Lightning has been mentioned as a possible cause of arcs - yet almost
immediately discounted. I would like to raise the question of whether the
dismissal should be quite so quick..
I understand little about discharge from the atmosphere - but I have felt
large enough voltage to shock me by simply touching a 30 foot wire antenna
with no more than a dark cloud passing over. And, I built an scr operated
burglar alarm years ago with a closed loop operating about 2 feet off the
ground. It picked up enough energy from dark clouds that the alarm would
fire every time a dark cloud passed overhead.
So, the question is, when the amplifier is actuated and relay closed, is it
possible that a static discharge returns down the antenna - and while not of
sufficient voltage to blow a hole in your roof, might add to the existing
voltage to create an arc which otherwise would not occur. Perhaps the rf
choke that all good amps have installed from antenna to ground would address
this and short all to ground. This might apply to dc - but the rf choke
might appear as a high resistance to the static.
Could this be one of the causes of the arcs?
73, Colin K7FM
--
FAQ on WWW: http://www.contesting.com/ampsfaq.html
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|