> >Or do they use a 3000 Hz BW for testing purposes and compare modes that way? > Yes to compare. For example, I want to compare modes at S/N=-10 dB: > > I send a a signal of 1 mWatt and 10 mW of noise in 3KHz (so 3.33 mW per KHz). > > Now among this noise you can send your 1 mWatt signal in the way you want > (RTTY, PSK...), the bandwidth you want (within 3 KHz) and also the coding you > want. > > The judge will be the error rate: 2% is good, almost 100 % is bad. >
I guess you mean 2% character errors after going through the FEC mill? For pskmail ARQ to repair that efficiently you want an error rate of < 1%. Anything worse generates lots of repeats or overhead through shorting of the packets. Fortunately we can often find a channel which is good enough by using the optimum band and/or going to a free frequency. 73, Rein PA0R Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/drsked/drsked.php Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/