Operating instructions

6.1.9.5 Fine Adjustment of Position and Gain
1. Turn on the power and place the machine in Rewind mode. If there is
any slippage of the tape on the capstan roller, adjust the SUP POS
trimmer on the REEL CONTROL PCB Assembly by turning it slowly
counterclockwise until the slippage is eliminated (Figure 6-9). Wind
time for a 10.5 inch reel (2500 feet) of 2.0 mil tape should be
approximately 85 seconds (1 minute 25 seconds). Final fast wind
adjustment procedures appear in § 6.1.10.2 and § 6.1.10.3.
2. If any swing arm instability or jitter is noted, slightly reduce the setting
of its GAIN trimmer (SUP GAIN or T.UP GAIN on the REEL CONTROL
PCB Assembly) to eliminate the jitter. If this problem persists, it is
possible that the Capstan Roller may need replacement. Contact OTARI
or your local OTARI dealer for this part and technical assistance in
proper installation.
6.1.9.6 Reel Size Detector Adjustment
1. The REEL SIZE DETECTION PCB Assembly (PB-4PKA) is one of the two
small PCB Assemblies beneath the transport assembly. The other is an
HOUR METER PCB Assembly (PB-45R).
2. Adjust VR1 (Take-up reel) and VR3 (Supply reel) so that the indicators
corresponding to the potentiometer illuminate for 14" reels only and are
off for all other reel sizes.
3. Reinstall the transport cover plate and confirm correct operation of the
Reel Size Detectors.
MTR-90III Operation and Maintenance Manual
October 1990
Section 6 Alignment
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