Aiwa NSX–SZ70 Service Manual page 29

< TUNER SECTION >
1. Clock Frequency Check
Settings : • Test point :
Method : Set to AM 1710kHz and check that the test
point is 2160kHz ± 45Hz.
2. AM VT Check
Settings : • Test point :
Method : Set to AM 1710kHz and AM 530kHz
and check that the test point is less
than 8.5V(1710kHz) and more than
0.6V(530kHz)
3. AM Tracking Adjustment
Settings : • Test point : TP8(Lch), TP9(Rch)
• Adjustment location :
L951(1/3)........................ 999kHz
Method : Set to AM 999kHz and adjust
L951(1/3) so that the test point is max.
4. FM VT Check
Settings : • Test point :
Method : Set to FM 108.0MHz and check that the test
point is less than 8.0V.
Set to FM 87.5MHz and check that the test
point is more than 0.5V.
5. FM Tracking Check
Settings : • Test point :
Method : Set to FM 98.0MHz and check that the test
point is less than 9.0dBµV.
6. AM IF Adjustment
Settings : • Test point :
• Adjustment location : L802
• Input level :
Method : Adjust L802 so that the output becomes max.
7. DC Balance / Mono Distortion Adjustment
Settings : • Test point :
• Adjustment location : L801
• Input level :
Method : Set to FM 98.0MHz and adjust L801 so that the
voltage between TP3 and TP4 becomes 0V ± 0.3V.
Next, check that the distortion is minimum.
< DECK SECTION >
8. Tape Speed Adjustment (DECK 2)
Settings : • Test tape :
• Test point :
• Adjustment location : SFR1
Method : Play back the test tape and adjust SFR1 so that
the frequency counter reads 3000Hz ± 5Hz(FWD) and ±
45Hz(REV) with respect to forward speed.
TP2 (CLK)
TP1 (VT)
TP1 (VT)
TP8(Lch), TP9(Rch)
TP8(Lch), TP9(Rch)
Variable
TP3, TP4
(DC Balance)
TP8(Lch), TP9(Rch)
(Distortion)
60dBµV
TTA–100(3kHz)
TP10(Lch), TP11(Rch)
9. Head Azimuth Adjustment (DECK 1, DECK 2)
Settings : • Test tape :
• Test point :
• Adjustment location : Head azimuth
Method : Play back the 10kHz signal of the test tape
and adjust screw so that the output becomes
maximum. Next, perform on each FWD PLAY
and REV PLAY mode.
10. PB Frequency Response Check (DECK 1, DECK 2)
Settings : • Test tape :
• Test point :
Method : Play back the 315Hz and 10kHz signals of the
test tape and check that the output ratio of the
10kHz signal with respect to that of the 315Hz
signal is within 0 ± 3dB.
11. REC/PB Frequency Response Adjustment (DECK 2)
Settings : • Test tape :
• Test point :
• Input signal :
• Adjustment location :
Method : Apply a 1kHz signal and REC mode. Then adjust
OSC attenuator so that the output level at the test
points becomes 9.0mV. Record and play back the
1kHz and 10kHz signals and adjust SFRs so that
the output level of the 10kHz signals becomes
0dB ± 0.5dB with respect to that of the 1kHz
signal.
12. REC/PB Frequency response Check (DECK 2)
Settings : • Test tape :
• Test point :
• Input signal :
Method : Apply a 1kHz signal and REC mode. Then
Adjust OSC attenuator so that the output level
at the test points becomes 9.0mV. Record and
play back the 1kHz and 10kHz signals and
check that the output is 0dB ± 2dB.
13. REC/PB Sensitivity Check (DECK 2)
Settings : • Test tape :
• Test point :
• Input signal : 1kHz (LINE IN)
Method : Apply a 1kHz signal and REC mode. Then adjust
OSC attenuator so that the output level at the test
points becomes 90mV. Record and play back the
1kHz signal and check that the output is -1dB ±
3dB.
14. µ-CON OSC Adjustment
Settings : • Test point :
• Adjustment location :
Method : Insert AC plug with pressing TUNER function
key. Adjust L101 so that the frequency across the
test point is 208.8Hz ± 0.2Hz.
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TTA–300 (315/10kHz)
TP10(Lch), TP11(Rch)
adjustment screw
TTA–300 (315/10kHz)
TP10(Lch), TP11(Rch)
TTA–602 (Normal)
TP10(Lch), TP11(Rch)
1kHz / 10kHz (LINE IN)
SFR351 (Lch)
SFR352 (Rch)
TTA-615 (CrO )
2
TP10(Lch), TP11(Rch)
1kHz/10kHz (LINE IN)
TTA-615 (CrO )
2
TP10(Lch), TP11(Rch)
TP5(K-SCAN)
L101