Hello John, I don't think it would be technically very difficult to do something equivalent to P3 with sound cards. I think that it would even possible to do much better with, for example, multi-users protocol.
The problem is the time necessary to do this. An amateur can work (with pleasure and passion of course), let's say a day per week, when a company can make work a small team 5 days a week. Now an amateur project must be short in time (several months at a maximum) as it is done for fun. Working on the same project during years seems very difficult (and surely boring) for amateurs. Another point is that the number of Hams really interested in ARQ modes is very weak... 73 Patrick Note: have tests on the minimum S/N versus the data rate done, for pactot P2 and P3? (as it is difficult to trust commercial data) ----- Original Message ----- From: John Bradley To: [email protected] ; [email protected] Cc: [email protected] Sent: Monday, February 23, 2009 9:47 PM Subject: [digitalradio] on another note As many of you know, I have been very active with digital communications over the past number of years, eagerly testing the latest and greatest, and was honored when Andy gave me recognition last year in with his digital awards. I have been and continue to be a strong proponent of digital communications within the emergency services field, have worked in emergency services as a planner, communicator, trainer and consultant. This, as well as a passion for Search and Rescue is a summary of most of my ham radio activities over the past 20 years. I have been known to be somewhat outspoken at times, I have locked horns with Bonnie more than once, I have had interesting off post political commentaries with Roger the lawyer, and from time to time, been called anti American, anti Canadian, Anti Ham, anti pactor, and anti auntie, even. I have gleefully participated in some of the lively debates on these posts and have come awfully close to being punted by moderator Andy. So you are asking yourself by now, where is this crazy Cannuck going with all this?? Simply put, ladies and gentlemen, I have seen the light ( actually a whole mess of little ones but who is counting) Over the past couple of weeks I have been testing a SCS PTC2 usb modem with a pactor3 license, and have come away amazed and humbled by what this thing can do. It is faster than ANYTHING else I have tried, including RFSM8000, and works further into the weeds than anything else I have tried. I have connected to a RMS station midday close to 1000 miles away on what I would call a "dead" band. I have connected to RMS stations at least 500 miles from me on 80M well into mid morning, and resumed these connections by about 3PM , still when nothing else could be heard on the band. I had in the past heard the claims that this modem would work 10db into the noise. At the time my reactions was "yah,right!!!" but it really does. If you have a chance, try it out . So my thinking has undergone an abrupt change of direction, from using soundcard modes with internet access, to using P3 for primary links and sound card modes for the last mile or so.. and would like to hear other opinions. we all know the givens about pactor: the modems are expensive, the operators insensitive, proprietary hardware and software etc etc. but how could this mode be incorporated with current soundcard software? John VE5MU
