Aiwa XR-HG5MD Service Manual page 31

< 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 : L981 (1/3)
Method : Set to MW 999kHz and adjust L981 (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 :
L772 ........................... 450kHz
TP2 (CLK)
TP1 (VT)
TP8 (Lch), TP9 (Rch)
TP1 (VT)
TP8 (Lch), TP9 (Rch)
TP8 (Lch), TP9 (Rch)
7. FM VT Check
Settings : • Test point :
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.
8. FM Tracking Check
Settings : • Test point :
Method : Set to FM 98.0MHz and check that the test point is
less than 13dBµV.
9. DC Balance / Mono Distortion Adjustment
Settings : • Test point :
• Adjustment location : L771
• Input level :
Method : Set to FM 98.0MHz and adjust L771 so that the
voltage between TP3 and TP4 is 0V ± 0.04V. Then
check the distortion is less than 1.3%.
10. Output Level Check
<MW>
Settings : • Test point :
• Input level :
Method : Set to MW 999kHz and check that the test point is
50mV ± 3dB.
<FM>
Settings : • Test point :
• Input level :
Method : Set to FM 98.0MHz and check that the test point is
220mV ± 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.
– 31 –
TP1 (VT)
TP8 (Lch), TP9 (Rch)
TP3, TP4 (DC balance)
60dBµV
TP8 (Lch), TP9 (Rch)
74dBµV
TP8 (Lch), TP9 (Rch)
60dBµV
TP8 (Lch), TP9 (Rch)
60dBµV