I homebrewed an insulated base using three large ceramic insulators obtained
for $20 from a local scrap yard. They likely came off some power company
transformer. Each is about 6-8 inches diameter and about 8-10 inches long. One
of them would have been sufficient to hold my 100-ft. Rohn 25 that is the
160-meter vertical, but I used three to spread the load out. (I tested a spare
one, which had a crack in it, by driving my 4000-pound Jeep over it a few
times, without damage.) The insulators are bolted to a Rohn flat base on the
top side, and to another flat steel plate on the bottom -- which sits on a pier
pin in the concrete base.
Here's a photo on my web site. It's the last photo on this page, click to
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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