[RFI] Line noise update
paul at n1bug.com
Tue Oct 9 17:58:36 EDT 2012
On 10/09/2012 11:41 AM, Jim Brown wrote:
> Great news on your progress, Paul. Ours is such a noisy world that it's
> become really common for our noise levels to be the combination of many
> sources. Now that you've knocked down the strongest ones, you're
> hearing weaker ones.
My description wasn't very clear. The remaining 'mystery' noise is
very intermittent and was clearly audible above my several constant
sources. I could also see its group of noise pulses rising between
and above the others on the scope when it kicked in. The trick was
as a I moved toward it, the strength of the constant source just
beyond came up more quickly than the 'mystery' noise, eventually
masking it as I approached. As you know they are all a little
different in how they radiate, how much they are conducted along
lines, etc. I discovered things can get really interesting when you
are tracking multiple sources in close proximity to each other! I'll
eat my hat if the remaining issue doesn't turn out to be on the 46
kV line (a number of clues suggest that), but it seems to radiate
from one point only; it isn't conducted along the line and radiated
from multiple structures like some of the others.
> Don't rule out the possibility that some of those
> that remain may be electronic noise generators in homes.
Absolutely. I've got a few of those, too, which I will begin to deal
with shortly. I think one may be an electric fence, but more
investigation is required to confirm that. Another is some unknown
device in a neighbor's home. The latter was a second or third tier
noise that only became known to me after the strongest constant
power line sources were eliminated.
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