Electrical Adjustments - Sony M-727V Service Manual

SECTION 3
ADJUSTMENTS
2-1. MECHANICAL ADJUSTMENTS
AND MEASUREMENT
PRECAUTION
1. Clean the following parts with a denatured-alcohol-moistened swab:
record/playback/erase head _ pinch roller
rubber belts capstan
2. Demagnetize the record/playback head with a head demagentizer.
Do not use a magnetized screwdriver for the adjustments.
4. The adjustments should be performed with the rated power supply
voltage unless otherwise noted.
Power supply voltage : 3 Vdc
TAPE SPEED switch : 2.4cm
w&
Torque Measurement
wr on
Tape Tension Measurement
Meter | Meter Reading
more than 30 g
CQ-403M
(more than 0.42 02)
2-2. ELECTRICAL ADJUSTMENTS
5~13g *cm
(0.07 — 0.1800z « inch)
more than 15 g* cm
(more than 0.210z ¢ inch)
Test Tape
WS-24 2.4
$-2-A030 | 3 kHz, — 20 dB |} Head Azimuth Adjustment
Record/Playback Head Azimuth Adjustment
Tape Speed Adjustment
setting:
VOLUME control : mechanical mid
TAPE SPEED switch : 2.4cm/s
VOR switch : OFF
Procedure:
1. Mode: playback
test tape
S-2-A030
(3 kHz, — 20 dB)
— set |
earphone jack
2. Turn the adjustment screw to obtain the maximum reading on.
VTVM.
Note: Several peaks may appear, but the maximum.
Adjustment Location:
First remove the cover
(azimuth).
bs
head azimuth
adjustment screw
Tape Speed adjustment
Setting:
VOLUME control : mechanical mid
VOR switch : OFF
Procedure:
®@ Reform 2.4 cm /s speed adjustment before 1.2 cm/s speed adjustment
mode : playback
speed checker
LFM-30
test tape or
WS-24: tape speed 2.4 cm frequency counter
WS-12: tape speed 1.2 cm
(3 kHz, — 10dB)
earphone jack
Tape Speed Speed checker
requency counter
3,000 + 90 Hz
Frequency difference between the beginning and the end of the tape
should be within 0.5%.
2.4cm/s (15 Hz)
1.2 cm/s (15 Hz)
Adjustment Location:
RV601
1.20m
speed adjustable resistors