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QT: 12HS/HR/HB/HY/BL
QT-12ES/ER/EB/EY
PINCH
ROLLER
PRESSURE
CHECK
1) Place the unit in play mode.
2) Push the pinch roller, at the point (A) shown in Figure 8—1,
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
270 gr. to 330 gr.
3) If the reading is outside the range of 270 gr. to 330 q;.,
bend
the pinch
roller spring or replace.
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 Table 8—1.
RECORD/PLAYBACK
HEAD
AZIMUTH
ADJUSTMENT
1) Connect instruments as shown in Figure 8—2.
2) Set the mode selector switch at ''TAPE"' position.
3) Put a test tape (TEAC, MTT-114,
10 kHz 250 pWb/mm,
—10dB
prerecorded)
into the unit and
play
it.
4) Adjust
the
head
azimuth
adjusting
screw
so
that
the
electronic
voltmeter
reading is maximal.
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.
TAPE
SPEED
ADJUSTMENT
1) Connect instruments as shown in Figure 8—3.
2) Play a test tape (TEAC,
MTT-111,
3 kHz
prerecorded).
3) Adjust the semi-variable resistor in the motor so that the
frequency
is 2965
~
3015Hz
on
frequency
counter.
MECHANICAL
ADJUSTMENT
TENSION
GAUGE
(500 gr)
CAPSTAN
PINCH
ROLLER
Figure 8—1
Torque
meter
cassette
Measured
torque
Playback
TW-2111
40 ~
60g-cm
Fast forward
TW—2231
85 ~
130 g-cm
Rewind
__TW-2231
85 ~
130 g-cm
Table 8—1
DUAL-TRACE
TEST
TAPE
MTT-114
TEST TAPE
MTT-111
OSCILLOSCOPE
HEADPHONES
PLAYBACK
ELECTRONIC
VOLTMETER
HEADPHONES
REC/PB
HEAD
Rech
Figure 8—2
REC/PB
HEADPHONES
FREQUENCY
Screwdriver
HEAD
pL AYBACK mode
COUNTER
for high-fre-
quency use.
Motor
Figure 8—3
ELECTRICAL
ADJUSTMENT
RECORD mode
BIAS OSCILLATOR
FREQUENCY
CHECK
1) Connect instruments as shown in Figure 8—4.
2) Set the function selector switch at 'TAPE', and the beat
cancel
switch
at "A"
position.
3) Place the unit in record mode, and see that the frequency
counter
is reading 60 + 3 kHz.
Change
the beat cancel switch from "A" position to "B"
Position, "B" position to "C" position. Then see that the
frequency counter's reading is changed as shown in Table
8-2.
PLAYBACK
AMPLIFIER
SENSITIVITY
CHECK
1) Connect instruments as shown in Figure 8—5.
2) Set the
function
selector switch at "TAPE", the volume
contro!
knob at "MAX",
and the tone control
knob at
"HIGH" position.
3) Playback a test tape (TEAC, MTT-118,
1 kHz, 250 pWb/
mm,
—10dB
prerecorded).
4) See that the electronic voltmeter is reading about
1.2V.
OSCILLOSCOPE
ERASE HEAD
ELECTRONIC
FREQUENCY
VOLTMETER
COUNTER
Figure 8—4
Position
B
Frequency
counter's
6143 kHz | 54.54 3 kHz
reading
Table 8—2
OSCILLO.
ELECTRONIC
SCOPE
VOLTMETER
HEADPHONES
PLAYBACK
mode
REC/PB
HEAD
Figure 8—5
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