Sharp 36US650 Service Manual page 11

36US650
Ë MTS ADJUSTMENT
MTS Level Adjustment
1. Receive the following composite signal.
Monaural signal: 400Hz, 100% modulation
2. Set the sound volume above 1.
3. Connect the rms voltmeter to pin (39) of IC3001.
4. Enter the service mode and select the service
adjustment "M01" and set to "09".
5. Enter the service mode and select the service
adjustment "EX4".
6. Adjust the data so that rms voltmeter reads
490±10mVrms.
7. For 2nd Tuner, adjust the "M06" until the voltage of
pin (36) of IC3001 becomes 490±10mVrms.
MTS VCO Adjustment
1. Keep the unit in no-signal state.
2. Connect the frequency counter to pin (39) of IC3001.
3. Connect a capacitor (100µF, 50V) in between
positive(+) side of C3005 and ground.
4. Enter the service mode and select the service
adjustment "M02"
5. Adjust the data so that the frequency counter reads
62.94 ±0.75kHz.
Filter Adjustment
1. Feed the following stereo pilot signal to pin (14) of
IC3001 .
Stereo pilot signal: 9.4kHz, 600mVrms.
2. Enter the service mode and select the service
adjustment "M03".
3. Adjust the data until "OK" appears in position on the
screen. Make sure the "OK" is displayed almost at
the center of the data range.
Separation Adjustment
1. Input "SIGNAL 1" (TU51and TU52) and vary the
"M04" and "M07" bus data to get the minimun AC
voltage to pin (39) of IC3001.
2. Input "SIGNAL 2" (TU51and TU52) and vary the
"M05" and "M08" bus data to get the minimun AC
voltage to pin (39) of IC3001.
SIGNAL 1: 300Hz, 30% modulation, Lch only, NR-ON
SIGNAL 2: 3kHz, 30% modulation, Lch only, NR-ON
Check the output of the speaker at the maximum
volume as stated below.
Confirmation spec:
ADJ spec: above 25 dB
CHK spec: above 20 dB
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