> wrote in message
>> That is certainly a good theroretical design goal but reality is the
>> power company and the telco/cableco share the same poles and
>> underground ducts so their wires do run parallel for hundreds of
>> miles.
>> If you are getting ingress on coax or twisted pair, you have another
>> problem. I bet you could see it using TDR in a second.
>
>On poles, they are often a few feet a part. What is the range or field that
>is going to matter? I would imagine the difference between a couple of feet
>and touching makes a difference in signal, magnetic field or whatever.

It will still add up and on a power pole in a neighborhood you usually have a single 13kv unbalanced primary. In your house they use balanced cables with a hot and neutral or 2 balanced hots.

When I was doing communication wiring we set up a torture chamber in the office and did everything you "can't" do like looping LAN cables around florecent fixtures and running along next to the building feeders from the transformer. We found that if everything was terminated properly it had zero effect. It was only when we had other problems that it screwed up the data. This was using test programs that collected LAN statistics with unusually high loading. Again, the TDR flagged these problems immediately. Coax and twisted pair are very good at eliminating outside interferance