I’m really not sure. Some of the military stuff I played with years ago had data embedded in the stream, but it all depends how the coding of the datastream is done and if there is any overhead to insert a bit more data to denote the hour, minute and second that the transmission started. Then the receiving end would have to decode it, figure the offset (e.g. the transmission started at :00 seconds but the time group was not transmitted until 10 seconds later) and update the clock. If there was overhead available, it could be included in every transmission, or just in a CQ or a 73, etc.
I've honestly not read up on how the current datastream is coded and I'm not a programmer or an RF guy - it was kind of an off-the-cuff idea - I just know it's been done in other applications, but those probably have a higher throughput and bandwidth. In reality, planning for that sort of SHTF situation probably takes digital modes (except CW) off the table. Hopefully, we never find out. Mike WM4B From: Dave Corsello [mailto:kd2...@gmail.com] Sent: Thursday, December 7, 2017 6:48 PM To: WSJT software development Subject: Re: [wsjt-devel] DXPedition System Clock Sync Then the idea of an automatic network isn’t feasible. Maybe it could work if every WSJT user who had access to NTP had the option to broadcast time data periodically from their station. How do you think embedding time data in the QSO data would work? Dave KD2JIP From: Mike Besemer Sent: Thursday, December 7, 2017 5:51 PM To: 'WSJT software development' Subject: Re: [wsjt-devel] DXPedition System Clock Sync Remember that in the U.S., automatically controlled beacons are not legal below 28.0 MHz. It would be much more efficient to encode time data within existing QSO data in the datastream. Mike WM4B From: Dave Corsello [mailto:kd2...@gmail.com] Sent: Thursday, December 7, 2017 5:39 PM To: WSJT software development Subject: Re: [wsjt-devel] DXPedition System Clock Sync Ria, Yes, I just ordered a cheap GPS receiver. I’m looking forward to using it with my Windows 10 tablet. Two of my primary interests are emergency communication and finding ways to function as off-gird as possible. To me, GPS is part of the grid, as vulnerable to failure as any other part. I’m knocked out by WSJT’s ability to perform under adverse conditions, and would love to see it freed from its dependence on local access to NTP. A network of WSJT “time servers” would be a grid of sorts, and would be tied to UTC. But each beacon could be an off-grid QRP rig, and NTP would not need to be available globally for it to work. Actually, a WSJT beacon network that’s in sync with itself could function independent of UTC. Of course, CW is as off-grid as it gets, although it requires an audible signal… 73 Dave KD2JIP From: Ria Jairam Sent: Thursday, December 7, 2017 4:32 PM To: WSJT software development Subject: Re: [wsjt-devel] DXPedition System Clock Sync Hi Dave, It was discussed and while it seems like a nice idea, I don't think it gained much traction among the dev team. Either way, GPS seems to be the most ubiquitous method to get time sync, as the satellites cover most of the Earth and receivers are very cheap. Even my DSTAR HT has one and I can access the GPS over bluetooth for time sync. 73 Ria, N2RJ On Thu, Dec 7, 2017 at 3:55 PM, Dave Corsello <kd2...@gmail.com> wrote: > Thanks, RIa. I did see more than one thread on time sync in which GPS was > discussed. I’m new to the list and was trying to contribute to a thread > from November, in which they were discussing alternatives to GPS. I didn’t > see any suggestions regarding a WSJT mode for time sync. Maybe I didn’t > look hard enough or maybe it’s too outlandish an idea. > > > > Given the current state of geo-politics, I think the probability of GPS > being knocked out by EMP is greater than zero. So I thought it was > worthwhile to continue the discussion. > > 73 > > Dave > > KD2JIP > > > > From: Ria Jairam > Sent: Thursday, December 7, 2017 3:25 PM > To: WSJT software development > Subject: Re: [wsjt-devel] DXPedition System Clock Sync > > > > I think this was discussed before and the consensus was that they > > could just use a GPS receiver instead. > > > > 73 > > Ria, N2RJ > > > > On Thu, Dec 7, 2017 at 3:18 PM, Dave Corsello <kd2...@gmail.com> wrote: > >> Would it make sense to develop a new WSJT mode for time sync? One > >> implementation might be through dedicated stations that grab UTC via NTP >> and > >> broadcast it, and an option in WSJT software to listen for the beacon, > >> calculate an offset between local system time and the received code, and > >> apply it to other modes during the current session. Not a lot to ask, > >> right? > >> > >> > >> >> ------------------------------------------------------------------------------ > >> Check out the vibrant tech community on one of the world's most > >> engaging tech sites, Slashdot.org! http://sdm.link/slashdot > >> _______________________________________________ > >> wsjt-devel mailing list > >> wsjt-devel@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/wsjt-devel > >> > > > > ------------------------------------------------------------------------------ > > Check out the vibrant tech community on one of the world's most > > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > > _______________________________________________ > > wsjt-devel mailing list > > wsjt-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/wsjt-devel > > > > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
