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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
