What connector is this?

[Apfelmus]

Hi all,

hope I'm not boring you, but me too I have a connector I'm trying to find out what it is.

It came together with some decifix adaptors for an older R&S RF measurement unit (the NAUS3): Adaptors from decifix to N, BNC and UHF.

The connector I could not identify has a threaded piece with just one gang(?). It has the pin on one end, and a hole of approx 5mm with a thread at the other end. I'm not sure if the connector is complete. I have 3 of them, all identical. The dimension is about the same as an N connector.

cheers
Martin

[Station X]

PL259 to mate with an SO239?

https://en.wikipedia.org/wiki/UHF_connector

[Radio Wrangler]

Definitely PL259. Sometines called "UHF Connectors"

Still pretty much the de-facto standard for amateur radio gear. They are pretty horrible really.

Firstly, they aren't proper constant-impedance designs, so they give reflections at VHF and above. Most plugs have a very nasty braid attachment scheme by soldering through holes in the plug. Old silver plate ones are better than the cheap nickel plate (almost unsolderable) ones often seen today. Some cheapo ones have the wrong thread and jam on the correct thread!

The braid soldering scheme means you have to get the body so hot that the coax dielectric and jacket melt, and the insulator in the plug which supports the pin softens.

If you have to use one, you beed big powerful soldering iron to get the body to active soldering temperature fast. bringing it up slowly with les power does more melting.

You can buy improved versions with more normal braid clamp gland attachment, but the centre pin still solders at the end.

In use they have a tendency to come loose, despite the detent zig-zag and tooth arrangement.

Think of it as a shielded banana plug with assembly problems.

David

[Techman]

I agree, these really are rubbish, but they’re the ‘standard’ that has to be used. There are versions with different entry sizes to take various different cable thickness, or which have screw in adaptors for the standard RG58, but can be removed for the much thicker ‘low loss’ stuff etc.

[Radio Wrangler]

All my gear in use has an N or BNC adaptor screwed onto it.

David

[G6Tanuki]

Originally Posted by Radio Wrangler

Some cheapo ones have the wrong thread and jam on the correct thread!

Be aware that there are 2 different flavours of these connectors: the "thread-jamming" is when you try to mate an original world-standard [5/8 inch 24 tpi] one and a Metric-standard [M16] one.

You often find the latter on Japanese ham radio accessories [SWR meters, frequency-counters, antennas]. When I find one it invariably gets replaced by a N-connector to preclude future confusion.

[Apfelmus]

Hello,

thanks for all your contributions. Indeed, I tried it on one of my UHF adaptors, and it fits.

On one side that is.

The other side is still a mystery to me. With a thread in the casing. Looking through it I can spot the hole of the pin, the one that goes into the UHF connector. It seems like there is another type of connector that screws into the thread.

And idea? Enjoy attached some more pictures...

cheers
Martin

[emeritus]

The threaded bore could be for a screw-in adaptor (reducer), as mentioned in #4. This type of plug and its reducers are illustrated in the attached extract from the 1987 Maplin catalogue.

[Radio Wrangler]

Without the reducer, the threaded bore was supposed to screw onto the plastic jacket of the non-reduced size cable. When you soldered the outer through the holes, it melted in and loosened, unfortunately.

David

[G6Tanuki]

Thankfully, various manufacturers have now got round to producing proper compression-gland PL259 plugs, and they're no more-expensive than the horrible solder-through-the-hole-and-hope versions. They're also semi-waterproof* unlike the solder-the-shield-through-the-hole type.

* I consider them IP33-class though that's with a good gob of silicone-grease squirted into the gland before assembly.

[turretslug]

I was surprised at how awful the concept of the soldered-screen type was when I first came across it a long time ago. The broadcasting industry used crimped collar types for many decades, and in large quantities- it puzzles me somewhat that other industries didn't use it more. In common with any crimp type, you need the right tool with the right insert on the appropriate outer conductor diameter connector but the result is so much more couth electrically and mechanically that it should have rendered the solder type extinct at birth.

[Apfelmus]

Hello,

and thanks again for your help.

Its apparently not really an adaptor, but a plug in which I could fix a cable in an awkward fashion that tends to be of questionable reliability.



cheers
Martin