On Thursday, 09 September, 1999 1:45 AM, Ron Youvan [SMTP:ka4inm@gate.net]
wrote:
> I have seen fiberglass antennae that have been struck by lightning,
> y'a know y'a wouldn't think the fiber glass and epoxy could be separated
once the epoxy sets, but they sure can.
I posted a question here earlier this year about dual band antennas. I'd
now like to relate an experience we just had with a Hustler G6-270
fiberglass antenna taking a lightning strike last weekend. When I
purchased the G6 (and 15 others for ARES) I was concerned about lightning
survivability, but the Hy-gain model that I really wanted wasn't available
due to the sale of Hy-Gain to MFJ.
It was installed last month on top of a one story bldg onto a roof mounted
tri-pod structure installed for and containing a 6 GHz microwave dish. The
strike completely exploded the G6's fiberglass radome into tiny shards, and
melted and split the metal that was at the base of the fiberglass. It
looked like one of those exploding bullets designed to rip open whatever it
hits.
Apparently the mounting structure wasn't properly grounded anywhere. We
did have a PolyPhaser installed that was grounded, but the lightning didn't
follow the coax at all; it followed the radials out and jumped to the 6GHz
microwave dish and down it's eliptical waveguide into the comm room where
it destroyed a PBX switch.
I have 15 others installed on other locations, some on 100 ft towers.
It'll be interesting to see how many we lose next spring when Nebraska
storms really get going. I'm pretty sure the other towers and mounts are
grounded properly, but I haven't seen them all.
Does anyone know of a non-fiberglass dual-bander with a better mechanical
mount than Cushcraft's models? Short of going to a commercial model like a
Decibel, Sinclair, or Scala, is there anything available in dual-banders
for amateurs that can survive lightning? I haven't found it yet.
73,
de ed -K0iL
-.-. --.- .... .- -- ... -.. . -.- ----- .. .-.. -.-
Ed Edwards -- K0iL
PO Box 375 k0il@arrl.net
Elkhorn, NE 68022-0375 k0il@qsl.net
496-3415 home 552-5425 work 552-5505 fax
Visit my home page: http://www.qsl.net/k0il
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