BNC as low cost alternative to high quality 4mm banana post ? for resistance box

[tooki]

Yes for PTFE , I have read that 75 Ohms have PTFE and most of the 50 Ohms have nylon ( PA66 ) but that possible to locate BNC 50 Ohms with PTFE , I will check in my available batches

I don’t think one can make such a generalization. 50 ohm BNCs use a wide variety of dielectrics: polypropylene (PP), PBT, nylon (PA), Delrin (POM), polymethylpentene (PMP, TPX) and PTFE were just what I found by looking at a couple of standard, low-cost (under $5) BNC connectors on DigiKey.

And conversely, it’s easy to find 75 ohm BNCs with dielectrics that aren’t PTFE.

The only concern I have seen on BNC is the maximum possible matting before contact surface damage as from main brand as Amphenol they rate at 500 connections before possible contact damage ( galling / fretting)

I would expect contact deformation to be a bigger issue than galling or fretting.

But regardless, I mean… BNCs are used on test equipment here and there. Like, say, every oscilloscope, function generator, and bench LCR. And tons of broadcast video equipment. Surely if BNCs lacked sufficient robustness, they would not be used on such a huge variety of equipment that is plugged and unplugged constantly.

If you use decent quality connectors, connector life should not even remotely be a problem.

[Overspeed]

Hello

As I have not succeed to remove / solve the quote ''mix''  I have cancelled the post and I post a new one

On point 1
Yes and No , if the connector is from a well know brand with a engraved type on , that easy to check what are the specs , when I speak of BNC that instruments quality BNC , they was on aerospace equipment dismantled for recycling . Most of them are Radiall brand
For ''other'' I agree and more if that ''aliexpress '' supply that just gambling
On point 2
I have run a lot of surface analysis from relay to Mil connector and other contacts for aerospace purpose , galling / fretting / wear is a real problem even on top the range brand as Glenair ( check the price on Mouser $$$$$ )
Gold plating is not homogenous when done by electroplating , only PVD coating is and even by using PVD , gold is not a hard metal at all , best is to use Osmium as use on probe tip for IC /wafer testing , you can use Ruthenium which is better than Osmium.
 
But the worth case for contact is friction as in slip rings or test connectors

I link a old but interesting doc on sliding metal for contact

Regards
OS