Glowmex VHF Antenna Thread Size?

[DJE]

Glomex VHF Antenna Thread Size?

The masthead mounts for these antennas seem to have a 17mm hole and the thread looks very fine (about 1mm pitch at a guess) and has an external diameter of about 15.5mm. I need a nut to fit it; does anybody know which thread they use?

 

[earlybird]

16mm x 1mm pitch is a recognised, but afaik, rare size. Could be that. Diameter will tend to be a bit undersized.
I think you will need some luck to find a nut, but you never know. Someone local with a lathe might be persuaded to make one.

 

[Salty John]

If the connector at the base is to take a PL259 connector, as on many other antennas, then the thread would be 5/8" 24tpi, a standard panel nut. It looks like it is for a PL259 connector but might be something of their own unique design.

 

[nigelmercier]

If you need a new nut because the old one was corroded, buy a new antenna.

 

[DJE]

Thanks for the suggestions. It is a fairly new antenna, I had it lashed up on a temporary timber post to get an AIS system working and now I want to make a more permanent mount on the top of a new stainless ensign staff. I suppose I could try the knurled ring off an old PL259 connector if I can’t find a nut.

 

[Salty John]

You can get panel nuts in many places, including SaltyJohn, you just have to be sure it is a standard panel nut you want - same thread as the PL259 - and not a Glomex special. If the connection to the base of the Glomex is a standard PL259 then you just need a panel nut, 5/8 24tpi. That's how we hold the Metz and the AlphaOne to their brackets.

 

[nigelmercier]

... If the connection to the base of the Glomex is a standard PL259 then you just need a panel nut, 5/8 24tpi...

Surely it must be a PL259 (actually SO259), otherwise how would you attach the down lead?

 

[Salty John]

Surely it must be a PL259 (actually SO259), otherwise how would you attach the down lead?

Most whip antennas have an SO239 in the base to accept a PL259 to which the down lead is attached. However, the Vtronix, for example, has some Micky Mouse arrangement whereby you strip the coax and coax (ha ha) it into the base of the antenna. Some have a factory crimped cable that you can't detach from the antenna. I'm unsure of what the Glomex has - some special arrangement of their own or an SO239. If the latter, the OP needs a standard 5/8" 24tpi panel nut. If the former, who knows?

 

[DJE]

Most whip antennas have an SO239 in the base to accept a PL259 to which the down lead is attached. However, the Vtronix, for example, has some Micky Mouse arrangement whereby you strip the coax and coax (ha ha) it into the base of the antenna. Some have a factory crimped cable that you can't detach from the antenna. I'm unsure of what the Glomex has - some special arrangement of their own or an SO239. If the latter, the OP needs a standard 5/8" 24tpi panel nut. If the former, who knows?

Just for reference Salty John's panel nuts do fit the base of the Glomex antenna. Here is the completed mount:-