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. The house suffered zero structural
damage, the roofline and 2 antennas on it was definitely not the source of
any of the strikes. The outbuildings also suffered no structural damage or
even marks. The coax(s) most definitely carried the lightning, now whether
they got it from the ground current, tower, tower ground radials, that's
anybody's guess. Coming into the shop, that was likely from the 20 meter
feedline, but the explosion inside the shop right next to my friend was just
"energy", the same kind that blew up floor tile from a patch cord hanging on
a hook by itself. The computers destroyed were from energy in the AC wiring
and cable modem network.
From all I have read here, this hit was (luckily) one of rare intensity and
diversity. Two strikes to the tower later in the summer of last year had
only minor impact on anything.
Jack
"Mark Keith" wrote
On Mon, 26 Jan 2004 21:07:24 -0500, "Jack Painter"
wrote:
Richard, my earlier posts described the grounding my friend, here is
quick
summary:
1.Well grounded 100' tower, hundreds of feet of many radials, rods,
etc.
Survived many strikes.
2. Feedline from tower's dipole was disconnected about 20' from tower
where
it enters a buried pvc conduit that travels 150' to house, then up to
second
story shack. Where nothing is grounded, except by virtue of house AC
wiring - a bad I know (not mine either).
3. Ground current from the tower strike most likely entered the coax
feedlines at the disconnect point as they entered the pvc conduit then
traveled on into house.
4. House current also took huge jolts, zorching all kinds of connected
equipment, phones, tv's etc.
5. Outbuilding with radio equipment connected took huge hit, ball
lightning
inside room fried test cords connected to nothing, hanging on test
bench,
where the leads touched tile floor, huge blow-out of tile. AC power
blew
wall warts across room, computers next to each other had .22 rifle
bullet
sized hole between them. Equipment in this bldg was grounded, and some
that
was was damaged, others not touched. In short, a massive, multiple
strike-path hit that may not be protectable from - but I realize there
was a
lot missing from a good ground picture here also.
Jack
Hi Jack,
You know, it sounds like the lightning hit your house/out-building and
went toward the tower.
73's
Richard Clark, KB7QHC
Sounds like it. I'm fairly sure it didn't hit the tower. Or if it did,
it also hit the houses at the same time. You don't get dime size holes
in the house, unless the strike is traveling in the house. I don't
think it's too likely ground currents traveled up the unconnected coax
to the house. It would have gone on to ground at the tower, being it's
well grounded. I think the upstairs part of the house was struck, and
the coax from the drake, along with power wiring was the return to
ground. Note all the damage in the house. Jack, you are one lucky $#^
*#^*@....
It could have burned the house down. The coax to ground
level from the upstairs drake may have routed a good bit of the strike
out to ground. Not enough to save damage though..MK