I concur with Graham on this. As a long time digital operator since I got back into ham radio in 1980 (first licensed in 1963), I quickly gravitated to HF and VHF RTTY (before VHF packet). I was one of the earliest adopters of Amtor and later Clover II for a short time. Because of my disastrous experience with the inferior HAL P-38 not possible to use in a practical manner with their P-mode (what they preferred to call Pactor), I was forced to abandon HF digital for a number of years until sound card modes ... changed everything.
But I do miss the connected modes. Even though Amtor was pretty good, it was not very fast for messaging, and if the mode got close to failure due to low SNR, it would begin to pass false characters. Pactor and Clover II did not do this. Piccolo and other similar systems used by government/commercial users is effectively what we now have with some of our current IFK sound card modes and they greatly outperform Amtor and probably Pactor in terms of weak signal capabilities. This may be especially true with higher levels of ISI and Doppler that may make Pactor inoperative, maybe even true for Pactor 2 and Pactor 3, but I have not seen any data on that. As I have said elsewhere, no current sound card connected mode can perform at the level of FAE400 from what I have found. Both messaging and keyboarding is all ARQ. It also includes memory ARQ which can get some frames through like is done in Pactor modes. But there just does not seem to be much interest in having this capability. The WINMOR protocol has the potential for messaging, keyboarding, and e-mail ... and has significant adaptive ability for varying conditions. No one has indicated that they would be willing to do this yet, but I am hopeful that there will be at least one ham who has the interest and ability to carry this out. In the meantime, I am hopeful that it will work quite well for the e-mail part. 73, Rick, KV9U Graham wrote: > ... the pk232 with amtor and pactor came as breath of fresh air, and hf > packet in the middle of the sun spots on 10 mtrs was something else , but > `we' seem to be loosing foreword momentum as that's was in the mid 1980's > ! > > Yes data rates have slowed , yes data is lost due to noise and qsb and yes > you can make a guess at the `missing bits ` but somehow it was nice to > know that spelling mistakes you made where reproduced at the other end and > the odd place names actually where printing correctly. But looking at the > advances in data processing and digital audio processing, it tantalising to > think that you could achieve error free live communications at or below the > noise level. It was established well back, that the picalo multi tone > diplomatic links out performed the sitor 2 tone arq system, but the arq > function was retained and resulted in longer traffic `windows' , The winmor > system looks like `missing link' multi tone and arq …. A quantum leap .. ? > > ------------------------------------ Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Recommended software: Winwarbler, FLDIGI, DM780, or Multipsk Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/digitalradio/join (Yahoo! ID required) <*> To change settings via email: mailto:digitalradio-dig...@yahoogroups.com mailto:digitalradio-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: digitalradio-unsubscr...@yahoogroups.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
