> Subject: Re: [TowerTalk] mechanical construction of 80m vertical
>
> Try this page:
> http://www.n6rk.com/irrigation.html
Thanks for the plug Tim :-)
> 73s Tim EI8IC
> www.qsl.net/ei8ic/
> Useful Maps and Newbie-Operator Resources
> >
> > I'd like to replace my bent and buckled 67ft vertical (built
> out of junk)
> > with a more sturdy version. In the UK I can get 6m (19.6ft) lengths of
> > aluminium tubing but the question is what size/guage of tubing
> > Ian GM0TGE
>
Some additional info not yet on my web site:
I have made numerous scaled down versions of the
90 foot vertical. 60 feet of 3 inch (.050 wall) tubing works well
when tilted up with a ginpole consisting of 30 feet of 2 inch (.050 wall).
You can also make the top 30 feet of the 60 foot
mast out of 2 inch tubing.
Although I haven't tried it, you could probably
walk up a 60 foot mast that was 3 inch
for the bottom 30 feet and 2 inch for the top 30 feet.
It would require the same force as 45 feet of 4 inch
tubing, which I walk up for the ginpole for the 90
foot antenna. However, the ginpole method makes it
a lot easier to go up and down.
Maybe in a few weeks I'll upload the
digital photos of the 60 foot antenna going up.
It really is effortless with the falling derrick method.
Keep in mind that the stiffness of the tubing goes
up faster than the cube of the diameter. This is why
you want to use large thinwall tubing, instead of say
2 inch tubing with 1/4 inch wall.
Rick N6RK
www.n6rk.com
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