Aiwa XR-DV3M, Service Manual

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ELECTRICAL ADJUSTMENT
L771
7
L772
4
TP7
TP2
TP4
TP3
L981
TP1
3
TUNER C.B
TP9
TP8
< TUNER SECTION >
1. Clock Frequency Check
Settings: • Test point: TP2 (CLOCK)
Method: Set to AM 1710kHz and check that the test point
becomes 2160kHz±45kHz.
2. AM VT Check
Settings: • Test point: TP1 (VT)
Method: Set to AM 1710kHz and check that the test point is
less than 8.5V.
Then set to AM 530kHz and check that the test point
is more than 0.6V.
3. AM Tracking Adjustment
Settings: • Test point: TP8 (Lch), TP9 (Rch)
• Adjustment location: L981 (1/3)
Method: Set to AM 999kHz and adjust L981 (1/3) so that the
test point becomes maximum.
4. AM IF Adjustment
Settings: • Test point: TP8 (Lch), TP9 (Rch)
• Adjustment location: L772
Method: Set to AM 999kHz and adjust L772 so that the test
point becomes maximum.
5. FM VT Check
Settings: • Test point: TP1 (VT)
Method: Set to FM 87.5MHz, 108.0MHz and check that the
test point is more than 0.5V (87.5MHz) and less than
8.0V (108.0MHz).
6. FM Tracking Adjustment
Settings: • Test point: TP8 (Lch), TP9 (Rch)
Method: Set to FM 98.0MHz and check that the test point is
less than 9dB.
7. DC Balance/Mono Distortion Adjustment
Settings: • Test point: TP3, TP4 (DC BALANCE)
• Adjustment location: L771
• Input level: 60dB
Method: Set to FM 98.0MHz and adjust L771 so that the
voltage between TP3 and TP4 becomes 0V±0.04V.
Next, check that the distortion is less than 1.3%.
8. Auto Stop Level Check
<AM>
Settings:
• Test point: TP7 (TUNE)
• Input level: 52dB
Method: Check to Auto Stop on AM 1000kHz and Level is
52dBµV+10/-15dB.
<FM>
Settings:
• Test point: TP7 (TUNE)
• Input level: 25dB
Method: Check to Auto Stop on FM 98.0MHz and Level is
25dBµV±10dB.
9. Output Level Check
<AM>
Settings:
• Test point: TP8 (Lch), TP9 (Rch)
• Input level: 74dB
Method: Set to AM 1000kHz and check that the test point is
200mV±3dB.
<FM>
Settings:
• Test point: TP8 (Lch), TP9 (Rch)
• Input level: 60dB
Method: Set to FM 98.0MHz and check that the test point is
800mV±3dB.
10. Separation Check
Settings: • Test point: TP8 (Lch), TP9 (Rch)
• Input level: 60dB
Method: Set to FM 98.0MHz and check that the test point is
more than 25dB.
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