Mechanical Adjustments; Electrical Adjustments; Tape Deck Section - Sony PMC-D305 Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback head pinch roller
erase head
capstan
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 Torque Meter
FWD
CQ-102C
FWD
Back tension
FF CQ-201B
REW CQ-201B
Tape Tension Measurement
Mode Tension Meter
FWD CQ-403A
rubber belts
idlers
Meter Reading
30-70 g•cm
(0.42-1.02 oz•inch)
2.0-6.0 g•cm
(0.028-0.076 oz•inch)
80-170 g•cm
(1.12-2.38 oz•inch)
80-170 g•cm
(1.12-2.38 oz•inch)
Meter Reading
more than 90 g (3.17 oz)

ELECTRICAL ADJUSTMENTS

TAPE DECK SECTION

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.
Standard Output Level
Load impedance
Output level 0.775 V (0 dB)
Test Tape
Type
WS-48B
P-4-A063 6.3 kHz, –10 dB
Record/Playback Head Azimuth Adjustment
Procedure:
1. Mode: playback
test tape
P-4-A063
(6.3 kHz, –10 dB)
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.
L-CH
peak
output
level
R-CH
peak
Screw
position
– 26 –
SECTION 5
0 dB=0.775 V
SP OUT PHONES
6Ω 32Ω
0.25 V (–10 dB)
Signal Used for
3 kHz, 0 dB Tape speed adjustment
Head azimuth adjustment
level meter
32 Ω
+
set
–
PHONES jack
within
1dB
L-CH R-CH
peak peak
within
1dB
Screw
angle