Lyle (KK7P), our DSP engineer--a very meticulous guy--just did a very careful re-test of the two versions of code referred to in this thread. He found no difference between 4.17 and 4.25.
I see that Arie (PA3A) also confirmed no difference when he repeated his own test. (Thanks for doing this, Arie.) 73, Wayne N6KR On Jan 28, 2011, at 2:51 AM, Arie Kleingeld PA3A wrote: > All, > > Measured the two FW's 4.17 and 4.25 with APF on S+N/N ratio at MDS > again, and again. > Question was: if the filter plots are exactly the same, where does the > measured (marginal) difference of 2 dB come from? > > Found no difference this time. Seems that the XG2 drifted a bit in > yesterdays measurements which, I think, caused the 2dB difference > (despite tuning the K3 on the right freq before measurement started). > > Positive thing is that I could measure the improvement of S+N/N ratio > with the APF switched on. Even with the 200Hz roofer and 50Hz DSP BW > it > adds a few dB. So for me it is a good tool for digging holes in the > noise looking for weak signals. > > 73, > Arie PA3A > > > > > ______________________________________________________________ > 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