Gents, Even *I* thought something had changed. (Lyle, our DSP engineer, assured me that it hadn't. The code hasn't changed.)
What's happening is that APF's effect is more obvious in the presence of certain band-noise conditions. These conditions will vary from band to band, and can change hourly, daily, maybe even monthly for a given QTH. I went back and listened the next day, and the APF was doing its job. I find it especially useful on the low bands, and many K3 owners have posted testimonials about this -- using the final version of the code. The APF algorithm, with its gradual slope and ~30 Hz wide peak, brings up a very narrow portion of the audio spectrum (around the center pitch) just a few dB, without bringing up the adjacent noise or causing a rapid phase transition. On several occasions I've measured a 3 to 5 dB improvement in S+N/N on weak signals using the K3's built-in audio voltmeter. 73, Wayne N6KR On Jan 26, 2011, at 12:19 PM, juergen wrote: > Hi Dave > > I asked the same question. > > The gurus at Elecraft indicated that nothing had changed. I still > have the original firmware and load it up in my spare K3. The > original version is the ESP version that works for me. > > I like you cant get the same results with the current release of the > APF that I go with the original. The original blew my socks off I > was so impressed with it. I have done the comparison test so many > times now that I know that the original was the better release and > its not my imagination. > > If the programmer says the hex code is the same then there must be > some other factors at play. I dont really have the answer. I am > keeping the original firmware just for contests. > > 73 > John > > > > --- On Wed, 1/26/11, David Lear <del...@charter.net> wrote: > >> From: David Lear <del...@charter.net> >> Subject: [Elecraft] APF >> To: Elecraft@mailman.qth.net >> Date: Wednesday, January 26, 2011, 11:27 AM >> Did anything change with APF in the >> latest release ? Seemed to perform >> better before rev 2.45. Maybe I 'm just loosing my touch. >> >> 73 Dave Lear NE5DL >> >> ______________________________________________________________ >> 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 ______________________________________________________________ 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
