[time-nuts] Fake leap second ntp servers
Hey folks, I just joined your email list to inquire about something which some of you may have some knowledge of... I'm developing some code (for linux with an ntp server/client running), for which I would like to verify that it handles positive (and negative) leap seconds correctly (I need good time stamps for cross-machine synchronization). Obviously this is hard to do in practice due to the extreme rarity of these events. (even more so, considering my home servers running ntp apparently for some reason saw leap seconds at the end of 2007...) I've thought about switching to djb's suggestion of keeping a non-posix time zone on the machines in question, but this is not feasible because of existing legacy code... Thus I am curious to know if someone somewhere has perhaps set up fake ntp servers which regularly insert and delete leap seconds (ie. reset their time every couple days and randomly simulate a positive or negative leap second 2-3 days down the line). If not, does anyone know how to go about setting up such a fake ntp server for testing purposes? Also, is there a known good list of ntp servers which are known to provide correct leap second announcements (as mentioned above, the stratum 1s at least 2 of my machines were synched to apparently broadcast a leap second at the end of 2008). I've heard horror stories about time synchronization going haywire the last time there was a leap second and some upstream ntp servers announced leap-seconds and others didn't (the time mis-synchronization brought down the application)... Cheers, Maciej. ___ 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] Fake leap second ntp servers
There's probably a good NTP hacker hanging around on this list, but the best place to answer your question is probably the NTP hackers mailing list: https://lists.ntp.org/mailman/listinfo jeff Maciej Żenczykowski wrote: Hey folks, I just joined your email list to inquire about something which some of you may have some knowledge of... I'm developing some code (for linux with an ntp server/client running), for which I would like to verify that it handles positive (and negative) leap seconds correctly (I need good time stamps for cross-machine synchronization). Obviously this is hard to do in practice due to the extreme rarity of these events. (even more so, considering my home servers running ntp apparently for some reason saw leap seconds at the end of 2007...) I've thought about switching to djb's suggestion of keeping a non-posix time zone on the machines in question, but this is not feasible because of existing legacy code... Thus I am curious to know if someone somewhere has perhaps set up fake ntp servers which regularly insert and delete leap seconds (ie. reset their time every couple days and randomly simulate a positive or negative leap second 2-3 days down the line). If not, does anyone know how to go about setting up such a fake ntp server for testing purposes? Also, is there a known good list of ntp servers which are known to provide correct leap second announcements (as mentioned above, the stratum 1s at least 2 of my machines were synched to apparently broadcast a leap second at the end of 2008). I've heard horror stories about time synchronization going haywire the last time there was a leap second and some upstream ntp servers announced leap-seconds and others didn't (the time mis-synchronization brought down the application)... Cheers, Maciej. ___ 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] Raltron OX-6000D-L1-10-50.000-TN
Hi, does anybody have specs for the 6000 series... not on the site. This XO seems to have 3 outputs. Thanks, Christophe begin:vcard fn:Christophe Huygens n:Huygens;Christophe org:K.U.Leuven;Dept. Computerwetenschappen adr;dom:;;Celestijnenlaan 200A;Heverlee;;3001 email;internet:[EMAIL PROTECTED] title:Gastdocent tel;work:+3216327561 x-mozilla-html:FALSE url:www.cs.kuleuven.ac.be/~xtof version:2.1 end:vcard ___ 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] Power Supply Questions
Does the power source for just a GPS module matter that much? Most that I've seen just use a cheap wallwort and a lm-whatever 5v regulator chip... nothing fancy. My second question is what do you guys think about Acopian power supplies? I picked up a couple 24v linear gold box models with good regulation and low ripple for super cheap on eBay (model A24MT210 if you want to look it up). I figure it has to be better for my GPSDO than the cheap switching PSU I have been using. Jason ___ 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] Clock Powers of Ten
There are good clocks and bad clocks. Most need power, one needs food, another runs all by itself. Take a trip across 15 orders of magnitude of clock performance: http://www.leapsecond.com/ten/ /tvb ___ 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] Clock Powers of Ten
At 03:55 PM 1/31/2008, Tom Van Baak wrote: Take a trip across 15 orders of magnitude of clock performance: http://www.leapsecond.com/ten/ Fun! What piece of equipment is that Isotemp OCXO (page 28) used in? -- newell N5TNL ___ 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] Power Supply Questions
