[RFI] Name that Noise

Gary Johnson gwj at wb9jps.com
Fri Sep 20 14:44:40 EDT 2019

I think you’ll need to walk around with a DFing loop and try to triangulate the source. There is a design on my RFI pages that would work nicely with your KX2. http://wb9jps.com/Gary_Johnson/RFI_files/Handheld_DF_Antenna.pdf <http://wb9jps.com/Gary_Johnson/RFI_files/Handheld_DF_Antenna.pdf> 

Offhand, it sounds like it has some modulation on it that makes me think it’s not just a simple switching supply (e.g., a lighting device) but rather something associated with a more complex system. For instance, the SolarEdge system next door sounds a bit like that because it’s leakage from their control signals. But who knows...

-Gary NA6O

> Date: Thu, 19 Sep 2019 12:12:41 -0700
> From: Dana Roode K6NR <dana.roode at gmail.com>
> To: rfi at contesting.com
> Subject: [RFI] Name that Noise
> My bigger problem is a dreaded 40m noise from the South; that is coming
> from a group of houses about 1200 ft away.  Earlier this week I was
> orienting a Pixel loop antenna to null the noise and made the following
> video of my KX2 as I tuned through the band:
> Its AM, and there is some wind noise you have to ignore.  The signal is
> strongest around 7mhz, peaking every 300khz or so.  Its weaker at 10mhz,
> and even weaker at 14mhz.  I think I hear it at 3.5 but there is lots of
> other QRN to hear as well.
> Any thoughts on what this is?  A friend traced it once to a house with an
> electric fence, but I wouldn't think those would have peaks ever 300khz.
>  Dana

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