Hi This is Time Nuts, not end of the world nuts …..
I most certainly did *not* design these systems. The *do* have timing requirements. If those requirements are not met, they stop working. That’s just the way it goes. Designing these systems at the timing level was done a decade ago. You can object to what they did, it’s about ten years to late to change anything. Tight timing gives then more capacity … tough to argue with even if you weren’t to late. If *you* believe there is an alternative system now in existence that will supply the timing these systems require … that *is* a Time Nuts topic. So, let’s hear about the numbers on the system you believe will supply what’s needed. I think we’ve all heard plenty of “the world is ending” stuff. Bob > On Sep 7, 2018, at 7:01 PM, Scott McGrath <scmcgr...@gmail.com> wrote: > > You are SO convinced that GPS will ALWAYS be there, I’m NOT (Think > Carrington Event) and i’ve been part of a few disaster exercises where both > Internet and GPS were considered ‘down’ for the exercise and these exercises > are done in conjunction with the military so PPS was also ‘off the table’. > > It was quite an eye opener to see how many networks could not keep time > synchronized within 5 minutes much less 5 seconds because of the cheap XO’s > used in servers and workstations(NTP will ALWAYS BE AVAILABLE). Just like > the old Sun workstations. > > It was also fun watching the multimillion dollar Harris radios drift once > they no longer had a 10 Mhz input from a GPSDO. One would think the local > timebase would be a bit better than it was. > > The older ‘Pacer Bounce’ and Falcon series radios did much better because > they had good local timebases and made no assumptions of the availability of > a external timebase. Whereas the new radios depend upon it. > > These exercises are intended to practice restoring government communications > after a large scale natural disaster. And without readily available > precision time it aint easy. > > Its also fun watching executives realizing that their phone during the > exercise is a paperweight useful only in weighting down stacks of Form 213’s > > Its not for nothing that Symmetricom is building more 5071’s than HP/Agilent > ever did. > > On Sep 7, 2018, at 5:18 PM, Bob kb8tq <kb...@n1k.org> wrote: > > Hi > > You are not trying to run a cell system when checking your local oscillator > against LORAN. > It’s two completely different things. The timing requirements of the modern > systems are indeed > way past what LORAN can deliver. We’re not talking about 1970’s state of the > art anymore. You > need a time source that is in the 10 ns range to keep this stuff running. > Multiple microseconds of > error in your timing source aren’t good enough for what they have up and are > rolling out. Full > end of holdover spec on many of them is below 2 microseconds. Normal > operation is under 100 ns. > Give the cell outfits another couple years and that’s all they will have on > the air. > > > Bob > >> On Sep 6, 2018, at 9:08 PM, Scott McGrath <scmcgr...@gmail.com> wrote: >> >> >> As to eLORAN, you can deny positioning but maintain timing service simply >> by modifying the GRI and since eLORAN is software based thats not a >> difficult change. >> >> Navigation receivers go into fail but timing receivers only need ONE >> station. As the users of SRS700’s and Austrons do when Wildwood is active. >> >> With GNSS its a hell of a lot harder and without SA your only option is to >> turn off all the C/A signals hence denying civillian use of GNSS >> >> I’m pretty sure if a non-state actor was doing weaponized drone attacks with >> GPS for guidance, GPS for civilian use would be shut down in a NY minute . >> >> Remember govt users would not be affected as they have access to the PPS and >> the ‘word of the day’ to make it active. >> >> You dont need conspiracies to think of conditions where GPS would be shut >> down for long periods of time and where reasonable people would agree with >> the shutdown. >> >> On Sep 6, 2018, at 8:44 PM, Scott McGrath <scmcgr...@gmail.com> wrote: >> >> Gee, thats strange especially for those of us who ran the Austron >> comparitors to check our local standards against the LORSTA’s >> >> >> >> On Sep 6, 2018, at 8:04 PM, Bob kb8tq <kb...