Hi Jim, Reading your below account made me feel sick, so sorry to hear
about the strike. I have a US Tower model HDX572MDPL with the same basic
grounding system as you have with the ground spokes running our in a circle
as yours with a ground rod every 16 feet etc etc.
Two years ago this September US Tower visited me to replace my cables as I
had had the tower a little over a year and the cables were rusting, and
they wanted to look it over etc. When they replaced the cables they took
every pulley out one at a time to check them. They showed me what to feel
for, that's right feel for. Placing both fingers on either side of the
center bearing and slowly rotating the larger aluminum part of the pulley.
If you feel any hesitation or little bump they replaced them. With a
lighting strike and with dissimilar metals a spark could have developed and
distorted or caused a imperfection between the bearing surface (in the
middle of the pulley) and the aluminum wheel. What they were concerned was
that it could eventually cause the aluminum to stop turning and thereby
causing a grove in the aluminum wheel and cutting into the cable. Hopefully
this will help with why they want to check every pulley. They only replaced
my cable but never the less checked every pulley. They were very
professional and showed me a number of items to be sensitized to. I learned
how to replace the cable in my tower when I need to. I live in Florida and
with the salt air it is very toxic and the UV is another thing I contend
At some point I would appreciate you telling me about climbing your tower
and about the Emergency Hand Crank. If I can be of any assistance please
feel free to call me at (352) 860-2385.
73 and good luck,
Pete Raymond, N4KW
----- Original Message -----
From: "Jim McDonald" <email@example.com>
To: "Towertalk" <firstname.lastname@example.org>
Sent: Wednesday, April 28, 2010 9:22 AM
Subject: [TowerTalk] US Tower damaged by lightning
> My US Tower HDX-589MDPL, which is motorized with the remote control
> recently took a very large, direct lightning hit. The antennas on it at
> time were (and still are) a Diamond 2M/450 vertical at the top, a 2L M2
> a Force-12 Delta 130 30M rotatable dipole, and a 4L (+26M directors)
> at the bottom.
> There are ICE lightning arrestors on the coax cables at the bottom of the
> tower and a large grounding panel with arrestors on every coax and control
> line at the house entrance. I also have lightning radials with ground
> every 16' going out from the base of the tower and the tower/radial ground
> connected to the entrance panel, the telephone, and the electric ground
> rods. With one exception, all ground rods with connected to #4 wire with
> Cadwelds, and the #4 wires were connected to each face of the tower with
> ground clamps on the cross bracings.
> The lightning apparently struck the tip of the 40M reflector, which is
> into a curl, and that element had the Phillystran linear-loading wire
> support break off. The large box of relays for the tower remote control
> exploded. Inside, the Yaesu rotor control, the SteppIR controller, and my
> K3 were damaged. The condition of my Alpha 87A is unknown, though the
> supply turns on, but the RS-232 doesn't work. I don't have another radio
> test it. The 2M and 450 radios are fine; I would have preferred them to
> I haven't climbed the tower yet, but measurements from the ground indicate
> the remote switch, rotor, and SteppIR are damaged.
> My question concerns the US Tower repairs. US Tower says the cable and
> pulleys need to be replaced and the tower inspected - all necessary to
> ensure structural integrity. The cables look to me to be undamaged, and
> pulleys seemed to turn, as I didn't have any difficulty lowering the tower
> with a US Tower emergency hand crank. BTW, anyone with a motorized tower
> should consider getting the emergency hand crank in case the tower has to
> lowered when the power if off.
> Obviously the relay box has to be replaced. US Tower's price to travel
> Kansas to the Chicago area and do the work is unreasonably high, in my
> opinion, and they haven't given me a technical explanation on why the
> and pulley need to be replaced to "ensure structural integrity." They
> that the inspection could be performed by another AWS-certified welder,
> I don't know of any locals with cable or pulley replacement experience.
> Any thoughts on the need to replace the pulleys and cables would be
> appreciated. Yes, I have homeowners' insurance, but they also are going
> ask why.
> Oh yes, one more question. After the strike, my unfinished basement walls
> have several cracks that we never noticed before. The house is five years
> old and is about 50' from the tower at the closest point. Has anyone
> experienced that? I haven't been able to find any literature on the
> Probably related, the water well is about 100' from the tower, and the
> was cloudy for two weeks afterwards. The well guys said that the aquifer
> can get disturbed in a lightning strike, causing cloudy water.
> I have pictures at
> http://picasaweb.google.com/jim.n7us/LightningStrike100405 . (The crawdad
> was magically transported to our drive; the nearest pond is several
> feet away.)
> It's a safe assumption that my wife isn't enthused about ham antennas
> Thanks for any information!
> Jim N7US
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