Mechanical Adjustments; Electrical Adjustments - Sony HCD-DR7AV Service Manual

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MECHANICAL ADJUSTMENTS

Precaution
1. Clean the following parts with a denatured alcohol-moistened
swab:
record/playback heads
erase head
capstan
2. Demagnetize the record/playback head with a head demagne-
tizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. After the adjustments, apply suitable locking compound to the
parts adjusted.
5. The adjustments should be performed with the rated power sup-
ply voltage unless otherwise noted.
Torque Measurement
Mode
FWD
FWD
back tension
REV
REV
back tension
FF/REW
FWD tension
REV tension
SECTION 5
pinch rollers
rubber belts
idlers
Torque meter
Meter reading
31 to 71 g • cm
CQ-102C
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
CQ-102C
(0.02 – 0.08 oz • inch)
31 to 71 g • cm
CQ-102RC
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
CQ-102RC
(0.02 – 0.08 oz • inch)
71 to 143 g • cm
CQ-201B
(0.98 – 1.99 oz • inch)
100 g or more
CQ-403A
(3.53 oz or more)
100 g or more
CQ-403R
(3.53 oz or more)
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18/2/2013

ELECTRICAL ADJUSTMENTS

DECK SECTION
1. Demagnetize the record/playback head with a head damagnetizer.
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 sup-
ply voltage unless otherwise noted.
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 adjust-
ment.)
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
P-4-A100
WS-48B
P-4-L300
Record/Playback Head Azimuth Adjustment
(Deck A, Deck B)
Note: Perform this adjustments for both decks.
Procedure:
1. Mode : Playback
test tape
P-4-A100
(10kHz, –10dB)
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
peak
R-CH
peak
screw
position
– 15 –
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SECTION 6
0 dB=0.775V
Signal
10 kHz, –10 dB Azimuth Adjustment
3 kHz, 0 dB Tape Speed Adjustment
315 Hz, 0 dB Level Adjustment
MD OUT
level meter
set
output
within
level
1 dB
L-CH R-CH
peak peak
Used for
+
–
within 1dB
screw
position