Jason Rabel wrote: Does the power source for just a GPS module matter that much? Most that I've seen just use a cheap wallwort and a lm-whatever 5v regulator chip... nothing fancy. Jason Wall warts do (as other supplies with high transformer primary secondary capacitance) have the unfortunate capability of coupling high amplitude transients on the mains from the primary to the secondary. The cure is simple: a non polar capacitor with an appropriate value (several hundred nF to 1uF or so) connected across the secondary - often omitted to save money. An AC traszorb connected across the secondary can also be used. Bruce ___ 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] Clock Powers of Ten
Tom Van Baak wrote: There are good clocks and bad clocks. Most need power, one needs food, another runs all by itself. Take a trip across 15 orders of magnitude of clock performance: http://www.leapsecond.com/ten/ /tvb I must say the drip clock was very nice. Re the mains frequency, I believe it changes with the load on the grid. Do you have a record of this? Sylvain ___ 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] Clock Powers of Ten
There are good clocks and bad clocks. Most need power, one needs food, another runs all by itself. Take a trip across 15 orders of magnitude of clock performance: Excellent stuff Tom! Best Rgds Rob K ___ 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] Clock Powers of Ten
Very cool, Tom! John Tom Van Baak said the following on 01/31/2008 04:55 PM: There are good clocks and bad clocks. Most need power, one needs food, another runs all by itself. Take a trip across 15 orders of magnitude of clock performance: http://www.leapsecond.com/ten/ /tvb ___ 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] Tracor 895A
Hi all, Can anybody lead me to information on the Tracor 895A Linear Phase / Time Comparator? A simple google search doesn't turn up much. Regards, Nic ___ 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] Clock Powers of Ten
Very nice, it reminded me of a NYT article about a year ago that describes the long zoom as one of the defining aspects of this generation: http://www.nytimes.com/2006/10/08/magazine/08games.html?ei=5090en=d551133c9414ebbdex=131796partner=rssuserlandemc=rsspagewanted=all jeff John Ackermann N8UR wrote: Very cool, Tom! John Tom Van Baak said the following on 01/31/2008 04:55 PM: There are good clocks and bad clocks. Most need power, one needs food, another runs all by itself. Take a trip across 15 orders of magnitude of clock performance: http://www.leapsecond.com/ten/ /tvb ___ 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 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] Clock Powers of Ten
On Jan 31, 2008 5:27 PM, Sylvain RICHARD [EMAIL PROTECTED] wrote: Re the mains frequency, I believe it changes with the load on the grid. Do you have a record of this? I forget the reasoning for frequency variation, but it is load or source related I believe. Part of the reason it A project for a easy to build AC frequency measuring device: http://www.sparetimegizmos.com/Hardware/AC_Monitor.htm I could log the frequency deviations from my local AC mains if you want some sample data. ___ 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] Clock Powers of Ten
michael taylor a écrit : On Jan 31, 2008 5:27 PM, Sylvain RICHARD [1][EMAIL PROTECTED] wrote: Re the mains frequency, I believe it changes with the load on the grid. Do you have a record of this? I forget the reasoning for frequency variation, but it is load or source related I believe. Part of the reason it It is a balance between production and grid load. In the European case, the grids are phase synchronous over several countries. The (oldish) data I have is - Nordel : Finland, Norway, Sweden, Denmark - Uktsoa : UK. - Atsoi : Irland - Ucte : everybody else in Western Europe : Portugal, Spain, France, Netherlands, Belgium, Luxembourg, Germany, Switzerland, Austria, Italy, Czech Republic, Slovakia, Poland, Hungary, Romania, ex-Yougoslavia During the 2006 blackout, the frequency went down by several hertz before some customers were disconnected (load shedding). The so familiar 50Hz line on VLF spectrograms took a dip. A project for a easy to build AC frequency measuring device: [2]http://www.sparetimegizmos.com/Hardware/AC_Monitor.htm I could log the frequency deviations from my local AC mains if you want some sample data. This gadget looks nice, but I think I'll pass. Good night Sylvain References 1. mailto:[EMAIL PROTECTED] 2. http://www.sparetimegizmos.com/Hardware/AC_Monitor.htm ___ 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] Tracor 895A
Hi Nic these are difficult to find for free but Ridge Electronics have one for Tracor 895 at $20. I just got a Montronics Freq Diff meter manual from them. Alan G3NYK - Original Message - From: Nic McLean [EMAIL PROTECTED] To: 'Discussion of precise time and frequency measurement' time-nuts@febo.com Sent: Thursday, January 31, 2008 11:24 PM Subject: [time-nuts] Tracor 895A Hi all, Can anybody lead me to information on the Tracor 895A Linear Phase / Time Comparator? A simple google search doesn't turn up much. Regards, Nic ___ 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] Clock Powers of Ten
