On Mon, 7 Jun 2010 14:11:58 +0100, Gaius wrote:

In article fda40c34-830f-438d-830e-0c1c23d2bc44
, says...

BNC's are still 50 or 75 Ohm. Old versions had different diameter
centre pins in order to acheive the correct characteristic impedance.

Can you (or anyone !) provide some evidence of this, in terms of actual
measurements or manufacturers' specifications showing a difference in
the "Old" versions ?

I downloaded the mechanical drawings from the Amphenol web pile and
found that the center pin diameter is missing from the drawings. I'll
look elsewhere when I have time.
http://www.amphenolconnex.com/products/bnc.asp

I have a box full of 75 coax patch cables I salvaged from a radio
station cleanup. They all mate fine with a 50 ohm BNC jack. The only
difference is that the 75 ohm plug has no dielectric, while the 50 ohm
jack does.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558