Hello,

I have a VHF whip that mounts to my radar pedestal. The radar is on one
side and the other is a flat plate for mounting. I was having some
trouble with the VHF (poor reception) so I took the antenna off to check
the connection. When reinstalling the mounting screw/bolt jumped
overboard.

My question: Does anyone have a clue what size scew/bolt I need?

Yes, silly question with little info, but maybe............

The boat, with the antenna, is on the hard very far away (1,000 miles)
and not readily available for inspection.

The antenna mount is such:
The base of the antenna has a threaded hole.
There is a matching hole in the aluminim mounting plate.
The coax has the outter shield stripped back and the center conductor is
terminated in a ring connector.
The coax connection is covered with heat shrink.

I bought the boat with this arrangement so I have no first hand
experience with it.

It is a whip fiberglass antenna, maybe 8' long.

The antenna has no external markings indicating make.

Sent with cautious optomisim,

Howard

"Howard" wrote in message
rvers.com...
Hello,

I have a VHF whip that mounts to my radar pedestal. The radar is on one
side and the other is a flat plate for mounting. I was having some
trouble with the VHF (poor reception) so I took the antenna off to check
the connection. When reinstalling the mounting screw/bolt jumped
overboard.

My question: Does anyone have a clue what size scew/bolt I need?

Yes, silly question with little info, but maybe............

The boat, with the antenna, is on the hard very far away (1,000 miles)
and not readily available for inspection.

The antenna mount is such:
The base of the antenna has a threaded hole.
There is a matching hole in the aluminim mounting plate.
The coax has the outter shield stripped back and the center conductor is
terminated in a ring connector.
The coax connection is covered with heat shrink.

I bought the boat with this arrangement so I have no first hand
experience with it.

It is a whip fiberglass antenna, maybe 8' long.

The antenna has no external markings indicating make.

Sent with cautious optomisim,

Howard

This may be useless information, but many US made antenna mounting
fixtures and whip attach bolts are 3/8" by 24 threads per inch.
What sounds alarming to me is that the type of connection I think you
are describing, and the length of the whip, make it sound an awful lot like
you are messing with a "marine" CB antenna. If that's the case, the VHF
radio would tend to be less than red hot.

Old Chief Lynn

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.


"Lynn Coffelt" wrote in message ...

"Howard" wrote in message
rvers.com...
Hello,

I have a VHF whip that mounts to my radar pedestal. The radar is on one
side and the other is a flat plate for mounting. I was having some
trouble with the VHF (poor reception) so I took the antenna off to check
the connection. When reinstalling the mounting screw/bolt jumped
overboard.

My question: Does anyone have a clue what size scew/bolt I need?

Yes, silly question with little info, but maybe............

The boat, with the antenna, is on the hard very far away (1,000 miles)
and not readily available for inspection.

The antenna mount is such:
The base of the antenna has a threaded hole.
There is a matching hole in the aluminim mounting plate.
The coax has the outter shield stripped back and the center conductor is
terminated in a ring connector.
The coax connection is covered with heat shrink.

I bought the boat with this arrangement so I have no first hand
experience with it.

It is a whip fiberglass antenna, maybe 8' long.

The antenna has no external markings indicating make.

Sent with cautious optomisim,

Howard

This may be useless information, but many US made antenna mounting
fixtures and whip attach bolts are 3/8" by 24 threads per inch.
What sounds alarming to me is that the type of connection I think you
are describing, and the length of the whip, make it sound an awful lot like
you are messing with a "marine" CB antenna. If that's the case, the VHF
radio would tend to be less than red hot.

Old Chief Lynn

Howard wrote:
Hello,

I have a VHF whip that mounts to my radar pedestal. The radar is on
one side and the other is a flat plate for mounting. I was having
some trouble with the VHF (poor reception) so I took the antenna off
to check the connection. When reinstalling the mounting screw/bolt
jumped overboard.

My question: Does anyone have a clue what size scew/bolt I need?

Yes, silly question with little info, but maybe............

The boat, with the antenna, is on the hard very far away (1,000 miles)
and not readily available for inspection.

The antenna mount is such:
The base of the antenna has a threaded hole.
There is a matching hole in the aluminim mounting plate.
The coax has the outter shield stripped back and the center conductor
is terminated in a ring connector.
The coax connection is covered with heat shrink.

I bought the boat with this arrangement so I have no first hand
experience with it.

It is a whip fiberglass antenna, maybe 8' long.

The antenna has no external markings indicating make.

Sent with cautious optomisim,

Howard

I have a feeling this is a wetsuit job!

Dennis.

"Chuck Tribolet" wrote in message
...
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 sounds like a good guess, too. My guess was based a little on the
coax termination method........... from OP:
"The coax has the outter shield stripped back and the center conductor is
terminated in a ring connector"
Haven't seen many marine VHF antennas that used anything except some
sort of UHF or N connector arrangement.
Old Chief Lynn

"Dennis Pogson" wrote in
:

I have a feeling this is a wetsuit job!

Dennis.



FEDEX coulda had a new part here...by now.

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)

In article ,
Jack Erbes wrote:

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


When making custom mounts for the Marine 1"X14 Mount Threads, I use
my pipe threader with an adjustable die set, and cut the threads
just slightly deeper than the normal 3/4 NPTS setting. Been doing
that for years, and it works very well. Morad builds a Standard
1"X14 to 3/4 Pipe Slip-over Adapter, with Setscrew locking, that works
well, also.

Bruce in alaska
--
add a 2 before @

Larry wrote:
"Dennis Pogson" wrote in
:

I have a feeling this is a wetsuit job!

Dennis.



FEDEX coulda had a new part here...by now.

I think I'm gonna just buy a whole new antenna and be done with it.