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Topband: Common mode noise on power lines?

To: <topband@contesting.com>
Subject: Topband: Common mode noise on power lines?
From: n0tt1@juno.com (n0tt1@juno.com)
Date: Fri, 10 Jan 2003 01:57:52 +0000
Hi TBers!

While on the hunt for some power line noise near my QTH,
I was thinking about common mode noise on antennas and
how that might relate to noise out on the power line noise...

We all know now that the transformers we wind for Beverage
antennas work best (as far as noise is concerned) if the primary 
is isolated from the secondary....this is to separate the "signal" 
ground from "trash" ground to help reduce noise in our
receiving antennas.

I'm pretty sure that the neutral of the high voltage line is 
connected to the neutral conductor of the 220v service line 
that runs underground from a ground-mounted transformer 
to my house.  At the entrance panel, the neutral is connected to 
a #2 (yes, #2) groundING wire that is permanently connected 
to a copper cold-water pipe where the pipe enters my house.

Now if there happens to be noise on the neutral wire somewhere
out on the power line, I would think that noise would be on the 
neutral wire (and most likely the hot leads) in my shack as well.

I know that a filter on the two hot leads AND the neutral would
certainly reduce the noise in the shack power leads, but would
the noise be even less if the neutrals were *not* connected together?

No, I wouldn't get in there and make any changes to the 
power transformer connections myself!!!!  hi hi  I'm just asking.  :)

73!
Charlie, N0TT

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