Sony PMC-D305, Service Manual

Page: 26 / 75

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SECTION 4
MECHANICAL ADJUSTMENTS
SECTION 5
ELECTRICAL 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 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 sup-
ply voltage unless otherwise noted.
Torque Measurement
Mode Tension Meter Meter Reading
FWD CQ-403A more than 90 g (3.17 oz)
Mode Torque Meter Meter Reading
FWD
CQ-102C
30-70 g•cm
(0.42-1.02 oz•inch)
FWD 2.0-6.0 g•cm
Back tension (0.028-0.076 oz•inch)
80-170 g•cm
FF CQ-201B
(1.12-2.38 oz•inch)
80-170 g•cm
REW CQ-201B
(1.12-2.38 oz•inch)
Tape Tension Measurement
Standard Output Level
Test Tape
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode: playback
2. Turn the adjustment screw for the maximum output levels. If these
levels do not match, turn the adjustment screw until both of out-
put levels match together within 1 dB.
+
–
set
32
Ω
PHONES jack
level meter
test tape
P-4-A063
(6.3 kHz, –10 dB)
Screw
position
L-CH
peak
within
1dB
output
level
L-CH
peak R-CH
peak
within
1dB
Screw
angle
R-CH
peak
1. The adjustments should be perfomed in the order given in the
service manual. (As a general rule. Playback circuit adjustment
should be completed before performing recording circuit ad-
justment.)
2. The adjustments should be performed for both L-ch and R-ch
unless otherwise indicated.
0 dB=0.775 V
TAPE DECK SECTION
SP OUT PHONES
Load impedance 6
Ω
32
Ω
Output level 0.775 V (0 dB) 0.25 V (–10 dB)
Type Signal Used for
WS-48B 3 kHz, 0 dB Tape speed adjustment
P-4-A063 6.3 kHz, –10 dB Head azimuth adjustment