HCD-EC69/EC79/EC99
18
SECTION 5
ELECTRICAL ADJUSTMENTS
CD SECTION
Note:
1. CD Block is basically constructed to operate without adjustment.
2. Use YEDS-18 disc (Part No. 3-702-101-01) unless otherwise indicat-
ed.
3. Use an oscilloscope with more than 10 MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent when the
signal level is low than specifi ed value with the following checks.
5. Check the focus bias check when optical pick-up block is replaced.
FOCUS BIAS CHECK
+
–
CD board
oscilloscope
(DC range)
TP121 (RFI)
TP124 (VC)
Procedure :
1. Connect the oscilloscope to TP121 (RFI) and TP124 (VC) on
the CD board.
2. Press the [
?/1
] button to turn the power on, and press the
[FUNCTION] button to select CD function.
3. Set disc (YEDS-18) and press the [u] button to playback.
4. Confi rm that oscilloscope waveform is as shown in the fi gure
below (eye pattern).
A good eye pattern means that the diamond shape (◊) in the
center of the waveform can be clearly distinguished.
VOLT/DIV: 200 mV
TIME/DIV: 500 ns
level:
1.2 ± 0.3 Vp-p
Checking Location:
TP124
(VC)
– CD Board (Conductor Side) –
TP121
(RFI)
IC101
TUNER SECTION
0 dB = 1 μV
Adjustment Location: MAIN board (See page 19)
[AM]
Setting:
FUNCTION: AM
AM RF signal
generator
30% amplitude
modulation by
400 Hz signal
Output level: 54 dBuV
60 cm
set
loop antenna A
loop antenna B
+
–
level meter
32 Ω
JACK board
PHONES jack (J492)
MAIN board
CN801 pin
[FM]
Setting:
FUNCTION: FM
FM RF signal
generator
75 kHz frequency
deviation by 1 kHz
signal
Output level: as low as possible
(8 dBuV)
+
–
level meter
set
32 Ω
0.01 F
JACK board
PHONES jack (J492)
MAIN board
CN801 pin
MAIN board
CN801 pin
digital voltmeter
100 kΩ
MAIN board
IC801 pin XL (TUNER VT)
• Repeat the procedures in each adjustment several times.
( ): EC69: AEP, Russian/EC79: AEP/
EC99: AEP and Russian models
AM FREQUENCY COVERAGE CONFIRMATION
Frequency Display Reading on Digital Voltmeter
530 kHz (531 kHz) 1.45 ± 0.3 V
1,710 kHz (1,602 kHz) 7.7 ± 0.5 V (7.2 ± 0.5 V)
( ): EC69: AEP, Russian/EC79: AEP/
EC99: AEP and Russian models
AM TRACKING ADJUSTMENT
Adjust for a maximum reading on level meter
L805 530 kHz (531 kHz)
FM FREQUENCY COVERAGE ADJUSTMENT
Adjustment Part Frequency Display
Reading on Digital
Voltmeter
L803 87.5 kHz 1.75 ± 0.1 V
Confi rmation 108 kHz 6.2 ± 0.5 V
FM TRACKING ADJUSTMENT
Adjust for a minimum reading on level meter
L804 98 MHz
Ver. 1.2
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