How long is the vertical section? The insulation should have minimal effect.
Wes N7WS
On 3/25/2021 8:07 AM, N4ZR wrote:
I have been trying to replace my inverted L, which broke a few weeks ago, and
am having all sorts of puzzlements. Please be kind - I was a history major.
1. The inverted L broke at the turn, so I went looking for sturdier wire. I
wound up with some #14 insulated recommended by our local RF maven, and put up
140 feet initially, figuring I would prune it *up* into the CW part of the
band. Imagine my surprise when it showed up resonating at 1977 KHz (on an
AA-55 Zoom). Does insulation have such a profound effect on velocity factor?
2. My feedpoint arrangement has 17 turns of RG-400 as a common mode choke,
with the radial field connected to the RG-400 shield at the antenna end.
Initially I tried measuring the resonance without the radial connection. No
resonance and infinite SWR. I connected the radial field (8 X 70-foot radials
on the ground) and that's when I saw the 1977 KHz resonance (X crossing
zero). SWR at minimum was above 2:1. Does this make sense? I know the
radial field is inadequate for good performance, but...
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