-37-
ELECTRICAL ADJUSTMENT -3/7
<AM Adjustment>
Make the following preparations for AM adjustment.
Preparations
•
Standard Signal Generator (S.S.G.) / Loop antenna / Oscilloscope / Millivoltmeter / Dummy resistance (6
Ω
)
1) Connect the unit and measuring instruments as shown in the diagram below
2) Position the loop antenna connected to S.S.G. and the one connected to the unit 60 cm apart.
6. IF Adjustment
Requirements: As instructed in preparations.
•
Adjustment point: L802
2) Tune the receiving frequency of the unit at AM 1,000 kHz.
degree of noise is monitored).
4) Adjust L802 so that the millivoltmeter points maximum.
4. Tracking Adjustment
Requirements: As instructed in preparations.
•
Adjustment point: L952 / L953
1) Set S.S.G. to AM; carrier of 1,000 kHz with 30% modulation, and source at 1 kHz, position output at maximum.
2) Tune the receiving frequency of the unit at AM 1,000 kHz.
3) While monitoring the waveform at 1kHz through the oscilloscope, lower the output level of S.S.G. maximum (till a certain
degree of noise is monitored).
4) Adjust L952 so that the millivoltmeter points maximum.
5) Set S.S.G. to AM; carrier of 600 kHz with 30% modulation, and source at 1 kHz.
6) Tune the receiving frequency of the unit at AM 600 kHz.
7) Adjust L953 so that the millivoltmeter points maximum.
8) Repeat above steps 1) to 7) 2 to 3 times.
5. Auto-Stop Check
Requirements: As instructed in preparations.
1) Set S.S.G. to AM; carrier of 1,000 kHz with 30% modulation, source at 1 kHz, and output of 74 dBuV.
2) Apply the tuning search function, and check that the unit automatically stops at AM 1,000 kHz.
Standard Signal Generator
AC MILLIVOLTMETER
OSCILLOSCOPE
OUTPUT
CH2
CH1
CH2
CH1
SET
60cm
DUMMY
LOAD
SPOUT(L)
SPOUT(R)
6
Ω
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