@n1k.org> wrote: >> >> Hi >> >> No, eLoran *never* on it’s best day could ever deliver the kind of timing >> that the vast majority >> of these systems require. It simply is not and can not do the job. The world >> has moved *way* >> past the sort of timing it can actually deliver. >> >> Bob >> >>> On Sep 6, 2018, at 6:35 PM, Scott McGrath <scmcgr...@gmail.com> wrote: >>> >>> Actually we DID have a radio based system that provided sufficient accuracy >>> it was called eLORAN but it was killed by US politicians because they did >>> not want a much more inexpensive to operate system ‘competing’ with GPS. >>> Shutting down LORAN saved 32m dollars annually the NAVSTAR GPS program >>> costs billions annually. >>> >>> Ironically while LORAN’s absolute accuracy is less than GPS, repeatability >>> was much better so fishermen liked LORAN better. >>> >>> Once again the empty suits won and the navigation and timing community lost. >>> >>> Wrt cellsites staying operational i imagine the oscillators in holdover >>> would probably remain sufficiently synchronized for a month or so. >>> >>> >>> >>> On Sep 6, 2018, at 4:56 PM, Bob kb8tq <kb...@n1k.org> wrote: >>> >>> Hi >>> >>> Well, we *do* have experience with that. It was called selective >>> availability. Indeed it might get turned back on again. It’s impact on a >>> properly designed GPSDO - not much. It takes a bit longer to get to best >>> stability. System time wise, it still works “good enough”. >>> >>> A four hour long test format also does basically nothing to a GPSDO based >>> system. You didn’t read anything in the papers about all cell service in >>> three states going away. The devices did what they are supposed to do and >>> everything did it’s boringly normal thing ….. it worked fine. >>> >>> I still don’t quite understand just what people think could replace >>> satellite based timing in these systems. None of the “radio based” systems >>> are within a factor many thousands to a few million of being adequate. >>> >>> ===== >>> >>> Now, if this is headed off into a “the government is coming to break down >>> the doors and take away all my toys sort of thing. That’s very much *not* a >>> Time Nuts topic. >>> >>> Bob >>> >>>> On Sep 6, 2018, at 11:34 AM, Scott McGrath <scmcgr...@gmail.com> wrote: >>>> >>>> And there is the other significant vulnerability since GPS is a MILITARY >>>> system the DoD can take it offline for any reason at any time. >>>> >>>> Leaving civilian users with nothing, >>>> >>>> If its a national security threat its likely the other GNSS systems will >>>> be unavailable as well. >>>> >>>> >>>> >>>> >>>> >>>> On Sep 6, 2018, at 9:53 AM, John Sloan <jsl...@diag.com> wrote: >>>> >>>> >>>> Folks: >>>> >>>> Well blow me down. It took some Google Maps fu on the web on my part, but >>>> my time and place does indeed coincide with this “GPS Interference >>>> Testing” at >>>> White Sands Missile Range. I just happened to be in my home office watching >>>> several of my GPS-disciplined NTP servers when this occurred. Thanks, >>>> Graham! >>>> >>>> :John >>>> >>>>> ZDV DENVER (ARTCC),CO. [Back to Top] !GPS 08/260 (KZDV A0287/18) ZDV NAV >>>>> GPS (WSMR GPS 18-20) (INCLUDING WAAS, GBAS, AND ADS-B) MAY NOT BE AVBL WI >>>>> A >>>>> 359NM RADIUS CENTERED AT 333345N1063840W (TCS054036) FL400-UNL, 311NM >>>>> RADIUS AT FL250, 215NM RADIUS AT 10000FT, 223NM RADIUS AT 4000FT AGL, >>>>> 169NM >>>>> RADIUS AT 50FT AGL DLY 1830-2230 1809031830-1809082230 >>>> >>>> -- >>>> J. L. Sloan Digital Aggregates Corp. >>>> +1 303 940 9064 (O) 3440 Youngfield St. #209 >>>> +1 303 489 5178 (M) Wheat Ridge CO 80033 USA >>>> jsl...@diag.com http://www.diag.com <http://www.diag.com/> >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>> To unsubscribe, go to >>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>> and follow the instructions there. >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- time-nuts@lists.febo.com >>>> To unsubscribe, go to >>>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>>> and follow the instructions there. >>> >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@lists.febo.com >>> To unsubscribe, go to >>> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >>> and follow the instructions there. >> >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. >> >> _______________________________________________ >> time-nuts mailing list -- time-nuts@lists.febo.com >> To unsubscribe, go to >> http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com >> and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
