-55-
ELECTRICAL ADJUSTMENT -1/5
TUNER ADJUSTMENT
1. Clock Check
Requirements
Measuring equipment: Frequency counter
Test point: TP1 (CLOCK), GND
1)
Adjust the reception frequency of the main unit to 1710KHz.
2) Check that the test point frequency is 2160
±
0.045KHz.
2. VT Adjustment (FM)
Requirement
Measuring equipment: Digital multi-meter
Test point: TP4 (R962), GND
Adjustment point: L907
1) Adjust the reception frequency of the main unit to 108.0MHz.
2) Adjust L907 until the test point voltage (VT) is 7.0V
±
1V.
3) Adjust the reception frequency of the main unit to 87.5MHz.
4) Check that the test point (VT) voltage is about 1.5V.
3. VT Check (MW)
Requirement
Measuring equipment: Digital multi-meter
Test point: TP4 (R962), GND
1) Adjust the reception frequency of the main unit to 530KHz.
2) Check that the test point (VT) voltage is about 0.5V.
3) Adjust the reception frequency of the main unit to 1710KHz.
4) Check that the test point (VT) voltage is below 9.0V.
4. DC Balance Check
Requirement
Measuring equipment: Digital multi-meter
Test point: TP2, 3
(1) Adjust the reception frequency of the main unit to 98.0MHz.
(2) Check that the test point voltage difference between TP2 and TP3 is
0mV
±
500mV.
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