Hmmm,
The stuff I saw on the rainforrent Web site seems entirely unsuited to large
vertical antennas. They call it lightweight aluminum, which would suggest
its designed to cross horizontal spans and be supported at regular
intervals.
Seems to me the cheapest solution is to simply build a non-conductively
guyed tower using used bits. I think 40 or even 50 feet of guyed GN or
whatever is available, topped with an appropriately sized stinger (or
top-loading of some description) would not be that difficult or costly,
compared with trying to engineer complicated plastic towers or risking
mechanical failure by failing to get proper materials. It's probably even
easier when you consider the nightmare that trying to get flimsy tubing
vertical would be. It would be like pushing on a string. Shouldn't be too
hard to either insulate from base or feed with a gamma.
You can often get GN for free just by taking it down for someone who no
longer uses it. Properly inspected, there's no reason it couldn't continue
to provide years of service. Even if you had to order it from RS, I think
the sections are still cheaper than Chris's estimated shipping costs plus
material. Looking at the TT web page, even if he started with 2.125 OD drawn
tubing, that's $3.50 US per foot, or almost $150 Cdn (assuming a 20-foot
first section and including shipping). Heck, 2 sections of GN new won't cost
that and the tubing vertical would still need to be guyed.
I would worry that trying to be frugal on this project will end up being
more expensive, particularly if it results in personal liability claims.
Probably best to do it right or not at all.
73, kelly
ve4xt
----- Original Message -----
From: "Jim Hill" <w6ivw@cox.net>
To: <towertalk@contesting.com>
Sent: Friday, March 21, 2003 4:45 PM
Subject: RE: [TowerTalk] mechanical construction of 80m vertical
> Finding tubing isn't easy. I've stopped at a number of businesses in
> farming areas with little luck. plastic tubing seems to be currently used.
> However, the following store in Bakersfield CA is a good choice:
>
> The Irrigation Store, 4001 State Road, Bakersfield, CA 93303 661-4421 or
> 800-742-7246. Their web site is: http://www.rainforrent.com/ Their web
> site shows tubing with end connections, but I thought I saw just plain
pipe
> when I visited them. The web site also shows stores at other locations.
>
> 73's Jim
>
> _______________________________________________
>
> See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.
>
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