CFD-121 - Sony Audio Service Manual (repair manual). Page 9

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3-1. TAPE RECORDER SECTION
• 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
P-4-A063
6.3 kHz, –10 dB
head azimuth adjustment
SECTION 2
MECHANICAL ADJUSTMENTS
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 demagnetizer.
    (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.
6. Power supply voltage : 6 V dc
Torque Measurement
Mode
Torque Meter
Meter Reading
30–70 g • cm
FWD
CQ-102C
(0.42–0.97 oz • inch)
FWD
CQ-102C
1.5–5.5 g • cm
Back Tension
(0.021-0.076 oz • inch)
more than 60 g • cm
FF
CQ-201B
(more than 0.83 oz • inch)
more than 60 g • cm
REW
CQ-201B
(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 3
ELECTRICAL ADJUSTMENTS
Tape Speed Adjustment
Procedure :
Mode: playback
Adjustment Value :
Speed checker
Digital frequency counter
– 0.5 to + 0.5 %
2,985 to 3,015 Hz
speed checker
LFM-30
           or
digital frequency
counter
set
phones jack
32 
test tape
WS-48A
(3 kHz, 0 dB)
Frequency difference between the beginning and the end of the tape
should be within ± 1.5 % (45 Hz).
Adjustment Location:
TAPE
SPEED
ADJ
0dB=0.775V
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