If A and B can hear each other but can't hear C or D then if A or B transmits and C is receiving D, then C is QRMed and can't copy D.
This is something that happens quite often on HF and I don't think that any amount of coding willremedy this problem. Walt/K5YFW -----Original Message----- From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Dave Bernstein Sent: Wednesday, December 13, 2006 11:44 AM To: digitalradio@yahoogroups.com Subject: [digitalradio] Re: Dec 15? The problem can be overcome, Walt; it requires equipping each station with a busy frequency detector. Attended stations already have a busy frequency detector: the operator. Unattended stations must be augmented to detect activity on the frequencies they use for transmission and never transmit when these frequencies are already in use. Multi-mode busy detection software was successfully prototyped in SCAMP more than a year ago, but has not been incorporated in WinLink or any other HF message passing service that employs unattended stations. If those complaining about "technology prison" spent half as much time coding as they do whining, HF message passing services could employ unattended stations that do not QRM in-progress QSOs, and thus could peacefully co-exist with the rest of the amateur community. 73, Dave, AA6YQ --- In digitalradio@yahoogroups.com, "DuBose Walt Civ AETC CONS/LGCA" <[EMAIL PROTECTED]> wrote: > > The "hidden transmitter" on any band and especially HF is always going to be a problem. It is not only a problem for us, but also in the commercial and military communications world. > > As hard as we try, as operators and using smart software, we will not overcome the problem. > > We then are left with two choices...understand it and live with it or not use HF. > > The problem isn't going away. > > 73, > > Walt/K5YFW > > -----Original Message----- > From: digitalradio@yahoogroups.com > [mailto:[EMAIL PROTECTED] Behalf Of Bill McLaughlin > Sent: Tuesday, December 12, 2006 11:06 PM > To: digitalradio@yahoogroups.com > Subject: [digitalradio] Re: Dec 15? > > > Hi Dave, > > We agree actually....the "hidden transmitter" syndrome is problematic > be it on ssb, packet, PAX, Pactor, cw, am... you-name-it....when one > listens or asks if the freq is in use it can only query a station > that it can hear. I ran "semi-automatic" for decades, was never sure > of the difference as I only transmitted when present at the > keyboard/station...of course I may have not been semi-automatic by > definition as I was always too scared to let the computer control the > radio (still am). The only "busy detector" was me... > > 73 > > Bill N9DSJ > > > --- In digitalradio@yahoogroups.com, "Dave Bernstein" <aa6yq@> > wrote: > > > > Unfortunately, semi-automatic operation is problematic. The > > initiating operator can know that the frequency is clear at his or > > her end of the QSO, but can't know whether the frequency is clear > at > > the automatic station. > > > > For example, I might connect with an automatic station in Nashville > > from my QTH here in Boston, confident that no one in the Northeast > > will be QRM'd. There's no way for me to know that the automatic > > station will QRM an already-in-progress QSO between a station in > > Houston and a station in Buenos Aires because I can't hear either > end > > of that QSO in Boston. > > > > Thus all automatic stations must be equipped with busy frequency > > detectors, even when their being initiated by a manned station. > > > > 73, > > > > Dave, AA6YQ > > > > --- In digitalradio@yahoogroups.com, "Bill McLaughlin" <bmc@> > > wrote: > > > > > > Dave, > > > > > > You cannot be suggesting actually listening before transmitting? > > > Would be a slap in the face of tradition. > > > > > > Seriously, it will be interesting to see how it all sorts out...I > > > will move the PAX2 station into the dustbin on 80 as I am not > about > > > to dump that wide a signal onto the new compressed band...hope > yet > > > doubt other wide-mode ops will do the same. Otherwise I plan on > > > operating the narrow band modes much as before the 15th....will > see > > > how it all plays out long term. I have no problem with semi- auto > > > stations as by definition they have a live op to initiate > contacts > > > that, in theory, actually listen before transmitting. "Automatic" > > > stations are a whole other discussion! > > > > > > Be well and 73 > > > > > > Bill N9DSJ > > > > > > --- In digitalradio@yahoogroups.com, "Dave Bernstein" <aa6yq@> > > > wrote: > > > > > > > > You could host the last automatic digital QSO on 80m. If you > > ensure > > > > that the frequency is clear at both ends beforehand, then the > QSO > > > will > > > > be unique on two counts. > > > > > > > > 73, > > > > > > > > Dave, AA6YQ > > > > > > > > --- In digitalradio@yahoogroups.com, "Andrew J. O'Brien" > <andy@> > > > > wrote: > > > > > > > > > > I assume the new regs go in to effect at midnight Eastern > time, > > > 0500 > > > > UTC DEC 15, 2006. Does anyone have a suggestion for something > > > digital > > > > that we can do at that time ? > > > > > > > > > > Andy. > > > > > > > > > > > > > > > > > > > Connect to telnet://cluster.dynalias.org a single node spotting/alert system dedicated to digital and CW QSOs. > > > Yahoo! Groups Links > Connect to telnet://cluster.dynalias.org a single node spotting/alert system dedicated to digital and CW QSOs. Yahoo! Groups Links