Mechanical Adjustments; Electrical Adjustments - Sony M-98V Service Manual

SECTION 4

MECHANICAL ADJUSTMENTS

PRECAUTION
1. Before adjusting, clean the following parts with a piece of
cotton moistened with alcohol.
record/playback/erase head
rubber belt
2. Demagnetize the record/playback/erase head using a head
demagnetizer. (Do not bring the head demagnetizer close to the
erase head.)
3. Do not use a magnetized screwdriver for adjustments.
4. After adjusting, apply screw-locking compound to the adjusted
parts.
5. Unless specified otherwise, use a specified voltage (2.5 V DC)
to perform the adjustments.
Torque Measurement
TAPE SPEED switch : 2.4cm/s
Mode Torque Meter
FWD, REV CQ-103M
FF, REW CQ-201M
Tape Tension Measurement
TAPE SPEED switch : 2.4cm/s
Mode Torque Meter
FWD CQ-403M
pinch roller
capstan
Meter Reading
5 – 10 g • cm
(0.07 – 0.13 oz • inch)
more than 15 g • cm
(more than 0.209 oz • inch)
Meter Reading
more than 15 g
(more than 0.53 oz)
– 8 –
SECTION 5

ELECTRICAL ADJUSTMENTS

Standard Input Level
Input terminal MIC (PLUG IN POWER) jack
300 Ω
Source impedance
Input level 0.77 mV (–60 dB)
Frequency 1 kHz
Standard Output Level
Output terminal EAR jack
Load impedance 10 kΩ
Output level 78 mV (–20 dB)
Test Tape
Type Signal
S-2-A030 3 kHz, –20 dB
WS-24 3 kHz, –10 dB
0 dB = 0.775 V
PRECAUTION
• Switch and control position
VOL control : 5 (Mechanical center)
TAPE SPEED switch : 2.4cm/s
V•O•R switch : OFF
FAST PB switch : OFF
MIC SENS switch : H
Record/Playback/Erase Head Azimuth Adjustment
Procedure :
– FWD/REV playback –
test tape
S-2-A030
(3 kHz, –20 dB)
set
• Rotate the screw to adjust level meter reading to the maximum.
Note : Adjust to the maximum peak though there may be two or
three peaks.
Adjustment Location :
REV side
adjustment screws
User for
Azimuth Adjustment
Tape Speed Adjustment
level meter
10 k Ω
EAR jack (J102)
FWD side