Teac A-4300SX - Measurement and Adjustment; Pinch Roller Pressure; Brake Torque

7. MEASUREMENT AND ADJUSTMENT
—MECHANICAL—
7-1 PINCH ROLLER PRESSURE
NOTE: Pinch roller pressure is supplied by the pinch roller
spring arm and it is most important that the sole-
noid plunger be fully bottomed before taking
pressure measurement.
. Load tape or block the shut-off arm in the ON position.
2. Attach a suitable spring scale to the pinch roller shaft.
3. Place the deck in the PLAY mode (>), and holding the
spring scale as illustrated, slowly draw it away from the
pinch roller.
4. Do not allow the string to rub against the pinch roller.
5. Note the reading on the spring scale at the instant the
pinch roller stops rotating.
6. The scale should indicate 2.3 to 2.5 kg (5.0 to 5.5 lbs).
Optimum value is 2.4 kg (5.3 Ibs).
7. If adjustment is necessary, loosen the 3 screws on the
capstan solenoid and position the solenoid for optimum
pressure.
8. Adjust solenoid-limit position so that the gap between
capstan shaft and pinch roller is approx. 7 mm when
solenoid is not actuated. Also make sure pinch roller
shaft does not contact edit arm B. Limit is adjusted by
loosening the mounting screw (A), then sliding limit
until proper position is obtained.
—
CAPSTAN SOLENOID LIMIT
Fig. 7-1 Pressure Measurement and Adj. Locations
10
7-2. BRAKE TORQUE
The brake torque is actuated mechanically. Pressure is set
by the leaf spring force. While making these measurements
and adustments, be careful not to bend the brake bands. As
brake torque will change with cleaning, brake drums and
brake shoes should be cleaned only when absolutely neces-
sary. If cleaning is required, use TEAC cleaner TZ-261B.
After cleaning, operate the brakes by depressing the play
and STOP buttons several times to completely dry out the
brakes before performing the following procedure.
NOTE: Brake adjustments are made with NO power con-
nected to the equipment.
1. Place an empty large hub reel on the left reel table, and
fasten one end of a 30” length of string to the reel
anchor.
2. Wind several truns of string counter clockwise around
the hub and attach a suitable spring scale to the free end
of the string.
3. Take a reading only when the reel is in steady motion
since the force required to overcome static friction will
produce a false, excessively high initial reading.
4. The Calculated value should be 800 to 1200 g-cm (11
to 17 oz-in).
5. If adjustment is required, loosen the 2 screws shown and
position the brake for optimum torque.
6. The adjustment of the right brake is the same, with the
exception that rotation is clockwise.
(wind string CLOCKWISE around ree! hub)
7. See note at the top of page 11 for explanation of torque
measurements.
Solenoid
Brake Drum
ADJUSTMENT SCREWS
T
H
Fig. 7-2 Torque Measurement and Adjustment Location