Sony ICF-C793 / ICF-C793L Service Manual ▷ View online
– 5 –
– 6 –
CHASSIS ASSY
POWER CORD SETTING
Note:
Follow the disassembly procedure in the numerical order given.
SECTION 3
DISASSEMBLY
1
screw (P3
×
14)
2
three claws
2
claw
6
button (DST)
5
Break the soldering of
speaker lead.
speaker lead.
7
chassis assy
3
rear cabinet
6
knob (brightness)
1
four screws (P3
×
14)
4
connector
(CN301)
(CN301)
rear cabinet
power cord
boss
rear cabinet
power cord
Put the secondary flat cable
between bosses to fix.
between bosses to fix.
Set the power cord as illustrated below,
then install the cabinet.
then install the cabinet.
– 7 –
FM VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L4
87.5 MHz
3 V ± 0.1V
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
AM (MW) VCO VOLTAGE ADJUSTMENT
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
L5
530 kHz (531kHz *1)
2.65 V ± 0.1V
Confirmation
1,710 kHz
Less than 10 V (9.5 V *1)
(1,602 kHz *1)
AM (MW) TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter.
L1 (L1-1 *2)
580 kHz (621 kHz *1)
TC1
1,490 kHz (1,404 kHz *1)
LW VCO VOLTAGE ADJUSTMENT
*
2
Adjustment Part
Frequency Display
Reading on Digital Voltmeter
TC4
153 kHz
2.25 V ± 0.05V
Confirmation
279 kHz
Less than 9.5 V
LW TRACKING ADJUSTMENT
*
2
Adjust for a maximum reading on level meter.
L1-2
162 kHz
TC2
243 kHz
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter.
T1
450 kHz
*1) Except US, Canadian models
*2) ICF-C793L
*2) ICF-C793L
SECTION 4
ELECTRICAL ADJUSTMENTS
0 dB = 1 µV
[FM]
Setting:
Band switch: FM
Band switch: FM
[AM (MW/LW)
*
]
* AM
: ICF-C793
MW/LW : ICF-C793L
Setting:
Band switch: AM (MW/LW)
Band switch: AM (MW/LW)
• 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 8)
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 +)
TP (SP +)
set
TP (FM-IN)
8
Ω
0.01
µ
F
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 +)
TP (SP +)
+
–
–
digital voltmeter
MAIN board
TP (VT)
– 8 –
TC2
L1-2
L1 (L1-1
*
)
AM (MW) Tracking Adjustment
LW Tracking Adjustment
*
L3
TC3
FM Tracking Adjustment
T1 AM IF
TC1 AM (MW) Tracking Adjustment
L4 FM VCO Voltage Adjustment
L5 AM (MW) VCO Voltage Adjustment
TC4 LW VCO Voltage Adjustment
*
TP (VT)
TP (SP+)
TP (SP GND)
TP (FM-IN)
– MAIN BOARD (Component Side) –
– MAIN BOARD (Conductor Side) –
Adjustment Location:
*) ICF-C793L
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