Open Circuit 'High Quality' PL259

[G4_Pete]

Without re igniting the debate on pros and cons of 'N' vs PL259 etc I am enquiring if anyone has the specific assembly instructions for the plug of the type in the photograph including insulation and braid trim lengths.

These 'High Quality' plugs are widely promoted and available with some videos of very similar types posted on installation, but I have not found a specific RG58 type instruction. However, if you trim the braid neatly as instructed in some videos you can assemble these with no braid to body connection whatsoever or at best incidental body contact from random braid strands.

I sectioned the plug to see what was going on and as can be seen and despite everything all looking the part there is no mechanical braid connection if it is trimmed neatly. This is proved by resistance checks. I ordered some more separately, and they all seem the same.

The only way I can see to get a positive braid connection is to fold the braid back as shown, or perhaps a bit shorter than shown so that the rubber forces the braid out on the body. Either way you then do potentially compromise the moisture seal.

I don't want to add to the numerous pl259 debates but if anyone has any specific info or thoughts on the above.

Pete

[Terry_VK5TM]

I've seen a pictorial of how to do that style but if I can find it at the moment.

I'll keep looking but from memory, that washer at the threaded insert end is the key and is used to trap the braid.

Faulty memory, here's a video on how to do it https://www.youtube.com/watch?v=GVV9uFAbbX0

[Jon_G4MDC]

I think your issue is the plug is badly made.

Normally the braid is fanned out between the two washers and trimmed around the circumference so that it will pass into the body.

Pressure from the nut is transferred via the rubber gland onto the washers compressing them on the braid and the inner washer against the body for screen electrical contact.

Bulging of the rubber makes the moisture seal.

Your washers in both cross sections don't hit the body because the bottom insulator is too thick. The assembly method in the first one is correct as far as I can see.

PS> Very nice job on the cross section cut!

[Terry_VK5TM]

Ignore that, read the post wrong, just seen it is a PL259

[Jon_G4MDC]

This is why it fails to make contact in my opinion.

[G4_Pete]

Also the washer is the same diameter as the PTFE bit which gives a clearance fit for the washer so even if the machined lip was further back you still would not have a strong mechanical connection.

[Jon_G4MDC]

It would seem you have cut one up in the interests of science.
Maybe you can get a refund on any others? Not fit for purpose.

[G6Tanuki]

I have not come across that type, the compression gland version I have used with great results has a top hat style ferrule that you push into the space between the inner insulation and the braid, then cut off the whiskers of braid rather than folding them back on to the rubber compression insert.

They have never been problematic for me.

[Jon_G4MDC]

You can't beat a Greenpar. They made exactly what you describe. A PL259 using the braid clamp technique from their N type and BNC series. All were excellent with proper silver plating having used none of the brighteners employed on the modern jewellery items from the far East.

If only you could still obtain them.

[Cruisin Marine]

Jon_G4MDC is correct, they have made that washer too small to reach the sides, add to this there is no flat metal to push on to when the compression is tightened.
What make are they ?(if they are branded at all that is).
There is great reason to always keep your old connectors and re-use them.

[G4_Pete]

No name, No Brand marks, which speaks volumes. But they have made it onto the shelves of established suppliers.

Shame as they were really easy to make a good-looking job and if I had not been so neat in trimming the braid and left a few more whiskers sticking out to touch the sides I might never have known!

Pete

[Jon_G4MDC]

That is a sobering thought. What a run around they could have given you if they made it into an antenna system. Random noise pickup and then not on receive. Bad VSWR and then not on TX. Doesn't bear thinking about!

[Radio Wrangler]

Originally Posted by G4_Pete

No name, No Brand marks, which speaks volumes. But they have made it onto the shelves of established suppliers.

Shame as they were really easy to make a good-looking job and if I had not been so neat in trimming the braid and left a few more whiskers sticking out to touch the sides I might never have known!

Has feedback gone to that distributor? Otherwise everyone who buys them will fall into the same problem.

David

[Radio Wrangler]

Arcing in an antenna connection is the one thing that will quickly destroy a modern transmitter.

Transmitter control and protection brings up the power in a controlled ramp while monitoring the reflected power. It will halt the power rise if it sees too much reflected power and so such a transmitter can be keyed-up into any impedance with low risk of damage.

With a bad connection, the impedance can change instantly. The transmitter protection cannot react in time, the energy has already been put into the system and power devices will experience transients. Maybe the devices are not immediately destroyed, but damage can be cumulative.

There have recently been issues with the ICOM IC7700 when used with other brand linear amplifiers. It was designed to go with Icom's diode-switched power amps. Use one with an old-style power amp with relay switching of the RF path, and the transmitter will be up to power before the contacts go over, leading to arcing, and the failure of a number of transmitters.

David

[G4_Pete]

Yes Email sent to supplier with pics - waiting for a response.
Pete

[G4_Pete]

Also ordered some more from the same source prior to the Email to them to check current stock condition as the bad ones were ordered some 9 months back.
Pete

[Cruisin Marine]

Would I be correct in assuming that quality connector manufacturers like Greenpar, Suhner etc. are no longer making them? I do hope it is not just left to the damn Chinese lottery

[Radio Wrangler]

I've not heard of them stopping, but they rarely make things obsolet, they usually just push the price up even higher, which has the same effect.

If the 239s are flange-mount, then it's easy enough to substitute a flange-mount N. N's don't have the self-loosening feature of the PL259.

Oh for added fun, some Japanese firms used an almost SO239 where the threads were cut just slightly wrong in pitch. They would bind up and gall, so you couldn't screw them on far enough to reliably connect the outer, and then you found the #%$#^#$% things had seized and you couldn't separate them. These cropped up on expensive diplexers, antennae etc.

David

[Rileyman]

Pete, Can I refer you to my posting on 8th. Aug., re" Parts for Sale", in particular Item (3) . ? They are Greenpar and Amphenol-Borg bits.

https://www.vintage-radio.net/forum/...d.php?t=193475

Anything there of any use ?

Laurie .

[m0cemdave]

Originally Posted by Radio Wrangler

Oh for added fun, some Japanese firms used an almost SO239 where the threads were cut just slightly wrong in pitch. They would bind up and gall, so you couldn't screw them on far enough to reliably connect the outer, and then you found the #%$#^#$% things had seized and you couldn't separate them. These cropped up on expensive diplexers, antennae etc.

David

Unfortunately these are quite common. At least one well-known Amateur Radio retailer's Chinese-made PL259's have this problem.
I don't have the details to hand, but I measured the thread and it was a metric size instead of the correct Imperial/Customary one.