Aiwa XR-EM30 Service Manual page 41

ELECTRICAL ADJUSTMENT -5/8
5. 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 TP4 and TP5 is
0mV±500mV.
<LW / MW ADJUSTMENT>
For LW / MW adjustment, do wiring and connection as in the following.
Standerd Signal Generaor
6. If Adjustment (MW)
Requirement
Measuring equipment: Oscilloscope or Millivoltmeter
Test point: TP8(Lch), TP9(Rch), GND
Adjustment point: L802
1) Adjust the setting of Standard Signal Generator (hereinafter S.S.G.) to 999KHz
of 30% variation.
2) Adjust the receiving frequency of the main unit at 999KHz.
3) While looking at the waveform on the oscilloscope, reduce the output level all the
way (till a certain degree of is monitored through the oscilloscope).
4) Adjust L802 until the waveform of the oscilloscope reaches the maximum.
7. Tracking Adjustment (MW)
Requirement
Measuring equipment: Millivoltmeter
Test point: TP8(Lch), TP9(Rch), GND
Adjustment point: L952, L953
1) Adjust the S.S.G. setting to 999KHz of 30% variation and reduce the output level
all the way (till a certain degree of is monitored through the oscilloscope).
2) Adjust the reception frequency of the main unit to 999KHz.
3) Adjust L952 until the value of the millivoltmeter reaches the maximum.
4) Adjust the S.S.G. setting to 603KHz of 30% variation and reduce the output level
all the way (till a certain degree of is monitored through the oscilloscope).
5) Adjust the reception frequency of the main unit to 603KHz.
6) Adjust L953 until the value of the milivoltmeter reaches the maximum.
7) Repeat the adjustment 2 or 3 times from step 1 to 6 above.
60cm
-41-
DIGITAL MULTIMETER
V
VT
GND
SET
TP
Lch
Connect to the respective
Rch
measuring equipment
GND
OSCILLOSCOPE
CH1
Lch
Rch
GND
AC MILLIVOLTMETER
CH1
TP8
GND
GND
TP9
GND
CH2
CH2