Re: Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration
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 BandwidthChar/sminimum SNR Words Per Minute 4500 7.81 -6db 94 8500 5.86 -9db 70 16 500 3.90 -13db46 *16 500 2.00 -14db24 32 500 2.44 -15db29 64 500 1.46 -17db17 128 500 0.85 -20db10 *Olivia 16/500 mode CONTESTIA 1000Hz Tones BandwidthChar/sminimum SNR Words Per Minute 4 1000Hz 15.6 -3db 187 8 1000Hz 11.7 -6db 140 16 1000Hz 7.8 -9db 94 32 1000Hz4.9 -12db 59 64 1000Hz 2.9-14db 35 CONTESTIA 250Hz Tones BandwidthChar/sminimum SNR Words Per Minute 4 250 3.91 -12db 46 8 250 2.93 -13db 35 16 2501.95 -15db 23 32 2501.22 -17db 15 64 2500.73 - 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
Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration
Patrick Lindecker wrote: As a thumb rule: For a same sub mode: Contestia has a double speed (+3 dB) but only 1.5 dB of loss in term of minimum S/N compared to Olivia. So it seems to be a better compromise. Assuming that the S/N is constant. In practice the S/N seems to vary wildly from second to second, with all kinds of interference popping up and disappearing again. Does Contestia deal with those as well as Olivia does? -- All rights reversed.
Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration
Contestia and RTTYM are variants of the character set used with Olivia. Olivia is 8-bit, Contestia is 7-bit and (I think) RTTYM is 5-bit or 6-bit. Simon Brown, HB9DRV www.ham-radio-deluxe.com - Original Message - From: Rik van Riel r...@surriel.com Assuming that the S/N is constant. In practice the S/N seems to vary wildly from second to second, with all kinds of interference popping up and disappearing again. Does Contestia deal with those as well as Olivia does?
Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration
Hello Rik and Simon, The block size (which is interleaved and scrambled) is equal to 64 symbols in Olivia and 32 in Contestia. Consequently, Contestia can't be as good as Olivia relatively to interferences (for the same symbol speed). Olivia has 7 bits characters, Contestia 6 and RTTYM 5 (with a double set of characters as in RTTY, so with the same problem of non-desired set of characters switching). 73 Patrick - Original Message - From: Rik van Riel r...@surriel.com To: digitalradio@yahoogroups.com Sent: Saturday, August 08, 2009 8:21 PM Subject: Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration Patrick Lindecker wrote: As a thumb rule: For a same sub mode: Contestia has a double speed (+3 dB) but only 1.5 dB of loss in term of minimum S/N compared to Olivia. So it seems to be a better compromise. Assuming that the S/N is constant. In practice the S/N seems to vary wildly from second to second, with all kinds of interference popping up and disappearing again. Does Contestia deal with those as well as Olivia does? -- All rights reversed. Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked Recommended digital mode software: Winwarbler, FLDIGI, DM780, or Multipsk Logging Software: DXKeeper or Ham Radio Deluxe. Yahoo! Groups Links
Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration
14073 contestia 500-16 928 rx tx calling lu2vc 2009/8/8 Patrick Lindecker f6...@free.fr: Hello Rik and Simon, The block size (which is interleaved and scrambled) is equal to 64 symbols in Olivia and 32 in Contestia. Consequently, Contestia can't be as good as Olivia relatively to interferences (for the same symbol speed). Olivia has 7 bits characters, Contestia 6 and RTTYM 5 (with a double set of characters as in RTTY, so with the same problem of non-desired set of characters switching). 73 Patrick - Original Message - From: Rik van Riel r...@surriel.com To: digitalradio@yahoogroups.com Sent: Saturday, August 08, 2009 8:21 PM Subject: Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration Patrick Lindecker wrote: As a thumb rule: For a same sub mode: Contestia has a double speed (+3 dB) but only 1.5 dB of loss in term of minimum S/N compared to Olivia. So it seems to be a better compromise. Assuming that the S/N is constant. In practice the S/N seems to vary wildly from second to second, with all kinds of interference popping up and disappearing again. Does Contestia deal with those as well as Olivia does? -- All rights reversed. Announce your digital presence via our Interactive Sked Pages at http://www.obriensweb.com/sked Recommended digital mode software: Winwarbler, FLDIGI, DM780, or Multipsk Logging Software: DXKeeper or Ham Radio Deluxe. Yahoo! Groups Links
Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration
Exactly what I would have expected, nice to see that you get these results. Simon Brown, HB9DRV www.ham-radio-deluxe.com - Original Message - From: Tony Hope you all find it interesting... Tony -K2MO
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 BandwidthChar/sminimum SNR Words Per Minute* 4500 7.81 -6db 94 8500 5.86 -9db 70 16 500 3.90 -13db46 *16 500 2.00 -14db24 32 500 2.44 -15db29 64 500 1.46 -17db17 128 500 0.85-20db10 *Olivia 16/500 mode CONTESTIA 1000Hz *Tones BandwidthChar/sminimum SNR Words Per Minute* 4 1000Hz 15.6 -3db 187 8 1000Hz 11.7 -6db 140 16 1000Hz 7.8 -9db94 32 1000Hz4.9 -12db 59 64 1000Hz 2.9-14db 35 CONTESTIA 250Hz *Tones BandwidthChar/sminimum SNR Words Per Minute* ** 4 250 3.91 -12db 46 8 250 2.93 -13db 35 16 2501.95 -15db 23 32 2501.22 -17db 15 64 2500.73 - 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
Re: Re: [digitalradio] Olivia - Contestia Tone / Bandwidth Configuration
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 BandwidthChar/sminimum SNR Words Per Minute 4500 7.81 -6db 94 8500 5.86 -9db 70 16 500 3.90-13db46 *16 500 2.00 -14db24 32 500 2.44-15db29 64 500 1.46-17db17 128 500 0.85-20db10 *Olivia 16/500 mode CONTESTIA 1000Hz Tones BandwidthChar/sminimum SNR Words Per Minute 4 1000Hz 15.6 -3db 187 8 1000Hz 11.7 -6db 140 16 1000Hz 7.8 -9db94 32 1000Hz4.9 -12db 59 64 1000Hz 2.9-14db 35 CONTESTIA 250Hz Tones BandwidthChar/sminimum SNR Words Per Minute 4 250 3.91 -12db 46 8 250 2.93 -13db 35 16 2501.95 -15db 23 32 2501.22 -17db 15 64 2500.73 - 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
