Hi John It is very interesting question. The following is my awkward idea. Pse point out a mistake.
Remember once early RTTY with WIDE-SHIFT FSK. There were mainly 3 SHIFT with 850,425,170Hz. At AFSK, MARK is 2125 and SPASEs are 2295(170), 2550(425), 2975(850). That is UP-SHIFT, SPACE is higher than MARK. At RFSK transmitted in sky, like MARK is 14,090,000Hz SPACE is 14,089, 830Hz. That is DOWN-SHIFT, SPACE is Lower than MARK, When receiving two or more SHIFTs. As for LSB, No need for VFO tuning, and change WIDTH. As for USB, tuning VFO and change WIDTH at same time. Although this was the convenience of LSB, it was lost now. Now. It is simple that also set AFSK to "DOWN SHIFT" and it transmits by USB. Consequently, the VFO dial direction and Waterfall direction are in agreement. (I think, TRUETTY is in this idea.) This is another convenience in narrow Digital Mode. Sri for poor English. Pse fill shortage with imagination. :-) 73 Hisami 7L4IOU ----- Original Message ----- From: John Becker <[EMAIL PROTECTED]> To: digitalradio@yahoogroups.com Sent: 2005年10月24日(月) 0時45分 Subject: [digitalradio] WHY ? ? ? >Can some one tell me why the sound card digital modes use USB >and not LSB like the other digital modes? > >John, W0JAB >Louisiana, Missouri >EM48LK > ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/ELTolB/TM --------------------------------------------------------------------~-> The K3UK DIGITAL MODES SPOTTING CLUSTER AT telnet://208.15.25.196/ More info at http:///www.obriensweb.com Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ <*> 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/
