Hi, Mike.
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.
We're in the middle of our monsoon season now so I have all my antennas
disconnected, which means I can't even do a proper simulation. Sorry ...
The app is pretty easy to set up, though ... but of course it needs two
antennas (almost ANY two antennas) and two phase locked receivers to
work. If you have that you should be able to decide for yourself
whether the app helps or not. Keep in mind that anything that's from
the same direction as the noise is going to be discriminated against
almost as well as the noise.
73,
Dave AB7E
On 7/19/2026 5:01 PM, Mike Fatchett W0MU via Elecraft wrote:
Have you test the app with FT8 or FT4. I have found that line noise
or hash will impact receiving. They say that FT modes can handle the
noise but I have found that a WNB or NB is required when a particular
noise is present.
Mike W0MU
On 7/17/2026 5:02 PM, David Gilbert via Elecraft wrote:
All true.
And of course if the noise is in the same direction as the signal you
want to receive these spatial discrimination techniques aren't much
help. I found that out early on when testing the first version of my
NoiseNuller app. I was listening to the local solar panel noise
while also transmitting a "desired signal" using a third antenna, but
I didn't get much discrimination at all. It turns out that the
spatial phase was the same for both, and when I transmitted the
"desired signal" using a fourth antenna located elsewhere on the lot
it all worked.
73,
Dave AB7E
On 7/17/2026 1:15 PM, Jim Brown via Elecraft wrote:
Exactly right. And I've written extensively about techniques both
find and suppress sources. k9yc.com/publish.htm
But the real world part of the multiplicity of noise sources
surrounding us is that only one can be nulled at a time, and in my
experience, only on the low bands. An important limiting factor with
some sources is that they are physically broad as a function of
wavelength! For example, an array of solar panels, with or without
inverters, and their wiring.
73, Jim K9YC
On 7/17/2026 12:58 PM, David Gilbert via Elecraft wrote:
Of course that's the ideal solution, and of course lots of people
have done (or tried) exactly that and it often works. But I doubt
very many people are going to have much luck getting their neighbor
to replace their cheap solar converters with better ones, and I
doubt many people are going to convince the owners of the adjacent
condo to replace their cheap wall warts ... especially since lots
of neighbors aren't all that happy to have hams next door in the
first place.
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