Hi David, no problem with your point of view. The manhood needs guys with visions. Good luck.
73, Helmut, DC6NY -----Ursprüngliche Nachricht----- Von: David Rowe <da...@rowetel.com> Gesendet: Sonntag, 6. Mai 2018 21:38 An: freetel-codec2@lists.sourceforge.net Betreff: Re: [Freetel-codec2] 700D vs SSB Comparison Hi Helmut, > May be you will remind our reports about our intensive tests (HB9EPU > and me) in 2016 and 2017. Everything is absolutely fine, when the > communications channel is clean, stable and undisturbed. On HF this can't be > assumed. Thank you for those tests, however 700D is not the same algorithm. Digital voice is under continuous development, and is steadily improving. SSB development (perhaps apart from noise reduction) has stopped, it is a 50 year old algorithm. It will not get any better. > I added 2 mp3-file to show the effiency of NR2: > > https://www.dropbox.com/s/scyced9ac5p4ryn/Weak_no_nr_no_nr2.mp3?dl=0 > > https://www.dropbox.com/s/qk63lyvz6uk86wz/Weak_no_nr_yes_nr2.mp3?dl=0 Thanks. I find the second sample is improved, but still has significant noise, and has distortion added to the audio, a little like a speech codec :-) It is a little nicer to listen too, but I wonder if the overall intelligibility has improved? Cheers, David > 73, Helmut, DC6NY > > > -----Ursprüngliche Nachricht----- > Von: David Rowe <da...@rowetel.com> > Gesendet: Sonntag, 6. Mai 2018 15:31 > An: freetel-codec2@lists.sourceforge.net > Betreff: Re: [Freetel-codec2] 700D vs SSB Comparison > > Hi Helmut, > > Could you pls process the analog parts of Mark's sample using the > HPSDRs noise reduction algorithms and post the results here for comparison? > > Another gentleman tried the NR2 algorithm last year: > > https://www.rowetel.com/?p=5472#comment-80095 > > However the NR2 algorithm at that time was not effective at such low SNRs. > > Thanks, > > David > > On 06/05/18 22:38, Helmut Oeller wrote: >> Thanks Mark! This result would be impressive, if reproducable. We >> refer to our tests with 700C together with innovative HPSDRs using >> high efficient noise reduction algorithms. As you see, we trust in >> digital solutions, where we can detect possible improvement. >> >> 73, Helmut, DC6NY >> >> *Von:*Mark Jessop <lenniethelemm...@gmail.com> >> *Gesendet:* Sonntag, 6. Mai 2018 14:40 >> *An:* freetel-codec2@lists.sourceforge.net >> *Betreff:* [Freetel-codec2] 700D vs SSB Comparison >> >> A comparison between 700D and SSB, recorded over a 40m path, with >> approximately the same TX power (100W PEP). >> >> https://soundcloud.com/mark-jessop/freedv-700d-vs-analog-comparison >> >> I've spliced in the decoded 700D audio into the analog recording >> where the 700D transmission started... >> >> 73 >> >> Mark VK5QI >> >> >> >> --------------------------------------------------------------------- >> - >> -------- Check out the vibrant tech community on one of the world's >> most engaging tech sites, Slashdot.org! http://sdm.link/slashdot >> >> >> >> _______________________________________________ >> Freetel-codec2 mailing list >> Freetel-codec2@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/freetel-codec2 >> > > ---------------------------------------------------------------------- > ------ > -- > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > > > ---------------------------------------------------------------------- > -------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Freetel-codec2 mailing list > Freetel-codec2@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Freetel-codec2 mailing list Freetel-codec2@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/freetel-codec2
