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Old December 18th 14, 11:09 PM posted to rec.radio.amateur.antenna
Ralph Mowery Ralph Mowery is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 702
Default swr goes up on antenna


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...
Hard to say really, but sounds sort of moisture related..

Maybe moisture freezing, and then melting, or wet moisture that
later dries out. Just a guess though..
If that balun warms up, it's adding a substantial amount of loss.
Not really related to your problem, but I hate to see perfectly useful
RF turn to heat. :|
Also kind of verifies my theory of the cause of the loss I saw when
using one of those antennas at a field day several years ago.
I had compared it to a regular coax fed dipole, and it was way
down from the dipole.
I always blamed the voltage balun it used, and your experience sort of
verifies that assumption.


While some of the RF is converted to heat, I also have a 80 meter dipole at
the same height and at right angles to the OCF antenna. Switching back and
forth between them, the OCF is usually beter. In a few cases the plane 80
mete dipole without a blun will work beter on 80 meters.

Just a few months ago I hung an 18 and 24 MHz dipole about 6 inches bleow
the 80 meter dipole and fed off the same coax. Still the OCF is usually
beter.

The ends of both antennas are about 50 to 60 feet off the ground and not
suported in the middle or at the feed point.



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