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(1) Purpose:
Adjust the oscillation frequency of crystal.
(2) Measuring instrument:
Frequency counter.
(3) Adjusting procedures:
1)
2)
Connect
the counter between
the MO termi-
nal of the unit and the GND terminal.
Set the AGC/CAL switch to 25kHz and rotate
the trimmer
TC1
on
the
unit
so that the
reading of counter is set to 25kHz #2Hz.
Setting of base current (Refer to Fig. 11)
(1) Purpose:
Adjust the base current to the power transistor in
the AF unit under the absence of input signal.
Measuring instrument:
DC ammeter or circuit tester with a calibration of
about 100mA in full scale.
Adjusting procedures:
(2)
(3)
1)
2)
3)
4)
Disjoint the red - white lead wire connected to
the terminal
'14°' on the AF unit (Power
switch must be in off condition).
Connect the ammeter between the red - white
lead wire and
the terminal
"14°
(lead wire
(+), terminal (—)).
Turn on the power switch.
But, the AF-GAIN
VR
must
be turned
fully counterclockwise
(minimum sound volume).
Set the current to 42mA
by turning the PC
trimmer potentiometer (VR1) in the AF unit.
{Note}
Check
that the line voltage is exactly AC 117
5)
volts.
Remove
the ammeter and restore wiring con-
nection.
02
VR1
AF
a
IN. PUT
08
04
AF
OUT PUT
06
03
vR2
3
SIDE TONE LEVEL
Fig. 11
27
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