[TowerTalk] Another aluminum question

[Jim Lux]

-----Original Message-----
>From: Alex Malyava <alex.k2bb at gmail.com>
>Sent: Dec 7, 2007 2:11 PM
>To: towertalk at 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)