Sony Walkman WM-FX661, Service Manual

Page: 8 / 24

— 8 —
TUNER SECTION
[AM]
BAND switch : AM
[FM]
BAND switch : FM
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L4 621kHz
CT1 1,395kHz
FM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
L3 10.7MHz
FM VOLTAGE ADJUSTMENT
1.05V to 1.15V (3.55 to 3.65V)
L2 76MHz (87.5MHz)
( ) : Saudi Arabia model
FM VCO Adjustment
Procedure :
1. Connect the frequency counter to the positions shown below.
2. Turn the set to 98MHz.
3. Adjust RV1 for 18,900 to 19,100 Hz reading on the frequency
counter.
Adjustment Parts Location :
[TUNER BOARD] — SIDE A —
AM RF signal
generator
30% amplitude modulation
by 400Hz signal.
Output level : as low as possible
Put the lead-wire antenna
close to the set.
Set
32
Ω
PHONES
+
–
FM RF signal
generator
22.5kHz frequency
deviation by 400Hz signal.
Output level : as low as possible.
0.01
µ
F
to ANT (TP1)
Level meter
FM RF signal
generator
Carrier frequency : 98MHz
Modulation : No moduration
Output level : 0.1V (100dB)
0.01
µ
F
to ANT (TP1)
100
Ω
+
–
Frequency counter
1
µ
F
TP23
(IC7 pin
!™
)
IC7 pin
9
L3 : FM IF Adjustment
TP1
TP13
L2 : FM
Voltage Adjustment
RV1 : FM VCO Adjustment
L4 : AM Tracking
Adjustment
CT1 : AM Tracking
Adjustment