Aiwa NSX-R90 Service Manual page 47

ELECTRICAL ADJUSTMENT-3/6
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<AM Adjustment>
Before starting the AM adjustment, perform the preparation shown below.
Preparation
Ÿ
Measuring equipment: Standard signal generator (S.S.G), loop antenna, oscilloscope, milli-volt meter and dummy resistor (6Ω)
1) Connect measuring equipment as shown below.
2) Place loop antenna of signal generator 60 cm apart from the loop antenna of the receiver as shown.
Standerd Signal Genertaor
4. IF Adjustment
Conditions: The same conditions as specified in Preparation.
Ÿ
Adjustment point: L802
1) Set up the S.S.G.. to AM, carrier 1,000 kHz, modulation degree 30% and source 1 kHz.
2) Tune the reception frequency to AM 1,000 kHz.
3) While observing the 1 kHz waveform with an oscilloscope, decrease the S.S.G.. output level. (Decrease until small noise is visible on
waveform.)
4) Adjust L802 until the milli-volt meter reading becomes maximum.
5. Tracking Adjustment
Conditions: The same conditions as specified in Preparation.
Ÿ
Adjustment point: L952
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1) Set up the S.S.G.. to AM, carrier 1,000 kHz, modulation degree 30% and source 1 kHz.
L 13942296513
2) Tune the reception frequency to AM 1,000 kHz.
3) While observing the 1 kHz waveform with an oscilloscope, decrease the S.S.G.. output level. (Decrease until small noise is visible on
waveform.)
4) Adjust L952 until the milli-volt meter reading becomes maximum.
6. Auto Stop Check
Conditions: The same conditions as specified in Preparation.
1) Set up the S.S.G.. to AM, carrier 1,000 kHz, modulation degree 30%, source 1 kHz and output 40 to 65 dBuv.
2) Let the NSX-R90 start the Tuning Search. Check that the Tuning Search stops at AM 1,000 kHz automatically.
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AC MILLIVOLTMETER
DUMMY
LOAD
SET
SPOUT(L)
SPOUT(R)
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OSCILLOSCOPE
OUTPUT
CH1 CH2
CH1 CH2
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