BM-23MK2 - Sony Audio Service Manual (repair manual). Page 10

10

1. Clean the following parts with a denatured-alcohol-moistened

swab :

playback head

rubber belts

capstan

idlers

pinch roller

2. Demagnetize the playback head with a head demagnetizer.
3. Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the rated power

supply voltage (3V) unless otherwise noted.

2.06 – 3.72 mN•m

FWD

21 – 38 g•cm

CQ-102C

(0.30 – 0.52 oz•inch)

0.05 – 0.29 mN•m

FWD

0.5 – 3 g•cm

Back Tension

(0.01 – 0.04 oz•inch)

2.06 – 3.72 mN•m

REV

21 – 38 g•cm

CQ-102RC

(0.30 – 0.52 oz•inch)

REV

0.05 – 0.29 mN•m

0.5 – 3 g•cm

Back Tension

(0.01 – 0.04 oz•inch)

FF

CQ-201B

more than 60 g•cm

REW

(more than 0.84 oz•inch)

1. Power supply voltage : 3V

Switch position
TAPE SPEED Switch : 4.8 cm

1. Play back WS-48A (tape center portion) in FWD mode.

Adjust the RV601 so that the frequency counter reads 2,980

±

30 Hz.

2. Play back WS-48A (tape center portion) in REV mode.

Confirm that the reading of frequency counter is within 2.5 %
from the reading in step 1.

WS-48A

3 kHz, 0 db

Tape Speed Adjustment

J102

set

18 

Ω

test
WS-48A
(3 kHz, 0 dB)

frequency 
counter

FF

CQ-403A

more than 40 g

(more than 1.42 oz)

REW

CQ-403R