Sanyo MR-939 - Page 2

MECHANICAL ADJUSTMENTS
Pressure Roller Tension Operated in each mode. Pull the thread in the opposite
'
.
direction,
and
reed
the
gauge
when
the
reel
stops.
Repeat
each
PRESSURE ROLLER TENSION * : ‘
aes ; reading several times. Normal torque should be as tollows:
LEFT REEL RIGHT REEL
ae esi FAST = —
reat
ou
ing
for
Pressure
FORWARD
1.0
1.2
ozs
1]
1.5
lbs
eee REWIND 1.0 — 2.1 Ibs 1.4 — 2.1 ozs
ressure Roiler
PLAY 1.0 — 2.1 ozs 3.5 — §.3 ozs
< i
\" Gauge Adjustment
Fig. 2 Forward & Playback
j Unsatisfactory take-up torq 2
Measurement (refer to fig. 2) belt, dirty take-up or: motor pulley, worn or oily felt washer,
or incorrect take-up torque.
1. Check the belt and take-up idler for wear and/or dirt.
Change the belt if necessary, cleaning the motor pulley and
take-up idler.
2. If the belt is in good condition check the felt washer for
oil or wear.
ue could be caused by a worn
Pressure between the pressure roller and capstan should be
gauged ; satisfactory tension is between 900 and 1300 grams. To
take the reading, play the tape then pull the pressure roller
away from capstan until the tape stops and read the tension
gauge. This process should be repeated two or three times.
Adjustment (refer to fig. 2) 3. If the felt washer is in good condition, check the springs.
Adjust the pressure roller spring. If spring tension is too Bend the springs or change the thickness of the nylon washer
weak, cut the spring 1 or 2 turns shorter or hook it to the to increase or decrease take-up torque.
next
hole.
Rewind
If spring tension is too strong, stretch the spring throughout Insufficient rewind torque could be caused by worn belt or
its length. incomplete travel of the rewind roller lever.
Adjust the nut of the action rod so that the rubber rewind
Winding Torque For Play, Rewind & Fast Forward
roller firmly presses against the motor pulley.
Prepare an empty reel (1-3/4” hub) with a few turns of
thread and hook a tension gauge (150-450 grams) to its end. Tape Pad_Pressure
Set the unit in Play mode. Press the tension gauge against
the top of the tape pad plate. Read the tension gauge at the
moment when the tape pads separate from the heads.
Normal pressure at the top of the tape pads should be 0.7-
(+ (5 ; 1.4 ozs.
U
Tension Gauce
for Fust Forward
and Play reading Erase or
: Record/Play Head
Fig. 3 Nas
Measurement (refer to fig. 3)
Left. Reel Right Reel
Tension Gauge 0. 7-1. 4 0zs.
Tension Gauge [-3/4"huby Reel
for Rewind Reading
_7 Felt Pad
Pad Plate
~ for Erase or R,’P. Head.
Fig. 4
ADJUSTMENT OF HEAD HIGHT & AZIMUTH
AZIMUTH
POSITIONING
RECORD/PLAY HEAD
CRASE HEAD
cae
TAPE GUIDE TAPE GUIDE
“4
-TAPE CENTER
LINE
TRANSPARENT
, TAPE
arene ADJUSTMENT i VERTIGAL & AZIMUTH ADJUSTMENT
| SCREWS & SPRINGS : * SCREWS & SPRINGS
VERTICAL POSITION
7
ERASE AND |
RECORD ‘PLAY HEADS}
\
NOTE: 1 The
-cord
Play
head
can
be
adjusted
in
iis
vertical
Fig
5
IP
nas:
Tens,
.
vad
1S
adiested
anfy
on
tts
vertical
bas
ton,