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13
CX-LDB10/LDB20
FOCUS BIAS CHECK
Adjustment and Connecting Location: CD board (See page 14)
Procedure :
1. Connect the oscilloscope to TP (RFACO) and TP (VC) on the
CD board.
2. Insert the disc (YEDS-18). (Part No. : 3-702-101-01)
3. Press the [CD ] button.
4. Confirm that the oscilloscope waveform is as shown in the
3. Press the [CD ] button.
4. Confirm that the oscilloscope waveform is as shown in the
figure below. (eye pattern)
A good eye pattern means that the diamond shape (
A good eye pattern means that the diamond shape (
◊
) in the
center of the waveform can be clearly distinguished.
• RF signal reference waveform (eye pattern)
CD SECTION
Note:
1. CD Block is basically constructed to operate without
adjustment.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10 M
3. Use an oscilloscope with more than 10 M
Ω
impedance.
4. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
following checks.
5. Check the focus bias check when optical block is replaced.
+
–
–
CD board
TP (RFACO)
TP (VC)
TP (VC)
oscilloscope
(DC range)
VOLT/DIV: 0.2 V (with the 10: 1 probe in use.)
TIME/DIV: 500 ns
TIME/DIV: 500 ns
1.1
When observing the eye pattern, set the oscilloscope
for AC range and raise vertical sensitivity.
for AC range and raise vertical sensitivity.
0.2 Vp-p
NX
3. Mode: Playback
4. After the adjustments, apply suitable locking compound to
the parts adjusted.
Adjustment Location:Record/Playback/Erase Head
Tape Speed Check
Mode: Playback
1. Insert the WS-48B into the deck.
2. Press the H button on the deck.
3. Confirm that the frequency counter reads 3,000
2. Press the H button on the deck.
3. Confirm that the frequency counter reads 3,000
±
90 Hz.
Sample value of Wow and Flutter: 0.3% or less W.RMS (JIS)
(WS-48B)
set
test tape
P-4-A100
(10 kHz, – 10 dB)
P-4-A100
(10 kHz, – 10 dB)
R-CH
oscilloscope
L-CH
R-CH
V
H
waveform of oscilloscope
in phase 45
°
90
°
135
°
180
°
good
wrong
MAIN board
SPEAKER terminal (J302)
L-CH
SPEAKER terminal (J302)
L-CH
+
–
–
set
test tape
WS-48B
(3 kHz, 0 dB)
WS-48B
(3 kHz, 0 dB)
MAIN board
SPEAKER terminal (J302)
L-CH, R-CH
SPEAKER terminal (J302)
L-CH, R-CH
frequency counter
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