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Author Topic: Pine Trees and Other Beautiful Problems  (Read 3822 times)
N6QTH
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Posts: 42




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« on: August 14, 2000, 01:26:38 AM »

The QTH under consideration rests in the Sierra foothills (elevation 2000 feet) where the pine trees reach 100 feet.  It's on a north/west facing slope in a "clearing" with trees towering on all sides.  There is a clear shot between two trees of about 130 feet and an open wire antenna could be set in that space at a height of 40 feet with no serious difficulty.  A dipole (or similar) attached between these trees would have roughly a NW/SE end to end orientation.  There is also room on the roof of the "shack" for a "you don't need no radials" vertical, and a thirty foot tower is already in place (supporting a TV antenna) but it's about ten feet from a young but vigorous fifty foot pine.
This "shack" has elevations above it to the south and east of about 150 feet; open space (except for those beautiful water filled, gound hugging pines) offers some relief  for approx. 1 mile to the west.
I'm wondering how some of you might handle an antenna selection question in this situation. Of course,  I'd like to avoid those 100+ foot runs of feed line.
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WB6BYU
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Posts: 13288




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« Reply #1 on: December 11, 2000, 12:48:07 PM »

I'd put up a big horizontal loop strung among the trees however
it will fit.  Feed it with at the closest point to the shack with
whatever feedline you have handy through a tuner.

Another option is a vertical loop: a delta (point down) can be hung
between two trees and fed at the bottom with minimum feedline
length.  Don't worry about the exact shape:  I rigged one loop for a
friend in a rather irregular shape, using one pine tree, a post on the
garage, a fence post, and his chimney.  The wires weren't even all
in the same plane, but it worked great.  We fed it with 11' of
twinlead at the point where the wire passed over the shack.  Actual
length was about 200' - a bit short for a full wave on 80m.

Of course, a dipole over the tops of the tallest pine trees isn't a bad
idea, either.  Feed it with open wire line to reduce the losses.  You
can afford a lot of wire and a good tuner for the price of a "no
radials required" vertical, and it probably will work better, too.

Good luck! - Dale WB6BYU
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K6SDW
Member

Posts: 70




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« Reply #2 on: January 11, 2001, 05:42:36 PM »

Dale, I too live in the foothills with tall pines on the lot, but not in the most advantageous spots...anyway, can you feed delta loops with open wire or must you use coax?

Thanks.....73
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