KA1GJU Super Stations #2,#3 & #4 have QRM

[KA1GJU]

I have powerline arcing once the lines dry out, and it makes the lowbands nearly impossible to RX during the daytime. Actively chasing it down with my RDF loop antennas and have it narrowed down to my neighbors driveway where there are at least two power poles, and one transformer. Once I get permission to walk up the driveway and locate the exact source, I'll advise the electric company of their issue. It's arcing randomly, with long stretches of continuous arcing... so at times it's hard to get a good fix on it.

This is 80m this AM a few hours after local sunrise:

[KA1GJU]

As it turns out, the neighbor is having the electric company out this week to connect a new service to their barn. I called it in and created a "ticket", so they may possibly fix it when they come out for the service drop. I have it narrowed down to a single pole, where a single 7200V line sits atop the pole. There's a wire wrap and insulator up there only. I have had wraps go bad before showing up ONLY during daytime, dry conditions (opposite of cracked insulator). This one started out very intermittent, but now it is continuous last night and into today and we had mist/dense fog last night and it's still very damp.
Peak noise is in the the 3.8 to 4.5MHz range, S-8 (-80dBm).

Fingers crossed this will get rectified... no pun intended!

[KA1GJU]

Here's what it looks like on my IC7300 with a resonant 75m antenna about 500' from the pole.

That's an S9+10dB noise!

[Max]

Here's what it looks like on my IC7300 with a resonant 75m antenna about 500' from the pole.

That's an S9+10dB noise!

Ouch! Let's hope the electric company sort it out when they visit.

Max

[Max]

As it turns out, the neighbor is having the electric company out this week to connect a new service to their barn. I called it in and created a "ticket", so they may possibly fix it when they come out for the service drop.

Kriss, did they come and fix it?

Out of interest, with a very strong broadband noise like this, how did you track it to an exact location? Would be interested in your technique and what kit you use to track it down? Maybe you could hear it physically arcing on the pole?

Max

[KA1GJU]

Hello Max!

I've been out of town for +3 weeks (4 day work trip, 12 days working at an airshow, 3 day work trip) so trying to catch up.
I used to have issues with the QRM when everything was dry. After sunrise and the AM dew dried off the lines, insulators, etc, the arcing would be intermittent. Progressively getting worse to full time noise. Once the sun had gone down and dew formed, the noise would go back to intermittent and eventually stop altogether. Been like that for about a year, and could never really pinpoint the source.

Then suddenly it jumped to S9+10. Using my DIY 1m active loop (for DX DFing) I narrowed it down to the neighbors driveway. Using a laptop, SDRC, Airspy HF+, and the Youloop antenna, all the nulls pointed to one particular pole. With her permission a got bearings to the same pole up to about 100' from it. Any closer and the null would be nonexistent. Shaking the pole via the guy wire or a firm kick (creosote soaked wood pole) would set the noise on/off with the shaking.

As it turned out, the neighbor was to have the power company come out and place another pole and get power to her barn. I informed the power company about the specific pole (they are numbered) to have them look at it while installing the new pole a few hundred feet down range. The pole was placed while I was gone, and not sure if they worked on the suspect pole. But in the past few days while on the road at work, I have been listening to Super Station #2 which is the nearest server and it has been relatively quiet. Today it is raining/snowing/sleeting, and all is good except for some new noises on 30m through 10m spaced every 40kHz:

Screenshot-2025-04-12-105003.jpeg (237.59 KiB) Viewed 10231 times

I may have a SPS out in repeater shed failing or the neighbor has something on in barn. Just another fox hunt for the loop antennas!