Sony CFD-W57 - Cd Radio Cassette-corder, Service Manual

Page: 15 / 74

– 15 –
PRECAUTION
1. Clean the following parts with a denatured alcohol-moistened
swab :
record/playback head pinch roller
erase head rubber belts
capstan idlers
2. Demagnetize the record/playback head with a head demagne-
tizer. (Do not bring the head demagnetizer close to the erase
head.)
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.
6. Power supply voltage: 12 V dc.
Torque Measurement DECK A DECK B
Mode Torque meter Meter reading
Forward CQ-102C
22.5 to 55 g • cm
(0.31 to 0.76 oz • inch)
Forward
CQ-102C
2 to 5 g • cm
back tension (0.03 to 0.07 oz • inch)
Fast Forward
60 to 120 g • cm
and CQ-201B
(0.83 to 1.67 oz • inch)
Rewind
Tape Tension Measurement DECK A DECK B
Mode Tension meter Meter reading
Forward CQ-403A
more than 150 g
(more than 5.29 oz)
SECTION 4
ELECTRICAL ADJUSTMENTS
SECTION 3
MECHANICAL ADJUSTMENTS
TAPE SECTION 0 dB = 0.775 V
Standard Output Level
Output terminal SP OUT PHONES OUT
load impedance 3.2
Ω
32
Ω
output signal level 0.775 V (0 dB) 0.25 V (–10 dB)
Test Tape
Tape Signal Used for
WS-48A 3 kHz, 0 dB tape speed adjustment
P-4-A063 6.3 kHz, –10 dB head azimuth adjustment
Tape Speed Adjustment DECK A
Procedure:
• Perform normal speed adjustment before high speed check.
Mode: playback (deck A)
record (deck B)
Deck
Tape Adjustment Frequency
speed point counter
A Normal (playback) RV301 2,985 to 3,015 Hz
A HI-SPEED DUBBING
(confirmation) 5,700 to 6,500 Hz
(playback)
B HI-SPEED DUBBING
——— ———
(record)
Frequency difference between the beginning and the end of the
tape should be within
±
1.5% (both Normal and Hi-speed).
Adjustment Location:
–set rear view–
0000
2
jack
digital frequency
counter
set
32 Ω
test tape
WS-48A
(3 kHz, 0 dB)
RV301
TAPE
SPEED
ADJ