Major RFI any ideas

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OHIOSCAN

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Been fighting a major RFI issue the past few months, here is a audio clip. vI have tried every trick I know to try and track it down from wandering around with AM radio to shutting off electronics throughout my house. Its much worse in the afternoon then after dark. The entire HF band is effected but the worse bands are 20m - 15m. There are spikes that show up every 20khz on the SDR display.

Audio Clip
https://copy.com/mkYWfXhQxn8gXaFO

Any ideas what this might be

Shows up on muliple radios and antennas.

Thanks
Mike
 

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jackj

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Sounds to me like an arc. Do you have any gas-discharge lamps or high-intensity discharge lamps that are on when you hear this noise?
 

majoco

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Have you been outside with your portable? It may be a plasma TV from a neighbour. I had a lot of broadband noise from a TV set top box (even when turned off - I had to turn it off at the wall) and a heatpump power supply - got a newer TV and the heatpump people replaced the box - solved! Now all I need to do is to stop the kids next door turning their TV on when they come home from school at 3pm - fortunately they turn it off about 6pm!
 

popnokick

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To determine whether the source is in your house or somewhere else, wait until some afternoon when the noise is peaking and very obvious. You'll need a battery-powered receiver tuned to the noise. Then go to your circuit breaker panel and shut off power to the entire house using the Main breaker. If the noise disappears, you know it's something in your house over which you have control. If it's still there when the power is off to the house.... switch your power back on and head out with a receiver to track it down. It's not in your house.
 

OHIOSCAN

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I did move around the yard last night with an AM radio and noticed no increase in static. Flip of the circuit breaker looks to be the next step.
 

Boombox

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Was unable to play the clip.

But I've had RFI from a neighbor's plasma TV, which wiped out numerous frequencies from 7 Mhz to 13 Mhz or so. Was really bad on 40-41 meters, 31 meters had issues, too.

I've had a DVD player that put harmonics out all over the place, seemed to have a lot of them on 20 meters.

Unplugging it when not in use helped.

I had a printer that put out whines on 20 meters, even when turned off (probably self cleaning or whatever). I unplug it most of the time when not in use.

My router puts out hash in various places when I plug the cable that goes to the computer. When I use it just on wireless the hash from the router is lessened.

Bad CFL bulbs will put out AC sounding hash even if they are putting out light correctly, so don't rule them out. I had one that wiped out the AM band below 650 khz.

A trip around the house with a portable *SW* radio will help you find interference on the SW spectrum. Put it on one of the SW bands -- especially the ones you see affected (if your SW radio only picks up AM modulation, still use it, the hash should still show up).

The AM band won't pick up a lot of interference that occurs in the HF spectrum -- in my experience, anyway.

If it's a power pole arc or bad CFL bulb, an AM radio will probably pick it up. But if it's digital in nature (switching power supplies, routers, plasma TV's etc.) I've found that putting a radio on one of the SW bands helps better. That was how I found a neighbor's washer which put out alien attack noises all over the HF band from 49 meters to 21 meters. It was using the power lines as a radiating antenna. :)
 

popnokick

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In the course of getting ready for the "big switch" off on the Main breaker.... shutting down computers, routers, printers, TVs, etc. that should be turned off before you pull the switch... you may discover your source of noise.
I had same experience as Boombox with a washing machine. Was odd because it started up suddenly on certain wash cycles with a washing machine that had been fine before. Noise all over my scanner. And about a month later the washer's clutch and general operation of the washer failed. Replaced the washer... scanner noises gone.
Another current source of RFI that I have: My DirecTV older satellite receiver / DVR. The new ones don't do it, but the older one upstairs puts a consistent whine in the background of 146.655 mHz... until I reboot the DVR. It stays gone for a a week or so, but often returns. It may be pumping out RFI in the HF bands as well... haven't checked.
 

WA0CBW

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Popnokick made a good point about making sure you don't have some battery powered device like a ups, clock radio or weather alert monitor that uses battery backup when you pull the main breaker. Shutting things off today doesn't always "shut it off".
BB
 

kilokat7

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Ohioscan - I'm listening to your audio clip but the buzz seems intermittent. Were you fiddling with controls or is the RFI constant? If it's constant then do you notice it cycling at regular intervals - like 12 hours on / 12 hours off? Look for patterns and report back. You've got an SDR - look closely at the waveform of the RFI. Is it a sawtooth pattern on your spectrum display when you zoom in on it?

What I hear in your clip sounds ominously familiar to me. You may want to compare with my notes here:

https://www.youtube.com/watch?v=iqexZsorHsw
 

k9rzz

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If you can hear it with a portable AM radio, then use the nulling feature of the loop antenna to direction find. You should be able to triangulate the location.
 

OHIOSCAN

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Success on 1 of 3 RFI issues my new Samsung 4k tv was the source of part of my local RFI. I did unplug every other stereo, Blu-ray, router..... still have some nasty RFI static & popping between 12Khz & 22Khz but the buzzing in the audio clip was the new Samsung. I still have a chugging waveform 11-12Khz. The circuit breaker job is going to be a project, my home has an Generac generator that kicks on if I lose power I also have sump pumps running 24/7 (basements suck). Probable going to try shutting down some circuits not all. Going to find an HF portable with USB to also hunt RFI. Did try rotating the loop to null the RFI did not help. I think if I move it back 75-100ft from the house that should help.

I really appreciate the help, this RFI hunt is driving me nuts.

Thanks
Mike
 

scowl

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When I got back into shortwave a few years ago, I was shocked at how much RFI was all over the bands. I assumed it was caused by all the electronics people own now.

I took my receiver on a camping trip to the top of a mountain, miles from anything, hoping to get away from the interference. I heard exactly the same RFI all over the bands. There was hardly any improvement.
 

k9rzz

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I've got my antenna (fed with coax) about 75 feet from my house and at least 150 ft away from the nearest neighbor and my HF is pretty RFI free. I also keep the radio itself 20 ft away from my computer, it's walwart, my wifi hotspot, etc. Even my cell phone charger is noisy.
 
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