"Frank Wilson" wrote in message
...
Any ideas for installing a new antenna mast into an old antenna hole?

OLD:
I have an old 3.5 inch ID steel tube sunk in 30 inches of concrete. I'm
guessing this was an old satellite dish cut off flush with the surface
(unfortunately). No threads but the steel is 1/4 thick (or so) and in
good shape and it goes down to 30 inches in the concrete.

NEW:
I simply need an antenna mast of about 12 feet high for a new WISP 802.11
antenna & radio setup. Winds can be high at times. Soil is rocky clay. I
prefer NOT to have guy wires as the kids play in that area.

IDEA:
The best idea is to find a way to shove a 3.5 inch OD pipe 30 inches into
the existing pipe and then thread successively smaller pipe down to 2
inches for the final mast. But I can't find a source for 3.5 inch OD pipe
that has threads on at least one end so that I can put a reducer on that
end.

stuff snipped

Why not fill the existing hole with cement and while it's wet center a
smaller pipe that has the correct (smaller) diameter fitting at the top for
maintenance? No large thread pipe needed, just some cement. Better
structurally speaking than a series of reducers.

--
Bobby G.