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— 4 —
SECTION 3
ELECTRICAL ADJUSTMENTS
FM VCO Adjustment
Procedure:
1. Connect the frequency counter to 2 and 1 pins of IC2 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
µ
F
FM lead wire antenna terminal
Connection:
Adjustment Location:
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
455 kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L5
520 kHz
CT1-4
1,650 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L2
620 kHz
CT1-1
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 IF ADJUSTMENT
Adjust for a maximum reading on level meter
T2
10.7 MHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L4
87.35 MHz
CT1-3
108.05 MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
87.35 MHz
CT1-2
108.05 MHz
[FM]
Setting:
BAND switch
BAND switch
: FM
[AM]
Setting:
BAND switch
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
µ
F
FM lead wire antenna terminal
level meter
set
SP1, SP2 (speakers)
32
Ω
+
–
–
Frequency counter
75,500 – 76,500 Hz
IC2 Pin
2
+
–
–
frequency counter
33 k
Ω
AUDIO Board
IC2 Pin
1
[AUDIO BOARD] (Component Side)
RV1: MPX VCO
IC2
L2: AM TRACKING
L3: FM TRACKING
T1: AM IF
CT1-4:
AM FREQUENCY
COVERAGE
CT1-1:
AM TRACKING
AM FREQUENCY
COVERAGE
CT1-1:
AM TRACKING
CT1-2:
FM TRACKING
FM TRACKING
CT1-3:
FM FREQUENCY
COVERAGE
FM FREQUENCY
COVERAGE
T2: FM IF
L5: AM FREQUENCY
COVERAGE
L4: FM FREQUENCY
COVERAGE
[TUNER BOARD] (Component Side)
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