Electrical Adjustments - Sony ICF-CD823 Service Manual

PRECAUTION
• Adjustment should be performed in the order given.
TUNER SECTION
[FM]
Setting:
Function switch : RADIO
BAND switch : FM
FM RF signal
generator
75 kHz frequency deviation
by 1 kHz signal.
Output level: as low as possible
[AM]
Setting:
Function switch : RADIO
BAND switch : AM signal
AM RF signal
generator
30% amplitude modulation by
400 Hz signal.
Output level: as low as possible
32 Ω
set
J301 (phones)
• 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
L2
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
CT1
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
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3
CT2
SECTION 4

ELECTRICAL ADJUSTMENTS

0 dB=1 µV
0.01 µF
FM lead wire antenna terminal
Put the lead-wire
antenna close to
the set.
level meter
+
–
87.5 MHz
87.5 MHz
108.0 MHz
450 kHz
530 kHz
600 kHz
1,400 kHz
FM VCO Adjustment
Procedure:
FM RF signal
generator
Carrier frequency: 98 MHz
Modulation: no modulation
Output level: 0.1 V (100 dB)
1. Connect the frequency counter to 4 and 7 pins of IC1 as shown
the figure right.
2. Tune the set to 98 MHz.
3. Adjust RV1 for 76 kHz Hz reading on frequency counter.
Specification Value:
Frequency counter
75,500 – 76,500 Hz
Connection:
frequency counter
Adjustment Location:
[MAIN BOARD] (Component Side)
CT1
FM Traking
Adjustment
L3
AM Traking Adjustment
— 10 —
0.01 µF
FM lead wire antenna terminal
MAIN Board
33 k Ω
IC1 Pin 7
+
IC1 Pin 4
–
RV1
FM VCO Adjustment
L2
FM Frequency
Coverage Adjustment
L1
FM Tracking Adjustment
T1
AM IF Adjustment
L4
AM Frequency
Coverage Adjustment
CT2
AM Traking Adjustment