[RFI] Noise located and FIXED

[Dave Hachadorian]

About 10 days ago, a big noise started up on 80 meters, S9+15 dB with the preamp off and attenuator off on my K3. The noise was present 24/7.

Today I found the source, reported it, and two hours later, it is fixed!  Here was my tracking procedure.

I started out with the portable flag antenna from March 2021 QST.  The flag fed a 20 dB HF preamp that I have had for years (ARR P1-30/20VD).  The preamp fed a Tecsun PL-660 Shortwave Receiver.  I could hear the noise easily on 80 meters with that combination, and took a bearing on the null.  I drove in the direction of the null, and stopped to take additional bearings along the way, which told me that I was going in the correct direction.  The noise kept getting louder.

Finally I got to a point where the noise was so loud on 80, even with a homemade 30 dB attenuator inserted in the line, that the flag was not giving me a good null.  At that point, I switched to my old 2 Meter mobile rig, which can receive on AM mode (Kenwood TM-261A), and for an antenna I used the back four elements of an old 2 Meter 11 element beam, lashed to a broomstick.  Unfortunately, the S-Meter on the TM-261A does not work in AM Mode, but I used the loudness of the audio signal to guide me.  I soon came to a pole where I could hear audible arcing with just my ear, without even listening to a radio!  At that point I hooked a Tiny SA Spectrum Analyzer to the 2 Meter antenna, just to use it as an S-Meter.  The Tiny SA is not very sensitive, but it showed a very raspy signal of –80 dBm all across the 2 Meter Band when the beam was pointed toward the pole.

I called the power company and reported it as “arcing on a pole.”  I didn’t mention anything about radio noise.  They gave me an incident number, and said they would get on it.  Two hours later, I happened to look at Panadapter on the home station, and saw the noise disappear!  I zoomed back to the pole, and talked to the lineman, who told me that it was a bad connection.  He said he was going to put in an order to replace all of the hardware on that pole, which includes two transformers, lightning arrestors, and some other stuff.  A picture of the pole is attached, unless the reflector strips off attachments.  Incidentally, this pole is 2.1 miles from my house.

Many thanks to all of the contributors on this reflector who have provided a valuable education on noise locating!

Dave Hachadorian, K6LL
Yuma, AZ