Tony, Thank you very much for the information.
See you on the air, philw de ka1gmn On Fri, Aug 7, 2009 at 3:01 PM, Tony <d...@optonline.net> wrote: > > > Hello Phil, > > >Very interesting. What simulator are you using? philw de ka1gmn > > I use Moe Wheatley's PathSim with VAC to route the digital mode > audio. Pangram text is used to test throughput. > > It's important to make sure that the audio amplitude is the same for each > mode when testing to keep things evenly matched. > > Tony -K2MO > > > > ----- Original Message ----- > From: Phil Williams > To: digitalradio@yahoogroups.com > Sent: Friday, August 07, 2009 2:48 PM > Subject: [Norton AntiSpam] Re: [digitalradio] Olivia - Contestia Tone / > Bandwidth Configuration > > > Very interesting. > > What simulator are you using? > > philw de ka1gmn > > > > On Fri, Aug 7, 2009 at 3:59 AM, Tony <d...@optonline.net> wrote: > > > 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 > > > >
