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