Technical information

?
RADTO
RETAtLtNG'S
",
.ARVIN
35.
Poor
tone
.
. Replace
both
.01
mfd.
audio
coupling
condensers
'with
mica
moulded
typel
oisame
value.
ARVIN
41,
51.
Distortion
at low
volume
conlrol
settings,
on strong
sig_
nals
Due
to
oueibias
of
6F/
cria.
Remove
100-ohm
resistor
from
catfrodi
of this
tube
and connect
the
cathode
io
g:ound
.through
an
800-ohm
resistor.
I he
volume
control,
in
other
words.
should
affect
bias
on
the
6.47
only,
rathei
than
on
this
tube
and
the
6F7
iogether.
The
6F7
should
be fr xed
biased
-"li
bt
itse
lf.
ARVIN
62.
Noisy
*
hen
tuning
clial
is
rotated.
.
Solcler
bottom
arlu
on
planetarv
drive
s1'stenr
to
bracket
at
fr.ont
end
oi
conclenser gang.
ARVIN
8IM
Ilunr
. reurove
p.p.
auclio
inprrt
choke
frorn
top
of chassis
and ntount
unclcrnc:rth.
Try
rotating
at
different
;t:rglcs
u'irile
tlre
set is
operating
to
6rr,l
lorvcst
hurn
position.
ARVIN
6I8
Hunr.
. .
.
Check for
high
resistance
contact
of lrrg
riveted
to
chassis
at
6Q7
socket.
ARVTN
t237.
1427
Dearl
look
for
shorted
moulc'lecl
bakclitc platc
bypass
in first
i.f.
tr:rus-
1.'rnrer.
Also
rcplace
1000
olrnr plarc
dropping
resistor
in
this
circuit.
ARVTN
1237_t427
'Ioo
muclt
bass
at
low
setting
of
volume
control
relnove
bass
ionr_
pensatirrg
contrectiorr
on
volume
control.
l'his
consists
of
an 18,000
ohm
resistor
in
series
rvith
a
.03 tnid
conclcnser.
ARVTN
t427
Bad
frequency
drift
. .. check
the
lorver paclder
condenser
strip.
If
of the
Irekclitc.
ba.e
type,
replace
ivith
one
of
po1'ceraln.
ARVIN
I427
Station
shift
on
push-buttons
replace
original
iibre
oscillator
trir.nmer
:j.il
rvith nc\\.
r).pc
isolantitc
type.
Seal
trinrnrt'r'-
:rft(.r
arljrrsting.
ARVIN
AUTO
RADIOS
Ignition
interference
In ntost
cases.
this is
caused
b1,
chassis
pickup.
It can
be
overcorne
b-v. removing
the
front
cover
and
cleaning
the
surface
of
the
joints
with 6ne
sandpaper
to
provide
greater
area of metallic
contact.
Also
check
the
acoustinator
plug
to
see
that
a
good
ground
contact
is
obtained.
On the model
65,
check the
right
hand
breather
screen
for
ground.
Spotting
it
with
solder
to the housing
is
sufficient
to
prevent
interfetence
from
feeding
in
at
this
point.
t0
ARVIN
AUTO
RADIO
\Iechanical
hum
, vibratrrr
clrat-
ters
against
chassis.
This
ula\.
be
elinrinated
by
r.enroving
vibratori
antl
increasing
the
tension
olt the
r.ibrator
grounding
spring
cup.
ARVIN.
Excessive
vibrator
hum
in
1935
models
of these
car
sets
Move
large
yellow
"A"
wire
running
from
volume
control
switch
to
power
supply
compartment
as far
as
possible
from
second
i.f.
coil.
ARVIN
I937
AUTO RADIOS
Vibr:rtor
h:rslr
warrn
up for
30
rrrilrrrtcs
tlrcn
tightcn
the
-l
scrervs
hold-
irrg
tlrc
porr'cr-transfoLutcr
to
cltassis.
It
is
inrport:rnt
to warnl
up
thc
set
first,
otlrclrr
ise
the
initial heat
will cause
thc
\cr(
\\'s to
lcxtscn.
ARVIN
I936
SERIES
Vibrator
hash
.
, Make
sure
chassis
is
well grounded
to
firewall
and
use
shakeproof
washer.
Make
sure good
ground
is obtained
for
transmission-line
box.
Ground
the
box
to the
frame
of
the
car if
an
under-car
antenna
is
used,
or, if
a top antenna
is
used,
ground
the
box to
some metal part
known
to
be at
the
same
r.f.
potential
as
the firewall.
