High Noise Levels on 20 and 40

[chrissim]

Hello:

Not sure how to eliminate this problem. I live in a newly developed subdivision with a severe HOA. I'm limited to wire antennas. I've put together two dipoles (both with a 1:1 current balun), one for 10 and one for 20, both at 50 feet. I also use a G5RV (inverted V) 60 feet at the apex, that's been commercially made.

On 10 meters, my 10 meter dipole and G5RV are in the S1 to S3 noise level. More than adequate. The G5RV on 10, 12, 15, and 17 meters provides a S3 noise level. Again, this is fine.

By time I reach 20 meters, the G5RV and the 20 meter dipole I made are both identical in noise level. S7. On 40, I'm a constant S9 with the G5RV. I imagine if I made a resonant dipole for 40, it would be the same.

I feel confident it's not the construction of the antennas. I use LMR 400 on the G5RV at about a 100 foot run. I use RG8X for the two home made dipoles, about 100 feet (I know I'm incurring losses, but that's another issue).

I walked around the outside of the house with a portable trying to find the noise and I got nothing. I also turned everything off in the house at the breaker with the exception of the room in which my radio gear is equipped. running only the transceiver and everything else pulled from the sockets, same thing.

It simply sounds like static, between S7 and S9.

If you please, my questions are:
Why would 10, 12, 15, and 17 be fine, but by time I reach 20 and 40, it's out of hand?
Is this something I should consider calling the electric company over? Do they even care?
What could I be overlooking?

Thanks for your advice.

 

[kj3n]

If you please, my questions are:
Why would 10, 12, 15, and 17 be fine, but by time I reach 20 and 40, it's out of hand?

Because, depending on the noise type and source, as you go lower in frequency, the further away the noise source can be. I've had power line noise sources that were undetectable at 15m, barely noticeable at 20m, but wiped out 75m because the actual noise source (in this case) was 1500 feet down the main road. In another case, I had power line noise from a source 3 miles away that only bothered 160m, while not being detectable on any other band.

Is this something I should consider calling the electric company over? Do they even care?

They should care and in most cases have to care. There are FCC regulations in place that say they have to make sure the power lines are reasonable clean of noise. However, until you can narrow down a source, I wouldn't bother calling them. They're not too fond of wasting time on a vague "I have power line noise" complaint without having somewhere to start.

What could I be overlooking?

A whole slew of things. There are many questions in need of answers. For example:

It's a bit unusual to have "static" of the levels you describe on 40m. More than likely, it's either power line noise, or a neighbors electric fence, or maybe a plasma TV next door. Can you identify the noise type from the samples listed here? Sounds of RFI

Are the electrical services underground, or on poles? Are they a combination of both?

What type of portable radio are you using to find the noise source?

Given the noise levels you state on the other bands, I'd lean towards power line noise coming from anywhere from 100-500 feet away. Have you walked around the neighborhood?

 

[k9rzz]

Is it power line noise (constant buzz/roar, across all frequencies equally) vs a white noise (hiss) vs a electronic frequency specific type noise?

Power line noise means losses to the power company and they will be more than happy to swap out an insulator or two.

I once had S9++ power line noise and the faulty insulator was 2 blocks away, another time I visually could see a bad insulator arc and smoke. I called 911, a fire engine came by in minutes to monitor the situation, and within 30 minutes the power company guy was up there fixing it! Ahhhh peace and quiet again.

Take your radio and slowly drive around the neighborhood. You'll find it.

The old timers used to WHACK the offending pole with the blunt side of an axe, but I would just call the power company and let them do it. =:^]

 

[chrissim]

Thank you for the response.

The noise sounds like a hiss, nothing more. I've listened to noise samples before and this is nothing like that.
All of the utility lines are buried - nothing overhead in the neighborhood.

Would you please suggest a frequency and mode to use as I walk around the neighborhood? I've been using the AM broadcast spectrum. Perhaps something else would be better. I use an old Radio Shack DX 398 to try to find the noise.

Thanks again!

 

[k9rzz]

I would listen to as close of a frequency to where you find it to be loudest at home, in whatever mode you hear it best in. Start right from your house and work your way out. Let us know what you find! :^)