Mechanical Adjustments; Electrical Adjustments - Sony HCD-DR8AV Service Manual

SECTION 5

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
demagnetizer.
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
supply voltage unless otherwise noted.
Torque Measurement
Mode Torque meter
FWD CQ-102C
FWD
CQ-102C
back tension
REV CQ-102RC
REV
CQ-102RC
back tension
FF/REW CQ-201B
FWD tension CQ-403A
REV tension CQ-403R
DECK SECTION
1.
pinch rollers
rubber belts
2.
idlers
3.
4.
5.
6.
7.
Meter reading
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
2 to 6 g • cm
(0.02 – 0.08 oz • inch)
31 to 71 g • cm
(0.43 – 0.98 oz • inch)
Record/Playback Head Azimuth Adjustment
2 to 6 g • cm
(Deck A, Deck B)
(0.02 – 0.08 oz • inch)
71 to 143 g • cm
Note: Perform this adjustments for both decks.
(0.98 – 1.99 oz • inch)
Procedure:
100 g or more
1.
(3.53 oz or more)
100 g or more
(3.53 oz or more)
2.
L-CH
peak
screw
position
— 15 —
SECTION 6

ELECTRICAL ADJUSTMENTS

0 dB=0.775V
Demagnetize the record/playback head with a head
demagnetizer.
Do not use a magnetized screwdriver for the adjustments.
After the adjustments, apply suitable locking compound to the
parts adjusted.
The adjustments should be performed with the rated power
supply voltage unless otherwise noted.
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.)
The adjustments should be performed for both L-CH and R-
CH.
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
Mode : Playback
test tape
P-4-A100
(10kHz, –10dB)
MD OUT
set
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.
output
within
level
1 dB
R-CH
peak
L-CH
peak
Used for
Azimuth Adjustment
Tape Speed Adjustment
Level Adjustment
level meter
+
–
within 1dB
screw
R-CH
position
peak