Hi James I concur with your observations and let us have an open minded discussion here.
Johnny vr2xmc Sent from my iPhone 4 "James Sarte (K2QI)" <k2qi....@gmail.com> 於 2010年11月27日 下午8:16 寫道： > 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 > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
