CHC-TB10, CHC-TB20, HCD-TB20 - Sony Audio Service Manual (repair manual). Page 23

23

3.04 – 6.96 mN • m

(31 to 71 g • cm)

(0.43 – 0.98 oz • inch)

0.20 – 0.58 mN • m

(2 to 6 g • cm)

(0.02 – 0.08 oz • inch)

3.04 – 6.96 mN • m

(31 to 71 g • cm)

(0.43 – 0.98 oz • inch)

0.20 – 0.58 mN • m

(2 to 6 g • cm)

(0.02 – 0.08 oz • inch)

6.97 – 14.02 mN • m

(71 to 143 g • cm)

(0.98 – 1.99 oz • inch)

0.98 N • m or more

(100 g or more)

(3.53 oz or more)

0.98 N • m or more

(100 g or more)

(3.53 oz or more)

CQ-102C

CQ-102C

CQ-102RC

CQ-102RC

CQ-201B

CQ-403A

CQ-403R

1.

Clean the following parts with a denatured alcohol-moistened
swab:

record/playback heads

pinch rollers

erase head

rubber belts

capstan

idlers

2.

Demagnetize the record/playback head with a head demag-
netizer.

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.

Procedure:
1.

Mode : Playback

FWD

FWD
back tension

REV

REV
back tension

FF/REW

FWD tension

REV tension

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.

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.

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.

test tape
P-4-A100
(10kHz, –10dB)

MAIN board
CN322
Pin 

5

 or TP42 (L-CH)

Pin 

9

 or TP46 (R-CH)

level meter

set

+

–

L-CH
peak

R-CH
peak

screw
position

output
level

within
1 dB

L-CH
peak

R-CH
peak

screw
position

within 1dB

P-4-A100

WS-48B

10 kHz, –10 dB

3 kHz, 0 dB

Azimuth Adjustment

Tape Speed Adjustment