Re: [digitalradio] Contestia 250 - new concept for usage
Skip, I agree with you. My considerations to prefer in HF Contestia 250/4 format is related to the idea to find some compromise for bpsk31 folk, Olivia light users, and rtty folk when the propagation is not enough good for bpsk31 and rtty. So Cnt 250/4 with 39wpm is the first alternative for bpsk and rtty folk and the last alternative for Olivia hardusers ;) The idea to use 250/4 format motivated also by fact that Cnt 250/4 signals are seen in wtrfl until the copy lost (-9dB). 250/8 is washed out from wtrfl around -10dB. Both, psk31 and rtty users was wont to see signals on wtrfl. To see signals is motivated also from QRM reducing viewpoint. The idea to make 2-step default switch from 250/4(-9dB) to 250/16 (-15dB) and so get additional snr -6dB is compensate 250/8 format snr-advantage. Default shift need default procedure what/how to do when the copy is lost. WPM considerations 29wpm (250/8) is good speed from cw-viewpoint, but too less from rtty/psk31 viewpoint. 39wpm (250/4) is somekind compromise between the different speed/snr expectations. vy73, Jaak es1hj 10.05.2010 2:59, KH6TY kirjutas: Hi Jaak, Great idea to start a long test of Contestia 250/4! Perhaps Contestia 250/8 can also be compared in actual practice to Contestia 250/4. Contestia 250/8 is slower (at 29 wpm), but decodes 2 dB deeper into the noise, which may be important when there is QSB (fading) and the signal is already near the noise level ( such as when the band is going out). Although I can type over 50 wpm, my personal feeling is that 29 wpm is fast enough for a QSO, but Contestia at 78 wpm (3 dB less sensitive) is more reasonable for passing traffic (if conditions can support 3 dB less sensitivity). If not, then to be able to pass the traffic at all, it has to be sent at a slower, more sensitive speed, such as Contestia 250/4. It all depends upon the average individual preference for typing speed for QSO's vs conditions.This may become clear during your tests. I hope the testers will make their minimum typing speed preferences known, as well as how well the mode works. 73, Skip KH6TY Jaak Hohensee wrote: Hi everybody * Contestia derived from Olivia. * Contestia 250/4 is channelfree like psk or rtty. BW less than rtty and same as psk125, 39wpm, snr -9dB. * So Contestia 250/4 is good narrowband alternative for psk31 or rtty folk, specially when propagtion is not for psk/rtty or signals are too weak. * Contestia 250/4 is good mode for mid- or high-latitude folk. Many times there are disturbed propagation path not suited for psk or rtty. * Concept testing period to the end of year 2010. Everybody is welcome. More info contestia.blogspot.com http://contestia.blogspot.com/ -- vy73, Jaak es1hj -- Kirjutas ja tervitab Jaak Hohensee
Re: [digitalradio] Contestia 250 - new concept for usage
Jaak, I agree with your reasoning in testing Contestia 250/4. I also think that a good approach would be for EVERYONE to use RSID so a station can shift the QSO mode according to typing preference or propagation conditions, as determined at either end of the QSO. Multipsk, DM780, and Fldigi already support both Contestia 250/4 and Contestia 250/8, so it will be easy to compare modes to see which one arises as the preferred one. Basically, Olivia has now become favored by many over MFSK16 because it is easier to tune, and works well into the noise. I suspect that the same will happen with Contestia, but it will be always more comfortably fast than Olivia under the same conditions, of course. Thanks again for the PathSim tests on the wider Contestia modes. That has been very helpful in deciding which is the best overall compromise between speed and lowest S/N on our UHF paths. On UHF, we have prepared macros in Fldigi to quickly switch between Contestia 1000/64 and Conterstia 2000/64, but it would be helpful if Patrick would assign Reed Solomon Identifiers to include those variants. Because there is much more space available on UHF, we can use the wider modes to withstand Doppler shift and spreading, whereas we find anything more narrow than 500 Hz simply does not survive. It is good to have choices! 73, Skip KH6TY Jaak Hohensee wrote: Skip, I agree with you. My considerations to prefer in HF Contestia 250/4 format is related to the idea to find some compromise for bpsk31 folk, Olivia light users, and rtty folk when the propagation is not enough good for bpsk31 and rtty. So Cnt 250/4 with 39wpm is the first alternative for bpsk and rtty folk and the last alternative for Olivia hardusers ;) The idea to use 250/4 format motivated also by fact that Cnt 250/4 signals are seen in wtrfl until the copy lost (-9dB). 