Sony CMT-ED1 / HCD-ED1 / HCD-ED1A Service Manual ▷ View online
– 9 –
2. Turn the adjustment scre
w and c hec k output peaks.
If the peaks
do not matc h for L-CH and R-CH, turn the adjustment scre
w so
that outputs match within 1 dB of peak.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
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Tape Speed Adjustment
P
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Mode : Playback
3. Mode : Playback
1. Inser t the WS-48B into the dec
k, and pla ybac k.
2. Adjust the VR770/RELA Y boar d so that the frequenc
y counter
reading becomes 3000
±
90 Hz.
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RELAY boar d
Sample Value of Wow and flutter
W.RMS (JIS) less than 0.3%
(test tape: WS-48B)
(test tape: WS-48B)
Playback Level Adjustment
P
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Mode : Playback
oscilloscope
MD OUT (JK301)
set
MD OUT (JK301)
test tape
P-4-A100
(10kHz, –10dB)
P-4-A100
(10kHz, –10dB)
L
R
Waveform of oscilloscope
good
wrong
in phase
45
°
90
°
135
°
180
°
L-CH
peak
peak
R-CH
peak
peak
screw
position
position
output
level
level
within
1dB
1dB
L-CH
peak
peak
R-CH
peak
peak
screw
position
position
within 1dB
+
–
–
MD OUT (JK301)
set
frequency counter
test tape
WS-48B
(3kHz, 0dB)
WS-48B
(3kHz, 0dB)
FWD side
REV side
Adjustment screw
level meter
MD OUT (JK301)
set
test tape
P-4-L300
(315Hz, 0dB)
P-4-L300
(315Hz, 0dB)
Dec k is VR703 (L-CH) and VR704 (R-CH)
so that adjustment within the f
so that adjustment within the f
ollo wing adjustment le
vel.
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Pla ybac k le vel: 301.5 to 338.3 mV (–8.2 to –7.2 dB)
level dif-
ference between the channels: within
±
0.5 dB
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TAPE PREAMP boar d
– 10 –
2. Mode : Playback
2. Mode: Playback
Confirm pla ybac k the signal recor
ded in step 1 become adjustment
level as f ollo ws.
If these le vels do not adjustment le
If these le vels do not adjustment le
vel, adjustment the
VR701 (L-
CH) and VR702 (R-CH) on the TAPE PREAMP boar d to repeat
steps 1 and 2.
steps 1 and 2.
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Pla ybac k output of 10kHz le
vel diffrence
against 315Hz ref
erence should be
±
0.5 dB.
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TAPE PREAMP boar d
Record Level Adjustment
P
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1. Mode: Record
Confirm pla ybac k the signal recor
ded in step 1 become adjustment
level as f ollo ws.
If these le vels do not adjustment le
If these le vels do not adjustment le
vel, adjustment the
VR705 (L-
CH) and VR706 (R-CH) on the TAPE PREAMP boar d to repeat
steps 1 and 2.
steps 1 and 2.
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Pla ybac k le vel : 47.2 to 53.0 mV (–24.3 to –23.3 dB)
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TAPE PREAMP boar d
Adjustment Location
[RELAY BOARD] (Component Side)
Record Bias Adjustment
P
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:
1. Mode : Record
level meter
MD OUT (JK301)
set
recorded
position
position
AF OSC
attenuator
600
Ω
set
MD IN (JK301)
1) 315Hz
2) 10kHz
1) 315Hz
2) 10kHz
blank tape
CS-123
CS-123
50 mV (–23.8 dB)
}
AF OSC
attenuator
600
Ω
set
MD IN (JK301)
315Hz 50 mV (–23.8 dB)
315Hz 50 mV (–23.8 dB)
blank tape
CS-123
CS-123
VR770
level meter
MD OUT (JK301)
set
recorded
position
position
VR704
VR703
VR706
VR705
VR701
VR702
IC703
1
21
22
42
[TAPE PREAMP BOARD] (Component Side)
– 11 –
P
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1. Connect oscilloscope to test point
TP (RF).
2. Turned P ower s witc h on.
3. Put disc (YEDS-18) in and playback.
4. Adjust R V101 so that the wa
3. Put disc (YEDS-18) in and playback.
4. Adjust R V101 so that the wa
vef orm is c lear .
(Clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.)
5. After adjustment, check the RF signal level.
• RF signal
VOLT/DIV: 200 mV
TIME/DIV: 500 nS
TIME/DIV: 500 nS
S Curve Check
Procedure :
1. Connect oscilloscope to test point
1. Connect oscilloscope to test point
TP (FEO).
2. Connect between test point
TP (FOK) and Gr ound b y lead wire .
3. Turn P ower s witc h on.
4. Put disc (YEDS-18) in and turned Power switch on again and
4. Put disc (YEDS-18) in and turned Power switch on again and
actuate the focus search. (actuate the focus search when disc
table is moving in and out.)
table is moving in and out.)
5. Check the oscilloscope waveform (S-curve) is symmetrical be-
tween A and B. And confirm peak to peak le
vel within 2.4
±
0.7
Vp-p.
S-curve waveform
6. After c hec k, remo ve the lead wire connected in step 2.
Note:
• Try to measure se
veral times to make sure than the ratio of
A : B or B : A is more than 10 :
7.
• Take s weep time as long as possib
le and light up the bright-
ness to obtain best waveform.
RF Level Check
Procedure :
1. Connect oscilloscope to test point
1. Connect oscilloscope to test point
TP (RF) on BD boar
d.
2. Turned P ower s witc h on.
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-
3. Put disc (YEDS-18) in and playback.
4. Confirm that oscilloscope waveform is clear and check RF sig-
nal level is correct or not.
Note:
Clear RF signal waveform means that the shape “
◊
” can be
clearly distinguished at the center of the waveform.
RF signal waveform
CD SECTION
Note:
1. CD Block is basically designed to operate without adjustment.
Therefore, check each item in order given.
2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated.
3. Use an oscilloscope with more than 10M
3. Use an oscilloscope with more than 10M
Ω
impedance.
4. Clean the object lens by an applicator with lens cleaning liquid
when the signal le
vel is lo w than specified v
alue with the f ol-
lowing c hec ks.
5. Adjust the focus bias adjustment when optical block is replaced.
Focus Bias Adjustment
–
+
oscilloscope
BD board
TP (RF)
TP (VC)
TP (VC)
level : 1.3
±
0.3 Vp-p
–
+
oscilloscope
BD board
TP (FEO)
TP (VC)
TP (VC)
symmetry
A
B
within 2.4
±
0.7 Vp-p
–
+
oscilloscope
BD board
TP (RF)
TP (VC)
TP (VC)
level : 1.3
±
0.3 Vp-p
VOLT/DIV : 200 mV
TIME/DIV : 500 nS
TIME/DIV : 500 nS
– 12 –
P
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1. Connect oscilloscpe to test point
TP (TE) on BD boar d.
2. Turn P ower s witc h on.
3. Put disc (YEDS-18) in to pla
3. Put disc (YEDS-18) in to pla
y the n umber five trac
k.
4. Press the “P (Pause)” button. (Becomes the 1 trac
k jump mode)
5. Confirm that the oscilloscope wa
veform is symmetrical on the
top and bottom in relation to 0Vdc, and check this level.
1 track jump waveform
E-F Balance (1 Track Jump) Check
(Without remote commander)
(Without remote commander)
Specified le vel: • x 100 = less than
±
7%
• A + B = 300
±
100 mVp-p
6. Remove the lead wire connected in step 1.
Focus/Tracking Gain Adjustment (RV102, RV103)
This gain has a mar
gin, so e ven if it is slightl
y off .
There is no problem.
Therfore, do not perform this adjustment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
Therfore, do not perform this adjustment.
Please note that it should be fixed to mechanical center position
when you moved and do not know original position.
A – B
2 (A + B)
Adjustment Location:
[BD BOARD] — Component Side —
–
+
oscilloscope
BD board
TP (TE)
TP (VC)
TP (VC)
A
B
0V
LEVEL : 300
±
100 mVp-p
RF
RV101
RV103
TEO
VC
FEO
RV102
TEI
FEI
FOK
IC101
IC104
GND
PCK
IC102
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