PL-259 and impedance

[KC9Q]

Here is an article by VK3JEG that covers the differences between the PL-259 and Type-N connector. I think it is only a concern if you go above 300 MHz per the article. The PL-259/SO-239 at 27 MHz is of little concern.

The UHF type connectors under network analysis

Mike

 

[Se7en]

Here is an article by VK3JEG that covers the differences between the PL-259 and Type-N connector. I think it is only a concern if you go above 300 MHz per the article. The PL-259/SO-239 at 27 MHz is of little concern.

The UHF type connectors under network analysis

Mike

I just recently removed the soldered pl259s for uhf and above and installed n male crimps. Haven't noticed any thing different.

 

[KM3F]

What difference did you expect to see?
From 50 mhz down, you would hardly see any difference on an SWR meter.
Signal wise you would not see or hear any diffeence unless there was a serious fault with the connector or the installation.

 

[BOOTY MONSTER]

I just discovered this.
The SO-239/ PL-259 connector on the back of virtually all CB's suffers from an impedance problem?
In the center of the connector the impedance is ~30-40 ohms.
Is this true at 26-30 MHz ?

How is this not ~equal to a SWR of ~1.6:1 before the signal even gets to the coax? (Simplified math)

Yes I know the definition of SWR involves the transmission line and connectors and antenna/load but impedance mismatches cause reflected signals where ever they happen right.

This has cause me to ponder a few things like:
Should performance seekers change the pl-259 type connectors on our 10-11 meter radios to N type connectors?

And:
Could this be why built in SWR meters are "notoriously inaccurate" ? Maybe they are just as or even more accurate than external SWR meters at least at measuring what the radio actually sees as it's SWR before the reflections of the 2-4 connectors required for an external SWR meter? (I know ... BLASPHEME !)

maybe he was expecting the same differences you suggested is your post that started this thread ???????

 

[jazzsinger]

the real issue with pl259 type plugs is not the non constant impedance, it is the inconsistent build quality through different makes, many of which use highly inferior materials, if you want porblem free pl259 insist on the amphenol 83-1sp series espcially the silver plated variants (original and best from the company who invented them), but be wary of ampenol fakes on e bay, if i recall the amphenol website has not only links to their dealers but also a stock list of their registered dealers. it also has proper instructionsfor installing them :http://www.amphenolrf.com/products/AssemblyInstructions/uhf.pdf

enter 83-1sp in the form in this link and it wll hw all amphenols dealer's stock of pl259's:

Amphenol RF- Products

shop about the registered dealers for best price, but bear in mind,quality isn't cheap and these plugs ARE available as fakes :thumbdown: with subtandard build quality outwith those dealers, you've been warned.