--- In digitalradio@yahoogroups.com, k...@... wrote: > > Quite frankly, RTTY could easily be replaced with PSK63 as the prime digital > contest mode. However, many PSK operators are so clueless and often > downright rude when it comes to contests that its an extremely uphill battle. > We could fit a lot more PSK63 signals on the band than RTTY... > > It would be interesting to see what happened if a semi-major RTTY contest was > moved to PSK63 only. >
Agreed, though the IMD might be a problem, especially as many RTTY contesters use class C amps. Of course, you could also argue that they wouldn't need to use as much power... As a not completely unrelated aside, a few of us have been helping to test G4HYG's APRS Messenger software which at the moment is an experiment to find an alternative publicly documented mode to FSK300 packet that gives better performance on the HF bands. We had been using PSK63 but very recently have been trying the GMSK modes (63, 125 and 250) which are implemented in the MMVARI free software. I don't know (and don't at the moment have time to find out) what exactly the technical differences are between PSK and GMSK but the performance seems to be even better, and apparently it doesn't have the amplitude variations that cause IMD products when using PSK. Just because a mode is better doesn't mean that people will want to use it, though, and I guess both RTTY and PSK31 are so established now that you'll never persuade people to give them up. Julian, G4ILO
