Consider that voice SSB requires over 2000 Hz for reasonable quality and 2700 Hz would be better. Speaking on the air may be about 120 wpm. That figures out to around ~ 20 Hz per wpm, give or take some. For passing traffic it would be much slower though with more Hz per wpm.
PSK31 is about the narrowest mode available to communicate at that speed. Even CW may be around the same bandwidth (~ 60 Hz). This allows enormous numbers of hams to set their dial frequency at one point and must move their cursor to read out or even contact or call other hams. PSK31 can be sent at an average speed of around 40 wpm in that 60 Hz bandwidth, or 1.5 Hz per wpm. If you only look at throughput per bandwidth you find that if you need high speed, robustness, and accuracy, nothing can touch Pactor 2 and 3. If you need keyboard speed, then it likely be a different story. Scaling different modes, under moderately good conditions and using Patrick's Multipsk information and some averages with ARQ modes from KN6KB's RF Footprint Powerpoint: Mode bandwidth (Hz) / speed (wpm) = Hz/wpm Olivia 32/1000 - 1000 / 24 = 42 ALE MIL-STD-188-141A - 2000 / 76 = 26 Olivia 16/500 - 500 / 20 = 25 Olivia 8/1000 1000 / 59 = 17 FAE = 2000 / 150 = 13 MT63 1000 / 100 = 10 45 Bd RTTY 600 / 60 = 10 (some will consider this narrower and with a better score) MFSK16 - 316 / 42 = 7.5 Pactor 1 200 / 600/200 = 3 ThrobX - 94/40 = 2.3 DominoEX/11 194 / 77 = 2.5 PSK31 60 / 40 = 1.5 Pactor 2 700 / 500 = 1.4 Pactor 3 2400 / 2225 = 1 If you adjust some of the numbers for conditions where the S/N is well below zero dB, then I think it would change things a bit. Some of these numbers are guesstimates so if anyone has other suggested numbers, it might be interesting. The main thing is to look at the relative comparison. But we need to keep things in perspective, since all things are not equal and a wide footprint mode for keyboarding would be difficult to justify unless it had special abilities to handle difficult conditions as some of these modes have. I could do another SWAG on this with say, -5 or -10 S/N. 73, Rick, KV9U
