Vojtech, Have you tried CCW(FSK) which is part of Multipsk program?
73, Jerry - K0HZI --- In digitalradio@yahoogroups.com, "Vojtech Bubnik" <[EMAIL PROTECTED]> wrote: > > Hi gang. > > I am thinking of learning my SW+40 to talk digitally. I know of only > two digital modes that may be exercised on this TRX without any > hardware modification: morse and feld hell. The third possibility > would be RTTY, but it would need to modify the TRX slightly. Although > it may be done on SW+, the VFO pulling will be more dificult on direct > conversion rigs, where the frequency shift is dependent on the frequency. > > The most used digital mode is still morse. The problem with computer > decoded morse is that it is usually asynchronous and speed varies. > Computers have great dificulty to decode morse signal under bad > conditions. I know there have been some synchronous CW experiments, > but the SCW mode was not widely accepted, mostly because PSK decoder > may decode -3dB weaker signal. > > But how about modifying PSK31 software modem to send CW modulated > signal? As far as my DSP knowledge goes it will be about 3dB worse > than PSK31, but the signal will be wider than of PSK31. Never mind, it > will be intended for QRP operation. > > PSK31 symbol speed is too fast for NVIS. PSK31 is hurt baddly by polar > flutter. The new CW modulated mode will probably be not too much > affected by polar flutter. Am I right? The speed of BPSK31 is about > 40WPM. It makes sense to go down to 16 symbols per second to make the > mode better for NVIS and still be usable. Or use the same symbol speed > 31 and add simple FEC, for example from QPSK31, 2dB will be gained. > > How about that? Does it make sense to create another mode? > > 73, Vojtech OK1IAK > Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) 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:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
