Sony ICF-C795RC Service Manual ▷ View online
– 5 –
CHASSIS ASSY
Note:
Follow the disassembly procedure in the numerical order given.
SECTION 2
DISASSEMBLY
2
claw
2
three claws
1
screw (P3
×
14)
1
four screws (P3
×
14)
3
rear cabinet
4
connector
(CN301)
(CN301)
7
chassis assy
5
Break the soldering of
speaker lead.
speaker lead.
6
button (DST)
6
knob (brightness)
POWER CORD SETTING
Set the power cord as illustrated below,
then install the cabinet.
then install the cabinet.
rear cabinet
power cord
boss
rear cabinet
power cord
Put the secondary flat cable
between bosses to fix.
between bosses to fix.
– 6 –
BOX (UPPER) , ANTENNA
ANTENNA CORD SETTING
2
claw
2
claw
3
box (upper), antenna
1
three screws
Set the antenna cord as illustrated below,
then install the antenna box.
then install the antenna box.
box (lower), antenna
coil lead
antenna cord
antenna, ferrite-rod
– 7 –
SECTION 3
ELECTRICAL ADJUSTMENTS
0 dB = 1 µV
[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 tracking adjustments should be finally done by the trimmer
capacitors.
capacitors.
• Remove FM antenna in FM adjustments.
Adjustment Location: MAIN board (See page 8)
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 GND)
MAIN board
TP (SP +)
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 GND)
MAIN board
TP (SP +)
set
MAIN board
TP (FM-IN)
8
Ω
0.01
µ
F
MAIN board
TP (FM GND)
digital voltmeter
100 k
Ω
TP (VT)
TP (FM GND)
+
–
–
MAIN board
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
450 kHz
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L5
531 kHz
2.65 V ± 0.1 V
Confirmation
1,602 kHz
Less than 9.5 V
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1
621 kHz
TC1
1,404 kHz
FM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L4
87.5 MHz
3 V ± 0.1 V
Confirmation
108 MHz
Less than 11.8 V
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L3
87.5 MHz
TC3
108 MHz
– 8 –
Adjustment Location:
L1
AM Tracking Adjustment
L3
TC3
FM Tracking Adjustment
T1
AM IF Adjustment
TC1 AM Tracking Adjustment
L4 FM VCO Voltage Adjustment
L5 AM VCO Voltage Adjustment
TP (VT)
TP (SP+)
TP (SP GND)
TP (FM-IN)
TP (FM GND)
– MAIN BOARD (Component Side) –
– MAIN BOARD (Conductor Side) –
ANTENNA SECTION
Antenna Adjustment
Setting:
Procedure:
1. Set a SSG.
2. Connect an oscilloscope to TP451 and TP452 on the AN-
1. Set a SSG.
2. Connect an oscilloscope to TP451 and TP452 on the AN-
TENNA board.
3. Adjust L451 on the ANTENNA board for a maximum wave-
form level on the oscilloscope.
Adjustment Location:
TP452
TP451
L451
Antenna
Adjustment
– ANTENNA BOARD (Conductor Side) –
SSG
Frequency:
77.5 kHz
Modulation:
no modulation
77.5 kHz
Modulation:
no modulation
antenna
unit
loop antenna
ANTENNA board
TP451
ANTENNA board
TP452
+
–
–
oscilloscope
(DC range)
Probe: 10:1,
10 M
10 M
Ω
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