Sony HCD-EC70 Service Manual page 19

TUNER SECTION
[AM]
Setting:
FUNCTION: TUNER
TUNER/BAND button: AM
loop antenna A loop antenna B
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: 54 dBuV
[FM]
Setting:
FUNCTION: TUNER
TUNER/BAND button: FM
FM RF signal
MAIN board
generator
ANTENNA
CNP802 pin 1
0.01 µ F
MAIN board
75kHz frequency
ANTENNA
deviation by 1K Hz
CNP802 pin 2
signal
Output level: as low as possible
(8dBuV)
MAIN board
TP (TUNER VT)
• Repeat the procedures in each adjustment several times.
0 dB=1 µV
60 cm
level meter
32 Ω
+
set
–
JACK board
PHONES jack (J102)
level meter
32 Ω
+
set
–
JACK board
PHONES jack (J102)
digital voltmeter
100 k Ω
AM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L852 530 kHz
Confirmation 1,710 kHz
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L851
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display Reading on Digital Voltmeter
L805 87.5 kHz
Confirmation 108 kHz
FM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L804
Adjustment Location: MAIN board (See page 20).
[FM DETECTOR ADJUSTMENT]
Setting:
FUNCTION: TUNER
TUNER/BAND button: FM
FM RF signal
generator
MAIN board
Carrier frequency: 98MHz
ANTENNA
Modulation:
CNP802 pin 2
deviation by FM 75 kHz
Output level: 60 dBuV
1. Tune the set to 98 MHz.
2. Adjust L806 so that modulation distortion may become the
best in the vicinity of the maximum value where the tuner out
level becomes –15dBuV or more.
HCD-EC70
1.5 ± 0.1 V
8 ± 0.5 V
530 kHz
1.75 ± 0.1 V
6.2 ± 0.5 V
98 MHz
MAIN board
IC801 pin qs
MAIN board
(TUNER OUT L-ch)
ANTENNA
CNP802 pin 1
level meter
+
set
–
MAIN board
TP (TUNER GND)
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