Mechanical Adjustment - Sharp RT-31 Service Manual

PINCH ROLLER PRESSURE ADJUSTMENT
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(See Figure 4-l and 4-2)
2. Use a tension gauge (0 - 500 gr.) to push it to a part
the capstan. Next gradually weaken the force in the
reverse direction until the pinch roller hits the capstan
(that is, it begins rotating), then see that tension gauge
is reading 295 to 365 grams.
3. Make sure there are clearances 6 0 , @and @ between
the pinch roller lever and sub. chassis.
4. If the above value is not satisfied, adjust the pinch roller
pressure spring by bending it, or replace.
TORQUE CHECK AT PLAY, FAST FORWARD AND
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REWIND MODES
1. Put a torque measuring cassette into the set.
2. The torque values, in each mode must be as tabulated
below.
TAPE SPEED ADJUSTMENT
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1. Using a test tape (TEAC, MTT-113C, 8 kHz record-
ed), play it back at the midpoint but not at the running
start or end point.
2. Connect a frequency counter to the line output socket.
TEST
TAPE
MTT-1
13c
RECORD/
PLAYBACK
HEAD
3. Use a bladed screwdriver to adjust, through the adjusting
PLAYBACK Mode
Line output socket (SO3 or S04)
Figure 4-3
Figure 4-l
hole at the bottom of motor, the semivariable resistor
so that the frequency counter reads 2975 to 2995 Hz.
Frequency Counter
0
Pinch Roller Spring
0 0