For what it's worth Rud, PSK31 appears much more susceptible to phase distortion that wider modes such as MFSK and OLIVIA.
Here, we are just over 50 degrees north latitude and have many more occasions to experience the Northern "flutter" from the aurora. This phase distortion knocks out PSK31 pretty fast. Also makes SSB ops Sound like Donald Duck.... There are times when this will show up on relatively short hops (less than 500km) on 80 and 40 M John VE5MU Would the phase distortion that can corrupt a PSK signal occur the same on a M-PSK signal? If the phase distortion affects all the sub channels then doing differential PSK among the sub channels would work where symbol to symbol DxPSK would not work. Rud Merriam K5RUD ARES AEC Montgomery County, TX <http://TheHamNetwork.net> http://TheHamNetwork.net
