Technical information

O
RADIO
RETAITING'S
,,,
eh{tice
ll
o
APEX
11,
42
Oscillation
over entire
scale.
Try 2,000 ohm
resistor in second
r.f.
grid
lead.
APEX
.16
Distortion
at low
volume.
This
trouble can
be overcome
by replacing
the old
control
and connecting in
a
slightly different
fashion. The old con-
trol
is
simply
a series
resistor in the
catl.rode circuits
of the
24
tubes.
For
proper
replacemcnt connect one end of
a
10,000 ohm tapered control to the an-
tenna
lead, the other end
to
the cathodes
of
the 24s through a 250 ohm resistor.
The
center arm should be connected to
ground.
The
open
circuit in the
wire
wound
resistor where the old
control
was connected should be bridged
with
;r
junrper.
APEX
46, +7, 48.
When
these models
lack volume
screw a smatl
piece
of tin
under stator
supports of tuning con-
densers. Tune as
trimmers by
raising
up or down. No
plate
voltage on otre
45
indicates
blown audio choke. It
may
be
shunted
with
no
appreciable changc
in tone.
Smoke
from
power
trans-
forme
r, set dead.
Unsolder
rectifiet
leads and run them
through spaghetti.
Resolder.
APEX 98
Weak
. .'.
inspect
dial
light
socket
for
partial
short.
This
lorvers filament
voltage, resulting in
poor
reception.
ARBORPHONE
ARBORPHONE
45
Noisy rvhen sct
is
jarred
(-heck
cap
of 1300
ohm
resistor in
rcsistor block
next to 80 socket.
ARVIN
ARVIN 5 TUBE A,C..D.C,
Rcgcrterirtivc susl)ecl lcirk\'
r)ric:I
cr)l)(l('rt\t'r Irrrrt Ii
rritttrs
to
l.r'.
lirrt al
srvitclr.
ARVIN
MODEL 6
Serial
t 5{}ot
ro
i{6{rrrl.
(
).t'illati,'rr
l,t'-
tu'eett
1l0tr :rrtrl
15{){) kv .
. tlri.
c'rrrli-
tion
nrav b.' rcnreditd
b-r
pl;rcing
a
20,0()0
ohrn
.1.
n"ntt resistol
in
the B
plus
lead to tlrt'o:cillatc)r. Aiso. con-
nect
a
.0()i
rlfrl corrrlenser
irom the B
plus
lrrg
of tlrt'
,rrcillator
cr"ril to
gt-ollnrl.
ARVIN 7,
17, 27, 37.
Intermittent
oscillation
or
motor-boating...
Re-
place
twin a.v.c. condenser
located
be-
tu'eeu the 78 socket
and the
antenna
coil. In the
model
7
the
condenser
is
located
between the 6F7
iocket
and the
anteuna coil.
ARVIN
10A. Bad howl when
set
is
very cold . .
Reverse.reflexed audio
transformer
primary
leads. Bad
howl
at
any
time
Replace 72 mike, 25
volt
electrolytic
condenser. Bad
hum
after
replacina 84
tube Put
metal
shield over tube
and
ground.
ARVIN I7
Hum
. Replace
original
12 4 mf.d
electrolytic
filter with
a triplt.
8
mfd
section.
This
can
be
obtained
in
one
can
to
fit in
the original mounting.
Con-
nect
two 8
mfd sections to cathode of
Il4. The
other section sl.rould
go
tc
connection
from which orisinal
4
mfd
unit
was removed.
ARVIN IOA
Intermittent
. . .
C,heck
brown lead
on if
transformers
for
poor
contact.
ARVIN 17
No reception
on lorv fletiuency end
oi
dial Replace
40,000 ohm re-
:istor in
series
with
oscillator screen.
ARVIN
17,
27,
Oscillation
while
tuning
.
Condensers
No. 17-4731
and
No.'17-4712
may
be making
poor
ground
contact
through
metal
collar
to
chassis.
Replace
with new
type No.
17-14020
and
No. 17-14007
equipped
with
separate
ground
leads.
Ignition'
noise
. .
Sec
that cables
are
grounded.
Some carnc
through
without
lugs.
ARVIN
I8
Distortion,
low volume
when
jarreci
. . . replace
.05
mfd.
160
volt condenser
mounted through
chassis near power
pack,
connected
between voiunte
control
and
resistor
on end
of
i.f.
transfornter.
l'his is
part
C-60 in the schematic.
ARVIN
19. 29,
39 AUTO
RADIO
Raspy
noise
when
dialing
i
re-
move
ground
6nger
springs
at each end
of
gang
condenser rotor
and replace
with new type of
heavier
cotrstluction.
