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Can anyone help me identify this RFI?

FredTx63

Well-Known Member
Oct 17, 2015
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I hear it on all 40 channels CB/11 meters (all channels at once) and most of 10 meters. On 11 meters it's stronger on every third channel it seems.

The noise is best described as a high pitch oscillating sound. Sometimes it speeds up, sometimes it slows down. Lately it's been present almost 24/7. Occasionally it disappears, but not often.

I've turned the breaker off at my QTH and checked various CB & HF radios via battery and the RFI persists. The signal isn't very strong but it makes listening very annoying.

I'd LOVE to find the source.

 
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Here's another example of it when the oscillating sound is slower



Anyone have any clue what this could be? I'm going to find a handheld digital shortwave radio this weekend so I can get a feel for what direction it seems to be coming from.
 
If you unhook the coax at receiver does the does it go away? Almost need a small hand held unit to see if it picks up anything in the house. Could also be a neighbor nearby that has an invisivisble fence. Hard to say. Have you tried turning off each breaker in the house 1 at a time to see if this has an effect?
 
Thanks for the reply, Crusher.

I have turned the main breaker off to my house (no power at all) and the signal is still there (radios running off of battery power). The signal in question definitely goes away when I remove the coax from any of my radios that I'm using.

The noise is pretty unique compared to other interference sources I've heard others asking about. Most of the time someone's got some kind of buzzing or hash type sound they are trying to locate.

Will work on getting a handheld and hopefully it picks the signal up as well. My antenna is pretty high up at almost 100 ft to the tip of the 5/8 wave. I guess the signal could be pretty far off with my antenna that high.
 
Do you have a mobile set up? If so, drive around the neighborhood a few blocks in every direction and see if you can locate it in the neighborhood. At at least see if you can better pin point which direction it is coming from.
 
It doesn't sound electrical to me but more like a data link. It may be a neighbor with a wireless weather station, wireless modem or other wireless device sending a data stream of dirty rf.
 
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the "slow" one sounds like SSTV,.... Scottie DX mode.... two tones 1500 and 2300 Hz

in fact, I injected it into my MMSSTV program set to AUTO Rx and it locked into RX mode for scottie dx.....
 
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Do you have a lot of house in your neighborhood maybe there is a small grow setup a few houses away. A large grow operation that is a next door or 2 houses away would put out a lot more noise that is a lot louder
 
Heard that before, coming from 5 houses away. AEP technician said grow operation. Once the RFI dude knocked at the door to tell them about my complaint.....The noise stopped. Imagine that.
 
Heard that before, coming from 5 houses away. AEP technician said grow operation. Once the RFI dude knocked at the door to tell them about my complaint.....The noise stopped. Imagine that.

Hmm.. All the videos with examples of grow light/ballast RFI that I've seen have all been more of a buzzing sound.
 
Very interesting. I feel for you. To imagine I ever complained about the 1s-unit clicking sound I had for about six weeks seems absurd.
I never did track it down. It has periodically returned but quickly drops out.
Purely out of quriously does it affect SSB and AM in the same manner? Good luck my friend
 
There is another possibility, FredTx63 have you pissed anyone off recently on the radio? I have seen in the past where someone will take an old junk micro cb radio, set it up on a 9 volt battery, solder it to transmit a constant noise. They then wrap it in duct tape and throw it in some bushes or on the roof of the house you want to recieve this nasty signal. The guy spends the next week wondering where this strange signal is comming from.

Here is another example.



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I've a noise from a neigbors house behind me. It does affect both AM and SSB modes. On AM I get an S7+ noise, on SSB it's about S3+. It's a constant noise, 24hrs and 7 days a week. It has not stopped for the lasted for over 8 months now this go around. It did stop for a bit, and noise levels were nothing, very quiet, then it just returned one day. It is annoying as the neigbors house that the noise has been emanating from, aren't the friendly type and others on the same street let a water main leak go for several weeks before I called the Water Dept. myself and let them know about the issue. Also have found bad cable coax and know there is more bad coax runs as the tech that came to a service call I made is a friend. I do know the noise is on several different frequencies including amateur bands as well as all of 10-12 meters and above/below on different freqs. from 3-54mhz and also on the chef freqs as well. Only real bad on my vertical. On my dipoles I don't hear it at all on the N/S one but the E/W one catches it a bit as it points at the house behind me. One driven around with an AM radio, used my hand held AM radio and like posted they are great tools to help track the noise to its source. It does make the radio experience bad at times, but for now I am only running my dipoles so it's not much of a bother. Just can't reach my locals out past 2-3 miles. But at least I can still shoot some dx!! Anyway, hope you find your noise issue FredTx63!!
 

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