Mechanical Adjustments; Electrical Adjustments Tape Section - Sony PMC-D407L Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened
swab:
record/playback/erase head
rubber belts
idlers
2. Demagnetize the record/playback/erase head with a head de-
magnetizer. (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
REV
CQ-102RC
REV
Back tension
FF, REW CQ-201B
Tape Tension Measurement
Mode Tension Meter
FWD CQ-403A
REV CQ-403R
pinch roller
capstan
Meter Reading
30 – 70 g•cm
(0.42 – 1.02 oz•inch)
2.0 – 6.0 g•cm
(0.028 – 0.076 oz•inch)
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)
Meter Reading
more than 90 g
(more than 3.17 oz)
– 12 –
SECTION 5
ELECTRICAL ADJUSTMENTS
TAPE SECTION 0 dB = 0.775 V
1. The adjustments should be performed 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
SP OUT
6 Ω
Load impedance
Output level 0.775 V (0 dB)
Test Tape
Type Signal
WS-48B 3 kHz, 0 dB
P-4-A063 6.3 kHz, –10 dB
Tape Speed Adjustment
Procedure:
Mode: playback
test tape
WS-48B
(3 kHz, 0 dB)
set
Adjust so that the value on the frequency counter is 3 kHz.
Specification Values:
Digital frequency counter
2,970 to 3,030 Hz
Adjust so that the frequency at the beginning and that at the end of
tape winding are between 2,970 and 3,030 Hz.
Adjustment Location:
adjustable
resistor
PHONES
32 Ω
0.25 V (–10 dB)
Used for
Tape speed adjustment
Head azimuth adjustment
digital frequency
counter
32 Ω
2 (headphones) jack
M691