K8RI's post on this topic finally prompted me to raise a
question that's been bothering me for some time.
Why is powerline noise vertically polarized? Power lines are
horizontal. Yes, it's true that there are vertical runs to
ground, every few poles. But why is the noise assumed to be
vertically polarized?
Is it because that noise seems louder on our vertical antennas?
Our UNBALANCED vertical antennas? If you read w1his's white paper
on common mode chokes (yccc.com), you'll find that he's reduced the
received noise levels substantially by decoupling the feedline.
Perhaps I should have said our POORLY DECOUPLED UNBALANCED vertical
antennas?
George Henf, who founded GAP antennas, maintained that power line noise
was horizontal, for the most part....and that his off center fed verticals
were quieter than a dipole. I didn't challenge him, but the voyager and
challenger models I put up to write his manuals, were no noisier than
my 40m dipole @ 50'.
I've pretty much accepted the common wisdom that manmade noise tended to
be vertically polarized, since I became involved with ham radio in 1959.
And in the ensuing years, I've heard the 'wisdom' often repeated...but
never seen any studies supporting the belief.
Anyone care to wade in?
n2ea
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