Sony ICF-SW7600GR - Portable Radio, Service Manual

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7
ICF-SW7600GR
NG
Center
NG
NG
OK
(3) 2nd Local Adjustment
Setting:
ATT switch : OFF
TONE switch : MUSIC
AM MODE switch : NORM
Procedure:
1.
Connect frequency counter to the TP OSC2 through the high
input impedance amplifier.
2. Tune the set to AM 150kHz.
3. Adjust CT202 so that the reading on the frequency counter
becomes in 55.39000MHz±30Hz.(55.38997 to 55.39003MHz)
Adjustment Location: MAIN board (See page 8)
(4) FM Tracking Adjustment
Setting:
ATT switch : OFF
TONE switch : MUSIC
Procedure:
1.
Set the frequency of the FM RF signal generator and the
frequency display of the set to FM 108.00MHz.
2. Adjust CT101 and CT102 so that the reading on level meter
becomes in maximum.
3. Set the frequency of the FM RF and the frequency display of
the set to FM 76.00MHz.
4. Adjust T101 and T102 so that the reading on level meter
becomes in maximum.
5. Repeat the above steps 1 to 4 several times.
Adjustment Location: MAIN board (See page 8)
(5) 76kHz (MPX) Adjustment
Setting:
ATT switch : OFF
TONE switch : MUSIC
Procedure:
1.
Insert Headphones plug into headphones jack (J202) (for VCO
operation).
2. Connect a capacitor (10
µ
F) between IC202 pin 1 and GND.
3. Connect frequency counter to the TP 76K (VCO) through the
high input impedance amplifier.
4. Tune the set to FM 108.00MHz.
5. Adjust RV203 so that the reading on the frequency counter
becomes in 76kHz±300Hz.
6. Remove the headphones plug.
Adjustment Location: MAIN board (See page 8)
(6) Just Tune Adjustment
Setting :
ATT switch : OFF
TONE switch : MUSIC
(FM RF signal generator)
Frequency : 93.025MHz
Moduration : 22.5kHz
Output level : 54dB
Procedure:
1.
Connect an oscilloscope to the TP SD.
2. Tune the set to FM 93.00MHz.
3. Adjust RV202 so that the waveform on the oscilloscope satisfy
as shown the figure.
Adjustment Location: MAIN board (See page 8)
(7) SSB 0 Beat Adjustment
Setting :
ATT switch : OFF
TONE switch : MUSIC
(AM RF signal generator)
Frequency : AM 150kHz
Moduration : None
Output level : 44dB
Procedure:
1.
Connect an oscilloscope to the TP DET.
2. Tune the set to AM 150kHz.
3. Set the AM MODE switch to SYNC.
4. Set the SYNC switch to USB.
5. Adjust CT201 so that the waveform on the oscilloscope is
minimized.
6. Set the SYNC switch to LSB.
7. Adjust CT201 so that the waveform on the oscilloscope is
minimized.
8. Repeat the above steps 4 to 7 several times.
9. Set the AM MODE switch to SSB.
10. Confirm that the beat sound is changed by turning the
SSB FINE TUNE control.
Adjustment Location: MAIN board (See page 8)