Sony PMC-107, Service Manual

Page: 13 / 51

– 13 –
TAPE SPEED
ADJ
phones jack
set
32 Ω
test tape
WS-48A
(3 kHz, 0 dB)
digital frequency
counter
TAPE SECTION 0 dB = 0.775 V
• Standard Output Level
Output terminal HP OUT
load impedance 32
Ω
output signal level 0.25 V (–10 dB)
• Test Tape
Type Signal Used for
WS-48A 3 kHz, 0 dB tape speed adjustment
Tape Speed Adjustment
Procedure:
Mode: playback
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 magnetizer 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.
Torque Measurement
Mode Torque meter Meter reading
FWD CQ-102C
30 – 70 g • cm
(0.42 – 0.97 oz • inch)
FWD
CQ-102C
1.5 – 5.5 g • cm
Back Tension (0.021 – 0.076 oz • inch)
FF CQ-201B
more than 60 g • cm
(more than 0.83 oz • inch)
REW CQ-201B
more than 60 g • cm
(more than 0.83 oz • inch)
Tape Tension Measurement
Mode Tension meter Meter Reading
FWD CQ-403A
more than 100 g
(more than 3.53 oz)
SECTION 4
ELECTRICAL ADJUSTMENTS
SECTION 3
MECHANICAL ADJUSTMENTS
Adjustment Value:
Digital frequency counter
2,985 to 3,015 Hz
Frequency difference between the beginning and the end of the
tape should be within
±
1.5 % (45 Hz).
Adjustment Location: