The antenna switch between the amp and either dummy load or antenna shows
signs of heat/arcing, introducing the possibilities:
1. The loose PL-259 caused the whole problem, or
2. The switch wasn't designed for QRO RTTY (true), so it started to break
down when it was hot enough, long enough.
Fortunately, I caught it soon enough that the tank coil tap connections to
the bandswitch are still intact, and the amp still works normally. However,
several of you who sent me a link that led to
http://www.vcnet.com/measures/bandsw.html, and now I want to know how safe
it is to use this bandswitch with the arcing residue on the ceramic?
If you don't want to bother looking at that link above, here are the
comments under a photo of an arced bandswitch: "Even though the contacts
are still intact, the bandswitch is unusable because the ceramic insulation
is coated with conductive material: (Courtesy of an amplifier repairman who
wishes to remain anonymous. )"
Is there anyway to clean up this residue? Mine still seems to work
normally, so apparently there's just not enough of the stuff to short it...?
Again - Pristine http://www.qsl.net/wa9als/pristine.jpg
Burned - http://www.qsl.net/wa9als/burned.jpg
BTW, this amp is for sale, if anyone's interested. I really think it's not
what I want for QRO RTTY, although others say they use theirs all the time
at KW RTTY without problems - darn hot though. 73
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