Mark:
"Mark Keith" wrote in
Thanks to all responding. A 20m antenna on top of the tower was
demolished,
pieces landing 100' away. That one single feedline was connected and
operating a wx-alert system in the shop.
Big omission... I now think the tower was hit, and piped the energy to
the wx-alert system which then routed it to the rest of the house via
the power wiring. Was that coax routed down to and snubbed to ground
at the base of the tower? From the damage, it almost sounds like it
was elevated in the air from the tower to the shop.
That feedline went underground at base of tower with all the rest. At the
main feedline disconnect point (20' from tower and about 50' from shop), it
went toward shop with two other feedlines, only the 20m was connected and
running SkyWarn. Skywarn tranceiver was powered by pair of 12vdc batteries,
which had a smart-charger (float) charge connected via AC power. All of that
equipment was destroyed including things near to it and not connected.
I bet the wx-alert box was the point where it got into the ac wiring.
I just can't see lightning energy traveling towards the house on a
coax that is on the ground. Once the lightning is at ground, normally
it should stay there. It's where it wants to go. I don't see it
ignoring the ground and radials at the tower, and preferring to go
towards the house on the coax, if the coax wasn't even connected close
to the tower. "I assume it was unhooked, and just laying on the
ground."
All other feedlines to shop and house were laying diconnected at the two PVC
risers coning up out of ground about 20' from base of tower, 50' from shop.
I wouldn't leave any more unprotected feedlines hooked up during
storms. I think all would have been ok, if not for that. Or at least
assuming there was no strike on the power lines a short distance from
your house when this happened. MK
Cable tv was knocked out for nearby homes as well, one or more utiilty poles
may have been hit at the same time.
On the 20m, It only takes one occurrence of bad judgement.
Jack
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