Sharp SA-201H - Page 10

SA-201H(BK)
©
FM IF/RF ADJUSTMENT
SWITCH
POSITION FM mono
eee
naioe
400
Hz,
40
kHz
dev.,
FM
modulated
DIAL AD-
TEST REF-
STEP POINTER | JUST- REMARKS
STAGE |QUENCY SETTING | MENT
1. Using a minus
driver, turn the
core of T103
counter-clock-
16.7 av | 1189) |r atin ator eke
MHz frequency bobbin.
2. Adjust for best
“IE curve.
: T103, | Adjust for best
Detection 7104 |S" curve.
L
Repeat steps 1 and 2 until no further improvement can be
made.
acs, a
87.35 Lowest
Band MHz frequency Adjust for
coverage 108.30 High maximal output.
f ighest
Band MHz frequency TC3
4
Repeat steps 4 and 5 until no further improvement can be
made.
Poten
10
tiometer
90MHz |90MHz |L3,L4
TCi,
Repeat steps 7 and 8 until no further improvement can be
made.
Adjust for
maxima! output.
Tracking
VR302~
306
Lowest
frequency
Band
coverage
Adjust for
maximal output.
11
ADJUSTMENT OF FM DETECTOR COIL
@ Apply a signal of 98 MHz to the Antenna Socket and set
the signal generator to produce an FM mono signal of
400 Hz (40 kHz dev., modulated at 1 kHz.)
@ Connect electronic voltmeter to TP4, 5 and adjust T103 to
that the voltmeter reads 0 V.
@ Adjust T104 so that the output at the headphones jack has
a minimum distortion (0.7% or less).
—12—
Sweep
Oscilloscope
Generator
|
Ground
Figure 12-1 FMIF
10.7 MHz
Figure 12-2 FMIF CURVE
10.7 MHz
Figure 12-3 FM “S” CURVE
Electronic
FM Signal Voltmeter
Generator
FM External Antenna
Socket
Figure 12—4 FM RF/POTENTIOMETER