I have been messing around with WSPR decoding on 630m with a pair of phase-locked receivers and two receive antennas.
I have put together some software to save two sets of coherent samples for each 2-minute period, and then after the fact I can combine the two sets of samples w/ a configurable relative gain and phase shift. I then wrote some scripts to call wsprd repeatedly w/ whilst sweeping the gain/phase parameters, and looking at the change in reported SNR. My real aim is to help hear a little bit better (i.e. have a higher chance of pulling out decodes near the limit) and quantify the benefit. In latest experiment, I am often able to see 2-3dB improvement in reported SNR from wsprd by tweaking gain/phase parameters. I'm wondering what this really means. Have I actually improved the SNR substantially? Or is it possible I am just affecting the SNR calculation (I think it is roughly measuring the average noise level in the 2.5kHz window, and comparing to peaks) in a way that doesn't necessarily imply increased probability of decode? If I happen to have cancelled some noise outside of the 150Hz WSPR passband, it might improve SNR but not really matter for the purposes of decoding? Are there other metrics within the decoder that might provide useful feedback for experiments here? Thanks for any thoughts/suggestions. Ben, N1VF _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
