Mystery antenna problem
Water in the balun or feedline?
Michael Coslo wrote:
After the bout of windy weather we had a week or so ago, my mini antenna
farm was wrecked. My HF6V sustained a broken mast, which was easily
repairable.
My OCF dipole on the other hand, stopped working properly.
Originally cut for the standard 80-40-20-10 config, the best SWR
near 80 meters has risen to around 4.37 MHz, 40 meters is around the
correct frequency, but has SWR has risen a bit to around 2.5. 20 meters
is over 3, and 10 is better than 7.
18 MhZ also has a 1.2:1 SWR.
SWR measured with a MFJ259 meter.
The specs of the antenna are (roughly, as I'm doing this from memory)
48 feet short side, 130 long side
4:1 Balun
Height around 50 feet.
Coax coiled balun near house entrance Coax split just above balun for
lightning arrester installation.
Since I bought a new 4:1 balun at Dayton last year to replace one that I
fixed a while back, I decided to replace it. Same result.
I took the choke balun and lightning arrester out of the picture to
isolate them, and measured from there. No difference.
Coax connectors look good.
So what I am left with is the coax and the antenna wire itself.
Unless someone has played an *awesome* practical joke on me, the
antenna dimensions haven't changed.
So can coax go bad in a way that will raise the lowest SWR in the
way I describe? Of course I could just replace it, but I'd like to know
why.
- 73 de Mike KB3EIA -
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