Aiwa NSX-R50 Service Manual page 27

<MW/LW Adjustment>
Make sure that the following settings are done before adjustment.
Preparation
* Measuring instruments:
Standard Signal Generator (S.S.G.) / Loop antenna / Oscilloscope / Millivoltmeter / Dummy resistor (6Ω)
(1) Connect the measuring instruments as shown in the diagram below.
(2) Keep a distance of 60cm between the loop antenna of signal generator and the one connected to the unit.
Standard Signal Generator
Standerd Signal Genertaor
5. IF Adjustment (MW)
Requirements
* Test point: SP OUT (Lch, Rch)
(1) Adjust the S.S.G. setting to AM; carrier at 999 kHz, distortion rate at 30 %, and source 1 kHz.
(2) Adjust the unit to MW 999 kHz.
(3) While monitoring the 1 kHz waveform through oscilloscope, decrease the S.S.G. output level (till slight noises appear in
the waveform).
(4) Adjust L802 so that the millivoltmeter indicates maximum.
6. Tracking Adjustment (MW)
Requirements: Same as Item 5.
(1) Adjust the S.S.G. setting to AM; carrier at 999 kHz, distortion rate at 30 %, and source 1 kHz.
(2) Adjust the unit to MW 999 kHz.
(3) While monitoring the 1 kHz waveform through oscilloscope, decrease the S.S.G. output level (till slight noises appear in the
waveform.
(4) Adjust L951 (1/3) so that the millivoltmeter indicates maximum.
7. Tracking Adjustment (LW)
Requirements: Same as Item 5.
(1) Adjust TC942 to the mechanical center.
(2) Adjust the S.S.G. setting to AM; carrier at 144 kHz, distortion rate at 30 %, and source 1 kHz.
(3) Adjust the unit to LW 144 kHz.
(4) While monitoring 1 kHz waveform through oscilloscope, decrease the S.S.G. output level (till slight noises appear in the
waveform).
(5) Adjust L941 so that the millivoltmeter indicates the maximum level.
(6) Adjust the S.S.G setting to AM; carrier at 290 kHz; distortion rate at 30 %, and source at 1 kHz.
(7) Adjust the unit to LW 290 kHz.
(8) While monitoring 1 kHz waveform through oscilloscope, decrease the S.S.G. output level (till slight noises appear in the
waveform).
(9) Adjust TC942 so that the millivoltmeter indicates the maximum level.
(10) Repeat the above steps 2 to 9 two to three times.
8. Auto-Stop Function Check (MW)
Requirements: Same as Item 5.
(1) Adjust the S.S.G setting to AM; carrier at 999 kHz; distortion rate at 30 %; source at 1 kHz, and output at 78 dBuv.
(2) Start the tuning search mode, and check that the auto-stop function is applied at MW 999 kHz.
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60cm
SET
SPOUT(L)
SPOUT(R)
– 27 –
AC MILLIVOLTMETER
OSCILLOSCOPE
DUMMY
CH1 CH2
LOAD
CH1
Ω
6
OUTPUT
CH2