Ive had good luck with psk-31
--- Bill McLaughlin <[EMAIL PROTECTED]> wrote: > Hello Brett, > > Not sure there is a "best" mode....all are > trade-offs to some degree > in terms of > speed/bandwidth/sensitivity/robustness/other-stuff. > Suspect if there was one best mode we would all use > it....The variety > of modes is part of the appeal; you want psk31 but > also FEC? Use > psk31F (for example). "verified delivery" - well > then an ARQ > mode such as Amtor/Pactor/PAX/PAX2/AX.25 and > others....more > sensitivity? > Try WSJT JT65, about the best I know of > offhand....speed? PSK220/220F > burns along if you have a good path......Chip and > MT63 seem very > robust but, like the rest, at a price. Tuning > tolerance? DominoEX > seems to only care if you take a stab in the dark at > the correct > frequency.....Would consider few other than > SlowFeldXPas for aircraft > reflection work on VHF...very short signal bursts? > Try JT6M 0r > FSK441; heck, I even use CW sometimes :) > > Not trying to be flip and know I included modes > outside your question > about "weak signal HF" modes, but I think it pays to > be flexible in > terms of mode, conditions, band, and desires. Best > advice I can give > is to try them all and see what you like and what > suits your > operation conditions and style. > > Be well, 73 > > Bill, N9DSJ > > > > > --- In digitalradio@yahoogroups.com, "Brett Owen > Rees VK2TMG " > <[EMAIL PROTECTED]> wrote: > > > > All, > > > > I find that I normally use PSK31 - as that is what > most other > stations use > > and is popular. But, I see a lot of stations that > I cannot work - > yet I can > > see their trace on the waterfall. Often, they are > responding to my > CQ and > > they just don't make it. Why do people respond to > a 2 * 3 call with > a 1*1 or > > 1*2 call? There seems to be a strategy for psk31 > mode that involves > sending > > information multiple times - like a poor man's > FEC. I expect that > is why > > they know who I am - from listening to my 2 * 3 > call. > > > > The thing is - is there a mode that if I can see > them on the > waterfall then > > I can work them? I see no reason why we can't just > go > narrower/slower/more > > FEC and go right down into the noise. And why not > have it be > adaptive - and > > be able to become faster and wider if conditions > are good - and > even have a > > feature of being able to set a max bandwidth for > those who may be > > constrained or for where a number of stations are > sharing a 2.4KHz > segment? > > > > Things I like about PSK31: > > - easy to tune with start bars, idle bars and > ending tail (sorry, > my naming > > scheme here) > > - narrow bandwidth > > - popular > > > > Things I dislike: > > - lack of RX sensitivity at times > > - errors at low SN > > > > Features that would be nice: > > - reliable, verified delivery > > - ability to use as part of a 'stack' so as to use > for APRS or > TCP/IP or > > file transfer or ALE or sounding or whatever > > - easy tuning > > - highly adaptive under trying conditions > > - be basis of keyboard mode DX mode > > - Open Source > > > > Please - I would like your opinions on this. > Perhaps one of the > current > > modes could be adapted - or am I trying to > re-invent the wheel? > What is the > > best that is out there currently and can we make > use of it? In an > ideal > > world what would be the theoretical best that we > could aim for? I > understand > > that with Turbo codes that it is possible to come > very close to > theoretical > > limits - are amateur protocols using such > techniques? Having done > some > > reading about DominoEX there appears to be various > workarounds > which may be > > required in order to make a mode practical - like > being able to > work around > > a carrier on the frequency. > > > > 73 de Brett VK2TMG > > > > -- > > =============== > > Brett Rees VK2TMG > > http://lisp.homeunix.net > > > > > ____________________________________________________________________________________ Do you Yahoo!? Everyone is raving about the all-new Yahoo! Mail beta. http://new.mail.yahoo.com
