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GF-4646HT (B)
©
FM
IF/RF ADJUSTMENT
SWITCH
POSITION
SIGNAL
GENERATOR
TEST
STEP | staGe |QUENCY
FM mono
400 Hz, 30%, FM modulated
1. Using a minus
driver, turn the
core of T2 counter-
clockwise before
10.7
High
taking it out of
MHz
frequency
this bobbin.
2. Adjust for best
"'E" curve.
Adjust for best
""S'' curve.
Detec-
tion
Repeat steps 1 and 2 until no further improvement can
be made.
63.5
Lowest
Band
MHz
frequency
coverage
i
78
Highest
Adjust for maximal
MHz
frequency
output.
L3
TC2
Creme
| 77 wie | ror
Repeat steps 4, 5 and 6, 7 until no further improvement can
be made.
VCO
FREQUENCY
ADJUSTMENT
DIAL
FREQUENCY | POINTER
SETTING
FM mono position
FM stereo position (unmodulated)
70 MHz at
REMARKS
Adjust for
38 kHz + 0.15 kHz.
Be ee
(TP1)
10.7 MHz
TELESCOPIC
FM SWEEP GENERATOR
0D ANTENNA
OSCILLOSCOPE
0.01MFO
GND
GNO
(TP2)
Figure 12—1 FM IF
7 | Ne
Figure 12—2 FM "IF" CURVE
Figure 12—3 FM "S" CURVE
(TP1)
TELESCOPIC
ROD ANTENNA
FM SIGNAL
(See Figure 12—6)
GENERATOR
Figure 12—4 FM RF
(TP1)
EM
TELESCOPIC
IC3
ROD ANTENNA
SIGNAL GENERATOR
j
© Pin 1000 pF
FREQUENCY
COUNTER
(See Figure 12—6)
DUMMY
Figure 12—5 VCO FREQUENCY
To Telescopic Rod Antenna
R1 = 37.5 0hm
Z= 75 ohm <—— Ro = 78 ohm
Rt = 50 ohm
Z = S50 0h
To Chassis GNO
Z: Output impedence of signa! generetor
Figure 12—6 FM DUMMY
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