250/8 is washed out from wtrfl around -10dB. Both, psk31 and rtty users was wont to see signals on wtrfl. To see signals is motivated also from QRM reducing viewpoint. The idea to make 2-step default switch from 250/4(-9dB) to 250/16 (-15dB) and so get additional snr -6dB is compensate 250/8 format snr-advantage. Default shift need default procedure what/how to do when the copy is lost. WPM considerations 29wpm (250/8) is good speed from cw-viewpoint, but too less from rtty/psk31 viewpoint. 39wpm (250/4) is somekind compromise between the different speed/snr expectations. vy73, Jaak es1hj 10.05.2010 2:59, KH6TY kirjutas: Hi Jaak, Great idea to start a long test of Contestia 250/4! Perhaps Contestia 250/8 can also be compared in actual practice to Contestia 250/4. Contestia 250/8 is slower (at 29 wpm), but decodes 2 dB deeper into the noise, which may be important when there is QSB (fading) and the signal is already near the noise level ( such as when the band is going out). Although I can type over 50 wpm, my personal feeling is that 29 wpm is fast enough for a QSO, but Contestia at 78 wpm (3 dB less sensitive) is more reasonable for passing traffic (if conditions can support 3 dB less sensitivity). If not, then to be able to pass the traffic at all, it has to be sent at a slower, more sensitive speed, such as Contestia 250/4. It all depends upon the average individual preference for typing speed for QSO's vs conditions.This may become clear during your tests. I hope the testers will make their minimum typing speed preferences known, as well as how well the mode works. 73, Skip KH6TY Jaak Hohensee wrote: Hi everybody * Contestia derived from Olivia. * Contestia 250/4 is channelfree like psk or rtty. BW less than rtty and same as psk125, 39wpm, snr -9dB. * So Contestia 250/4 is good narrowband alternative for psk31 or rtty folk, specially when propagtion is not for psk/rtty or signals are too weak. * Contestia 250/4 is good mode for mid- or high-latitude folk. Many times there are disturbed propagation path not suited for psk or rtty. * Concept testing period to the end of year 2010. Everybody is welcome. More info contestia.blogspot.com http://contestia.blogspot.com/ -- vy73, Jaak es1hj -- Kirjutas ja tervitab Jaak Hohensee
Re: [digitalradio] Contestia 250 - new concept for usage
Hello Skip, About Contestia: I think this mode is a better compromise between robustness and speed than Olivia (too much robustness) and RTTYM (very fast but with the problem of having two sets of characters as in RTTY, i.e letters and figures, and hence much risk of packet of errors). but it would be helpful if Patrick would assign Reed Solomon Identifiers to include those variants. RR for all, but I have not seen demands to our RS ID group... 73 Patrick - Original Message - From: KH6TY To: digitalradio@yahoogroups.com Sent: Monday, May 10, 2010 1:24 PM Subject: Re: [digitalradio] Contestia 250 - new concept for usage Jaak, I agree with your reasoning in testing Contestia 250/4. I also think that a good approach would be for EVERYONE to use RSID so a station can shift the QSO mode according to typing preference or propagation conditions, as determined at either end of the QSO. Multipsk, DM780, and Fldigi already support both Contestia 250/4 and Contestia 250/8, so it will be easy to compare modes to see which one arises as the preferred one. Basically, Olivia has now become favored by many over MFSK16 because it is easier to tune, and works well into the noise. I suspect that the same will happen with Contestia, but it will be always more comfortably fast than Olivia under the same conditions, of course. Thanks again for the PathSim tests on the wider Contestia modes. That has been very helpful in deciding which is the best overall compromise between speed and lowest S/N on our UHF paths. On UHF, we have prepared macros in Fldigi to quickly switch between Contestia 1000/64 and Conterstia 2000/64, but it would be helpful if Patrick would assign Reed Solomon Identifiers to include those variants. Because there is much more space available on UHF, we can use the wider modes to withstand Doppler shift and spreading, whereas we find anything more narrow than 500 Hz simply does not survive. It is good to have choices! 