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— 10 —
SECTION 4
ELECTRICAL ADJUSTMENTS
FM VCO Adjustment
Procedure:
Procedure:
1. Connect the frequency counter to 4 and 7 pins of IC1 as shown
the figure right.
2. Tune the set to 98 MHz.
3. Adjust RV1 for 76 kHz Hz reading on frequency counter.
3. Adjust RV1 for 76 kHz Hz reading on frequency counter.
Specification Value:
FM RF signal
generator
generator
Carrier frequency: 98 MHz
Modulation: no modulation
Output level: 0.1 V (100 dB)
Modulation: no modulation
Output level: 0.1 V (100 dB)
0.01
µF
FM lead wire antenna terminal
Connection:
Adjustment Location:
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
450 kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L4
530 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
600 kHz
CT2
1,400 kHz
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
done by the trimmer capacitors.
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L2
87.5 MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
87.5 MHz
CT1
108.0 MHz
PRECAUTION
• Adjustment should be performed in the order given.
• Adjustment should be performed in the order given.
[FM]
Setting:
Function switch : RADIO
BAND switch
Setting:
Function switch : RADIO
BAND switch
: FM
[AM]
Setting:
Function switch : RADIO
BAND switch
Setting:
Function switch : RADIO
BAND switch
: AM signal
AM RF signal
generator
generator
30% amplitude modulation by
400 Hz signal.
Output level: as low as possible
400 Hz signal.
Output level: as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
FM RF signal
generator
generator
75 kHz frequency deviation
by 1 kHz signal.
Output level: as low as possible
by 1 kHz signal.
Output level: as low as possible
0.01
µF
FM lead wire antenna terminal
level meter
set
J301 (phones)
32
Ω
+
–
–
TUNER SECTION
0 dB=1 µV
Frequency counter
75,500 – 76,500 Hz
IC1 Pin 4
+
–
–
frequency counter
33 k
Ω
MAIN Board
IC1 Pin 7
RV1
FM VCO Adjustment
FM VCO Adjustment
T1
AM IF Adjustment
AM IF Adjustment
CT2
AM Traking Adjustment
AM Traking Adjustment
L2
FM Frequency
Coverage Adjustment
FM Frequency
Coverage Adjustment
L4
AM Frequency
Coverage Adjustment
AM Frequency
Coverage Adjustment
L1
FM Tracking Adjustment
FM Tracking Adjustment
CT1
FM Traking
Adjustment
FM Traking
Adjustment
L3
AM Traking Adjustment
AM Traking Adjustment
[MAIN BOARD] (Component Side)
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