Amateur astronomers use dc powered "dew removal" tape which is essentially a
resistive band encapsulated in a rubber material. Some fabricate their own
with strings of resistors.
Don't know how practical such an idea would be on large yagis, but I suppose
one could place a few such bands around or along a boom. I can't see placing
such heaters on antenna elements and such an installation on large booms
would be quite and undertaking.
In broadcast antenna applications there are two approaches, heaters in the
elements or radomes, but we're talking elements resonant at 3 meters so
physical size isn't an issue.
The images from K1TTT and KC1XX are heartbreaking. We had a severe case of
wind damage here in September when the remnants of hurricane Ike blew
through Indiana and Kentucky...but nothing on the scale of this ice storm.
73, and Merry Christmas, K9GX
Mark Steven Williams
Elizabeth, IN 47117
(812) 969-9900
(502) 468-7172 cell
K9GX@N4GN.com
Astronomy@N4GN.com
-----Original Message-----
From: cq-contest-bounces@contesting.com
[mailto:cq-contest-bounces@contesting.com] On Behalf Of Michael Tope
Sent: Tuesday, December 16, 2008 7:49 PM
To: Ken Widelitz
Cc: cq-contest@contesting.com
Subject: Re: [CQ-Contest] Be Icephobic - Before You Put Them Back Up - Read
Ken Widelitz wrote:
>ICEPHOBIC COATINGS
>
>Yes, I am an icephobic. The January ice storm in PEI took down many
>antennas, including two stacked M2 125 MPH rated, 6 element 20 meter yagis
>on 59' booms.
>
>The booms broke right in half, about 2' from the mast, in the same place on
>both antennas. Before they went back up, I painted all the aluminum with an
>icephobic coating from http://www.wearlon.com/Eice.htm. $200 per gallon.
>About 1.5 gallons to do 5 large yagis. It is supposed to cut ice loading by
>a large factor. They have detailed charts on their website. I painted the
>first couple of antennas with a primer and two coats of the Wearlon, but
>then did one with just one coat of Wearlon and when it dried the cover and
>adhesiveness was no different than with the primer and two coats.
>
>I also used 1/2" thick aluminum in the center 10' insert for the 20 meter
>yagi booms, instead of the 1/10" inserts that failed.
>
>On the bright side, when Mother Nature brings an antenna down, you know it
>is big enough.
>
>73, Ken, K6LA / VY2TT
>
>
>
>
I am curious if anyone has ever tried developing an active de-icing
system for yagis whereby the elements are heated to prevent ice buildup
(no jokes about California KWs please)?
Mike W4EF.................
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