From my perspective, the thing that was so desirable for amateur radio, was the ability to use the computer to do the DSP and make it possible to come up with these newer modes at relatively low cost.
Ray Petit, W7GHM, invented CCW in the early 1970's, but it required extremely accurate timing using based on his hardware design. He is the same person who invented Clover around 1988 and this mode also required extremely accurate timing and frequency but he changed to a 40 msec raised cosine pulse at 25 bps. Needless to say it never was popular due to the need to homebrew the circuitry. This was a narrow band mode. Later on, Ray was able to leverage this knowledge to develop the Clover II system which was faster, but much wider, using a 31.25 baud with four tones. Because Clover II required a very costly hardware/software implementation, it never became very popular either although it is used in some proprietary commercial products along with an even faster, but much wider bandwidth system called Clover III. This is not unlike the Pactor I, II, and III deveopment. 73, Rick, KV9U Rein Couperus wrote: >>-----Ursprüngliche Nachricht----- >>Von: [email protected] >> >> > > > >>In my research, I found a field of study called CCW (Coherent CW). This was >>typically 12 wpm cw that had a special starting pattern and also an idle >>pattern. No doubt 12 wpm was some sort of magic number that they found worked >>the best. Then further reseach led me to find that CCW eventually mutated >>into PSK31. >> >> > >I was involved in CCW at the time (200 mW EU to JA on 14 MHz). The 12 wpm had >nothing to do with magic, it produced dits of exactly 100 ms long, a value >which was very easy to generate.... > >Rein PA0R > > > > > > 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/
