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3.
4.
3%
FM IF Adjustment
(1) Connect
an
FM signal
generator
to the
300-ohm
FM antenna
terminal
of this
unit
through
the
300-ohm
balun.
(2) Connect
the
center
meter
through
the
300-ohm
resistor
to the
terminal
Nos.
4 & 5 on
the PB-1396.
(See Fig.
2.)
(3)
Connect
an
AC voltmeter,
an
oscilloscope
and
a distortion
meter
to
REC
OUT
of
this
unit.
(See
Fig.
2.)
(4)
Make
this
unit
receive
at
the
tuning
point
where
no
station
is available
and adjust
the
IF primary
coil,
L104
on the PB-1396
to make
the
center
meter
read
0 (zero).
(5) Make
output
of the FM signal
generator
98MHz,
modulation
1KHz and 100%
monaural,
60OdB.
(6)
Tune
this
unit
at +0 on
the
center
meter
with
the
signal
specified
in the
.
foregoing
step
(5)%
(7) Adjust
the
IF secondary
coil,
L104
on the PB-1396
to make distortion
minimum.
(8) Repeat
adjustment
as per
the
foregoing
steps,
(4)-(7)
for a few
times
and
confirm
that
the
specs
meet.
FM Tracking
and
Sansitivity
Adjustment
(1) Make output
of an FM signal
generator
108MHz,
6dB and set
the dial pointer
at 1O8MHz
on the dial
scale
by the tuning knob.
Adjust
the local
oscil-
lator
trimmer
capacitor,
TC5
and
the
trimmer
capacitor
for
sensitivity
adjustment,
TC3
and
TC4
to make
output
maximum. .
(2)
Set
the unit
at 88MHz
on the dial
scale
and
activate
the FM signal
genera-
tor to make
the center
meter read O (zero).
FM Signal Strength Adjustment
(1) Make
output of an FM signal
generator
98MHz,
60dB and tune
this unit
at
+0 on
the
center
meter.
(2) Adjust
the
semi-fixed
resistor,
VR102
on the PB- 1396 to maké
all
of
5
signal
strength L.E.D.'s
light
up.
FM MPX and Muting
Adjustment
(1) Connect
a frequency
counter
to
the terminal
No.
11 on
the PB~1396.
(2) Make
output
of an FM signal
generator
60dB, modulation
0 (zero).
(3) Put
off
the mono
switch.
(4) Adjust
the
semi-fixed
resistor,
VR104 on the PB-1396
to make
frequency
19KHz+0
~1OHz.
|
.
.
(5) Make
output
of the FM signal
generator
12dB,
modulation
1KHz
100%
monaural.
(6)
Turn
the
semi-fixed
resistor,
VR101
on
the
PB-1396
to
the
endmost
of
the
counter-clockwise
position
to confirm
that
no
signal
appears
and
then,
turn
the semi-fixed
resistor,
VR101
clockwise
and
adjust
it to make
signal
come
out.
(7) Put
on the mono
switch.
7
(8) Make
output
of the FM signal
generator
60dB.
(9) Confirm
that
the center
meter
read
0 (zero)
and if it is slipped
out,
adjust
the
IF primary
coil,
L104
on the PB-1396.
(10) Make
output
of the FM signal
generator
60dB.
(11)
Confirm
that
distortion
is minimum.
If it is slipped
out,
adjust
the IF
secondary
coil,
L104
on the PB-1396.
(12)
Confirm
the
foregoing
steps
(9)~-(13)
and repeat
adjustment
unless
those
would
not
meet
rated
specs.
(13)
Make
the FM signal
generator
at stereo
modulation.
(14)
Put
off
the mono
switch.
(15)
Adjust
the
semi-fixed
resistor,
VR103
on the PB-1396
to make
stereo
separa-
tion both
at right
and
left
channels
well
balanced.
(16)
Adjust
the
IF coil
of the frontend,
Tl to make
stereo
distortion
minimum.
(17)
Confirm
the
steps
(6)-(16)
and
repeat
adjustment
unless
those
would
not
meet
rated
steps.
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