Yea, but that 100 word message could have been sent in about 3 minutes using 30 wpm CW. I've done both, and the SSB'ers have a hard time understanding that CW is that much faster than voice. Almost what you quote for the 300 baud text data, and in a much smaller bandwidth.
Also, using your info, a 300 baud modem can send 100 words in 3 minutes, while a 2400 baud modem can do it in one minute. That's about a 3:1 ratio. Yet I suspect the bandwidth will be 4 to 5 times as much and maybe 8 times as much, i.e. 2400 baud divided by 300 baud. I'm not sure the tradeoff's are good ones in a shared spectrum environment where people are competing for space. Jim WA0LYK --- In digitalradio@yahoogroups.com, "DuBose Walt Civ AETC CONS/LGCA" <[EMAIL PROTECTED]> wrote: > > Ah ha...well Bonnie I see that I am not the only one who is looking at the overall picture of band usage. > > Here is an example of what I saw in the military... > > SSB voice took 10 minutes to pass a 100 word message between really seasoned radio operators on an HF channel typical of most Q4-5 amateur radio QSOs. > > When they went to 300 baud text data, they send the same message in 2 or 3 minutes and sometimes 3 or 4 when they had to repeat the message...this was again with Q4-5 signals. The modem was not much more than a Bell 103 modem. > > With a MIL-STD-188-110 16 tone modem at 2400 baud, the message took 1 or 2 minutes and only every 5-6 messages was a it necessary to repeat a message. > > The band/channel usage went from 1=10 to 9 0r 9=10...almost a ten fold increase in band/channel usage. > > Today those same units are using 9600 BPS data and sending one page of text in a couple of minutes or sometimes "booking" messages and sending 20-50 messages at one time. > > The higher the throughput and mode robust the mode, the less channel usage there is going to be at a fixed amount of data. > > For testing of any text mode or DV mode, a standard text should be adopted. > > Walt/K5YFW > > -----Original Message----- > From: digitalradio@yahoogroups.com > [mailto:[EMAIL PROTECTED] Behalf Of expeditionradio > Sent: Saturday, October 21, 2006 9:08 PM > To: digitalradio@yahoogroups.com > Subject: [digitalradio] 3kHz or 500Hz Re: Updates on effect of FCC R&O > > > There's another way to look at spectrum use. It is better to use a > 3kHz bandwith for 10 minutes than to use a 500Hz bandwidth for 1 hour > to pass the same traffic. On HF, with short propagation openings, it > is better to be able to quickly send the message. Approximately 3kHz > is the defacto worldwide bandwidth standard for HF communication > transceivers. > > This R&O isn't an issue of FCC making rules for "encouragement" to > produce narrower bandwidth signals. It is the result of someone at FCC > that is out of touch with reality. > > The Bigger Issue: The freedom to use existing digital worldwide > standards for HF communications is important for Amateur Radio. > > It is very much like the freedom to use existing analog bandwidth > standards such as SSB and AM voice. Should FCC take take that freedom > away also, under the guise of "encouraging innovation"? Should hams be > forced to develop 500Hz bandwidth voice modes? > > Or, should a wide range of communications methods be "encouraged" in > USA like it is in the rest of the civilized world? > > Bonnie KQ6XA > > > > > 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 > 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/
