In article ,
"Tom" wrote:

Hi

Does the Shakespear or standard marine antenna base that is 1" 14tpi fit
anything else?

What about 1" national fine thread hex bolt? Or 3/4" npt plumbing type
thread? Anyone have any luck using something else without ruining the
threads? I cannot use one of their oem swivel base things for the
application I thinking of doing.

thnx for any advice,

73s

The thread is Straight Cut as opposed to NPT, which is Tapered...
HOWEVER,

I have cut 3/4" NPT Threads, using my Pipe Threader, that will work on
Marine Antennas. The trick is to have an Adjustable Die, and cut the
threads just a tad bit deeper than normal 3/4" NPT. It works well, as
long as your Pipe has enough wall thickness, to take the deeper
threading. I have used in in Alaska for years, and had no issues with
the antennas or mounts.

--
Bruce in Alaska add path before the @ for email

You really stuck your foot into this one Bruce, now you are going to be stuck answering stupid questions for the next couple of weeks.

The Fiberglass Shell as the OP called it is called a Radome.

http://en.wikipedia.org/wiki/Radome

The problem the OP has - besides being cheap and wanting something for nothing is the fact that he does not understand what is inside of the radome.

If you disassemble and Antron A99 or a Diamond X 500 - once inside, you will find a piece of copper wire or steel wire or stainless steel wire that is usually copper plated.
Between each section - spaced for certain wavelengths is capacitors of unknown origin which makes the antenna into segments - some for 2 meters and some for 70 CM.
This is what gives it its gain.
These are purpose built antenna's for those frequencies..

You cannot take a Marine antenna - that uses a different frequency and use it on amateur frequencies - due to the fact that there is no way to get internally inside of the antenna and change the lengths of the segments of the wires inside of the antenna.

Unfortunately - there is not a lot of educated Elmers out there that are willing to help a newbe - just due to the fact that most of the people who are left in Amateur Radio came from the CB radio and they were not knowledgeable - like the ones who came before them.

Most of them never built anything in their life and are just appliance operators.

I believe I had this conversation with this person or another person like this person previously.. My advice was that if the threads are of a ******* Origin and you are not willing to repair them or buy the mount to throw away the antenna..

They do not make a tap and die or make one that is economically feasable to repair a $10.00 antenna.. When you get into non standard threads - if you can find a tap and die - they tend to be quite pricey..

We are talking $60 - $100 each...

You would have to fix a whole bunch of antenna's just to break even, and it wouldn't be economical to buy it to fix one antenna.
You could buy a Diamond X 510 for about $150.00 and it would be already designed for the frequencys you desire to operate on.

JMHO
CJ

On Thu, 08 Nov 2012 15:29:10 -0900, Bruce Gordon
wrote:

The thread is Straight Cut as opposed to NPT, which is Tapered...
HOWEVER,

I have cut 3/4" NPT Threads, using my Pipe Threader, that will work on
Marine Antennas. The trick is to have an Adjustable Die, and cut the
threads just a tad bit deeper than normal 3/4" NPT. It works well, as
long as your Pipe has enough wall thickness, to take the deeper
threading. I have used in in Alaska for years, and had no issues with
the antennas or mounts.

That sorta works because 3/4" NPT is also 14 TPI (threads per inch).
Also, pipe is measured by the inside diameter, while nut and bolt type
hardware, which includes 1"-14 antennas, is measured by the outside
diameter. The result is that 3/4" NPT and 1"-14 UNS can be made to
fit.

I've seen the results of this method of antenna mounting. If the
antenna base is heavy and strong, it will work. If it's cheap pot
metal, the tapered pipe thread will crack the base when tightened. If
the 3/4" NPT is a little on the large side, it will be supported by
only by one or two threads. Hit the antenna with anything, and the
base will peel out of the mount.

The practice of using 3/4" NPT mounting is even more of a problem with
GPS antennas, which are usually mounted on some manner of pipe. In
order to avoid having two thread standards, Trimble and other have
standardized on an odd compromise threading that works with both 1"-14
and 3/4" NPT. For example:
http://trl.trimble.com/docushare/dsweb/Get/Document-8420/Bullet-III_DS.pdf
The socket accepts either a 1"-14 straight thread (typical
marine antenna mount) or a 3/4" pipe thread.
However, to the best of my knowledge, such a thread is not used in
marine antennas.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558