Hi all, I've been testing the JT4G decoder in WSJT-X 1.9.1 together with Wei Mingchuan BG2BHC, since this is the mode used by the lunar satellite DSLWP-B. We have noted that the SNR reported by the decoder is quite off. It is always something between -18 and -16 regardless of the actual SNR.
I'm using this to test: $ ./jt49sim "CQ EA4GPZ IN80" 4G 1 0 0 1 -5 $ ./jt9 -4 -b G -f 1000 000000_0001.wav 0001 -16 -0.1 1005 $* CQ EA4GPZ IN80 f This happens both in 1.9.1 and in the latest trunk (r8748), and it also happens with other JT4 submodes. A brief look at lib/sync4.f90 shows that the relevant code hasn't changed since 2016, but I don't know what is the problem. Another related question: DSLWP-B uses 312.5Hz of tone separation instead of the standard 315Hz. How much does this affect the decoder performance and would it be easy to add a variation supporting 312.5Hz? 73, Dani EA4GPZ. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
