Tuner Section - Sony CFD-Z125 Service Manual

TUNER SECTION

[AM]
AM RF SSG
30% amplitude modulation by 400Hz
signal.
Output level : as low as possible
[FM]
FM RF SSG
75kHz frequency deviation
by 1 kHz signal.
output level : as low as possible
set
SPEAKER terminal (JK302)
• Repeat the procedures in each adjustment several times, and the
frequency coverage and tracking adjustments should be finally
done by the trimmer capacitors.
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L4
CT4
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L3
CT3
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter.
L2
CT2
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1
CT1
Adjustment Locastion: MAIN board (See page 19.)
Put the lead-wire
antenna close to
the set.
FM telescopic
antenna terminal
0.01 µ F
set
level meter
3.2 Ω
+
–
455kHz
520kHz
1,780kHz
600kHz
1,400kHz
97.5MHz
108.5MHz
90MHz
106MHz
VCO Adjustment
Procedure:
FM RF SSG
Carrier frequency : 98MHz
Modulation : no modulation
Output level : 0.1V (100dB)
1. Connect the frequency counter to pin 4 of IC1 as shown the
figure below.
2. Tune the set to 98MHz.
3. Adjust RV1 for 75.95kHz to 76.05kHz reading on the frequency
counter.
MAIN board
IC1 pin 4
Adjustment Locastion: MAIN board (See page 19.)
— 18 —
FM telescopic
antenna terminal
0.01 µ F
set
frequency counter
1 µ F