I believe what you are describing is not only practicable, it has been done
many times before. QST, years ago (at least 25years) had a how-to-do article
on this type of tower which incorporated used oil field pipe. It also had a
tilt-over feature which made it very easy to install the antenna at the top.
A base pipe about 20 or 25 feet long was buried in concrete to about 6 or 7
feet and the tower was attached at the top at its balance point. A winch was
installed on the base pipe where the bottom of the tower contacted the base.
With the tower balanced, the weight of the beam allowed it to swing over and
it could then be pulled vertical with the winch.
The one I saw moved slightly in the wind which is to be expected. The main
objection to this type of tower probably is the mounting of the rotator if
you put a yagi on top.
I would like to build this type of tower just to raise and lower wire
antennas for 160 and 80 meters. I think I could go to 100 feet since only
wires would be used, not a yagi or other attachment with a higher windload.
I did a search on the web using Google last night looking for the OD and ID
of aluminum irrigation pipe but found nothing helpful. If you run across any
articles or design data, please let me know. Good luck es 73.
Jan Rehler, W5KNZ, Corpus Christi, Texas