[Elecraft] Noise Nuller

[Jim Brown]

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