You don't need that.  Just a straight vertical pipe is perfect for a GPS
antenna.  All the outdoor are designed with the coax dropping straight down
vertical into a pipe.    All of them have a mount with pipe threads that
makes a 100% waterproof connection.    Lacking a mount, use a pipe flange
and four stainless bolts.  You will need either some sealent or a gasket
between the flange and the antenna.

Here is what it looks like on my house, using telephoto lens from down the
street
https://www.dropbox.com/s/2qec0lf48occeom/DSC_3134%20copy.jpg

Notice that the coax and the connector is completely inside the pipe and
never gets wet in the rain.  Inside the attic the iron pipe transitions to
plastic conduit.

On Mon, Nov 26, 2012 at 2:35 PM, lists@lazygranch.com wrote:

--

Chris Albertson
Redondo Beach, California

The antenna I got fron Nichegeek on ebay uses British Pipe Threads! Just can't
get anything here that matches it.  Perhaps I should just get a unit with
regular NPT size threads?  Can anyone recommend a specific model which works
well with the Thunderbolt and has such a threaded bottom?

Peter

On 11/26/2012 8:05 PM, Chris Albertson wrote:

On 11/26/2012 8:51 PM, Peter Gottlieb wrote:

Why not just get a pipe nipple of close size, and grind off enough of
the threads (if necessary) so you can JB Weld it in place, then go from
there?

On Mon, Nov 26, 2012 at 5:51 PM, Peter Gottlieb nerd@verizon.net wrote:

The typical antenna has a flat bottom that is bolted to some kind of
mounting adaptor.  Perhaps the thing with the British treads will un-bolt.
THen you can buy a pipe flange at any hardware store.

Chris Albertson
Redondo Beach, California

I suppose, although interestingly there isn't anything close.  It just misses
one size and the next smaller one it swims in.  Although with enough epoxy...

OTOH, who cares, it's sitting up where nobody will look closely and it's not
like it's a structural element.  So your suggestion looks like a winner, thanks!

Peter

On 11/26/2012 9:19 PM, Mike S wrote:

Unfortunately not, it's part of the molded bottom piece of the antenna casing.

On 11/26/2012 9:24 PM, Chris Albertson wrote:

You might better use RTV. I's plenty strong enough and can be taken apart
if needed.

-John

=========

In practice, I suspect what I use will be what I have on hand at the moment ;-)

On 11/26/2012 9:34 PM, J. Forster wrote:

While NPT (US) and BSPT (UK) are different, 1/2" and 3/4" variants are
both 14 threads per inch and are similar enough to intermate, but are
unlikely to seal.  Since sealing is not a requirement here it ought to
be good enough.

Failing that, maybe one of our members on the continent would send you a
short piece for a nominal fee.  As I understand it, all continental
European plumbing that is not hard metric is BSPT, and most is not hard
metric so it's a hardware store item.

Rich

On 11/26/2012 8:28 PM, Peter Gottlieb wrote:

--
mailto:oz@ozindfw.net
Oz
POB 93167
Southlake, TX 76092 (Near DFW Airport)