FW pre-beta 4.16 release was actually the first to have APF, not 4.17. Here's an interesting comment made shortly APF was finally released to the public. http://elecraft.365791.n2.nabble.com/K3-APF-td5735159.html#a5736718
Steve N4LQ ----- Original Message ----- From: "Arie Kleingeld PA3A" <p...@xs4all.nl> To: <elecraft@mailman.qth.net> Sent: Thursday, January 27, 2011 6:44 AM Subject: [Elecraft] APF measurements: FW 4.17 better results by 2 dB > Hello all, > > Did some measurements on the different frimware versions. This time not > a BW-plot but I measured S+N/N ratio's. > > > I have no lab equipment but I have a K3 with dBV measurements, XG2 and > the stepped attenuator from elecraft. > I measured the difference of the K3 dBV-reading in signal off (=N) and > signal on (=S+N) > AGC off, mode CW, 400Hz BW and 400Hz Roofing. > RX gain of the K3 has been calibrated with XG2 and the K3 utility. > > > This is what I found. > > _FW 4.25 and 4.21 (both give the same measurement values):_ > At MDS level (stepped att on 20dB to reach this level) > normal 400 Hz BW: S+N/N = 3dB (as expected, hi) > 400 Hz BW + dual PB: S+N/N = 10 dB > > Now signal level 6dB under MDS (26dB att instead of 20dB): > normal 400 Hz BW: S+N/N = 0.5 dB > 400 Hz BW + dual PB: S+N/N = 4 dB > > > _FW 4.17_ > At MDS level (stepped att on 20dB) > normal 400 Hz BW: S+N/N = 3dB (as expected) > 400 Hz BW + dual PB: S+N/N = 12 dB (THIS is 2 dB BETTER) > > Now signal level 6dB under MDS: > normal 400 Hz BW: S+N/N = 0.5 dB > 400 Hz BW + dual PB: S+N/N = 6 dB (THIS is 2dB BETTER) > > > There are probably people that can measure this far more better than I > did with better equipment. > But this is what I can come up with here. > > 73, > Arie PA3A > > > > Op 27-1-2011 0:52, Barry N1EU schreef: >> Forget it - full stop! >> >> I just ran a spectral analysis of the current firmware versus the very >> first >> APF implementation (mcu 4.17 dsp 2.65) from 11/3/10 AND THE PLOTS ARE >> ABSOLUTELY CONGRUOUS! The APF implementation hasn't changed a bit (or a >> byte). >> >> Have a look: http://n1eu.com/k3apf.gif >> >> magenta and green plots are taken with width = 200hz >> aqua and yellow plots are taken with width = 100hz >> >> Barry N1EU > ______________________________________________________________ > 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
