I spent most of my holiday vacation tracking down various electric fence
noises. This is starting to turn into an obsession - and I feel like my
work will never end.
However, I think I have learned a few things and am hoping to create a
web page so I can share the information with others who have similar
problems.
I am sure some of you have valuable experience as well - and I would like
to hear from you. I will list as many case studies as I can in order to
give concrete examples on how fences were located and fixed.
One problem I had - is that I can hear something around 8 or 9 fences at
the same time during the day on 160 meters. I believe that at least one
of these fences is over a mile away - and perhaps some of the weaker ones
are even furthur.
This "symphony" of fence noise needs to be broken down so you can determine
how many fences you are actually listening to - and what the "beat" is for
each. This will enable you to drive around listening to the various fences
around you with your AM radio - and see which ones match up with the ones
you are hearing. I have found at least one fence that is about 1/2 mile
away that is pretty loud on the AM radio, but doesn't seem to be showing
up in the symphony.
My first attempt at isolating each fence took many hours of work. I
recorded about 10 seconds of the symphony and would look carefully
for a repeating pattern that would indicate a single fence. I would
remove the clicks for that fence out of the pattern and then try to
find another fence.
I am happy to report that I have now written a piece of software that
does this in a few seconds. It even takes the .WAV file input and
detects the clicks on its own, so you don't have to do this yourself
using a .WAV file editor.
I would be interested in having some beta-testers for this software.
So, if you can hear a few different fences, you can try this program.
http://www.kkn.net/~tree/NOISE.EXE. Make a 10 second or so recording
with 16 bits at the maximum sample frequency. Try to get a sample that
only has the clicks - using your widest filters - in the AM mode.
Crank the RF gain down so that you don't get much background noise.
Tree N6TR
tree@kkn.net
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