Mechanism Adjustments - Teac A-4000 Service Manual

MECHANISM ADJUSTMENTS
PINCH ROLLER PRESSURE ADJUSTMENT
2. With the POWER switch in the ON position, press the PLAY button,
and note whether the capstan solenoid plunger is bottomed. The
pressure against the capstan shaft should be approximately 4.4
pounds,
3. If it is desired to measure pinch roller pressure, press the STOP
button, and using a string about 20 inches long, tied in a loop
Slip the loop between the pinch roller and roller arm so that the
string rests against the pinch roller shaft.
4. Attach the other side of the loop to a 0 to 8 pounds scale, let-
ting the string remain slack.
5. Press the PLAY push-button, causing the pinch roller to clamp
against the capstan.
6. Pull the scale away so that the string is taut and makes a 90
degree angle with the pinch roller arm.
7. Slowly pull the scale away with sufficient strength to cause the
pinch roller to pull away from the capstan, reading the scale at
the instant the pinch roller leaves the capstan. The scale read-
ing should be 4~ 5 pounds, If necessary, adjust the nut (28,
Fig. 6).
NOTE: Reduced pinch roller pressure can result from either two
extremes of adjustment. Remember that maximum efficiency
is obtained from the solenoid only when its plunger is
"exactly bottomed",
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