Electrical Adjustments - Sony CF-CD73 Service Manual

TUNER SECTION
[AM]
Setting:
Function: RADIO
Band: AM
Put the lead-wire
AM RF signal
antenna close to
generator
the set.
30% amplitude
modulation by
400 Hz signal
Output level:
as low as possible
[FM/TV/WEATHER]
Setting:
Function: RADIO
Band: FM (ICF-CD73)
FM/TV/WEATHER (ICF-CD73V)
TUNER board
FM RF signal
TP (ANT)
generator
0.01 µF
75 kHz frequency
deviation by 1 kHz
TUNER board
signal
TP (GND)
Output level:
as low as possible
TUNER board
TP (VT)
TP (GND)
• Repeat the procedures in each adjustment several times, and the
tracking adjustments should be finally done by the trimmer ca-
pacitors.
• Remove FM/TV/WEATHER antenna in FM/TV/WEATHER
adjustment.
SECTION 5

ELECTRICAL ADJUSTMENTS

0 dB=1 µV
JACK board
CNP304 pin 1
level meter
3.2 Ω
+
set
–
JACK board
CNP304 pin 2
JACK board
CNP304 pin 1
level meter
3.2 Ω
+
set
–
JACK board
CNP304 pin 2
digital voltmeter
100 k Ω
AM IF ADJUSTMENT
Adjust for a maximum reading on level meter
T1
AM VCO VOLTAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L4 (L6) 530 kHz (531 kHz)
Confirmation 1,710 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L3 (L5)
CT3 (CT5)
FM IF ADJUSTMENT
Adjust for a minimum reading on level meter
T2
FM VCO VOLTAGE ADJUSTMENT (ICF-CD73)
Adjustment Part Frequency Display Reading on Digital Voltmeter
L2 108 MHz
Confirmation 87.5 MHz
FM TRACKING ADJUSTMENT (ICF-CD73)
Adjust for a maximum reading on level meter
L1
CT1
FM/TV (2 – 6 CH) VCO VOLTAGE ADJUSTMENT (ICF-CD73V)
Adjustment Part Frequency Display Reading on Digital Voltmeter
L4 TV 2 ch
CT3 108 MHz
FM/TV (2 – 6 CH) TRACKING ADJUSTMENT (ICF-CD73V)
Adjust for a maximum reading on level meter
L2
Confirmation
TV (7 – 13 CH)/WEATHER (1 – 7 CH) VCO VOLTAGE ADJUSTMENT (ICF-CD73V)
Adjustment Part Frequency Display Reading on Digital Voltmeter
L3 WEATHER 2 ch
CT4 TV 13 ch
TV (7 – 13 CH)/WEATHER (1 – 7 CH) TRACKING ADJUSTMENT (ICF-CD73V)
Adjust for a maximum reading on level meter
L1
CT2
Adjustment and Connecting Location: TUNER board (ICF-
ICF-CD73/CD73V
450 kHz
( ): ICF-CD73V
1.0 ± 0.05 V (1.0 ± 0.1 V)
5.3 ± 0.7 V
( ): ICF-CD73V
620 kHz (580 kHz)
1,400 kHz (1,490 kHz)
10.7 MHz
3.0 ± 0.2 V
1.3 ± 0.3 V
87.5 MHz
108 MHz
1.0 ± 0.15 V
4.0 ± 0.15 V
TV 2 ch
108 MHz
1.0 ± 0.15 V
4.1 ± 0.15 V
WEATHER 2 ch
TV 13 ch
CD73)
(See page 14)
TUNER board (ICF-
CD73V)
(See page 15)
13