[Collins] Need Advice - KWM 2A Transmitter Problems
Dr. Gerald N. Johnson, electrical engineer
[email protected]
Fri, 11 Jul 2003 08:23:13 -0500
After cleaning all the bandswitch contacts with a quarter drop each of
DeoxIT, you need to attack the Erie 8-50 trimmers for each band switch
position. They have a tendency for their internal connection from shaft
to terminal (accessible on the bottom side) to go open. DeoxIT should
work there too, but the necessary twisting to break down the oxide will
destroy the alignment. It is also possible that the ceramic may be stuck
making rotation difficult of impossible. Then replacement may be
necessary.
I'm NOT a fan of test by alignment. Some of the slug tuned coils
especially are fragile and the fiberglass has roughened the threads over
the decades and one too many turns locks the slug and then breaks the
coil form loose (if the epoxy hasn't already failed from old age) cause
far more problems than if the coil was just a little off perfect
alignment.
73, Jerry, K0CQ, Technical Advisor to the CRA.
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