Hi Michael, a quick and easy test right in your shack is to measure the
resistance from feedline center conductor to shield with a good ohm meter. You
should see an infinite resistance. If you don't, there is moisture in the coax
or in the antenna driven element insulators. Water has a dielectric constant
of around 5 so only a little really upsets things. Only antennas with a direct
coax feed and non shorting baluns can be tested in this manner. I have seen
far more problems of this type in the feedline than in the antenna over the
years.
73 de Gerald Williamson,K5GW
Owner/Genaral Manager, Texas Towers
Call 1 800 272 3467 or visit www.texastowers.com
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