Sharp GF-4343H - Vco Frequency Adjustment

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FM IF/RF ADJUSTMENT
SWITCH
SIGNAL
GENERATOR 400 Hz, 30%, eM modulated.
STEP
REMARKS
1. Using a minus
driver, turn
the core of
T2 counter-
clockwise
before taking
it out of the
_.. bobbin.
2. Adjust for
best ‘IF’
curve.
Adjust for best
“S"’ curve.
10.7 MHz | High :
frequency
Adjust for
maximal output.
VCO FREQUENCY ADJUSTMENT
SIGNAL 400 Hz, 30%, FM modulated
GENERATOR (mono signal)
FM
mono
position
FM
stereo
position
(unmodulated)
Adjust for
38 kHz + 150 Hz.
DIAL
FREQUENCY | POINTER
SETTING
98 MHz at
54 dB
<
=
1) COPE.
10.7 MHz, _ OSCILLOSCOP
FM SWEEP GENERATOR
Telescopic
Rod Antenna
Figure 10—1 FMIF |
Figure 10—2
FM “IF’’ CURVE
Figure 10—3
FM “S"* CURVE
ELECTRONIC
Telescopic VOLTMETER
(See Figure 10-6) Rod Antenna
FM SIGNAL
GENERATOR
FM STEREO
SIGNAL GENERATOR Telescopic IC3 FREQUENCY
© pin 1000PF COUNTER
G
(See Figure 10-6)
OUMMY
Figure 10—5 VCO FREQUENCY
RI
To Telescopic Rod Antenna
P R1 = 37.5 ohm
6 OO ee oe 96 oki
es R1 = 50 ohm
o7 POND i = 50 ohm
To Chassis GND
2: Output impedance of signal generator
Figure 10-6 FM DUMMY
—10—