I built a W2PV 4el 20 using 40' (two 20' lengths) of 3" irrigation tubing.
Spliced in the center using about 18" of Schedule 40 aluminum pipe. Also
used some 3" scrap from the supplier that I cut into 6" lengths, slit
lengthwise and slid over the boom. This provided extra crush strength for
the element plate U bolts. Boom support was Phillystran. Elements used 1
1/8" thru 1/2" tubing with a rather severe taper; sag was minimal and it
rode many severe winds and ice storms with ease.
This antenna survived about 19 years at 2 QTH's with no damage. It will
probably go up again this summer on a different tower.
Carl
KM1H
----- Original Message -----
From: "Robert Chudek - K0RC" <k0rc@citlink.net>
To: <TowerTalk@contesting.com>
Sent: Monday, June 11, 2007 11:06 AM
Subject: [TowerTalk] Where is the best place to buy aluminum tubing?
Jack,
In my "yout" I build a 6-element 15m yagi using a single section of 2" by 40
foot irrigation aluminum tubing I obtained at a local Agri-supplier. I used
an top truss to help support the ends. I didn't have any side trusses. I
probably got away with this configuration because a 15m element is
relatively small and there were no "freak" wind storms while I had it up on
my 104 foot tower. It worked real fine and lasted a long time. I ruled 15
meters in this area with that antenna in the early 1970's!
Yes, tower sections have been used for booms, especially the monster 80
meter yagi's. Google 80 meter yagi and I'm sure you will find some examples.
Your construction decisions will depend upon the band of interest and your
location's wind and ice loading circumstances. One of the bibles for
guidance is "Physical Design of Yagi Antennas" by David B. Leeson W6QHS
(ISBN 0-87259-381-9). I bought my copy from the ARRL Bookstore years ago.
And I know both Texas Towers and the MFJ catalog have aluminum tubing for
sale in a wide variety of sizes and thickness.
73 de Bob - KØRC in MN
- - - - - - - - - - - - - - - - - - - -
Message: 2
Date: Mon, 11 Jun 2007 02:04:34 -0400
From: "JACK CAMPBELL" <videorov@verizon.net>
Subject: [TowerTalk] Where is the best place to buy aluminum tubing?
To: <towertalk@contesting.com>
Message-ID: <000601c7abee$62f92610$0401a8c0@internet>
Content-Type: text/plain; charset="iso-8859-1"
Looking for some small 1"1/4 inside diameter to go on the bottom of some
spreaders and some 3" to 4" boom stuff
for some long booms.
Wonder how long of a boom can be made from 3" aluminum tubing. Looking at a
60ft boom.
Wonder if anyone has played with small aluminum tower for a boom. Does
anyone make stuff smaller then 20G.
I guess aluminum irragation aluminum pipe could work, anyone tried that
before.
Looking for some input.
Jack
KZ4USA
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