Below the procedure.
Adjustment of Potentiometer R57 (used to set the tracking of the phase-lock loop):
Run the belt at the desired speed (Normally 40 inches/second = 200 feet/minute).
Connect a DC digital voltmeter: positive to U32-9; negative to ground.
Adjust R57 so that the voltage at U32-9 is +2.5 Volts DC.
This completes the operation,