ORIGINAL MESSAGE: (may be snipped)
n 1/18/2014 9:52 AM, Jim Garland wrote:
There is another problem, which can come from stray capacitance. At 28MHz,
stray capacitance of only 1-2pF can turn the shorted coil into a parallel
resonant LC circuit, and that can lead to further arcing problems. Thus,
shorting together the unused ends of the coil may be better than leaving
them completely floating, it's not a cure-all for bandswitch arcing.
REPLY:
I had this same problem with my homebrew 8877. The 160 meter coil
accidentally was self-resonant on 15 meters. It produced such high
voltage that the fluorescent lamp hanging from the ceiling actually
started flashing. I added a small coil of a microhenry or so in series
to shift the resonant freq and that cured it.
Incidentally, despite the extraordinarily high "tesla-effect" voltage,
my model 88 band switch did not arc.
73, Bill W6WRT
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