TopBand: ARRL 160 at OT7T - ON4UN

John Devoldere (ON4UN)
Sun, 07 Dec 1997 15:03:35 +0000

Hello fellow top-band contesters,

Since a few months a chemical plant, located about 7 miles from my QTH has
installed new electronically regulated (speed control) electrical motors
(up to 200 KW in power). They were installed without observing the
installation guidlines and rules from the manufactures, using long fed
lines (over 100 ft, while max 10 ft is presecribed!), which make nice
antennas, and without the necessary filters and of course not using
shielded cables.

In the immediate vicinity of that factory the noise generated by this
equipment is 60 dB over S9, on a small loop antenna. At my QTH, it reads S7
(approx 30 uV) on a quarter-wave vertical. Problem is that this factory is
located 290 degs fropm here, which is exactly my stateside direction.

All of this to explain, why I only could hear the top layer of the
US-sinals, and why I was only on a few hours.

Our autorities have been visiting the site, and will be back in about a
week with specilists (university professor etc) to make an evaluation and
prescribe the necessary action. 

A similar thing happed about 18 months ago, in the same plant, and then
they installed the correct filters etc, and all noise was gone.

The noise sounds very much like the noise we all know that us generated by
a badly shiuelded PC. It has peaks and valleyts, and in this case, the
peaks are 3 KHz apart. In my QTH the signals are S7 from 1500 Khz to well
above 2000 KHz...

And I live way out in the country... the closest factory (palnt) is 7 miles

I know many stations called me when I was on last nite, but you had to be
S7 to overcome that horrible noise. Evetually I was so frustrated (you
too?) that I gave up and went to be..

I'd just like you to know what is the problem here.

Hope Santa Claus can fix it!

73 and good DX / contests to all.

John, ON4UN - OT7T
*            John Devoldere, ON4UN, AA4OI, OT7T               *
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