[TowerTalk] Low Cost 20 Foot Mast

[jimlux]

On 10/24/20 1:06 PM, Tony wrote:
> All:
> 
> I'm looking for a low-cost 20 foot mast that can handle a modest 2 meter 
> EME setup. The mast will be cemented in place and attached to the side 
> of a 9 foot tall shed for support. I can't anchor guy wires to the 
> ground, but I can run a couple to the shed.
> 
> The challenge is home brewing something that can handle the weight of 
> the azimuth and elevation rotors mounted at the top so the mast.
> 
> I thought of threaded galvanized pipe sections, but they are a bit 
> pricey. Also thought of 2 inch schedule 40 PVC with some kind of 
> internal support to make it more rigid.
> 

The key on stiffness is diameter - a 4" diameter thin wall tube is 
enormously stiffer than a 2" diameter solid bar- because it goes as the 
fourth power of radius.

Rick N6RK used 4" (?) aluminum irrigation tubing for verticals.  You 
might be able to find it used ("Rain for Rent", for instance).

You might also find some of that lattice TV tower stuff - it looks like 
standard mast material (like Rohn 25), but is about 6" on a side. That's 
fairly stiff, also.