[Elecraft] BNCs

[Jim Brown]

On Mon,10/13/2014 9:30 AM, Peter Torry wrote:
> It may not make a difference to performance on HF but it does matter 
> because the centre pins have different diameters of solder pot / crimp 
> barrel to match the cable impedance used. 

What matters is that the connector match the physical dimensions of the 
cable so that it can be properly installed, and this is true regardless 
of impedance.

> Also incorrectly mated connectors risk damage to their centre 
> connectors by forcing the engagement.  Use the correct connector for 
> the cable in use. 

Zo depends upon o.d. of the center conductor with the connectors mated, 
and would be established by the o.d. of the female pin receptacle, not 
the o.d. of the male tip. Although I have not studied the mechanical 
Standard for 75 ohm BNCs, I would VERY surprised if the dimensions of a 
proper 75 ohm connector would prevent it from mating with a proper 50 
ohm connector. Have you studied such a spec?  I'm quite active in 
international Standards work (with the AES) and that sort of 
incompatibility is something we make certain to avoid!

73, Jim K9YC