Remove
front
cover
from
set
and tighten
four
screws
holding power
transformer
in
place.
Wiggle vibrator
in socket
and
make
certain
that
each
grounding
tooth
makes
contact
with
the sides of
the
vibrator
case. Try
a condenser
in
addition
to the
generaior
or
dome
con-
denser,
across
the
car's
A circuit, plac-
ing it
directly
on
either terminal
of the
ammeter
or fuse
block.
Solder
a
l|-inch
piece
of shielding
from
the 6,{7 grid
cap
tube
shield
to
the frame
of
the
variable
condenser.
Check
to see
that
transmis-
sion
line
shielding
is firmly
contacting
plugs
at both
ends.
ARVIN
AUTO
SETS
Nois,v
cltcck
1re tal
blaid
glr-ruld
on
gang
conclenser.
Often
this
breaks
and
causes
r.roise
sincc
rotor
is
insulated
from
chassis
by
rubber
grommets.
Replace
ground
with
longer
braid.
Dead
oscillator
stator
learl
too
short when gang
rocks
and
breaks
lead.
Lengthen
lead
slightly,
if
too
long
set
will not
align.
Intense
motor
noise
these
sets
use nratching
transformer
in
aer.ial
lead.
Check
transformer
{or
short
to
cha-ssis.
ATWATER.KENT
AK
30
SIIRIES.
Improving
sensi_
tivity,
selectivity
Replace
intenna
choke,with
a compensator
ioil,
a center_
.
tapped
coil
with
one
end
to
giid,
one
to
,
ground
and
the
tap
to
the
anlenna
oost.
AK 7D,
217D,
,127D,
667D.
Squealing
at
low
volume levels .'.
Replace
condenser
Cl8
as
it has
probably
developed leakage.
Use an 8 mike,
40O
volt
unit.
Sometimes
one section
of the
i.f.
transformer
T5 will
also be
found
open.
AK
30,
/Kt.
A
cotnmon
headaehc
is
shorting
of the
uire-uo*nd
resistor
bcuath
the
chassis
to
ground.
The
fibrc
basc
uwps,
cortsing
the trouble,
zahich
can
be
correcied
by
sliding
a
piece
ol
fiber
utder
the
unit.
No
reception:
Check
the
speaker
flter
con-
den,rer.
AK
35, 15,
52.
Lack
of
volume.
Drill
one
eyelet
on
second
r.f.
transformer
:.upport
and
turn
just
far
enough
out of
line
to keep
set under
oscillation
at
high
lrequencles.
AK
37.
Intermittent
reception
and
rasping.
Press
rear
of
chassis.
If
this
causes
noise
insulate
shielded
antenna
cable
leading
from
rear
of metal
cabinet
to front
of chassis.
It frequently
touches
the
bare
ends
of
the
power
cable.
AK
37.
'l'o
iucrease
selectivity
Ilorrut
tlrree-garrg
trimmer
olt
top
of
tuning
gang
arrd
re-balance
rvith
ihcse
trirnnrers
connected
in
the
circuit.
trlake
sure
that
the
rotor
section
is
u ell
grounderl.
Stunt
also
ok
on
\Iodrl
40.
A.
K.
37,
,O
-
Dead
.
replace
0.3
mfd
speaker
bypass
condenser.
AK
37, 10
Installing
pilot
light
in these
rnetal.
encased
sets
Remove
the
metal
cover
from
the
powerpack.
Connect
two
wires
to the lI
volt
winding,
or
terminal
strip for
the 26
tubes.
Connect these
two
wires to
a miniature porcelain
base
socket
and
use
a
2.2
volt
bulb. By
means
of a
small metal
clamp,
the
socket may
be
placed
at any
point
along the
front
oJ
the set.
Just
raise
the
lid
and slip
the
clamp beneath
it.
AK
37,
40.
Oscillatron,
after
re-
placemcnt
of r.f.
and
detector
tubes
.
. .
Bend
a
piece
of brass
about
ll
in.
square
in
the form
of an
"L.',
Drill
a
hole
through
it
and bolt
it in
place
be-
tween
the
first
and second
stage
tuning
conden
sers.
AK
37,
38, 40,
42.
Low
power
stage
plate
voltage
or
none
at
all . . . Discon-
nect
one
speaker
lead
and
plug
analyzer
into
7lA
socket.
If plate
voltage
now
appears
nornral
replace
speaker
output
conoenser.
AK 37
to 60.
When
dial belts
are
not
obtainable
use heavy
dial cable.
Anchor
to
pulley-pins,
spot with
drop
of solder.
Move
condenser
to
take up slack.