Instead of AL Tubing, why not try this:
http://www.spiderbeam.net/sb/product_info.php?info=p71_Spiderbeam%2018m%20fiberglass%20pole.html
I reckon it would be easier than AL Tubing etc.
73
Adrian MW1LCR
________________________________
From: towertalk-bounces@contesting.com on behalf of Yo3ctk
Sent: Fri 27/10/2006 12:40
To: towertalk@contesting.com
Subject: [TowerTalk] 80m vertical: reality check
I am trying to design an 80m lambda/4 vertical for a 4-square. My plan is to
use 6 ft sections of AL tubing, 0.058" wall, as advertised on Texas Tower
website:
http://www.texastowers.com/aluminum.htm
Starting with biggest O.D of 2.125", twelve (12) more 6 ft sections of
progressively smaller O.D. will be telescoping with 1 ft overlap at each joint.
Joints will be fastened with AL rivets. The entire vertical will have an
(adjustable) height of 66 ft (20m) and a total weight of about 22 pounds (10
kg).
Unfortunately I have no expertise in calculating if such a structure is
mechanically sound, hence following questions for the experts on the list:
1. Is the vertical expected to break at the lower joints in stiff winds (say no
more than 65mi/100km/h)?
2. Must the vertical be guyed? Where?
3. Is it feasible to raise the vertical from the ground, by fixing the largest
section to the base and telescoping sections starting with the smallest
diameter, and riveting as we go?
Thank you all for any comment.
73 de Mike, YO3CTK
YR7M stationmaster
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