Chuck Tribolet wrote:

Sounds like an 8' 6dB VHF antenna to me.

We're talking about a BIG bolt that goes through the pedestal and into the bottom of the
antenna? Standard size is 1" diameter, 14 threads per inch.

That thread is the 3/4" NPTS, the nominal O.D. is just under 1" so it
has become called 1"-14 TPI in the marine industry. NPTS means National
Pipe Thread Straight, it is the same as common 3/4" pipe and fittings
but not tapered.

Standard 1" bolts are either 8 TPI (NC) or 12 TPI (NF) and a strong and
yard mechanic can get 1" NF bolts to work on the antenna stubs. For a
few threads anyway. :)

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)