Mechanical Adjustments; Electrical Adjustments Tape Section - Sony CFD-S39 Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab :
record/playback head
erase head
capstan
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
Forward CQ-102C
Forward
CQ-102C
back tension
Reverse CQ-102RC
Reverse
CQ-102RC
back tension
Fast
CQ-201B
Forward
Rewind CQ-201B
Tape Tension Measurement
Mode Tension Meter
Forward CQ-403A
Reverse CQ-403R
pinch roller
rubber belts
idlers
Meter Reading
25 – 60 g • cm
(0.35 – 0.83 oz • inch)
1 – 5 g • cm
(0.014 – 0.069 oz • inch)
25 – 60 g • cm
(0.35 – 0.83 oz • inch)
1 – 5 g • cm
(0.014 – 0.069 oz • inch)
55 – 140 g • cm
(0.76 – 1.94 oz • inch)
55 – 140 g • cm
(0.76 – 1.94 oz • inch)
Meter Reading
more than 170 g
(more than 6.00 oz)
ELECTRICAL ADJUSTMENTS
TAPE SECTION
• Standard Output Level
Output terminal
load impedance
output signal level
• Test Tape
Type
WS-48A 3 kHz, 0 dB
Tape Speed Adjustment
Procedure:
Mode: playback
test tape
WS-48A
(3 kHz, 0 dB)
set
1. Playback the test tape in the FWD playback mode.
2. Confirm that the digital frequency counter reading indicates a
value in the range of 2,940 to 3,060 Hz at tape top.
3. If the specification is not satisfied, adjust variable resistor of
motor until the frequency counter reading is as close to 3,000
Hz as possible at the FWD tape top.
Specification : 2,910 to 3,090 Hz
4. Frequency difference between the beginning and the end of the
tape should be within 1.5% (45 Hz).
Adjustment Location:
– 13 –
SECTION 5
0 dB = 0.775 V
HP OUT
32 Ω
0.25 V (–10 dB)
Signal Used for
tape speed adjustment
digital frequency
counter
32 Ω
2 jack (J301)
Tape speed adjustment