Aluminum tubing for vertical antenna
Hank,
Just wanted to add that you don't need 1/4 inch wall stuff anywhere in
a 33 foot vertical.
If you have it lying around you could use it, but the extra weight
really isn't worth it. Same for reinforcing by thickening the tubing
on the inside.
A hollow tube 2" in diameter with 0.058" walls is about 3 times stiffer
than a SOLID 1" rod.
Now, strength and stiffness are two different things, but you're better
taking the aluminum and making a fairly thin wall tube of large
diameter if you're trying to make a strong, stiff element.
For the price of one 12 foot 1/4" wall 2" tube you can buy the whole
vertical in 2" 0.058 wall tubing and the next telescoping size for
joints.
1/4" wall would be good if you're going to guy it and put a tribander
on top!
I'd go with Roy's vertical design, in fact. My antenna was a mess of
found aluminum, tent poles, etc. Might have even been 7/8" now that I
think of it.
This means that Roy's bottom section, if 0.058 wall 1.25" diameter 6061
was at LEAST 3 times as stiff as my 7/8" OD 3/4" ID 1/16" wall stuff,
and that's assuming I was using a good, stiff grade of aluminum, which
I wasn't.
Incidentally, Cecil, I think the 12 footers are more expensive because
you can UPS ship 6 footers anywhere and can't do that with 12
footers... it may be that it's just cheaper to keep the 6 footers in
stock because the market is bigger. Could also be that it's cheaper
for TX Towers to get them in .... dunno. It's too bad though, 12 foot
continuous sections would be good for this sort of thing.
73,
Dan
|