[RFI] Power line Noise

RFI Services mike at rfiservices.com
Wed Jun 7 13:50:38 EDT 2006

A Power line noise source will remain at a particular level. The level of
the source is determined by the actual hardware causing the arc and it's
proximity to the voltage and neutral conductors that become the transmitting
antenna for the noise. If the level is changing throughout the day, that is
due to multiple sources. Some are stronger than others due to the above
factors. Overall noise increases throughout the day because of the sun
drying out the hardware creating more opportunity for gap sources.
Power line sources radiate many frequencies at the source from below 1 meg
to over 1000 and the higher frequancies weaken as you increase distance.
However, this is effected by the physical position of your antenna as well
as the sensitivity of the antenna at a particular band. If the source is
weaker as you lower frequency, that could mean one of several things and not
limited to or necessarily in this order:

  The lower freq antenna happens to be in a null portion of the wave length.
If it were a little closer or a little further away from the source the
results would be different.
  The antenna used on the lower freq is not as sensitive as the higher freq
antenna being used.
  The noise source antenna (power co equipment) is more resonant at the
higher freq. and close by.
  The source may not be power line.

Regardless of the cause, the symptoms suggest it is not very far away and I
would suggest you use my "How to locate instruction" before continuing.


I would have responded sooner but for some reason I don't get most of the
postings. Sometimes even my own.

I hope this helps.
Best wishes,
RFI Services
Michael C Martin
6469 Old Solomons Island RD
Tracys Landing, MD 20779
mike at rfiservices.com

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