Strangely enough there are these devices called ‘computers’ which are rumored to be able to perform measurements and mathematical calculations.
One of these ‘computers’ might be profitably employed to perform the necessary measurements calculations and deliver a useful output, Employing a Mentat would be expensive for this task... On Aug 31, 2018, at 11:37 AM, Tom Holmes <[email protected]> wrote: Uh, folks...Would the apparently still on hiatus TVB approve of this on-going Urinary Olympiad? Just asking. And hoping post this won’t start another one. Tom Holmes, N8ZM -----Original Message----- From: time-nuts <[email protected]> On Behalf Of Bob kb8tq Sent: Friday, August 31, 2018 11:16 AM To: Martin VE3OAT <[email protected]>; Discussion of precise time and frequency measurement <[email protected]> Subject: Re: [time-nuts] WWV and legal issues Hi That works fine if you are doing things manual to check a local standard. If you are trying to disipline a few thousand cell towers 24 hours a day … not so much. It also works for checking frequency. What modern systems need is time. That gets you into a whole world of resolving and identifying individual edges. The WWVB signal really was never set up for this. Loran-C is an example of a signal that was designed to identify a specific edge. Bob > On Aug 31, 2018, at 10:30 AM, Martin VE3OAT <[email protected]> wrote: > > But the diurnal phase shifts at VLF are predictable and largely repeatable. > Ignore the phase at night and use only the phase records during the day when > an all-daylight propagation path exists. You might have to "correct" the > absolute phase reading by some multiple of the RF period, but with a low rate > of local standard oscillator drift, this is a simple matter of arithmetic. > Back in the day, I managed Sulzer crystal oscillators at 5 field sites from > my office and could maintain phase continuity for weeks at a time, until we > had to diddle the dial on one or several of them to correct for crystal > aging. Then it was just more arithmetic again. Several of the oscillators > had such low drift rates that all I needed was one daily phase reading from > the VLF phase tracking receiver (Tracor 599Js) at those sites to know the > frequency of the Sulzers there. > > ... Martin VE3OAT > > On Thu, 30 Aug 2018 12:27:12 -0400 > Bob kb8tq<[email protected]> wrote: > >> WWVB as transmitted ( = right at the input to the antenna) is a wonderfully >> stable signal. As soon as >> that signal hits the real world things start to degrade. Propagation between >> transmit and receive sites >> is a big deal, even at 60 KHz. On top of that, there is a*lot* of manmade >> noise at 60 KHz. The receive >> signal to noise will never be as good as you might like it to be ?. > >> I don't know about WWVB, but for DCF77 it's known that sunrise/sunset >> causes a phase shift of several 100?s at even moderate distances >> (like ~500km). Unfortunately I don't have any measurements at hand. >> Attila Kinali > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
