Tuner Section - Aiwa AV-D57 Service Manual

ADJUSTMENT <TUNER / FRONT>

TUNER SECTION

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1. Clock Frequency Check
Settings : • Test point : TP2(CLK)
Method : Set to AM 1602kHz and check that the test point is
2052kHz ± 45Hz.
2. AM VT Check
Settings : • Test point : TP1(VT)
Method : Set to AM 1602kHz, AM 531kHz and check
that the test point is less than 8.0V(1602kHz) and
more than 0.6V(531kHz).
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 is maximum.
4. FM VT Check
Settings : • Test point : TP1(VT)
Method : Set to FM 108.0MHz and check that the test point is
less than 8.0V.
Then set to FM 87.5MHz and check that the test point is
more than 0.5V.
5. FM Tracking Check
Settings : • Test point : TP8(Lch), TP9(Rch)
Method : • Set to FM 98.0MHz and check that the test point is
less than 9.0dBµV.
6. AM IF Adjustment
Settings : • Test point : TP8(Lch), TP9(Rch)
• Adjustment location :
L772 ................................................ 450kHz
7. DC Balance / Mono Distortion Adjustment
Settings : • Test point : TP3, TP4 (DC Balance)
TP8(Lch), TP9(Rch) (Distortion)
• Adjustment location : L771
• Input level : 60dBµV
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%.
< FRONT SECTION >
8. µ-CON OSC Adjustment
Settings : • Test point : TP1 and GND
• Adjustment location : L801
Method : Insert AC plug while pressing ECO key and POWER
key. Adjust L801 so that the frequency across the test
point is 78.40Hz ± 0.08Hz.
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