Sony ICF-C793 - Electrical Adjustments; FM Band Adjustments; AM;MW Band Adjustments; LW Band and AM IF Adjustments

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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
SECTION 3
ELECTRICAL ADJUSTMENTS
0 dB = 1 µV
[FM]
Setting:
Band switch: FM
[AM (MW/LW)*]
*AM : ICF-C793
MW/LW : ICF-C793L
Setting:
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.
• 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
+
–
level meter
MAIN board TP (SP GND)
MAIN board
TP (SP +)
set
FM antenna in
8 Ω
0.01 µ F
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: as low as possible
Put the lead-wire
antenna close to
the set.
+
–
level meter
set
8 Ω
MAIN board TP (SP GND)
MAIN board
TP (SP +)
+
–
digital voltmete
r
MAIN board
TP (VT)