Sharp SG-315H - FM ALIGNMENT PROCEDURES; FM IF and RF Alignment

FM IF ALIGNMENT
SIGNAL GENERATOR
CONNECTION) FREQUENCY
Detune the secondary core of T203 completely
PROCEDURE
NUMBER
DIAL POINTER |FUNCTION
SETTING SETTING | CONNECTION AESUSTMENT
Thru 10PFD 10.7 MHz High end of T201
to base of +300 kHz Dial T202
Q203 the primary
core of T203
Set curve at maximum as
shown in the Figure A
Repeat 2 or 3 times
Thru 10PFD 10.7 MHz High end of the secondary | Adjust ‘‘S” curve at maxi-
to base of +400 kHz Dial core of T203 | mum. Adjust 10.7 MHz at
Q203 the center of “S” curve.
Repeat adjustment to obtain ‘“‘S” curve as shown in Figure.
= PRECAUTIONS ON DETUNING
Turn the core of T203 two or more times.
®
10.7MHz Ss" CURVE
FM IF
CHARACTERISTIC
SWEEP
SIGNAL
GENERATOR
10PF
10.7 MHz
BASE
OF
Q203
OSCILLOSCOPE
GROUND
GROUND
Figure 11 FM IF ALIGNMENT EQUIPMENT CONNECTIONS
FM RF ALIGNMENT
PROCEDURE SIGNAL GENERATOR DIAL POINTER| FUNCTION
NUMBER CONNECTION FREQUENCY SETTING SETTING
METER
CONNECTION ADJUSTMENT
REMARKS
FM ANT terminal
(through 300 ohm
matching pad)
109 MHz High end of
Modulated Dial
TP203 Oscillator
trimmer TC3
Band
Coverage
Same as above 87.4 MHz Low end of Same as above Oscillator coil
Modulated Dial L104
Same as above 106 MHz 106 MHz
Same as above
If necessary, repeat step 1 — step 4.
Same as above RF trimmer TC2
ANT trimmer
Tracking
TCl
Same as above RF coil L102
TC3
LIO4
Adjust for
maximum
output.
Repeat 2 or 3
times.
Same as above
Same as above
Same as above
Figure 12 FM RF ALIGNMENT POINTS
FM SIGNAL
GENERATOR FM
ANT
Terminal
GROUND
Figure 13.) FM RF ALIGNMENT EQUIPMENT CONNECTIONS
10