ARVIN 20A, 30A. No reception
al-
though
set sounds alive
. Inspect
r.f.
chassis unit and if tube heaters
are not
lit repair broken
"A"
choke
in audio
unit. Tubes in
r.f. chassis
light but vi-
brator is not heard
Check
same
choke
for break at opposite
end. Set
overloads on
powerful
local signal
Replace 75 with 85, which
witl cut sen-
sitivity somewhat' but
give
better tone.
AuDtoLA
23-5-t0
Neon
tuning indicator rlead
check
the
10,000
ohm
resistor ancl 1
rnfd
condcnser connected in
this
cir-
cuit.
ARVIN 25.
Set
cqmpletely dead
.
Check
for
shorted tone
control.
This
is a tapped
condenser type. In-
termittent
reception
Replace
dual
.015
mfd, antenna coupling
condenser.
No reception,
vibrator
sounds weak .
.
Check
for
shorted dual
.02 condenser
used as a
buffer across
power
trans-
former
secondary.
ARVIN
28
Continually
blorving
fuses .
exanl-
ine vibrator for sticking
points.
orFet&rsERutct
tr
2
(lRK
RADIO & TECHl'IIGAL
PUBLISHIIIG
CO.
45
Astor Placo, l{cw
York. Dept. nR-4O
Methods
and Practice
Eero 1s the famous
Ghinrdl
traiuing course
ln
practical
radio serrico work conplete
In
this
1:100-Dage
book, It's
an
lllustrated
"gold
niI."
of
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stJrtlng
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of serricinS l6tru6enta
an(l
(ontinuins
with nearly
900
Eoro
pag6
of a coEDlete rteD-
by-8tep
Drocedure
cou!sg
ln
troublr-shooting,
testtng,
allgn-
l[
ond
r€psiring
all
bker ol
Ftr-all ba!.d on Dnctic.l
.a-
tcrlcnco.
Ilere'E
what
you
learD:
a
T.st €quipn6nt-Theory,
ll{srrrrtir)rs, l)irgrarrri
of a1l
(-orru).r,
iii lnstrur)renls,
llorv
Tlror
\\'ork.
Constrtlction Datx.
a
Trouble.Shootinc
-
Newert
rhort-cut Detlrods tor
trouble-
ahmting oren
th9
most
co&-
pli(al.,l
r.cei\frs:
a
Repalring-Advanced
"Ftc-
tory
llethods" for Repairlrg
rll
parts.
exDlalned
fully.
&orZA'
13OO PAGES
7(,4 TLLUS.
BIE
Everyday
Job Data
Ilere'a
a
nelv klnd
ol
aerilclng
telereD.g
Danual.
a tlme-ser6r
lor setricg
Detr-diferht
troD
anytlring
tou
v6
ev€r
8en be-
lore.
It s
chork-full
ot
factory-
cl'Rked
"bench
dats',
tltat,
sill
!p6€d
up.very
6erylcc
job
you
dol It s tho
sreatest bass
of
practical
$orking
dsta eler
lssembled
ln
oilo
b@k-
including,
3,313
cAsE
ilrsToRlEs
<f tho
nrodrls an{l
nrnln's
of
Irceivers
Dtrrst
lx!lu€nil!
ser-
ric(d t{xht-
(;ft
rht
wilid's
bisarst
(
nse
llistorr
(olleclirtrr
all asscnll)led
aDrl
(lassilit(l
l0r
l1trr
jn
()hirar{li's
onr
l)ia
irandbooli.
\\'ilh
il
Jou
(dn
''li(:k"
r\flr torrgh seNiring
job
that
corres rl('ng. l'or in
a lerv:crords
il will shos
t]trl
\hat
rll
llx, likoll tfoubl.
sources are
fi,r i.:ll3 nr(xlels
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illa.tut?lsl Whrr's
nrorr',
il
trils
roll
f\a( ll\ lxtrv to rrt'rir
t[c ier- nitr s-irh a lot
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rlost {wts\lul f\peri.n(t 0l
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orgtnizrl:r)n\.
Sil!. lr(trlble
slxxtilrr
Nitlr
rll
ir: hcrrl
a(lres
u56 this
great
Tl M E-
SAVEB !
Moro
Oata. B.sides!
I-l'I'eak.
-
alirnn)ent
(hrr
for ov(r
1;,llIll
sllDrrlil{s
|
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lr, ltadio inslrllnlion an(l
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aril
ral)l(.-
514
PAGES
134 ttLUS.
Sbadard l'anutt
Si.e
letxttl,
Fabrikotd-
boudd,
Qlt;,a,,a
'
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