National messaging system

[dubose at texas.net]

Curt asked:

> At what level does Pactor-III fail?  At what levels do MFSK16 and
> MT63 fail to display?  I understand that the way the text is worded
> he wasn't trying to give exact specs, but we can at least get
> ballpark figures out of it to strive for.

According to richard's, G4HPE, paper I presented at the DCC, MT63 will
maintain  200 WPM at near 100% error free throughput at a -5dB SNR on a poor
CCIR channel.  You probably can't see that on a waterfall display.

MFSK16 will copy about 98% error free down to -15dB SNR on a poor CCIR
channel...no way you can see the signal on a waterfall display.

The difference is that MFSK16 has a speed limitation of as fast as you can
type or about 60-80 WPM.

Walt/K5YFW