This
condenser
is
connected in
series
with
tone
control
condenser, is located
in
tone
control
housing.
PHTLCO
6t0
Chirping
oscillation,
decreases in
in-
tensity when
tone
control
is
on full .
.
.
replace
volume
control.
PHTLCO
6t0
X{ushy
Voltage.on
-12
screerr
much higher
than
plate.
Insert 2000
or 3000 ohnr
resistor
in
series
rvith
screen lead.
PHILCO
620
No reception
test
condenser
bypassing
plate
supply of
75 second
detector
for
short.
Unit
is housed in
.bakelite
contaiuer,
one
lead being
con-
nected to
juncture
of 70,000
and,
99,-
000 ohms resistors, other lead
to
chassis through screw holding unit
to
chassis. Though capacity
value
varies
in different
runs,
0.1
mfd.
replacement
is okeh in
most
cases.
PHTLCO 620
Noisy .
ground
6,\7
control
grid
temporarily,
If noise
stops
suspect
primary
of 78
r.f.
coil.
PHILCO 623
Low
volume
replace
'30
sec-
ond detector
even though
original
tube
tests
O.K. Grounding
the
grid
of the
'34
through.
a I
meg.
resistor
will
also
rncrease
votume.
PHILCO
630
High pitched
rvhistle
with
the volume
control
about
$
on, disappears
when con-
trol
is
turned
in
either direction.
Look
for
open condenser
(part
#30-
40-12
connected
fror.n
plate
of
42
to B
minus.
PHTLCO
635
When replacing tubes in
this set be
sure the
grid
cap lead of the 75 tube
is inside
the
tube
shield
otherwise
"birdies"
will
be
present
at one
set-
ting
of the volume control,
PHTLCO
643. 643A
Weak,
all voltage and capacities
check
okeh
replace outDut
transformer.
PHTLCO 550
Reluctant
oscillator,
oscillator
won't
start
when
set is
first turned
on
leaky
condenser
part
No. 714.
in
screen
circuit of 6A7.
PHTLCO
650
Erratic
volume
control operation
.
. .
Put
a .00005
condenser between the
tap of the control
and
ground.
PHtLco
700
The
large
tubular condenser
under
the
chassis
(part
number
304146) fre-
quently
breaks
the leads under its
own
weight.
Always check this
and sup.
port
more rigidly.
PHILCO
806.
Rattles...
Bond
all
ground
terminats
riveted
to
sockets
to chassis,
PHTLCO
806,
807,
80s, 809,
8t6.
8t7,818,8t9
Vibrator
hash
. insert
an iron
core
"A"
choke
in series
with the
speak-
er field.
Choke
must
be
of low
resist-
ance and
a few
henries
inductance.
PHfLCO
8t7-821
Intermittent hunr.
loss
of volume
. replace 4
sectiorr
b,n-pass
block
housed in
carr.
PHTLCO
F-t640
Distorted
reception
check
speaker
cone for
alignment. \{ay
also
be a bad
or open volume
cotrtrol
which
opens
up the
75
grid
circuit. In
case
the
speaker is
out of alignnrent,
take
the
cone
out
an(l realrgn
u.ilg
shints.
In
most
instances,
this
happens
to
sets
still within
the rvarrant_v
period
an<l
replacements
can
be obtaiued
flom the
manufacturers.
PHILCO
I936
FORDS
Intermittent
fading.
Look for
poorly
soldered
connection
on one ot
the
lugs
of oscillator
coil.
PHILCO
AUTO
RADIO
Noisy,
motor
noise,
motorboating
.
check
the
antenna
connector for
poor
contact.
Often this
coupler
be-
comes
corroded,
or
the spring
loses
tension.
Stretching
the
spring is onl.v
a temporary
repair.
For
a
permaneht
job
insert
an
additional
spring
under
the
original
one.
A fibre
washer
lie-
tween
the
two will
help
to
keep
them
in
place.
?HILCO AUTO RADIOS
Burned
fuse and
power
transformer
.
vibrator sticking
caused
'direct
short
on
power
transformer.
Bend
right
angle lip
on
vibrator
reed enough
to
clear magnet.
PHILCO
CONE-CENTRIC TUNING
MODELS
Noise when
dial is turned
clean and
polish
spring, also
clean
and
polish
facing
on
which this spring
rides.
Spring
located
under dial.
PHILCO
CUSTOM AUTO RADIOS.
Burning
of wires to
control
head .
. .
Two wires
coming
from the
tuning head
are held
in
position
by a thin clamp.
This is
not
necessary and in
some
cases
where
the
U clamp
is
drawn tight
it
punctures
the insulation.
PHILCO
DODEE
Insensitive
on rod antennas .
.
re-
nrove
shield can
on side of
set
to which
antenna is connected and short
small
choke found in
series
with antenna lead.
Realign first r.f. stage,
PHILCO
MAGNETIC TUNINE
MODELS
Magnetic
tuning
or
AFC
will not
balance
correctly
on both sides
of
channel-replace
type
6N7 oscillator
control
tube.
?HILCO MIDGETS
Vernier
inoperative
due
to wear in
ballrace
.
. . remove
collar,
pull
out
shaft
being careful
not
to lose
ball
bearings,
place
small end of
shaft
on
flat
of vice
and give
several good
taps
with large
hammer
after
having
made
sure condenser proper
runs free
in its
own
bearings.
PHILCOPHONE
90I
Barl
huur
irr:rtlating
\\'i[:]t('rs,
()lr
Pilot
light
rrllt)u irrs
light
sockct lo slrort
to
grortttrl.
PHILCO
PHONO-COMB.
Hum not
traceable
to
pooJ
tubes
or defectivc
parts.
Ground frame
of motor
to set
chassis.
PHILCO
TRANSITONE
5.
Os-
cillation
"birdies"
in
older models
. . .
Generally curable
by
pullins
15,0ff
ohm
resistor
in 2A7
circuit
up
toward front
of set.
Tendency
to
"swish"
. .
.
Change 78.
45