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MECHANICAL
ADJUSTMENT
Before
the
adjustment,
be sure
to
insert
the
headphones
plug into the headphones jack to turn on the unit.
When
adjusting the playback
head
azimuth,
only open the
cassette lid and it is not needed to open the cabinet. Open the
cassette
lid
and
using
a
bladed
screwdriver,
remove
the
azimuth hole cover indicated by the arrow in Fig. 8—1. Then
insert the bladed
screwdriver
into the hole to adjust the
playback head azimuth.
Azimuth Hole Cover
Figure 8—1
PINCH
ROLLER
PRESSURE
CHECK
1) Place
the unit in play mode.
2) Push the pinch roller, at the point A) shown in Fig. 8—2,
by using a tension gauge (500 gr.) so that it will come off
the capstan. Then, slowly release the tension until the pinch
roller hits the capstan again (i.e., the pinch roller is about
to rotate again). Check, then, the tension gauge is reading
165 + 15gr.
3) Place the unit in reverse play mode, and check the pinch
roller pressure
in the same way as in the step 2) above.
Figure 8—2
TAPE
SPEED
ADJUSTMENT
1) Connect
a wow/flutter meter, across a 100K ohm resistor,
to the headphones jack.
2) Play
a test tape
(TEAC,
MTT-111,
3kHz
prerecorded).
3) Put a plastic screwdriver on the motor control P.W.Board
and
adjust
the semi-variable
resistor so that the output
frequency
is 3000
+ 45 Hz on the wow/flutter
meter.
4) Place
the
unit
in reverse
play
mode,
and
perform
the
same adjustment as above.
5) Repeat the adjustment until no further improvement will
be made for both forward and reverse play modes.
PLAYBACK
HEAD
AZIMUTH
ADJUSTMENT
1) Make
connection
of instruments
as shown
in Fig. 8—3.
2) Set the mode selector switch at ''tape'' position.
3) Put a test tape
(TEAC,
MTT-113,
6.3 kHz 250 nWb/m,
—10dB
prerecorded)
into the unit and
play it.
4) Adjust
the
head
azimuth
adjusting
screw
so
that
the
electronic
voltmeter
reading
is maximal.
5) Place
the
unit
in reverse
play
mode,
and
follow
the
adjustment mentioned above.
6) Repeat
the
adjustment
until
no
further
improvement
will be made
for both
forward
and reverse play modes:
the play output must be the same for both modes.
Note:
If a dual-trace
oscilloscope
is available, perform
the adjust-
ment so that the reading of the oscilloscope is maximal and
with
the
least
phase/output
difference
between channels.
After the work, check that the head azimuth adjusting screw
has been
secured
completely.
dual-trace
syncroscope
electronic
voltmeter
\
Headphones jack
Figure 8—3
Playback
head
TORQUE
CHECK
AT PLAY, FAST
FORWARD
AND
REWIND
MODES
Put a torque meter cassette
in the cassette compartment
of the
unit,
and see that the measured
torque
in each
mode
is normal
as follows:
Mode
Torque meter cassette | Measured torque
TW-2111
TW-2121
Forward playback
~37
'
Reverse playback
so
eee
Fast forward
TW-2231
Over 60 gram.cm
Rewind
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