NWI 31MHz interference

[Napalm]

Alright y'all.

I used to live in Lowell, and after dark I would get wicked noise floor increases around the VHF air and. I went through my entire house with a portable and couldn't find the source

Anyway, I moved to Crown Point a few months ago and I finally got my radios set up again.

Well no ****, same issues. I finally decided to try and track it down and guess what - it's actually strongest (insanely so) at 31MHz. I'm hearing harmonics of it at 121 and at 60 too

SS attached.

Any ideas? It's nothing in my shack because the lights stay on 24/7 anyway and turning them off doesn't help.

 

[Napalm]

Well the screen shot was too big but it's a wideband noise signal that takes up around 5MHz

 

[wtp]

i had a computer that caused some noise at 121.5.
i did not search the other bands.

 

[west-pac]

If you're using a portable radio, turn the power off to your house, and see if the noise goes away. It sounds like it followed you, so it's likely a device inside your house. A fish tank, heating pad, electric blanket, Alexa, wireless phone charger, etc... Start flipping breakers until the noise stops, then turn that breaker back on, go to that room, and start unplugging devices until the noise stops again.

 

[Napalm]

If you're using a portable radio, turn the power off to your house, and see if the noise goes away. It sounds like it followed you, so it's likely a device inside your house. A fish tank, heating pad, electric blanket, Alexa, wireless phone charger, etc... Start flipping breakers until the noise stops, then turn that breaker back on, go to that room, and start unplugging devices until the noise stops again.

Yeah it's the weirdest thing it happens after dark, but there's nothing that is light related 🤣. Nothing I brought with me anyway. I don't get it. I was hoping the whole house move would've cured it.

 

[AK9R]

You have to do what west-pac suggested. Kill power to the entire house. If the noise goes away, it's something in the house that is powered from the mains. If the noise is still there, it's a portable device in your house or a source outside the house. If the noise went away with the mains off, turn each circuit on one-by-one until the noise comes back. Once you know which circuit the noise generator is on, you can work through the devices on that circuit until you find the source. You have to approach this systematically until you narrow it down.

 

[Napalm]

I've done that 🤷‍♀️ I just don't understand.

 

[AK9R]

What don't you understand?

Starting at the beginning...Did you turn off the main breaker to the house? Did the noise go away?

 

[Napalm]

What don't you understand?

Starting at the beginning...Did you turn off the main breaker to the house? Did the noise go away?

No I don't understand why the noise still remains LOL. I get what you're saying.

 

[wtp]

is there a battery backup on or in any of the devices.
the in-laws router has a batter inside of it AND it is plugged into a battery backup.
and at my house there are (usually) 4 computers on 3 battery backups.
just saying that flipping breakers might not help.
or you have a 5Mhz 'birdie' in there.
birdie: internally generated noise.
try the portable near the radio.

 

[Chris155]

I’ve got high noise level on 11m at one end of our shop. Greatly reduces rx and it’s coming from outside. Go 100’ down the road and it’s gone. Turn the main off and it’s still there, I’m waiting for a local power outage to further investigate but I’m thinking it’s coming from lightning on a neighboring business, possibly a power line or transformer I guess.

 

[west-pac]

No I don't understand why the noise still remains LOL. I get what you're saying.

Do as directed and you'll understand why.