All, It's interesting to see how the different Olivia mode configurations compare when put through the HF path simulator.
I ran Contestia through the simulator this evening and these are the results. Olivia 16/500 is shown for reference. CONTESTIA 500Hz Tones Bandwidth Char/s minimum SNR Words Per Minute 4 500 7.81 -6db 94 8 500 5.86 -9db 70 16 500 3.90 -13db 46 *16 500 2.00 -14db 24 32 500 2.44 -15db 29 64 500 1.46 -17db 17 128 500 0.85 -20db 10 *Olivia 16/500 mode CONTESTIA 1000Hz Tones Bandwidth Char/s minimum SNR Words Per Minute 4 1000Hz 15.6 -3db 187 8 1000Hz 11.7 -6db 140 16 1000Hz 7.8 -9db 94 32 1000Hz 4.9 -12db 59 64 1000Hz 2.9 -14db 35 CONTESTIA 250Hz Tones Bandwidth Char/s minimum SNR Words Per Minute 4 250 3.91 -12db 46 8 250 2.93 -13db 35 16 250 1.95 -15db 23 32 250 1.22 -17db 15 64 250 0.73 - 20db 8.8 It's clear by looking at the chart that the slower the throughput, the better the weak-signal performance. This no doubt has to do with symbol rate etc (experts comments welcome). Reducing the number of tones by half will yield 1-to-4db better weak signal performance, but at the cost of slower wpm rate. The nice thing about being able to change the configuration is that it lets you try different combinations to squeeze the most out of the modes to suit conditions. The modes with the higher tones are extremely sensitive so the skies the limit in terms of weak signal work as long as you don't mind the slow pace. It pays to take a good look at each configuration and compare; for example; Conestia 32/500 mode vs. Olivia 16/500. The Contestia mode is 5 wpm faster and slightly more sensitive than Olivia. This simple change lets you pick-up the pace without sacrificing weak signal performance. For those who are conscious about spectrum; take a look at Contestia modes 8/250 and 64/1000Hz. They both have the same wpm speed and nearly the same sensitivity, but the 8/250 mode performance is the same and it does it in 1/4th the bandwidth. Getting late here so will have to wrap it up and let the group look at the figures and send some feed back. Hope you all find it interesting... Tony -K2MO
