[Elecraft] DSP question

[Lyle Johnson]

Hello Vic!

> My thought was that perhaps the NR could process the signal BEFORE the
> narrow (DSP) filter was applied.  Then you could use a narrow filter
> without making the noise that the NR sees more coherent.  Maybe this
> would take two DSP chips?

It could be done, but then the denoiser is working on noise you won't hear
anyway, due to the narrow filter.

Keep in mind that the denoiser is just a filter, too.  You can get a feel
for this if you look at audio on spectrogram or some similar tool and play
with the settings.  You'll discover that the denoiser is, in effect,
providing bandpass filters for what it thinks are signals, and thus
suppressing "noise."  But a tight band pass filter is already better than
the filter that the denoiser can provide.  Thus, the denoiser's greatest
effect is when the bandpass is wide, rather than narrow.

If you have an outboard DSP filter, you can try it as you suggest, by using
a wideband filter in the KDSP2 and then using the outboard filter for the
tighter passband and see how it sounds.

73,

Lyle KK7P