Sharp SYSTEM-W7H Serviceanleitung Seite 14

SYSTEM-W7H
FM IF/RF ADJUSTMENT
SWITCH
FM mono
POSITION
SIGNAL I kHz. 75 kHz dev., FM modulated.
GENERATOR
TEST
FRE-
TEP STAGE
QUENCY
1
10.7 MHz
2 Detection
3
Repeat steps 1 and 2 until no further improvement can
be made.
4
87.1 MHz
Band
coverage
5
109.0 MHz Highest
6
Repeat steps 4 and 5 until no further improvement
can be made.
7
90 MHz
Tracking
8
106 MHz
9 Repeat steps 7 and 8 until no further improvement can
be made.
VCO FREQUENCY
SIGNAL I kHz.
GENERA- (mono signal)
TOR
DIAL
FREQU-
POINTER
ENCY
SETTING
FM mono position
98 MHz
98 MHz
at 60 dB
DIAL
AD.
POINTER
JUST. REMARKS
SETTING
MENT
. using
driver , turn
the
T 3 counter.
Tl clockwise
before taking
H igh
it out
frequency
bobbin.
2. Adjust for
best
curve.
T3
Adjust for best
"S" curve.
Lowest L4
frequency
Adjust for
maximal
TC3
output.
frequency
90 MHz L2, L3 Adjust for
maximal
106 MHz TCI ,TC2 output.
ADJUSTMENT
75kHz dev., FM modulated
REMARKS
JUST.
MENT
FM stereo position
(unmodulated)
VRI Adjust for 38.00 kHz
± 60 Hz.
Generator
o
a minus
core of
of the
"IFO
FM Signal
Generator
o
FM Singal
Generator
o
— 18 —
1
1.5 pF
TP2
unit
Ground Ground
Figure 18—1 FM IF
10.7 MHz
Figure 18—2 FM IF CURVE
10.7 MHz
Figure 18—3 FM "S" CURVE
FM External Antenna
TP2
Terminal
unit
Ground
Ground
Figure 18-4 FM RF
FM External
Antenna Terminal
TP3
unit
Ground
Ground
Figure 18-5 VCO FREQUENCY
Oscilloscope
Electronic
Voltmeter
o
Frequency Counter