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ADJUSTMENT OF TUNER CIRCUIT
FM
IF/RF
ADJUSTMENT
®
8Sefore the adjustment, foosen 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.
e@ Set the AFC switch at off position.
@
Set the signal generator to produce a signal of 1kHz, 40kHz dev.,,
FM modulated.
AD-
JUST-
REMARKS
MENT
IF (Connect instruments as shown in Fig. 12—1.}
iF
ae
Aafust for best "IF
High
une
10.7MHz
frequen
Detec-
quency | 1103, | Adjust for best: "S"
T104
Curve
tion
Repeat steps 1 and 2 unti! no further improvement can be made,
DIAL
POINTER
SETTING
RF (Connect instruments as shown in Fig. 12-4.)
Lowest
87.35MHz
L4
Band
esa
Iequency
ghest
408,30MHz
frequency
TC3
Adjust for
maximal
output.
Tune to
SOMHz
Tracking
Tune to
TC,
Repeat steps 4, 5 and 6, 7 until no further improvement can be made.
Potentiometer (Connect instruments as shown in Fig. 12-4.)
VR302~309
Band
maximal
coverage
87.35MHz
Adjust for
ADJUSTMENT OF FM DETECTOR COIL
® Anppiy a signal of SBMHz 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.
®
Set the signal generator to produce a signal of 1kKHz, 40kHz dev.,
FM modulated (mono signal).
®
Connect instruments as shown in Fig. 12~—5.
DIAL
FREQUENCY
POINTER
ee
REMARKS
SETTING
S98MHz at 60dB
Tune to
Adjust for 76.00KHz +
FM STEREO
SEPARATION
ADJUSTMENT
@
Set the wave band selector switch at FM stereo position.
®
Set the
FM
stereo
modulator to produce a signai L+ R: 20kHz,
-—--—- A> 20kHz,-pilot. signal: 6kHz,..1kHz FM_stereo_modulated,____Modulator
®
Connect instruments as shown in Fig. 12-6,
ADJUST-
MENT
REMARKS
Tune to
Adjust
for
maximal
FREQUENCY
98MHz at 60dB
Oscilloscope
Sweep
generator
TP101 @
Ground
Figure 12—1 FM IF ADJUSTMENT
m/
\ 10.7 MHz
Figure 12-3 FM "S" CURVE
10.7 MHz
LN
Figure 12—2 FM "IF" CURVE
Electronic
FM External Antenna
voltmeter ©
Socket
FM Signal
generator
TPI01®@
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:
20kHz dev,
L-R:
20 kHz dev,
Pilot:
6 kHz dav.
Electronic
FM stereo
FM Signal
FM External
Voitmeter
____Generator_AntennaSocket _
Figure 12—6 FM SEPARATION ADJUSTMENT
—12-
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