http://elecraft.85.s1.nabble.com/K3-noise-reduction-performance-tp5779574p5788448.html
hopes that the K3's NR performance will improve. I believe one of the
biggest issues is related to audio fidelity when the NR is activated. I
drop in speech volume when NR is on. Doing so however increases the volume
> Hello Elecrafters,
>
> Regarding the issue of NR, I know this can be a touchy subject and most
> will say its very subjective. This post isn't intended as a complaint or
> criticism. Instead, I hope through constructive discussions, more
> improvements to the K3's NR performance will be realized. I'd like to begin
> by saying that Lyle and crew have a done a fantastic job to date with the
> K3's NR. I've had the privilege of watching the K3's NR function improve
> over time. The boys at Aptos should really be commended for listening to
> their customers.
>
> With that said, the recent CQSS has made me realize that there is still
> room for improvement. During the SS, I used NR extensively in combination
> with RF gain and filter hi-cut/lo-cut/shift settings. NR when used in
> combination with the aforementioned K3 adjustments can and does work well.
> The problem that I believe remains however is the algorithm used still
> seems too broad in its rejection calculations; what I mean is that SSB
> settings (i.e. F5-1 and higher) don't seem to be selective enough to reduce
> noise while allowing speech patterns to remain unaffected. In other words,
> the DSP sounds like its reducing everything within its passband. To my
> ears, the NR doesn't seem to make speech "pop out" quite as effectively has
> other NR implementations. This can be seen by a not-so-subtle reduction in
> speech volume whenever the NR is turned on. The NR behavior is consistent
> regardless of AGC slope or threshold settings.
>
> Below are several links to audio recordings of a product I used to own. It
> is called the BHI ANEM (Mk. II). Sadly, I sold it after getting the K3. I
> should have hung on to it as it has become my benchmark for NR performance.
>
> These are some sample recordings of the ANEM being turned on and off.
> These recordings are found on W4RT's website
>
> 20 m SSB <
http://www.w4rt.com/BHI/20Mband-ssb.wav>
> 80 m SSB <
http://www.w4rt.com/BHI/80conv-ssb.wav>
> 80 m SSB <
http://www.w4rt.com/BHI/80Mconv2-ssb.wav>
>
> I've also compared the K3's NR performance to that of the Icom 756 Pro 3
> which has similar NR reduction properties - albeit not as effective - as the
> ANEM.
>
> Perhaps I am being subjective or overly critical, but one thing you can
> easily notice with the ANEM recordings is that speech volume doesn't get as
> affected as the K3s. This is really surprising to me as the NR for the ANEM
> is AF rather than IF like what's used in our radios. This leads me to
> believe that the ANEM's NR algorithms are more effective in reducing
> background noise while leaving speech unaffected.
>
> What do you guys think?
>
> Sorry for the long email. Many thanks in advance for your
> ideas/suggestions.
> <
http://www.w4rt.com/BHI/20Mband-ssb.wav>
> --
> 73 de James K2QI
> President UNARC/4U1UN
>
>
--... ...-- -.. . .--- .- -- . ...