Operating instructions

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Figure
38.
Rad,io
Eeceiuer
R-lf4/URR,
top
aiew
of
Note.
Do
not
remove
r-f
and
i-f
shields
from
the
chassis
or
shield
cans
from
the tuned
units
until
the
trouble
has
been
traced
definitely
to
the
particular
unit.
Do not
damage
wiring
by
pushing
it
back
and forth
during
inspection.
Be
careful
not
to damage
the
re-
ceiver in
any
other
way.
d.
Misalinement
of one
or
more
stages
of the
receiver
will
cause
reduced
output.
Misaline-
ment
of the
h-f
(high-frequency)
oscillator
may
prevent
any
output.
e.
When trouble
is
localized
in
a
given
stage,
test the
tube,
measure
the voltage,
and measure
the
resistance
of the tube
socket
of
that
stage.
/".
Troutrle
in
a circuit
or
stage
may
not
cause
changes in
voltages
and
resistance
meas-
rrements
at the
tube
socket.
The notes
included
n
this
paragraph
are merely
a
guide
and
-houlcl
suggest
other
procedures,
such as
volt-
64
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chassis
toítlt coaer
remooed.
age and resistance
measurements
on
individual
parts.
g.
Remove
only
one tube
at
a time
when
testing.
Check
the number
of
the
tube
and
test
it;
if
the
tube
is not
defective,
return
it
to
its
proper
socket
before
another
tube
is
removed.
h.
Each
step
presupposes
the
satisfactory
completion
of all
previous
steps.
Isolate
ancl
clear
any
trouble
located
before
proceeding
with
any
succeeding
steps.
80. A-f
Signol
Substitution
Tesrs
a. High
OutTtut.
In
these
tests,
turn
OUT-
PUT
HIGH-LOW
switch
54 to HIGH,
and
ap-
ply
a 1,000-cycle
audio
signal
from
an audio
generator
through
a .05-pf
(microfarad)
capac-
itor.
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AGO
313A