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
