Aiwa SX-NBL25 Service Manual page 23

ADJUSTMENT – 1 <TUNER / FRONT>
< TUNER SECTION >
1. Clock frequency Check
Settings : • Test point :
Method : Set to MW 1602kHz and check that the test point is
2052kHz ± 45Hz.
2. MW VT Check
Settings : • Test point :
Method : Set to MW 1602kHz and check that the test point is
less than 8.0V. Then set to MW 531kHz and check that
the test point is more than 0.6V.
3. MW Tracking Adjustment
Settings : • Test point :
• Adjustment location : L951(1/3)
Method : Set to MW 999kHz and adjust L951(1/3) so that the
test point becomes maximum.
4. LW VT Adjustment
Settings : • Test point :
• Adjustment location : L942
Method : Set to LW 144kHz and adjust L942 so that the test
point becomes 1.3V ± 0.05V. Then set to LW 290kHz
and check that the test point is less than 8.0V.
5. LW Tracking Adjustment
Settings : • Test point :
• Adjustment location :
L941 .................................................... 144kHz
TC942 .................................................. 290kHz
Method : Set up TC942 to center before adjustment.
The level at 144kHz is adjusted to MAX. by L941.
Then the level at 290kHz is adjusted to MAX. by
TC942.
6. AM IF Adjustment
Settings : • Test point :
• Adjustment location :
L802 .................................................... 450kHz
7. FM VT Check
Settings : • Test point :
Method : Set to FM 87.5MHz check that the test point is more
than 0.5V. Then set to FM 108.0MHz and check that
the test point is less than 8.0V.
8. FM Tracking Check
Settings : • Test point :
Method : Set to FM 98.0MHz and check that the test point is less
than 13dBµV.
All manuals and user guides at all-guides.com
TP2 (CLK)
TP1 (VT)
TP8 (Lch), TP9 (Rch)
TP1 (VT)
TP8 (Lch), TP9 (Rch)
TP8 (Lch), TP9 (Rch)
TP1 (VT)
TP8 (Lch), TP9 (Rch)
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9. 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 ± 300mV
with minimum distortion.
10. Output Level Check
<MW>
Settings : • Test point :
• Input level :
Method : Set to MW 999kHz and check that the test point is
40mV ± 3dB.
<FM>
Settings : • Test point :
• Input level :
Method : Set to FM 98.0MHz and check that the test point is
140mV ± 3dB.
11. FM Separation Check
Settings : • Test point :
• Input level :
Method : Set to FM 98.0MHz and check that the test point is
more than 12dB.
< FRONT SECTION >
µ
12. -CON OSC Adjustment
Settings : • Test point :
• Adjustment location : L951
Method : Insert AC plug while pressing of "POWER" key and
"TUNER" function key.
Connect a frequency counter across TP10 and TP11.
Then adjust L951 so that the test point becomes
92.470Hz ± 0.092Hz.
[ Manual Reset ]
Make up for RESET after adjustment.
* Reset is to press "POWER" key while pressing of
"CLEAR (STOP)" key.
TP3, TP4 (DC)
60dBµV
TP8 (Lch), TP9 (Rch)
74dBµV
TP8 (Lch), TP9 (Rch)
60dBµV
TP8 (Lch), TP9 (Rch)
60dBµV
TP10 (KEY-SCAN)
TP11 (GND)