Help identify what kind or type of connection this is?

[CorwinScansNM]

I am confused & wondering what in the heck kind of connection this is considered to be on the NMO Base of the Browning BR-137? Please see my images.

I took the screw-on part of the Browning BR-137 NMO antenna off as for I just purchased & own one of the JETSTREAM JT776SMA Antennas that I wanted to & had plans of screwing on & installing on the heavy duty Browning BR-137 NMO Antenna Base to then put on my NMO ground plane kit that is installed on my antenna mast outside. The turnout was not what I expected it to be & did not go smoothly as planned. The Female connection on the NMO base of the Browning BR-137 is a tiny bit bigger/wider than a normal SMA Female connector & has a hole for a medium sized connection/contact pin. Therefore, I am now stuck & trying to figure out what type of connection adapter I need if it even exists to be able to install my new JETSTREAM JT776SMA Antenna which has a Male SMA connector with a center pin in it (onto the Browning BR-137 NMO Base)?

Any clues, ideas or suggestions on what type of Female connection is on the Browning BR-137 NMO Base? I certainly do not know & am currently at a standstill which is why I decided to post the images & question here on RadioReference.

 

[CorwinScansNM]

On second thought? I think that I am going to go with a different approach & plan on this idea of mine to make it easier & to make what I am trying to do & figure out more possible without the guessing & troubles that I just ran into today by trying to do this in a difficult way that did not work using only the NMO base from my Browning BR-137 Antenna.

I am going to still make it 100% possible to install my newest JETSTREAM JT776SMA Antenna outdoors on my NMO ground plane simply by purchasing a Tram 1296 NMO to UHF Adapter & then another additional adapter that is called a UHF Male to SMA Female Adapter which I will then screw on & install on the Tram 1296. This which will easily & simply make it possible for me to use my JETSTREAM JT776SMA Antenna outside on my NMO ground plane the way that I had planned to install & use it for my receiving needs.

 

[mmckenna]

If that is the top of the base coil from the antenna, it's just the mounting stud for the whip. It's no a coaxial connector. Not sure what size Tram/Browning/Jetstream uses.

Swapping coils and whips won't work unless you are swapping the same style antenna parts. In other words, putting a 1/4 wave whip on top of a coil that's for a 5/8th's wave antenna isn't going to work.

I'm a bit confused by your final paragraph in your last post. The NMO mount is standard, and one brand NMO antenna should fit just fine on an NMO mount from another manufacturer.
I'm not sure I see the reason for multiple adapters.

If you are simply trying to put an antenna with an SMA base, like what would be on the top of a hand held scanner, you can buy an NMO - UHF test adapter, like one of these: https://www.amazon.com/Tram-1296-Mo...pID=51Lz87N6HeL&preST=_SY300_QL70_&dpSrc=srch and get a UHF to SMA adapter.
If this is going outdoors, you are going to have to put some effort into waterproofing all those adapters.

 

[CorwinScansNM]

If you are simply trying to put an antenna with an SMA base, like what would be on the top of a hand held scanner, you can buy an NMO - UHF test adapter, like one of these: https://www.amazon.com/Tram-1296-Mo...pID=51Lz87N6HeL&preST=_SY300_QL70_&dpSrc=srch and get a UHF to SMA adapter.
If this is going outdoors, you are going to have to put some effort into waterproofing all those adapters.

Yes, correct. That is exactly what I am going to do now & I typed that up in my last reply to my thread started here on RadioReference. I just ordered both the Tram 1296 Adapter as well as a UHF Male to SMA Female adapter both on eBay. Thanks for your help & suggestions though. As they saying goes, "GREAT MINDS THINK ALIKE" & both of us had the same idea to make this simpler & easier for me & for what I was trying to accomplish. I definitely will & planned on waterproofing all of my coax & adapters with COAX-SEAL.

 

[mmckenna]

OK, got it. That'll be an "elevated feed" antenna, the way you plan on doing it. With the ground radials a few inches below the antenna feed point, it might make the SWR a bit funky if you are going to transmit.

If it's just for receive, it'll be fine.

One issue you might run into:
An antenna designed to sit on top of a portable radio may not last very long if it's outside in the heat, cold, sunlight (UV) etc. It might fail fairly quickly. It'll no doubt work for a while, though.
Might want to consider a more permanent solution for long term use.

 

[CorwinScansNM]

OK, got it. That'll be an "elevated feed" antenna, the way you plan on doing it. With the ground radials a few inches below the antenna feed point, it might make the SWR a bit funky if you are going to transmit.

If it's just for receive, it'll be fine.

Yeah, no transmitting for me. Receive only on my digital public safety scanner from my outdoor antenna.