[Elecraft] Noise Nuller

[David Gilbert]

I'm not sure what you're saying, Jim, but I ever said that all noises 
were similar.  In fact the application I built literally requires the 
user to spend a few seconds training the application on the specific 
noise at hand.  And if the noise changes significantly you'd have to 
retrain it.

But this application doesn't discriminate based upon the SOUND (i.e., 
amplitude/frequency profile) of the noise.  It discriminates based upon 
the spatial PHASE of the noise, just as many beamforming microphones do 
from your professional audio world.

Did you watch the video or try the application?

73,
Dave   AB7E



On 7/19/2026 9:36 PM, Jim Brown via Elecraft wrote:
> On 7/19/2026 8:01 PM, David Gilbert via Elecraft wrote:
>> I tried it with FT8 a couple of times but I the local solar panel 
>> noise I hear is pretty narrow band ... just a few KHz wide.  It moves 
>> around a bit but so far I haven't been able to find it overlapping 
>> the FT8 frequencies.  My noise otherwise is pretty low.
>
> Hi Dave,
>
> Electronic noise sources vary widely in their spectral and dynamic 
> characteristics at RF. Some are, indeed, rather narrowband, but many 
> are not. Some are stable in frequency, some are not. Many are unstable 
> in frequency, quite rich in harmonics, and are show up as drifting 
> humps of noise thanks to frequency modulation. It is totally 
> unreasonable to say that a noise at one QTH from one source or type of 
> source is representative of all others.
>
> I have, at one time or another, experienced all of these sorts of 
> electronic noise. The only noise I don't have is impulse noise 
> generated by equipment on the utility's distribution system (knock on 
> wood).
>
> A year or so ago, I bought a noise reduction device built by a Greek 
> ham that the guys at the KP4AA said solved their serious problem. I 
> found no noise sources on which it did anything. Neither did K6XX, a 
> serious contester and engineer at Elecraft. Nor did NA6O, a retired EE 
> whose experience was EMC testing, and is one of the guys maintaining 
> the N6RO superstation. A few months ago, I saw an add for it from a 
> company who might have taken it over, and who made clear that it was 
> designed to address impulse noise.
>
> 73, Jim K9YC
>
>
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