On Jan 23, 7:39*pm, tom wrote:
As I sit here not participating in the Jan VHF QSO party partially due
to a cold but mostly due to freezing rain, I wonder. *I wonder what
stories and advice the group has about this sort of situation on VHF and up.

What sorts of design and fabrication details work to make antennas
perform well in environmental extremes?

tom
K0TAR

I'm thinking of what we did in the Navy: Encapsulation of one sort or
another. Radomes got mentioned already so I'll add rubber boots over
connectors and a generous coating of Scotchkote (or equal) over
exposed hardware.

Military antennas are usually over-built, as are the mounts. They
WILL stay together in one piece and they WILL stay up or somebody's
going to hear about it! For hams in vicious-weather zones, maybe it
means using plumbing pipe masts instead of thin-wall galvanized
tubing. Maybe it means more guy wires. Maybe it means paying ten
times extra to buy the absolute toughest item you can find. Maybe it
means buying something tough -- something made for a nearby commercial
band -- and laboriously modifying it to work at 2m, 220 or 440.

Without intending to demean any single approach, you may be facing a
tradeoff: Do you need to build a $2000 indestructible antenna setup
or can you replace a $300 one a few times? When the welfare of 6000
men on a billion-dollar ship is involved, the Navy's choice is easy.
For us hams, not so easy.

Aside: Wire antennas (not what you asked) usually had a "sacrificial
link" in the elements. In case of severe stress due to wind, the link
would part, putting some slack in the element but not bringing it
down. Until it was repaired, the antenna didn't tune quite like
before, but you could still get a match. The link was variously also
called the "weak link" or the "breaking link."

Emergency fallback (of which I have several) is the attic antenna.
The wet/icy roof attenuates the signals but it's not a blackout.

Sal
KD6VKW