Would like some opinions.
Suddenly experiencing high SWR on all bands during heavy rain,high enough to
kick the Alpha off. I am only a few hundred feet back from the beach. When
the rain stops and things begin to dry out a little, the SWR begins to drop
and dry returns to normal. Normal dry SWR is below 1.2 at the tuned freq.
When raining the SWR will go up to 1.8 @100 W and up to 2 or more @ 500W
kicking the amp off. As a temporary fix I have been using the MFJ-986 tuner
with a small amount of inductance and differential capacitance. Works for
now and can make contacts and hear OK.
Shot the coax with a Tek 1502 TDR and it looks fine. My suspicion is some
insects have gotten into the HyGain BN-86 balun (I know this is a poorly
built balun but it had been working just fine) through the weep holes and
their nests are sucking up water. I suspect the higher power is literally
boiling the water as after some short operation the SWR will begin to drop
slightly. Totally dry SWR looks like it did when the antenna went up.
Am I off base and should be looking at something else?
Don W7WLL
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