Here is a direct link to where Joe Taylor talks (with intro of his creds) about WSJT-X modes. Very interesting. This starts at the 4 hour 50 minute spot in an 8 hour + symposium video. Hope you enjoy this: https://www.youtube.com/watch?v=j1sWCtVzzak&feature=youtu.be&t=4h50m3s 73, PeteR N8PR