"Bill VanAlstyne" wrote in message ...
I'm starting a project with some other guys on a 6M beacon
which will end up on a mountaintop at around 10K ft in New
Mexico. During winter, that means sub-zero temperatures,
high winds, and ICE build-up on everything exposed. We would
ideally like to put up an omnidirectional horizontally
polarized antenna like a loop. Anyone have experience with
building (or purchasing) such an antenna that would be
sufficiently bulletproof to stand up to a severe weather
environment? We could go vertical, of course, but since this
beacon will be operating in a CW weak-signal environment
under a wide variety of propagation modes (including ground
wave, troposcatter, etc., where polarization is more
important than it is with ionospheric propagation), we'd
like to stay with horizontal if it's physically realistic to
do that. What we don't want to have to do, however, is trek
up to the mountain top every weekend to put the antenna back
up. g

I'd immediately consider a ruggedized Squalo.

http://www.wia.org.au/armag/2002/AR_May02_TA1.pdf

I doubt that the specific design shown in the article would take the
kind of abuse you're talking about but it's a conceptual and
dimensional starting point I'd make the loop from one inch copper
water tube and 90 degree soldered copper elbows. I wouldn't use a
gamma match, they're trouble looking for a place to start in an
application like this. I'd attach a few feet of some kind of good RG-8
size coax directly to the feedpoints and string (suitable) ferrite
beads on the coax right at the feedpoint. Then run the coax down the
antenna support to a sealed box which contains some sort of simple
tuning network which would be completely out of the weather. I'd also
make really sure the loop was well supported including nonconductive
struts from the support mast to the far corners of the loop.

There would be a good bit of cut and try involved, material selection
issues and mechanical details to be worked out but hey, that's ham
radio for ya!


Bill / W5WVO
Albuquerque NM

Brian w3rv


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The neat thing about running a loop is you can put some DC through
it in the winter to keep the ice off.

Where are ya gonna get those kinds of amps? As in amperes.

KC*VIF
Greg Z
to thine own sound be true