Crazy George wrote:
All the contact pressure in a BNC derives from the rubber washer inside
the bayonet ring. A good BNC should need quite a hard twist to make the
bayonet click into place... and in old surplus plugs, this springiness
does wear out.


Ian, you need to chop one apart again and look at the construction.
The contact pressure is provided by the wavy washers behind the
shoulder. The rubber washer, which is on the other side of the
shoulder, if anything opposes the contact pressure direction as it
'seals' against the end of the female cylinder.

Well, thank you, George - they do say "Learn a little every day"! I've
sawn up several BNC plugs, but never in that particular way.

Even though it's a wavy washer, the fact remains that the spring
eventually weakens (it happens it in C plugs also).


--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
Editor, 'The VHF/UHF DX Book'
http://www.ifwtech.co.uk/g3sek