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5. AM Tracking Adjustment
Requirement: As instructed in preparation.
•
Adjustment location: L952/L953
1) Set S.S.G. to AM, carrier of 1000kHz with 30% modulation, source at 1kHz, and output at MAX.
2) Tune the unit to the receiving frequency at AM 1000kHz.
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 indicates maximum.
5) Set S.S.G. to AM; carrier of 600kHz with 30% modulation, and source at 1kHz.
6) Set the unit to the receiving frequency at AM 600kHz.
7) Adjust L953 so that the millivoltmeter indicates maximum.
8) Repeat the above step 1 to 7 two to three times.
6. AM Auto-Stop Check
Requirement: As instructed in preparation.
1) Set S.S.G. to AM; carrier of 1000kHz with 30% modulation, source at 1kHz, and output at 74dBuv.
2) Apply the tuning search function, and check that the unit automatically stop at AM 1000kHz.
<FM Adjustment>
Make the following preparations for FM adjustment.
Preparation
•
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) Connect the output of S.S.G. to the antenna input of the unit.
7. FM Tracking Adjustment
Requirement: As instructed in preparation.
•
Adjustment point: L904
1) Set S.S.G. to FM; carrier of 87.5MHz with 75kHz modulation, source at 1kH and output at MAX.
2) Tune the unit to the receiving frequency at FM 87.5MHz.
4) Adjust L904 so that the millivoltmeter indicates maximum.
Requirement: As instructed in preparation.
1) Set S.S.G. to FM, carrier of 98MHz with 67.5kHz modulation, source at 1kH and output at 60dBuv.
2) Switch S.S.G. to PILOT ON and set to PILOT 7.5kHz.
3) Tune the unit to the receiving frequency at FM 98MHz.
4) Set the output of S.S.G. available only from LCH, and check that the difference between LCH and RCH is 25dB or above while
monitoring the millivoltmeter.
5) Apply the above check to RCH.
9. FM Auto-Stop Check
Requirement: As instructed in preparation.
1) Set S.S.G. to FM, carrier of 98MHz with 75kHz modulation, source at 1kHz and output at 10 ~ 35dBuv.
2) Apply the tuning search function, and check that the unit automatically stop at FM 98MHz.
6
Ω
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