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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
