Re: gEDA-user: Contact reliability

[Karel Kulhavy <clock@xxxxxxxxxxxxx>]

On Wed, Jan 19, 2005 at 01:51:30PM -0600, Igor Izyumin wrote:
> Karel Kulhavy wrote:
> 
> >
> >
> >Currently, Ronja is using wire nuts. We haven't yet noticed a failure 
> >tracked
> >down to a wire nut and they are mechanically rugged. Also they seem to 
> >perform
> >fairly well up to say 300MHz (when the incoming and outgoing cables are
> >impedance-matched coaxials) according to edge observations on oscilloscope.
> > 
> >
> Technically, these aren't wire nuts, they are terminal strips.  Wire 
> nuts are used (at least in the USA) as a sloppy (but code-compliant) way 
> to connect power wires together (you twist the cables together and screw 
> on the wire nut).  Here's a picture of some: 
> http://www.dansmc.com/wire_nuts.jpg
> 
> What's wrong with high-quality gold-plated BNC connectors?  If it won't 
> be exposed to weather, they will work very well.

We tried it. I don't know whether it was high-quality. The inner pin was
gold-plated, the outer shell silver-plated probably. It failed despite not
being directly on weather. It was deep in a horizontal plastic pipe where rain
couldn't in, but humidity and temperature could. It failed after 1.5 years.

The BNC that was indoor had problems too. Excessively high resistance was
between shell and panel (the panel was too thin so a ring of solder had
to be placed, and then tightened tightly). Also the cable wouldn't hold
properly inside the BNC connector. Frequent handling impaired the connection
between shield and connector body.

Cl<

> -- Igor
>