[Elecraft] More on NoiseNuller Latency

[David Gilbert]

You are probably right.  It  just won't do full break in then of course.

But everything is a tradeoff, right?

73,
Dave  AB7E



On 7/29/2026 1:37 PM, Gwen Patton wrote:
> I still say turning off the thing while transmitting would solve it. 
> You don't need to process the side one.
>
>
> -=-=-=-=-=-=-=-=-
> 73,
> Gwen, NG3P
>
> On Wed, Jul 29, 2026, 15:12 David Gilbert via Elecraft 
> <elecraft at mailman.qth.net> wrote:
>
>
>     ChatGPT tells me that almost all of the latency is due to the
>     frame size
>     of the FFT processor.  At the application's default sample rate of
>     2024
>     that works out to be just barely under the 43 msec I measured.  That
>     sample rate is needed to do the actual processing with decent
>     results,
>     so the best workaround seems to be a two path approach ... use a much
>     lower frame size when the sidetone is detected and the default frame
>     size when it isn't.  Theoretically the latency could be dropped to
>     maybe
>     less than 5 msec.
>
>     And as you say, if everything was implemented inside the radio, the
>     keying itself could control that with almost zero latency.
>
>     73,
>     Dave   AB7E
>
>
>
>     On 7/29/2026 10:30 AM, Walter Underwood via Elecraft wrote:
>     > The algorithm probably has inherent latency regardless of where
>     it is implemented. This is one of the challenges of digital
>     processing.
>     >
>     > But…if implemented internal to a radio, the sidetone could
>     bypass the processing.
>     >
>     > wunder
>     > K6WRU
>     > Walter Underwood
>     > CM87wj
>     > http://observer.wunderwood.org/ (my blog)
>     >
>     >> On Jul 29, 2026, at 10:03 AM, Gwen Patton via Elecraft
>     <elecraft at mailman.qth.net> wrote:
>     >>
>     >> Can it just turn off when sending CW? When you go back to
>     listening, turn
>     >> it back on? It doesn't need to be on while you're manually
>     sending CW, you
>     >> can't hear the noise anyway because you're transmitting.
>     >>
>     >>
>     >> -=-=-=-=-=-=-=-=-
>     >> 73,
>     >> Gwen, NG3P
>     >>
>     >>
>     >> On Wed, Jul 29, 2026 at 2:19 AM David Gilbert via Elecraft <
>     >> elecraft at mailman.qth.net> wrote:
>     >>
>     >>> A ham that has been experimenting with my NoiseNuller application
>     >>> pointed out to me where the current latency is indeed a
>     problem, and
>     >>> that is when listening to the sidetone while sending CW with a
>     key or
>     >>> paddle.  The sidetone audio coming out of the computer is
>     delayed enough
>     >>> to throw off your keying at anything other than pretty slow
>     speeds if
>     >>> you depend upon that for feedback.  It wouldn't be a problem
>     for keying
>     >>> from a keyboard, but it is when manually keying.
>     >>>
>     >>> I'm working to improve that.
>     >>>
>     >>> In my opinion, though, it's just another reason why this kind of
>     >>> processing really belongs inside the rig itself.
>     >>>
>     >>> 73,
>     >>> Dave   AB7E
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