-----Original Message-----
>From: Alex Malyava <alex.k2bb@gmail.com>
>Sent: Dec 7, 2007 2:11 PM
>To: towertalk@contesting.com
>Subject: [TowerTalk] Another aluminum question
>
>Hi,
>that's me again with a question very related to the previous one :)
>
>I recall a lot of discussions of verticals in this reflector - verticals
>build out of irrigation pipes or build for permanent installation etc.
>
>I want to build a vertical out of aluminum pipes from TexasTowers - the only
>source of telescopic tubing I know about. That vertical suppose to be
>portable - I have no place for it at home, but would like to take it
>overseas or at least to Poconos, PA where we rent a house once in a while.
You might consider a sort of inbetween strategy. Get one of the very
lightweight collapsible fiberglass/carbon composite poles (a 20 footer is a
couple pounds or so... longer ones are available) and use it to support a
single wire to a loading network at the base. (there are portable flag pole
for banners and such) Very fast to erect, pretty stable, very easy to carry
around. Radials can be a bunch of pieces of wire with little shotbags at the
end (ankle/wrist weights work well) to hold them down.
I think if you do some modeling, you'll find that the performance difference
between something like a AWG 20 wire and a 1" diameter tube isn't all that
huge. The losses aren't so much in the radiator itself, as in the ground
losses, etc. Might want to carefully check the benefits from added height.
The extra efficiency from 3 or 4 more feet might not be worth it.
You can build a pretty low loss loading network that would fit in something
like a plastic tool box.
The reason to go to irrigation pipe, aluminum tubing, etc., is if you need it
to be sturdy and survive the weather. In a portable operation, if it falls
over, you just pick it back up.
(Of course, if your portable operation is on some gale-blasted rock sticking
out of the North Sea... maybe the sturdier scheme might be more appropriate)
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|