What type of coax connector is this?

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It's the gold one, what I consider a standard VHF connector is above it as scale reference. Flopping around behind my electrical panel it may be connected to a stubby antenna on the pushpit.
 
Thank you all. Bit of a mystery as, AFAIK, the boat has never had AIS. The top connector is for my VHF, a PL259.

BNC connectors are bog standard for connecting many types of antennae via coaxial cables. It's the usual one for television antennae, for example, and I'm pretty sure that the VHF on my boat uses BNC connectors at the tranceiver.
 
PL259 isn't a great connector for VHF. It's messes up the impedance of the line, isn't at all waterproof, and has variable connections to the coax. BNC is good, N type even better.
 
BNC connectors are bog standard for connecting many types of antennae via coaxial cables. It's the usual one for television antennae, for example, and I'm pretty sure that the VHF on my boat uses BNC connectors at the tranceiver.

Certainly here in Oz one never sees a BNC connector for TV antenna which are usually 75 ohm coax. They use what I think is called a Belling Lee push in no screwing. Yes the bottom one is a BNC connector. If indeed the cable is connected to the stubby antenna on the pushpit which is a VHF antenna it would be worth either changing the connector to PL259 or buying an adaptor like this https://www.ebay.com/itm/1Pcs-UHF-m...148949?hash=item2ca4b90155:g:QzYAAOSwcNFcnHRk so that the stubby atenna on the pushpit can be used in emergencyif mast top antenna fails. (as in loss of mast). ol'will
 
PL259 isn't a great connector for VHF. It's messes up the impedance of the line, isn't at all waterproof, and has variable connections to the coax. BNC is good, N type even better.

Is there a VHf radio on the market that doesn't have an SO239 socket for the antenna, to take a PL259? I don't know of one.
 
A lot of older VHF handhelds had bnc connectors built into their stub antennas. It could be that this is a connector to allow a h/h to be connected to a better aerial...?

Rob.
 
VHF radio manufacturers? Pah, what do they know!
Not sure I'd believe BNC or N were especially superior either.

What VHF transceiver manufacturers know is that at VHF frequencies an SO239 (the socket part) and a PL259 (the plug) is just about adequate so long as it’s kept dry. They use them because they’re cheap and the PL259 is not too difficult to fit.

BNC (and the screw collared version TNC) are very much superior RF wise. N Connectors are even better. Forty plus years ago I was an RF engineer at the Royal Radar Establishment if you are wondering how I know any of this and sometimes I used to measure impedance mismatches in coaxial lines. (It’s a bit more complex than that but you get the gist)
 
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What VHF transceiver manufacturers know is that at VHF frequencies an SO239 (the socket part) and a PL259 (the plug) is just about adequate so long as it’s kept dry. They use them because they’re cheap and the PL259 is not too difficult to fit.

BNC (and the screw collared version TNC) are very much superior RF wise. N Connectors are even better. Forty plus years ago I was an RF engineer at the Royal Radar Establishment if you are wondering how I know any of this and sometimes I used to measure impedance mismatches in coaxial lines. (It’s a bit more complex than that but you get the gist)

+1. Many moons ago I worked on prototype ice sounding radars, and it was BNC for ordinary connections and TNC for critical connections where mechanical integrity might be a problem.
 
A lot of the proliferation of connector types is driven by the military wanting to prevent oiks from connecting things up wrong. so you get PL259 used where it's adequate, avoiding somebody mis-connecting a UHF line to it.

Most pl259's you see on boats are crap. They don't seal the cable. Basically they are junk intended for the CB market.

You can get quality PL259 plugs at a price. Or you can fit a decent BNC plug and use an adaptor. Or you can use the cheap plugs and accept that your coax corrodes and goes lossy because it's not sealed.
 
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