73, Skip KH6TY Jaak Hohensee wrote: Skip, I agree with you. My considerations to prefer in HF Contestia 250/4 format is related to the idea to find some compromise for bpsk31 folk, Olivia light users, and rtty folk when the propagation is not enough good for bpsk31 and rtty. So Cnt 250/4 with 39wpm is the first alternative for bpsk and rtty folk and the last alternative for Olivia hardusers ;) The idea to use 250/4 format motivated also by fact that Cnt 250/4 signals are seen in wtrfl until the copy lost (-9dB). 250/8 is washed out from wtrfl around -10dB. Both, psk31 and rtty users was wont to see signals on wtrfl. To see signals is motivated also from QRM reducing viewpoint. The idea to make 2-step default switch from 250/4(-9dB) to 250/16 (-15dB) and so get additional snr -6dB is compensate 250/8 format snr-advantage. Default shift need default procedure what/how to do when the copy is lost. WPM considerations 29wpm (250/8) is good speed from cw-viewpoint, but too less from rtty/psk31 viewpoint. 39wpm (250/4) is somekind compromise between the different speed/snr expectations. vy73, Jaak es1hj 10.05.2010 2:59, KH6TY kirjutas: Hi Jaak, Great idea to start a long test of Contestia 250/4! Perhaps Contestia 250/8 can also be compared in actual practice to Contestia 250/4. Contestia 250/8 is slower (at 29 wpm), but decodes 2 dB deeper into the noise, which may be important when there is QSB (fading) and the signal is already near the noise level ( such as when the band is going out). Although I can type over 50 wpm, my personal feeling is that 29 wpm is fast enough for a QSO, but Contestia at 78 wpm (3 dB less sensitive) is more reasonable for passing traffic (if conditions can support 3 dB less sensitivity). If not, then to be able to pass the traffic at all, it has to be sent at a slower, more sensitive speed, such as Contestia 250/4. It all depends upon the average individual preference for typing speed for QSO's vs conditions.This may become clear during your tests. I hope the testers will make their minimum typing speed preferences known, as well as how well the mode works. 73, Skip KH6TY Jaak Hohensee wrote: Hi everybody a.. Contestia derived from Olivia. b.. Contestia 250/4 is channelfree like psk or rtty. BW less than rtty and same as psk125, 39wpm, snr -9dB. c.. So Contestia 250/4 is good narrowband alternative for psk31 or rtty folk, specially when propagtion is not for psk/rtty or signals are too weak. d.. Contestia 250/4 is good mode for mid- or high-latitude folk. Many times there are disturbed propagation path not suited for psk or rtty. e.. Concept testing period to the end of year 2010. Everybody is welcome. More info contestia.blogspot.com -- vy73, Jaak es1hj -- Kirjutas ja tervitab
Re: [digitalradio] Contestia 250 - new concept for usage
Hi Patrick, Yahoo reports there is no RSID group. Where should I request additional RSID codes? 73 - Skip KH6TY Patrick Lindecker wrote: Hello Skip, About Contestia: I think this mode is a better compromise between robustness and speed than Olivia (too much robustness) and RTTYM (very fast but with the problem of having two sets of characters as in RTTY, i.e letters and figures, and hence much risk of packet of errors). but it would be helpful if Patrick would assign Reed Solomon Identifiers to include those variants. RR for all, but I have not seen demands to our RS ID group...
Re: [digitalradio] Contestia 250 - new concept for usage
Skip, It is an informal group composed by the Hams able to program RS ID in their own respective programs (i.e Votjech, Simon, Dave, Cesco and myself). A RS ID number can't be virtual. It must be really implemented in a program... 73 Patrick - Original Message - From: KH6TY To: digitalradio@yahoogroups.com Sent: Monday, May 10, 2010 10:04 PM Subject: Re: [digitalradio] Contestia 250 - new concept for usage Hi Patrick, Yahoo reports there is no RSID group. Where should I request additional RSID codes? 73 - Skip KH6TY Patrick Lindecker wrote: Hello Skip, About Contestia: I think this mode is a better compromise between robustness and speed than Olivia (too much robustness) and RTTYM (very fast but with the problem of having two sets of characters as in RTTY, i.e letters and figures, and hence much risk of packet of errors). but it would be helpful if Patrick would assign Reed Solomon Identifiers to include those variants. RR for all, but I have not seen demands to our RS ID group...
