Michael Lawson wrote:
Are you speaking of the signal level on the power lines
outside the house, or as it flows through into your house?
It would be nice if you are talking about the latter, and
have the local power company come out and put a filter
and/or power conditioner on your service entrance.

A filter at the service entrance would only serve to make the wires
to the pole a great big antenna. It would either put a very high
impedance at your end, helping the electric field, or a very low one,
helping the magnetic field.

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Consider http://www.clifto.com/goodguys.html before you vote.