Sony HCD-J3MD Service Manual page 43

CASETTE SECTION
Note: Before starting the adjustment, measure performance of the
machine. Perform adjustment only when the measured
performances do not satisfy the specifications.
1. Demagnetize the record/playback head with a head demagnetizer.
2. Do not use a magnetized screwdriver for the adjustments.
3. After the adjustments, apply suitable locking compound to the
parts adjusted.
4. The adjustments should be performed with the rated power supply
voltage unless otherwise noted.
completed before performing recording circuit adjustment.)
5. The adjustments should be performed in the order given in this
service manual. (As a general rule, playback circuit adjustment
should be completed before performing recording circuit
adjustment.)
6. The adjustments should be performed for both L-CH and R-CH.
7. Switches and controls should be set as follows unless otherwise
specified.
Tape Signal
P-4-A100 10 kHz, –10 dB
WS-48B 3 kHz, 0 dB
P-4-L300 315 Hz, 0 dB
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode : REV playback
tast tape
P-4-A100
(10kHz, |10dB)
set
2. Turn the adjustment screw and check output peaks. If the peaks
do not match for L-CH and R-CH, turn the adjustment screw so
that outputs match within 1 dB of peak.
L-CH
output
peak
within
level
1 dB
R-CH
peak
screw
position
0 dB=0.775V
Used for
Azimuth Adjustment
Tape Speed Adjustment
Level Adjustment
level meter
47kΩ
LINE OUT
within 1dB
screw
L-CH R-CH
position
peak peak
3. Phase check
Model: REV playback
test tape
P-4-A100
(10kHz, |10dB)
R-CH
set
L-CH
4. Perform steps 1 to 3 in the FWD playback mode.
5. Confirm that phase error between L-ch and R-ch is in the range
of same phase to 90 degrees.
6. After the adjustments, apply suitable locking compound to the
parts adjusted.
Waveform of oscilloscope
in phase 45° 90°
good
Adjustment Location:
Adjustment screw
(FWD mode)
oscilloscope
47kW
V H
47kW
LINE OUT
135° 180°
wrong
Adjustmednt screw
(REV mode)
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