--- In [email protected], "Dave Bernstein" <[EMAIL PROTECTED]> wrote: > > Your software has access to the entire transceiver pass band -- it > can hear what you would QRM if you transmitted. If there is no > signal within the transceiver pass band, then the range of > frequencies on which you will transmit is clear, and you can > transmit with confidence that you aren't QRMing an ongoing QSO. > >
You're missing the point entirely. Start out with this: Define "signal." You must define it so that it can be *unambiguously* differentiated from atmospheric noise, geomagnetic noise, static crashes, etc. You must also define it so that it encompasses all modes - past, present, and future - without requiring that thousands of stations constantly update themselves when a new mode comes out. Can you do that? Some of the best software and hardware engineers out there have been trying for years, without notable success. Do you have some secret method that you just haven't gotten around to publishing? I don't intend to be snarky, but when someone says "Just look for a signal", they obviously haven't the slightest idea about how difficult it actually is. Commercial and military systems get around the issue by using strict channelization and mode requirements - something we in the Amateur service won't do. So, in the meantime, we're stuck with stations in the automatic sub-bands, which is the best solution so far. Yes, yes, I know, some people will start crying out about how "I can operate anywhere I please", and "Nobody owns a frequency!" But guess what? The amount of bandwidth they take up is very small, and it is very, very easy to avoid them. And until someone comes up with that fabled universal signal detector, that's the best compromise we have. - Rich ------------------------ Yahoo! Groups Sponsor --------------------~--> See what's inside the new Yahoo! Groups email. http://us.click.yahoo.com/2pRQfA/bOaOAA/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/
