Hi Eric,
> I also tired of loosing the termination resistors to transient
> overloads. So I tried a desperate measure. I connected small
> gas tube surge arrester capsules directly across the resistors.
I found that carbon film and metal film resistors, no matter what the size,
failed almost every time a storm occurred. They fail even when the
lightning is cloud to cloud, or cloud to ground miles away.
What I did after changing resistors a few times was go to carbon
compositions. They are made almost exclusively by Allen Bradly, and are
special order parts. They are generally used in parasitic suppressors and
surge suppression applications. These resistors, when cut open, have a
solid carbon core instead of the thin carbon or metal spiral all other
resistors have. I have yet to lose a carbon comp, even after direct strikes
on my towers. On the other hand 5 watt metal films and regular two watt
carbons opened up like clockwork without nearby strikes.
Your gas tube idea is a good one, I wonder who sells them?? I also want to
test MOV's (especially for IMD and other problems). For now, the carbon
comps with a small spark gap across them have stopped the failures, but I'd
like to be sure I don't have to walk through that spooky woods at night
with the Brown Recluse spiders, Snakes, and odd Werewolf or two waiting to
get me.
73 Tom
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