tom:
if you use the heavier wall gage PVC, it'll work fine.
even the thin wall stuff would certainly be strong enough, even at a 30FT, 
unguyed height, but it would be too flexible and probably break the wires as 
it moves around in the wind.
we're not talking about 1 inch PVC like you see for household fosets and so 
on, but more like the 2.5 inch drain or irrigation pipes.
4 inch sooer PVC pipe would be too big and too heavy and over kill, but 
anything around the 2 or 2 and a quarter or 2 and ahalf inch variety with 
the heavier walls would be great.  Cheap, light, and you can easily drill 
holes in the plastic for guying, or running antenna wires through.
it'll flex, but won't break under normal weather conditions...that is, no 
major hurricanes or tornados.
If you can locate a farm or agracultural supply store nearby, you can 
probably buy irrigation pipe or land drain pipe that will suit your needs 
cheaply and in whatever lengths you need.

the only down side to not using a conductive mast, is that lightening will 
most definitely try to come down the feedline instead of straight to the 
ground through a metal support.
You can always run a heavy duty ground wire down the non-conductive mast to 
a ground rod for this purpose.  Lightening is always a tricky beast, but 
giving it a direct path to ground, not through the equipment in your shack 
is certainly a plus in my mind.
You could also check out square channel tubing...most hardware stores have 
this in 8 and 10 foot sections...very strong due to the square channel 
instead of the round, so you can go to a smaller diameter for less cost this 
way.  Also, far easier to drill out compared with round metal tubing, for 
connecting sections or guy points, or wire insulators etc.
73
Colin, V A6BKX
----- Original Message ----- 
From: "tom behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, July 19, 2010 7:43 AM
Subject: Re: Another Antenna Support Idea


>    Mike:
>
> I have some of that stuff to support my Diamond X200A dual-band antenna.
>
> Regarding the PVC pipe possibility, I had thought of that too, but wonder 
> if
> it would be strong enough, though, for what I want?
>
> Just thinking out loud here.
>
> 73 de KB8TYJ
>
> ----- Original Message ----- 
> From: "Mike Duke, K5XU" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, July 19, 2010 4:40 AM
> Subject: Another Antenna Support Idea
>
>
> Check out the item on this subject in the Hints and Kinks section of
> QST for April of this year.
>
> It is 2 or 3 sections of uni-strut fastened together.
>
> This material is available at Lowes, Home Depot, etc.
>
> It would need to be guyed, but it is a cheap alternative.
>
> I also know people who use large diameter heavy gage PVC pipe.
>
>
>
>
> Mike Duke, K5XU
> American Council of Blind Radio Amateurs