Technically the insulation should electrically lengthen the antenna
about 1.5-2 % (lower the frequency)
As Wes said the dimensions would be helpful. is the flat op horizontal
or does it slope down if it slopes how low is the far end?
I dont think 17 turns of RG400 is doing much for you on 160M but with a
ground mounted radials (IMO) not likely needed...what is the "R" at X=0.
�Are you measuring R+jX at the antenna or at the shack end of the coax?
How long is the coax
Dave
NR1DX
On 3/25/2021 11:54 AM, Wes wrote:
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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