On Sun, 28 Nov 2004 12:15:40 -0500, "- XC -" wrote:

So my 2 cent theory is that the original antenna location lies in a power
line noise pattern null (or no low angle) and at the new height it's now in
a lobe.

Hi John,

The simple wavelength mechanics of that negate the premise. For any
structure, much less a power line, to exhibit a null due to a dipolar
distribution; then that would have to arise from certain constraints.
Chief among them is isolation from ground by a significant portion of
one wavelength, in this power line case 5000000 meters.

However, the noise is not 60Hz. In the case of the actual frequency
of the interference, it is equally unlikely to be emanating from the
power lines - from the 60 Hz generation end. It would necessarily be
emanating from a load that is using the line as an antenna (although,
not purposely except in your nightmare of BPL).

In this case of higher frequency nuisance, the same powerlines would
present an enormously long structure (unless the noise were snubbed at
the nearest isolation transformer). that would create a huge number of
lobes. And still, it is unlikely that any null to peak of those lobes
would match the characteristic of no noise to S-9 variation. As such,
the odds are on square-law ruled proximity. Where in quieter times
past the noise was 10's of feet away, with change that noise got
within inches. That, or the description of noise levels has been
exaggerated.

A noise survey should be performed with a simple handheld transistor
SW receiver. Walk around and listen. If push comes to shove, then
tie a string to the receiver, turn up the volume and hoist it up.
More can be determined by this than all the arm-chair prognosis.

73's
Richard Clark, KB7QHC