Aiwa NSX-TR77 Service Manual page 38

ELECTRICAL ADJUSTMENT -4/7
QQ
3 7 63 1515 0
<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
7. Tracking Adjustment
Requirements: As instructed in preparations.
• Adjustment point: L904
1) Set S.S.G. to FM; carrier of 87.5 MHz with 75 kHz modulation, and source at 1 kHz, position output at maximum.
2) Tune the receiving frequency of the unit at FM 87.5 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 L904 so that the millivoltmeter points maximum.
8. 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.
TE
L 13942296513
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 22 dB or above.
5) Apply the above check to Rch.
9. 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 35 dBuV or less.
2) Apply the tuning search function, and check that the unit automatically stops at FM 98 MHz.
www
.
http://www.xiaoyu163.com
SET
FM ANT
SPOUT(L)
SPOUT(R)
x ao u163
y
i
http://www.xiaoyu163.com
2 9
8
AC MILLIVOLTMETER OSCILLOSCOPE
DUMMY
CH1 CH2
LOAD
CH1
6Ω
Q Q
3 6 7 1 3 1 5
co
.
-38-
9 4 2 8
OUTPUT
CH2
0 5 8 2 9 9 4 2 8
m
9 9
9 9