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SA-107H
©
ADJUSTMENT OF TUNER CIRCUIT
FM
IF/RF ADJUSTMENT
@
Before the adjustment, loosen the core of T103 by about 1mm.
@
Set the wave band selector switch at FM mono position.
@
Set the FM preset switch at MANUAL position.
@
Set the AFC switch at off position.
@
Set the signal generator to produce a signal of 1kHz, 40kHz dev.,
FM modulated.
DIAL
POINTER
SETTING
REMARKS
IF (Connect instruments as shown in Fig. 12-1.)
Adjust for best
"IF"
IF
T101
Cine
10.7MHz | , High
frequency
T103
T104
Repeat steps 1 and 2 until no further improvement can be made.
Adjust
for best: "S"
Curve
RF (Connect instruments as shown in Fig. 12—4.)
—————
Lowest
87.36MHz
frequency
Band
coverage
Highest
10830MH2 | sequency
Adjust
for
maximal
Tune to
output.
S0MHz
Tracking
Tune to
106MHz
8
Repeat steps 4, 5 and 6, 7 until no further improvement can be made.
Potentiometer (Connect instruments as shown in Fig. 12—4.)
106MHz
VR302~309
Lowest
frequency
Band
coverage
Adjust
for
maximal
87.35MHz
output.
ADJUSTMENT OF FM DETECTOR COIL
e Apply a signal of S8MHz to the FM External antenna socket and set
the signal generator to produce an FM mono signal of 1kHz
(40kHz dev., modulated at 1kHz).
© Connect electronic voltmeter to TP102 and adjust T103 so that the
voltmeter reads OV.
@ Adjust T104 so that the output at the headphones jack has a
minimum distortion (0.7% or less).
VCO
FREQUENCY
ADJUSTMENT
@
Set the wave band selector switch at FM at FM stereo position.
e@
Set the signal generator to produce a signal of 1kHz, 40kHz dev.,
FM modulated (mono signal).
®
Connect instruments as shown in Fig. 12—5.
DIAL
POINTER
SETTING
ADJUST-
FREQUENCY
MENT
REMARKS
Tune to
98MHz
Adjust for 76.00KHz +
VR202
FM
STEREO
SEPARATION
ADJUSTMENT
@
Set the wave band selector switch at FM stereo position.
@
Set the FM
stereo
modulator
to produce a signal L+ R: 20kHz,
L —
R: 20kHz,
pilot signal: 6kHz,
1kHz
FM stereo modulated.
©
Connect instruments as shown in Fig. 12—6.
DIAL
POINTER
SETTING
ADJUST-
FREQUENCY
MENT
REMARKS
Tune to
98MHz
Adjust
for
maximal
VR201
separation.
98MHz at 60dB
Oscilloscope
Sweep
generato' ls
TP101
@
Ground
Figure 12—1 FM IF ADJUSTMENT
o/
DS 10.7 MHz
Figure 12-3 FM "S" CURVE
10.7 MHz
Se
Figure 12—2 FM "IF" CURVE
Electronic
FM Signal
voltmeter
generator
FM External Antenna
Socket
TP1010
TP101@
Ground
Figure 12-4 FM RF/POTENTIOMETER ADJUSTMENT
FM Signal
generator
FM External
Antenna Socket
Frequency counter
TP201@
TP201 @)
Ground
Figure 12-5 VCO FREQUENCY ADJUSTMENT
L+R:
20 kHz dev.
L-R:
20 kHz dev.
Pilot:
6 kHz dev.
Electronic
FM stereo
FM Signal
FM External
Speaker Voltmeter
Modulator
Generator
Antenna Socket
Socket
Figure 12—6 FM SEPARATION ADJUSTMENT
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