>>>>>> On Sat, 17 Apr 2010 10:37:31 -0700, Brian Lloyd said: > >> (I forgot to reply to all.) > >(I removed one level of > characters below) > >> On Sat, Apr 17, 2010 at 9:49 AM, Brian Lloyd wrote: > >[snip] > >> It is really Really *REALLY* important to understand what is going on with >> these protocols in the presence of propagation anomalies in order to be able >> to make decisions about which modes work best under what conditions. My own >> recent experiments in monitoring and graphing the phase/frequency changes of >> the WWV carrier over time (20-30 minute samples typically) have convinced me >> that sequential testing of protocols, i.e. transmitting a message and then >> immediately transmitting the same message using the other protocol, is not >> likely to produce valid results unless repeated numerous times and then the >> results averaged with outliers discarded. > >True, and I seriously doubt that anyone has bothered to do that. >
The pskmail client - server communication does this all the time. It looks at the result of the last frames (both S/N and arq result) and decides on the mode to use for the next frame (separately for client and server mode). That way we always use the most effective mode for the circumstances. We don't need modes wider than 500 Hz to be fast, and change between raw PSK, robust PSK, MFSK and THOR modes. This way we are gathering lots of information on this subject automatically :) The contestia and olivia modes do not transmit the right character set so we cannot use them. 73, Rein PA0R
