Saturday, January 17, 2015

Driveby System - Possible NW source detected

2015-01-16 @ 4:30 pm CST 


  • winds calm (0-3 mph)
  • temp about 55F
  • skies clear and sunny

Yesterday I was out testing some tweaks to the Driveby System and after a long drive-test I came across an area that was causing the noise floor to rise considerably on both 50 Mhz and 144 Mhz.  From what I know, this is usually a good sign that there is a power line noise arcing source nearby.

It so happens that this location also coincides with an azimuth where I have noise from my home location.  The Azimuth I had previously noted on this blog was between 315 and 355 degrees from my tower.  After reviewing this test drive this morning I checked the Azimuth of this location using Google Earth's "Measurement Tool" and the Azimuth from my tower is almost exactly 335 degrees which places this noise source smack in the middle of where my large yagi at home had indicated there was a strong noise source on 50 Mhz.

This direction is particularly problematic when I'm attempting to talk to Japan,China,Korea on 50 Mhz in the summertime.

Here you can see the area I'd previously mapped out as a likely problem area from home.

I've marked the Azimuth and distance using Google Earth's Measurement Tool.

(click on the image to see a larger version)

Here is an audio recording of what it looks and sounds like from home.

And here is the mapped data from the Driveby System showing where is spotted high noise floors on 50 and 144 Mhz.

(click on the image to see a larger version)

And here is the graph showing the noise at this exact location.

(click on the image to see a larger version)