Sony ICF-C490 / ICF-CD863 / ICF-CD863L Service Manual ▷ View online
ICF-C490
4
• This set can be disassembled in the order shown below.
2-1.
DISASSEMBLY FLOW
SECTION 2
DISASSEMBLY
Note:
Follow the disassembly procedure in the numerical order given.
2-2.
CABINET (UPPER) ASSY
3
screw (P3
×
14)
S101
1
cap (R)
4
screw (P3
×
30)
2
screw (P3
×
30)
1
cap (L)
2
screw (P3
×
30)
S102
5
cabinet (upper) assy
knob (alarm)
knob (clock)
Note : When installing
cabinet (upper) assy,
adjust S102, S101 and
the knobs (clock, alarm).
adjust S102, S101 and
the knobs (clock, alarm).
SET
2-2. CABINET (UPPER) ASSY
(page 4)
2-3. MAIN BOARD
(page 5)
ICF-C490
5
2-3.
MAIN BOARD
•
MAIN BOARD SETTING
1
knob (band)
qs
claw
3
2
screw (P3
×
14)
qd
main board
6
speker (6.6 cm) (SP1)
5
LED board
9
washer
8
two screws
(P3
(P3
×
14)
7
screw
(PTPWH3
(PTPWH3
×
8)
qa
power cord (PC1)
0
power board
9
washer
4
antenna (wire) (W7)
knob (vol)
knob (tuning)
B
A
RV1
shaft of CV1
Note 1 : When installing the main board,
adjust RV1 and the knob (vol).
Note 2 : When installing the main board,
turn the shaft of CV1 in the direction
of arrow
of arrow
A
fully and the knob (tuning)
in the direction of arrow
B
fully
before adjusting the shaft of CV1
and the knob (tuning).
and the knob (tuning).
6
ICF-C490
0 dB = 1
µ
V
[AM]
Setting:
BAND switch: AM
BAND switch: AM
[FM]
Setting:
BAND switch: 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.
done by the trimmer capacitors.
• Remove FM antenna in FM adjustments.
Adjustment Location: MAIN board (See page 7)
FM RF signal
generator
22.5 kHz frequency
deviation by 400 Hz
signal
Output level: as low as possible
deviation by 400 Hz
signal
Output level: as low as possible
+
–
–
level meter
MAIN board
TP (SP –)
TP (SP –)
MAIN board
TP (SP +)
TP (SP +)
set
MAIN board
TP (FM ANT)
TP (FM ANT)
8
Ω
0.01
µ
F
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
455 kHz
AM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L4
515 kHz
CT1-4
1,750 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L1
600 kHz
CT1-1
1,400 kHz
FM FREQUENCY COVERAGE ADJUSTMENT
Adjust for a maximum reading on level meter
L3
86.5 MHz
CT1-3
109.5 MHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L-2
86.5 MHz
CT1-2
109.5 MHz
SECTION 3
ELECTRICAL ADJUSTMENTS
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
modulation by
400 Hz signal
Output level: as low as possible
Put the lead-wire
antenna close to
the set.
antenna close to
the set.
+
–
–
level meter
set
8
Ω
MAIN board
TP (SP –)
TP (SP –)
MAIN board
TP (SP +)
TP (SP +)
ICF-C490
7
7
Adjustment Location :
– MAIN BOARD (Component Side) –
– MAIN BOARD (Conductor Side) –
FM Frequency Coverage Adjustment
T1
AM IF Adjustment
TP
(FM ANT)
TP
(SP –)
TP
(SP +)
L3
CT1-3
CT1-3
FM Tracking Adjustment
CT1-2
L2
L2
AM Frequency Coverage Adjustment
CT1-4
L4
L4
AM Tracking Adjustment
CT1-1
L1
L1
