[RFI] RFI 80 through 10 meters every 10 KHz tracked down to neighbors house

[Dave (NK7Z)]

Hi Jim,

Another aspect of SDR viewing is that many other data points can be 
inferred by looking at RFI sources via wide spectrum SDR.  What you 
thought were several independent sources, are really just one source, 
that source that seems to follow sunup and sundown, may be related to 
solar, or street lights, that noise that come on at the exact same 
second every day, then ends at the exact same second that night, is 
probably on a timer, and all that implies...

Looking at RFI in an SDR prior to a hunt can save you days to weeks...  
One needs to view, and understand the entire RFI gestalt before 
hunting.  It gives you a real edge in location if you have a rough idea 
what is causing the issue, or when teh issue happens, or on what 
frequencies it is happening on.

I now, analyze every source, prior to hunting.  I do a two day scan, and 
sometimes, a week long scan.  I also take a full a spectrum of RFI 
recording once a year now, so I can compare last year, and see just how 
bad things have become...

Just hunting, or just looking at RFI on an SDR, are not the way to go 
anymore, using BOTH options will help you locate RFI far faster, and 
understand your RFI environment far better, than either alone.  See:

https://www.nk7z.net/sdr-rfi-survey-p1/

It's a statistical universe, so when I see a RFI source on an SDR, I 
take a best guess at what it might be, I never assume I am right, but as 
I locate more, and guess more, I am getting a lot better at guessing 
what the source might be...

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist, RFI
ARRL Asst. Director, NW Division, Technical Resources


On 12/1/24 17:19, Jim Brown wrote:
> On 12/1/2024 4:09 PM, Don Kirk wrote:
>> Just FYI, and this case once again proves that I should never guess the
>> source as I would have guessed wrong.
>
> Yes, BUT -- Studying the RF spectrum and waterfall (NOT the audio 
> spectrum) can yield clues about the NATURE of the noise source -- 
> electronic, power control, power line, or lightning static. Is it 
> impulse noise or not? This information can give us clues about how to 
> locate it. Most electronic noise must be chased on the frequencies 
> where we hear it, while we can zero in on most impulse noise by going 
> to VHF and UHF when we get close.
>
> Great that you're using an SDR's spectrum display!  That's a great way 
> to make sure that the source we have found is what we're hearing at home.
>
> Thanks for sharing your experience. Quite valuable!
>
> 73, Jim K9YC
>
>
>
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