Re: [digitalradio] Contestia 250 - new concept for usage
Patrick, Thanks. I'll ask Dave to request the number. He is already going to add Contestia 64/1000 and Contestia 64/2000 to Fldigi because those are needed on UHF when SSB cannot get though due to poor propagation, Doppler speading, and multipath. 73 - Skip KH6TY Patrick Lindecker wrote: Skip, It is an informal group composed by the Hams able to program RS ID in their own respective programs (i.e Votjech, Simon, Dave, Cesco and myself). A RS ID number can't be virtual. It must be really implemented in a program... 73 Patrick - Original Message - *From:* KH6TY mailto:kh...@comcast.net *To:* digitalradio@yahoogroups.com mailto:digitalradio@yahoogroups.com *Sent:* Monday, May 10, 2010 10:04 PM *Subject:* Re: [digitalradio] Contestia 250 - new concept for usage Hi Patrick, Yahoo reports there is no RSID group. Where should I request additional RSID codes? 73 - Skip KH6TY Patrick Lindecker wrote: Hello Skip, About Contestia: I think this mode is a better compromise between robustness and speed than Olivia (too much robustness) and RTTYM (very fast but with the problem of having two sets of characters as in RTTY, i.e letters and figures, and hence much risk of packet of errors). but it would be helpful if Patrick would assign Reed Solomon Identifiers to include those variants. RR for all, but I have not seen demands to our RS ID group...
Re: [digitalradio] Contestia 250 - new concept for usage
Patrick, I failed to point that every combination of bandwidth -125, 250, 500,1000, 2000, and tones - 2,4,8,16,32,64, 128, 256, for Contestia and Olivia are ALREADY implemented in both Fldigi and MixW. It is only because of this that were were able to discover the benefits of Contestia 64/2000 and 32/2000 which are not yet supported in Multipsk. By copy of this email, I am formally requesting Dave, W1HKJ, to request RD ID numbers for all these combinations, as it is just not possible to guess which combination will prove to be very useful under certain conditions. It took us weeks of daily tests to find out that Contestia 64/1000 is the MOST dependable mode to use for digital QSO's on UHF because of the extreme conditions there. 73 - Skip KH6TY Patrick Lindecker wrote: Skip, It is an informal group composed by the Hams able to program RS ID in their own respective programs (i.e Votjech, Simon, Dave, Cesco and myself). A RS ID number can't be virtual. It must be really implemented in a program... 73 Patrick - Original Message - *From:* KH6TY mailto:kh...@comcast.net *To:* digitalradio@yahoogroups.com mailto:digitalradio@yahoogroups.com *Sent:* Monday, May 10, 2010 10:04 PM *Subject:* Re: [digitalradio] Contestia 250 - new concept for usage Hi Patrick, Yahoo reports there is no RSID group. Where should I request additional RSID codes? 73 - Skip KH6TY Patrick Lindecker wrote: Hello Skip, About Contestia: I think this mode is a better compromise between robustness and speed than Olivia (too much robustness) and RTTYM (very fast but with the problem of having two sets of characters as in RTTY, i.e letters and figures, and hence much risk of packet of errors). but it would be helpful if Patrick would assign Reed Solomon Identifiers to include those variants. RR for all, but I have not seen demands to our RS ID group...
Re: [digitalradio] Contestia 250 - new concept for usage
Hi Jaak, Great idea to start a long test of Contestia 250/4! Perhaps Contestia 250/8 can also be compared in actual practice to Contestia 250/4. Contestia 250/8 is slower (at 29 wpm), but decodes 2 dB deeper into the noise, which may be important when there is QSB (fading) and the signal is already near the noise level ( such as when the band is going out). Although I can type over 50 wpm, my personal feeling is that 29 wpm is fast enough for a QSO, but Contestia at 78 wpm (3 dB less sensitive) is more reasonable for passing traffic (if conditions can support 3 dB less sensitivity). If not, then to be able to pass the traffic at all, it has to be sent at a slower, more sensitive speed, such as Contestia 250/4. It all depends upon the average individual preference for typing speed for QSO's vs conditions.This may become clear during your tests. I hope the testers will make their minimum typing speed preferences known, as well as how well the mode works. 73, Skip KH6TY Jaak Hohensee wrote: Hi everybody * Contestia derived from Olivia. * Contestia 250/4 is channelfree like psk or rtty. BW less than rtty and same as psk125, 39wpm, snr -9dB. * So Contestia 250/4 is good narrowband alternative for psk31 or rtty folk, specially when propagtion is not for psk/rtty or signals are too weak. * Contestia 250/4 is good mode for mid- or high-latitude folk. Many times there are disturbed propagation path not suited for psk or rtty. * Concept testing period to the end of year 2010. Everybody is welcome. More info contestia.blogspot.com http://contestia.blogspot.com/ -- vy73, Jaak es1hj
