(5) If there is a bend at the top of the picture, correct for best vertical
linearity by adjusting the tension control on the recorder/reproducer.
Figure 2-10.
Helical scan head drum, showing direction of rotation compared to
direction of tape travel
2.
Many maintenance problems can be prevented by the analysis of maintenance
records and by following recommended maintenance practices, or by the use of the
experience you have had with a specific model of machine.
a. As an example, it is recommended on some models to adjust the video head
after 100 hours of operation.
It would perhaps be appropriate to check the head
every additional 100 hours of operation until replacement is necessary.
b. The proper cleaning of heads and visual inspection prior to each day's use
eliminates many of the problems caused by dirty heads. This is true for both the
video and audio heads.
c. Follow the manufacturer's recommendations for cleaning materials, or the
military standard material that has been approved for cleaning the parts.
d. Be sure to use the correct type of cleaner.
Some cleaners will dissolve
plastic parts or otherwise damage parts.
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