— 8 —
SERVICE ADJUSTMENTS (Continued)
MULTI-SOUND SECTION ADJUSTMENTS
Note: Multi-Sound Section must be adjusted after
IC101 (Signal Processor), IC3401 (MTS Decoder),
IC802 (EEPROM), or T131 (Sound I.F. transformer)
is replaced.
INPUT LEVEL ADJUSTMENT
1. Turn off the receiver and disconnect the AC power cord
(AC 120V line).
2. Connect audio signal generator output (300 Hz,
150 mVrms) to TP301 and ground.
3. Ground TP21 with a short jumper lead.
4. Connect voltmeter (RMS) to TP317 and ground.
5. While pressing the Menu key, reconnect the AC power
cord. The Service Menu will now appear.
6. Select NO. 32 INP (Input Level) with the
▲
or
▼
key.
7. Adjust the + or – key for a voltmeter reading of 400 ± 5%
mVrms at TP317.
STEREO VCO ADJUSTMENT
8. Turn off the receiver and disconnect the AC power cord
(AC 120V line).
9. Remove signal generator from TP301 and voltmeter
from TP317.
10. Connect frequency counter to TP317 and ground.
11. While pressing the Menu key, reconnect the AC power
cord. The Service Menu will now appear.
12. Select NO. 33 STE (Stereo VCO) with the
▲
or
▼
key.
13. Adjust the + or – key for a frequency counter reading of
15.734 ± 0.1 KHz at TP317.
FILTER ADJUSTMENT
14. Turn off the receiver and disconnect the AC power cord
(AC 120V line).
15. Remove frequency counter from TP317.
16. Connect audio signal generator output (15.734 KHz, 100
mVrms) to TP301 and ground.
17. Connect voltmeter (RMS) to TP317 and ground.
18. While pressing the Menu key, reconnect the AC power
cord. The Service Menu will now appear.
19. Select NO. 34 FIL (Filter) with the
▲
or
▼
key.
20. Adjust the + or – key until voltage is at trap point.
Voltage change in the filter adjustments is shown in
Figure 7.
SEPARATION ADJUSTMENT
21. Turn off the receiver and disconnect the AC power cord
(AC 120V line).
22. Remove jumper lead from TP21, signal generator from
TP301 and voltmeter from TP317.
23. Connect oscilloscope CH1 to TP317 and CH2 to TP318
and ground.
24. Connect an MTS TV/Stereo generator to antenna termi-
nal.
25. Select pilot, 300Hz audio frequency and Left modulating
signal.
26. While pressing the Menu key, reconnect the AC power
cord. The Service Menu will now appear.
27. Select NO. 35 LSP (Low Separation) with the
▲
or
▼
key.
28. Adjust the + or – key for minimum low frequencies at
TP317. (See Figure 8.)
29. Select 4 KHz audio frequency and Right modulating signal.
30. Select NO. 36 HSP (High Separation) with the
▲
or
▼
key.
31. Adjust the + or – key for minimum high frequencies at
TP318. (See Figure 8.)
Repeat adjustments (steps 27–31) until no further decreases
in amplitude can be obtained.
SAP VCO ADJUSTMENT
32. Turn off the receiver and disconnect the AC power cord
(AC 120V line).
33. Remove oscilloscope from TP317 and TP318, and MTS
TV/Stereo generator from antenna terminal.
34. Connect frequency counter to TP317 and ground.
35. Ground TP21 with a short jumper lead.
36. Connect a 1 M
Ω
resistor between TP316 and ground.
37. While pressing the Menu key, reconnect the AC power
cord. The Service Menu will now appear.
38. Select NO. 37 SPV (SAP VCO) with the
▲
or
▼
key.
39. Adjust the + or – key for a frequency counter reading of
78.67 ± 0.5 KHz at TP317.
40. Press the MENU key to turn off the Service Menu display.
PURITY AND CONVERGENCE ADJUSTMENTS
Purity and Convergence have been aligned at the factory.
No re-alignment is necessary.
Figure 7. Filter Adjustment
Figure 8. Separation Adjustments
