Re: [time-nuts] Q/noise of Earth as an oscillator
There might be two Qs: one relating to the axil rotation and another concerning the volume behavior of the earth as a giant bowl of Jello. But you'd have to figure out how to really slam the planet to excite the entire volume. Earthquakes are probably too wimpy. Ron From: Chris Caudle To: time-nuts@febo.com Sent: Wednesday, July 27, 2016 8:50 AM Subject: Re: [time-nuts] Q/noise of Earth as an oscillator On Wed, July 27, 2016 10:33 am, Chris Caudle wrote: > Does that imply that this value is not constant: >>> And if you take the classic definition >>> Q = 2 pi * total energy /energy lost per cycle >>> then it would seem earth has a Q factor. After re-reading "The Story of Q" I agree that Q of a rotating body could be non-constant, but also consistent with the original definition of Q as the ratio of reactance to resistance of an inductor, which of course would vary almost completely linearly over a wide frequency range where the resistive dissipation was not frequency dependent (i.e. where skin effect was negligible). Perhaps a more useful question is whether that is still a useful definition compared to how the term is more typically used now to refer to resonance bandwidth. -- Chris Caudle ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
[time-nuts] Using the HP 58503a to correct your PC clock
This has probably been covered in the past, but is there a way correct or control a PC (Windows 7) clock with the HP 58503A GPS receiver? I just bought one (on the way now) and have a copy of satstats50 on hand. I've been using Dimension 4 and I'm surprised at the size of correction every couple minutes to my PC clock. I'd be happy if my PC clock were accurate to plus/minus 100ms. Ron ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Using the HP 58503a to correct your PC clock
Thanks. Although I'm brand new here, I've seen some posts talking about Lady Heather (some with amusing suggestions) and will look into it. Might just be what I need. I'm working with NTP right now, using Dimension 4, after having discovered D4's history info. Thanks again, Ron From: Mark Sims To: "time-nuts@febo.com" Sent: Wednesday, August 3, 2016 8:50 PM Subject: [time-nuts] Using the HP 58503a to correct your PC clock Lady Heather has the ability to set the system clock from any just about any GPS receiver. It can set the clock every day, hour, minute, or when system time and receiver time diverge by more than "x" milliseconds. Most stock Windows systems have a clock granularity of +/- 15.6 milliseconds, so the default "time set anytime" divergence threshold is 40 milliseconds. Lady Heather now talks to SCPI devices and has support for the HP5 devices, but I don't have one and have not verified that the program works with them or analyzed their time stamp message arrival time offset. You can get something like a cheap Ublox GPS module for less than $20 and they work really well. -- > This has probably been covered in the past, but is there a way correct or > control a PC (Windows 7) clock with the HP 58503A GPS receiver? ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Using the HP 58503a to correct your PC clock
My granddaughter would love to know I have a Tardis program. (-;> Lots of things to try here, just to get a more accurate clock. No wonder there's a time-nutz group! From: David To: Discussion of precise time and frequency measurement Sent: Thursday, August 4, 2016 11:47 AM Subject: Re: [time-nuts] Using the HP 58503a to correct your PC clock The old Tardis program for Windows (Tardis2000 now) handles it correctly by altering the rate and only jamming the time if it is outside of a specified window but I do not think its GPS mode supports the 1 PPS signal. I am not sure if Tardis works with Windows 7 and above though; I forget to test it on my Windows 7 test system when I had it. It is a pretty old (but free) program. On Tue, 2 Aug 2016 23:28:06 -0700, you wrote: >The WRONG way to adjust a PC clock is to set the TIME periodically from >some standard. When you do this then the time on the PC is not running at >a constant rate. The correct way to do this is to adjust the PC's clocks >RATE. You make it runs slightly faster if you notice it is getting behind >and slightly slower if it is running fast. > >Think about what you would do to a real physical clock. You would not set >it every few minutes, you'd adjust the rate and wait a little while to see >if the adjustment needs refinement or not. > >... > >Most operating systems in use today run NTP to keep their clocks in order. >Well most OSes except for Windows. Microsoft uses a vey much simplified >version of this that does the wrong thing and periodically sets the PC's >clock. You could enable this and likely, maybe reach your +/- 100ms goal. > Not the "real" NTP is a free program and not hard to set up so you can >have 1ms level accuracy without much effort and better with some work. > >On Tue, Aug 2, 2016 at 8:13 PM, Ron Ott wrote: > >> This has probably been covered in the past, but is there a way correct or >> control a PC (Windows 7) clock with the HP 58503A GPS receiver? I just >> bought one (on the way now) and have a copy of satstats50 on hand. I've >> been using Dimension 4 and I'm surprised at the size of correction every >> couple minutes to my PC clock. I'd be happy if my PC clock were accurate >> to plus/minus 100ms. >> Ron ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Tardis [WAS: Using the HP 58503a to correct your PC clock]
That's encouraging!! I'm working on NTP and have no idea what's happening. The description says it takes over the PC clock, excluding other apps. I like the rate correction concept, but not if I lose my hair or have to wipe the drive. Ron From: Charles Steinmetz To: time-nuts@febo.com Sent: Thursday, August 4, 2016 1:08 PM Subject: Re: [time-nuts] Tardis [WAS: Using the HP 58503a to correct your PC clock] David wrote: > I am not sure if Tardis works with Windows 7 and above though; I > forget to test it on my Windows 7 test system when I had it. It is a > pretty old (but free) program. About five years ago, after a lot of experience with Tardis under XP, I worked for several weeks trying to get it to work under Vista. I never succeeded, and it fatally corrupted the system. I had to wipe the boot drive and start over. Best regards, Charles ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Using the HP 58503a to correct your PC clock
The Meinberg page I'm reading has NTP downloads for Windows XP and newer and for older versions of Windows. If you meant a special version of NTP for Windows 7, I didn't see mention of it. Ron From: David J Taylor To: time-nuts@febo.com Sent: Friday, August 5, 2016 12:30 AM Subject: Re: [time-nuts] Using the HP 58503a to correct your PC clock Doesn't Meinberg have a Win7 version of ntp on their homepage ? Why not use that CFO === Installation guide and Win-7/8/10 notes here: http://www.satsignal.eu/ntp/setup.html Cheers, David -- SatSignal Software - Quality software written to your requirements Web: http://www.satsignal.eu Email: david-tay...@blueyonder.co.uk Twitter: @gm8arv ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
