Surprised nobody mentioned this suggestion yet:
Don't build a dipole. It'll be barely useful at that height. Build an
Inverted L.
Feed it at the base of the tree. Run the wire up the back side of the tree,
over the top of it (the highest branch you can get it over), and then run it
over to the back of the lot and tie off the other end as high off the ground as
you can get something to tie it to.
Total wire length: About 140', with an egg insulater at the top end of the wire
(in the back yard), and string or dacron rope for the rest of the journey.
Tune it with a variable capacitor at the feedpoint. Run as many radials as you
can fit on your lot, the more the merrier. Add a ground rod at the feedpoint
as well for good measure.
Mine works great, although the vertical portion is 70' not 40'. I don't know
how much you'll lose by having a shorter vertical section, but I'm *guessing*
it's still going to work better than a dipole. Maybe somebody with some
modeling software (or, better yet, somebody who has tried it) can confirm.
Another thought: Plant some tall-growing trees in the desired location(s) and
fertilize them well.
John
W2ID
> Message: 9
> Date: Mon, 12 Dec 2011 08:08:57 -0800 (PST)
> From: Rick Scott <w7psk@yahoo.com>
> Subject: [TowerTalk] Frestanding Dipole Support - inexpensive
> To: towertalk@contesting.com
> Message-ID:
> <1323706137.4178.YahooMailClassic@web111501.mail.gq1.yahoo.com>
> Content-Type: text/plain; charset=iso-8859-1
>
> I have a limited lot and want to try to put up a 160 loaded Dipole I have.?
> In the front of the lot I have a 35-40 tree I can use (Yes I know NVIS, But
> only looking at 160m States) but in the back I have nothing to hold up the
> other end with.? I have a Chain link meeting a Wood fence back there, but
> what ever I use must be free standing.? Dont think it has to be that high
> maybe 20ft or so.?
>
> I have a 25ft Push up flag pole in the front yard that would be ideal. It
> holds a 4x6 flag? really well even with the huge winds we had recently.
> However, I dont think the wife would like me moving it to the back yard.?
> Plus the expense precludes me getting another one, after the 746pro and the
> steppir the ham budget is spent :).?
>
> So Im down to asking for ideas of what i could use thats
>
> A. easy to assemble
> B. Relatively Cheap.
>
>
> Ideas to ponder are welcome
>
> Scotty W7PSK
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