Ray Benny wrote:
> 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.
>
What I worry about in that case is oscillation under the right wind
conditions.
I think Davis, The RFConnection, and I know there's a third one selling
what they call "Poly", double braid. I don't know what "Poly" it is,
but it doesn't stretch much and I actually use the 1/4" for guy line on
a 40' tower with an antenna on top. It does not move around. I also use
it as a back guy to a 30' pole used as a raising fixture. Plus it's UV
resistant and inexpensive. I've had that back guy up two years and it
still tests good. I'm finding poweldirects.com blocked at present (says
there's an infected site) At any rate I have 1/8, 1/4, 5/16, and 3/8"
in the shop as I find the stuff so handy for temporary work and it's
cheap enough to purchase 500 to 1000' at a time. Just check the lengths
available if you need more than 500'. Just burn the ends so they don't
unravel AND *don't* get the melted poly on your fingers. It won't let go
and it is HOT. If that sounds like the voice of experience..."I left my
gloves in the shop but it's only one end so I'll be careful"...It just
might be.
73
Roger (K8RI)
> 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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