My experience with irrigation pipe:
I've had a two similarly constructed phased 67ft phased verticals for 80m up
for 20 years. Mine are 30 ft of 4 in at the base, next, about 28ft of 3 in,
(two foot overlap) then 9 ft of 2 in coming out of the top.
They are only guyed at the top of the 3 in and at the 3 in / 2 in joint with
Dacron. They do move around a lot in the wind, but since they are so light
there is very little moment/inertia to make them go anywhere. They pivot at
the base, so my wife and I can raise and lower them with ease.
Even if they did come down in the wind, the material is cheap, I'd just
replace the bent parts and go for another 20 years.
Ray,
N6VR
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Richard (Rick)
Karlquist
Sent: Monday, March 16, 2009 5:42 AM
To: Richards
Cc: towertalk@contesting.com; larryjspammenot@teleport.com
Subject: Re: [TowerTalk] DX Engineering 66-Foot Vertical?
> larryjspammenot@teleport.com wrote:
>
> interested in the construction of the 66' DX Engineering vertical,
> not to use as an actual vertical antenna, but to mount in a tripod
> on my roof and then use it as a tall support for an 80M inverted vee.
A data point. I had an inverted vee at 60 feet, using irrigation
tubing. The bottom 30 ft was 3 inch O.D., and the top 30 ft was 2 inch
O.D. Wall thickness was 0.050 inch. This is about the flimsiest
that I would recommend. It wiggled around quite a bit in 70+ MPH winds,
but never fell down. It had 4 way guying at the top and another
set of guys halfway up. Additional guying wouldn't have hurt.
I am currently using 3 inch for the whole 60 feet. I'm not worried
about that at all in the wind. OTOH, those tapered verticals I would
worry about a lot.
Rick N6RK
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