On 09/01/2017 21:45, Joe Taylor wrote: > ... about FreqCal mode in WSJT-X ...
Hi Joe, I have just been looking at a problem with FeqCal when FTol>DF, I have a fix for that but I also noticed that, when I connect another WSJT-X instance as a tone generator back to back (digital loopback) with an instance running FreqCal, I see slightly broader peaks from the DFT for all but a few frequencies. These cause the peakup routine be less accurate. For the following tone frequencies, and probably others: 500Hz 750Hz 1000Hz 1250Hz 1500Hz 1750Hz 2000Hz 2250Hz ... 4500Hz I see accuracy >3DP but most other frequencies I see accuracy to only ~1.5DP. I can't work out if the issue not real and is in the synthesis, maybe at some integer fractions of 48000 accuracy is better. Or is the issue inherent in the DFT or maybe at the peak detection, for sure the three magnitudes going into peakup are much flatter when the error is greater. Perhaps I am expecting too much and 1/10Hz accuracy is all that is possible with this sampling period and rate but the comb of more accurate values at the tone frequencies above makes me think there may be better accuracy possible for any tone. 73 Bill G4WJS. ------------------------------------------------------------------------------ Developer Access Program for Intel Xeon Phi Processors Access to Intel Xeon Phi processor-based developer platforms. With one year of Intel Parallel Studio XE. Training and support from Colfax. Order your platform today. http://sdm.link/xeonphi _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
