Sony ICF-C490 - SECTION 3 ELECTRICAL ADJUSTMENTS; AM IF Adjustment; AM Frequency Coverage Adjustment; AM Tracking Adjustment

6
ICF-C490
0 dB = 1 µV
[AM]
Setting:
BAND switch: AM
[FM]
Setting:
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.
• 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 mete
r
MAIN board
TP (SP –)
MAIN board
TP (SP +)
set
MAIN board
TP (FM ANT)
8 Ω
0.01 µF
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
Put the lead-wire
antenna close to
the set.
+
–
level mete
r
set
8 Ω
MAIN board
TP (SP –)
MAIN board
TP (SP +)