XM240
One thing you should do before raising that antenna. Check the continuity
of the coils. Mine had four coils that were open, two on each antenna.
Cushcraft relies on pressure from a self-tapping screw to cut through the
wire enamel. Two of these screws had not cut through the enamel. My solution
was to cut back the heatshrink on the coils and scrape the enamel off the
wire and retighten the screws. This solved all the problems.
Also, end caps are a bad idea. Alway leave them off the boom and elements
and tighten the boom trusses so there is slight amount of sag in the boom so
water will run out the ends. I am on the south Oregon coast and water in
antennas is a serious problem and leaving the caps on fixed everything.
73 de Larry K7MI
----- Original Message -----
From: "K4SAV" <RadioIR@charter.net>
To: <towertalk@contesting.com>
Sent: Saturday, July 09, 2005 13:07
Subject: [TowerTalk] Water in my XM240
For the past eight weeks, my XM240 has been sitting in my back yard on
concrete blocks, awaiting the arrival of my 4 element SteppIR. Today I
removed a couple of the elements and found a lot of water inside. (Much
more than can be accounted for by condensation.) Then I noticed that
there are no weep holes on this antenna anywhere, and the element ends
have rubber caps. I inspected the elements for a possible hole to let
water enter. I found that the loading-hat-cross was mounted by two holes
drilled through the elements. That looked like the best spot for water
to enter. I packed duct seal around the screws.
There was also water in the element sections, closer to the boom. This
section was blocked from the end section by the solid fiberglass rod
that the loading coil was on. I don’t know how water got in this
section. Maybe it’s coming in around where the sections are telescoped
together and clamped with hose clamps, although the fit looks tight and
there are no obvious holes.
I am beginning to wish I had used Noalox on the areas where elements are
telescoped together and clamped. The manufacturer didn’t say to do this,
but it sounds like a good idea to me. Can any of you think of any reason
why this is not a good idea? What do other antenna manufacturers
recommend? It’s a lot easier to do this while the antenna is still
sitting on the ground.
It won’t bet the first time I have violated the prime directive with
this antenna, I used Noalox on the bolts when the manufacturer said to
use liquid soap. Soap just seemed too water soluble to me for this
application.
Jerry, K4SAV
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
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