Aiwa NSX-TR99 Service Manual page 47

ELECTRICAL ADJUSTMENT -4/8
8. Auto-Stop Check (MW)
Requirements: As instructed in preparations.
1) Set S.S.G. to AM; carrier of 999 kHz with 30% modulation, source at 1 kHz, and output of 40 to 65 dBuV.
2) Apply the tuning search function, and check that the unit automatically stops at MW 999 kHz.
<FM Adjustment>
Make the following preparations for FM adjustment.
Preparations
• Standard Signal Generator (S.S.G.) / Loop antenna / Oscilloscope / Millivoltmeter / Dummy resistance (6Ω)
1) Connect the unit and measuring instruments as shown in the diagram below.
2) Connect the output of S.S.G. to the antenna input of the unit.
Standard Signal Generator
9. Tracking Adjustment
Requirements: As instructed in preparations.
• Adjustment point: L901/L902/L904/L905
1) Set S.S.G. to FM; carrier of 98 MHz with 75 kHz modulation, and source at 1 kHz, position output at maximum.
2) Tune the receiving frequency of the unit at FM 98 MHz.
3) While monitoring the waveform at 1kHz through the oscilloscope, lower the output level of S.S.G. maximum (till a certain
degree of noise is monitored).
4) Adjust L905 -> L904 -> L902 -> L901 -> L902 -> L904 -> L905 sequentially and repeat adjustment 2 to 3 times, so that
the millivoltmeter points maximum.
10. Separation Check
Requirements: As instructed in preparations.
1) Set S.S.G. to FM; carrier of 98 MHz with 67.5 kHz modulation, source at 1 kHz, and output at 74 dBuV.
2) Switch S.S.G. to PILOT ON, and set PILOT at 7.5 kHz.
3) Tune the receiving frequency of the unit at FM 98 MHz.
4) Allow the output of S.S.G. only from Lch, and check that the difference between Lch and Rch is 12 dB or above.
5) Apply the above check to Rch.
11. Auto-Stop Check
Requirements: As instructed in preparations.
1) Set S.S.G. to FM; carrier of 98 MHz with 75 kHz modulation, source at 1kHz, and output at 10 to 35 dBuV.
2) Apply the tuning search function, and check that the unit automatically stops at FM 98 MHz.
AC MILLIVOLTMETER
SET
DUMMY
CH1
LOAD
FM ANT
SPOUT(L)
SPOUT(R)
6Ω
-47-
OSCILLOSCOPE
OUTPUT
CH2
CH1 CH2