[RFI] Short wideband noise bursts 3-100+ mhz

Dale svetanoff at earthlink.net
Thu Sep 26 00:53:01 EDT 2013


Aaron,

A has been stated several times prior on this reflector, spend your time locating, not speculating as to the source.  There are so many possible causes, BUT, before you try locating, be absolutely certain that the problem is not within your own house.  Assuming that you have a radio that can hear the noise and which operates from batteries, kill ALL power in your house and confirm that the noise remains.  If that is the case, then it is time to start locating.

You have already found that FM will not work for this problem.  You will need to take that air band scanner (or any other portable type of radio with VHF/UHF AM capability) and go walking.  Once you have narrowed it down to a specific house, you then have to decide if you are going to try talking with the owner(s) or continue to suffer.  Let us know what you find and how it resolves.  You do mention wide bandwidth, so if you are lucky, it might be a power line issue and you may have better luck with the power company than with individual home owners.

73, Dale
WA9ENA      


-----Original Message-----
>From: Aaron Kreider <aaron at campusactivism.org>
>Sent: Sep 24, 2013 5:35 PM
>To: rfi at contesting.com
>Subject: [RFI] Short wideband noise bursts  3-100+ mhz
>
>I've got very short noise bursts coming from a nearby house.  Unlike my 
>other noises (power supplies, general hash) this is the first one that I 
>can really narrow down - as I can hear it from 3-110 mhz and it is 
>probably coming from one of six houses.  The noise has a range of 
>several hundred feet.  On my antenna it is around S5-S7.
>
>It is extremely broadband.  I'm guessing that is has a 100 mhz+ 
>bandwidth like a spark gap transmitter.
>
>It is probably audible above 110 mhz, but I cannot hear it in FM mode 
>and the air band is the highest band that my scanner can get in AM.
>
>It sounds like a click in AM.  It is on 24 hours.  It is occurs roughly 
>every second, but not in a regular pattern (ranges from several per 
>second to a gap of 3-5 seconds).
>
>I'm guessing I don't hear it below 3 mhz because other noise dominates 
>at those frequencies. However I am surprised that it doesn't come 
>through at all around 500 khz which often has a low noise level.  So it 
>is possible that the signal is weaker at lower frequencies.
>
>Any ideas what it could be?
>
>For a while I was thinking it could be lightning, but lightning bursts 
>are much longer and don't continue into the higher frequencies.
>
>Aaron
>
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