Sony HCD-EC68 Service Manual page 20

HCD-EC68/EC78
0 dB = 1 μV
TUNER SECTION
[AM]
Setting:
FUNCTION: AM
60 cm
loop antenna A loop antenna B
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
MAIN board
Output level: 54 dBuV ANTENNA
CN801 pin
[FM]
Setting:
FUNCTION: FM
FM RF signal
MAIN board
generator
ANTENNA
CN801 pin
0.01 F
MAIN board
75kHz frequency
ANTENNA
deviation by 1K Hz
CN801 pin
signal
Output level: as low as possible
(8dBuV)
MAIN board
100 k Ω
IC801 pin (TUNER VT)
• Repeat the procedures in each adjustment several times.
20
level meter
32 Ω
+
set
–
JACK board
PHONES jack (J492)
level meter
32 Ω
+
set
–
JACK board
PHONES jack (J492)
digital voltmeter
AM FREQUENCY COVERAGE ADJUSTMENT
(EC68: Mexican, Argentina, Australian/
EC78: Mexican, Argentina models)
Adjustment Part Frequency Display
L801 530 kHz
Confi rmation 1,710 kHz
AM FREQUENCY COVERAGE ADJUSTMENT
(Except EC68: Mexican, Argentina, Australian/
EC78: Mexican, Argentina models)
Adjustment Part Frequency Display
L801 531 kHz
Confi rmation 1,602 kHz
AM TRACKING ADJUSTMENT
(Except EC68: Mexican, Argentina, Australian/
EC78: Mexican, Argentina models)
Adjust for a maximum reading on level meter
L805
AM TRACKING ADJUSTMENT
(EC68: Mexican, Argentina, Australian/
EC78: Mexican, Argentina models)
Adjust for a maximum reading on level meter
L805
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display
L803 87.5 kHz
Confi rmation 108 kHz
FM TRACKING ADJUSTMENT
Adjust for a minimum reading on level meter
L804
Adjustment Location: MAIN board (See page 21)
[FM DETECTOR ADJUSTMENT]
Setting:
FUNCTION: FM
FM RF signal
generator
MAIN board
Carrier frequency: 98MHz
ANTENNA
Modulation:
CN801 pin
deviation by FM 75 kHz
Output level: 60 dBuV
1. Turn the set to 98 MHz.
2. Adjust L802 so that modulation distortion may become the
best in the vicinity of the maximum value where the tuner out
level becomes –15dBuV or more.
Reading on Digital
Voltmeter
1.5 ± 0.1 V
8 ± 0.5 V
Reading on Digital
Voltmeter
1.5 ± 0.1 V
7.2 ± 0.5 V
530 kHz
531 kHz
Reading on Digital
Voltmeter
1.75 ± 0.1 V
6.2 ± 0.5 V
98 MHz
MAIN board
IC801 pin
MAIN board
(TUNER OUT L-ch)
ANTENNA
CN801 pin
level meter
+
set
–
MAIN board
JW801 (TUNER-GND)