On Thu, 16 Mar 2006 13:13:38 +0000, Glenn Richards
wrote:

Roderick Stewart wrote:

In a conversation I had with a friend, we determined that power
cables are good at carrying low frequencies, and poor at carrying
higher frequencies. So RFI picked up at the substation won't make
it to your house, but interference sources in your house will cause
RFI to reach your kit.
How do you determine the electrical properties of cables by
conversation?

By applying known principles of engineering.

The losses at high frequencies are significantly higher in 2.5mm mains
wiring cable than screened co-ax, if you don't believe me try running a
composite video signal down mains cable (rather than 75ohm co-ax) and
see how far you get.

Just as far as you would with coax, if you match impedance properly
and don't mind some intereference.

It's like saying "how can you determine that an Audi Quattro is going to
go around a hairpin bend at 100mph faster than a Ford Fiesta", for example.

Indeed, but a poor analogy, since neither car will achieve this. Lack
of engineering knowledge noted yet again........

--

Stewart Pinkerton | Music is Art - Audio is Engineering