I know this has been discussed before, but mostly in
the context of verticals in heavily wooded areas. I am
wondering if anyone has thoughts on having just a
couple of trees very close to a vertical radiator on 160
meters. I've been working very hard to improve my
postage stamp lot setup on 160 meters and have
been feeling a bit frustrated with the results. I am
running about 1KW, but I still feel like I am running
barefoot. There may be a number of reasons for this:
a) Very dry rocky soil
b) Suboptimal radial system (radials run along narrow
strip between base of vertical and my house and then
fan out about 20 feet from the base into the front and
back yards)
c) Nearby trees
d) Some combination of all of the above
With regard to (c), my 60' top loaded vertical is right
next to a small stand of trees. This has the advantage
that I don't have to worry about my neighbors above
me (I am on a hillside) complaining about my mast
blocking their view since the trees essentially hide it.
There is a large ~60' tall pine tree about 10' away from
the vertical and a couple of ~50' tall Leyland Cypress
trees about 20 feet away. The modeled radiation
resistance of the vertical is about 14 ohms (60 vertical
section with 66' top hat wire sloping down to 50'). The
measured feedpoint R is around 30 ohms.
Wondering if that big pine tree and the Cypress trees
are what is turning my antenna into an air cooled dummy
load?
Thanks,
Mike W4EF.....................................
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