Ok...if I were using a keyboard-to-keyboard mode...and I was REALLY using the keyboard, a 20-40 WPM mode would be fine if it were 99% error free and worked down below a 0 dB SNR...and a 500 Hz or even 1 KHz bandwidth mode would be Ok. However, if I wanted/needed to send a text ot binary file, I would want want a high thoughtput, error free mode that worked down below -5 dB SNR. If that took 3 or 4 Khz, I woudln't care.
I tune across the hand and really don't hear that much CW or data...just in very small segments of the band. What bothers me is that we have 150 KHz of band space for "data" (as we do on 40M in the U.S.) and the total throughput of the entire spectrum is less than 19200 bps. Another thing that is bothersome to me is that we don't use modes that can be offset a few Hz from each other and still interoperate. I have just finished reading some papers on DRM and like OFDM systems and it seems that if you had 3 Khz band width you might be able to put 3 or 4 OFDM QSOs in that bandwidth and not bother each other. Its really not pie-in-the-sky, its just utilizing the modes that we have or modifying them slightly so that we can accomplish this task. While I'm on a roll, I just hate a QSO between just two individuals...let's open it up to 3 or 4 individuals and pass the token around between the members of the QSO. Wacha Think, Walt/K5YFW -----Original Message----- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Sent: Thursday, July 20, 2006 1:10 PM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Best Mode for QRP? The bandwidth issue to me is significant in that ... if all other things are equal ... I prefer using the narrower BW mode. If PSK31 was using 3 to 4 KHZ instead of < 100 Hz, you would likely feel much differently since the bands would be frequently clogged with signals. The only time I would support wider modes would be for emergency use. With the probable coming of BW limits here in the U.S., some of the modes we are now using will likely have to move up in the bands in order to comply with the proposed BW limits. Some modes, such as Olivia, that can change BW from < 500 Hz to > 1000, will require some operator restraint at times and might move those modes to the wider BW areas. It will be interesting to see how this shakes out. 73, Rick, KV9U DuBose Walt Civ AETC CONS/LGCA wrote: >I agree on three items Rick...as you, I want correctness...I want to know for >sure what the individual says. Second is speed. While I can't type very >fast, I can pre-type information and transmit it as a file or load a buffer so >speed is important. For me I would like at least 200 WPM for long pre-written >text files. Also, I do want to be able to see 156(?) ASCII characters. > >But as far as bandwidth goes, I don't care. If I don't care. I want a robust >mode so if it takes 5 or 10 KHz bandwidth and lots of bits for error >correction and interleaving, go for it. With FFT detection, I should be able >to fill up individual tone bandpasses with a tone and leave little empty space >for noise. Of course realistically, I wouldn't want to go over 3 or 4 KHz. >And then I wojuld expect something more than 200 WPM...maybe 600-1200 WPM. > >Walt/K5YFW > > > > 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 ------------------------ Yahoo! Groups Sponsor --------------------~--> Check out the new improvements in Yahoo! Groups email. http://us.click.yahoo.com/6pRQfA/fOaOAA/yQLSAA/ELTolB/TM --------------------------------------------------------------------~-> 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/ <*> 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/
