Section 4 Electrical Adjustments - Sony ICF-C135 Service Manual

ELECTRICAL ADJUSTMENTS
[FM]
Setting:
BAND switch: FM
FM RF signal generator
level meter
0.01 F
+
set
–
22.5 kHz frequency
speaker terminal
deviation by 400 Hz
signal
FM lead wire antenna terminal
[AM]
Setting:
BAND switch: AM
Put the lead-wire
antenna close to
AM RF SSG
level meter
the set.
+
set
–
30% amplitude
speaker terminal
modulation by
400 Hz signal
Output level: as low as possible
Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally done
by the trimmer capacitors.
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L4 CT4
86.5 MHz 109.5 Hz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
CT3
Frequency max
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L2 CT2
520 kHz 1,750 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1 CT1
600 kHz 1,400 kHz
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
455 kHz
SECTION 4
• Adjusting Location: RADIO board (Component Side)
L1: AM TRACKING
CT3:FM TRACKING
ADJUSTMENT
ADJUSTMENT
T1:AM IF
CT1:AM TRACKING
ADJUSTMENT
IC1
L4: FM FREQUENCY CT2:AM FREQUENCY
COVERAGE
ADJUSTMENT
CT4:FM FREQUENCY L2: AM FREQUENCY
COVERAGE COVERAGE
ADJUSTMENT ADJUSTMENT
Clock Frequency Check
Confirm that the reading on the frequency counter is 900
If frequency is higher, change capacitor value of C101.
If frequency is lower, change resistor value of R101.
frequency counter
10 pF
+
IC101 pin wj
–
— 5 —
ADJUSTMENT
COVERAGE
ADJUSTMENT
+ 200
Hz.
– 100
— 6 —