[TowerTalk] FW: 80 meter vertical question
maflukey at gmail.com
Fri Mar 21 03:20:22 EDT 2014
>> I have put up a 80 wire vertical in some trees seeing I do not have a
tower. I cut it 62ft6in so it should be on 3.750 however it seems long and
the swr is 1:1 at 3550 or so. I have 10 radials and my longer version worked
just fine. Any feedback would be helpful.
I have put up quite a few tree-hung 80m wire verticals with on-the-ground
radials for field operations from various locations. When the ground
conductivity has been on the poor side (especially dry sandy soil), I have
noticed that the number of radials had a very pronounced effect on the SWR
and made the antenna "appear" long based strictly on SWR. Increasing the
number of radials (any reasonable length didn't seem to matter) brought the
SWR into a more reasonable range. I don't recall ever having to put out
more than about 25 (maybe 30 at the most) radials when dealing with poor
soil - but I can certainly recall when 8 would not do the trick. So I
would suggest adding some more radials to see if it improves your situation
- especially because if you just shorten the antenna to compensate then you
are effectively bringing the impedance into line via the losses in ground
system and the resulting performance suffers unnecessarily. If adding some
extra radials does not have much effect, then I would trim the length.
Hope this help & GL.
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