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Joined: Sat, Apr 4th 1998, 00:00 Roles: N/A Moderates: N/A

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Noise location question Mar 28th 2016, 14:00 2 1,345 on 28/3/16

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Noise location question K5ESW on 28/3/16
I’ve had some experience with locating powerline noises over the years, but I'm a bit puzzled by a recent one. I noticed broadband noise of a few S units from 160 m through 10m.

I first noticed it on 12m when I pointed my beam to the northeast. I have an MFJ-856 noise locator, which is a portable 3-element yagi with an attached receiver for the aircraft band around 135 MHz. It has a strength meter and headphones can be plugged in. Standing not far from my tower, I found that I could hear noise weakly on this noise locator, and the noise peaked in exactly the same direction as my larger tower-mounted beam.

I drove to various locations and used the small yagi to get fixes on the noise source. On a map, the headings converged around some stores on a busy highway about three-quarters of a mile from my home. Around power lines in front of the stores, the meter on my noise locator was about pegged. I also took with me a Tecsun PL-660 portable receiver. It does not hear the noise at my house on 12m, but it has only short whip antenna. When I tuned to 12m near these power poles where the noise was so loud on my small yagi with aircraft band receiver, I expected the 12m noise to be loud because I was so close to the noise source, but I didn't hear noise.

Now I wonder if the noise I located at power poles near the highway have anything to do with the 160m - 10m noise causing me problems at my home station when working weak signals. It could be a coincidence that the tower-mounted beam headings for the 12m noise and the beam heading on the aircraft band beam happened to be the same. Do you see any other possibilities?


73,
Paul
K5ESW

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