Hi, I dont know about other counties but the oad shedding is certainly still dont this way in the UK, BUT the incremental frequency adjectments are corrected for the mean daily frequency to be correvt at 06:00 in the morning so that all the clocks read correctly and we get to work on time!! Despite quartzz clocks I think this is still the caseit is probably enshrined in law in the UK. Also Our nominal voltage is 240v not the 230v decreed by the EU fortunately we can still be fed 240v within the tolarance allows otherwise my toaster would take forever. There is actually a considerable difference in the light output of a tungsten bulb over that range maybe that is why we are being forced into using polluting CFBs...nutting to do with time ...sorry pardon Great site Tom !! Alan G3NYK . - Original Message - From: Sylvain RICHARD [EMAIL PROTECTED] To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Friday, February 01, 2008 12:25 AM Subject: Re: [time-nuts] Clock Powers of Ten michael taylor a écrit : On Jan 31, 2008 5:27 PM, Sylvain RICHARD [1][EMAIL PROTECTED] wrote: Re the mains frequency, I believe it changes with the load on the grid. Do you have a record of this? I forget the reasoning for frequency variation, but it is load or source related I believe. Part of the reason it It is a balance between production and grid load. In the European case, the grids are phase synchronous over several countries. The (oldish) data I have is - Nordel : Finland, Norway, Sweden, Denmark - Uktsoa : UK. - Atsoi : Irland - Ucte : everybody else in Western Europe : Portugal, Spain, France, Netherlands, Belgium, Luxembourg, Germany, Switzerland, Austria, Italy, Czech Republic, Slovakia, Poland, Hungary, Romania, ex-Yougoslavia During the 2006 blackout, the frequency went down by several hertz before some customers were disconnected (load shedding). The so familiar 50Hz line on VLF spectrograms took a dip. A project for a easy to build AC frequency measuring device: [2]http://www.sparetimegizmos.com/Hardware/AC_Monitor.htm I could log the frequency deviations from my local AC mains if you want some sample data. This gadget looks nice, but I think I'll pass. Good night Sylvain References 1. mailto:[EMAIL PROTECTED] 2. http://www.sparetimegizmos.com/Hardware/AC_Monitor.htm ___ 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] Clock Powers of Ten
From: Sylvain RICHARD [EMAIL PROTECTED] Subject: Re: [time-nuts] Clock Powers of Ten Date: Fri, 01 Feb 2008 01:25:54 +0100 Message-ID: [EMAIL PROTECTED] michael taylor a écrit : On Jan 31, 2008 5:27 PM, Sylvain RICHARD [1][EMAIL PROTECTED] wrote: Re the mains frequency, I believe it changes with the load on the grid. Do you have a record of this? I forget the reasoning for frequency variation, but it is load or source related I believe. Part of the reason it Over-production compared to consumption raises the frequency. Under-production compared to consumption lowers the frequency. To balance the frequency, the production of electricity is raised or lowered as required. In addition, the reactive effect is balanced. During failures, creating lower consumption converts under-production to over-production and thus raises the frequency again. There was once a good posting on this on Synth-DIY upon my request. Can't find it by quick google attacks. Cheers, Magnus ___ 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] Tracor 895A
Thanks Alan, I'll give them a try. 73's Nic VK2KXN / VK5ZAT Hi Nic these are difficult to find for free but Ridge Electronics have one for Tracor 895 at $20. I just got a Montronics Freq Diff meter manual from them. Alan G3NYK ___ 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] Tracor 895A
Hi all, I also have a Tracor 895 and have a copy of the manual. It is all discrete stuff , no IC's. If you reqire a copy, that should be no problem. Max VK3YBA Subject: Re: [time-nuts] Tracor 895A Hi Nic these are difficult to find for free but Ridge Electronics have one for Tracor 895 at $20. I just got a Montronics Freq Diff meter manual from them. Alan G3NYK ___ 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] Clock Powers of Ten
Hi Tom: Nice overview. Charles and Ray Eames did: Powers of Ten http://www.imdb.com/title/tt0078106/ Toccata for Toy Trains http://www.imdb.com/title/tt0051091/ and the Eames chair which is still available from Herman Miller: http://www.hermanmiller.com/CDA/SSA/Product/1,1592,a10-c440-p47,00.html I think in your Powers of Ten you showed a timepiece for which I don't remember any data. Since it's shown on the last page does that mean the hour glass has very good specs? Have Fun, Brooke Clarke http://www.prc68.com/Alpha.shtml All my web pages listed based on html name http://www.PRC68.com http://www.precisionclock.com http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam Tom Van Baak wrote: There are good clocks and bad clocks. Most need power, one needs food, another runs all by itself. Take a trip across 15 orders of magnitude of clock performance: http://www.leapsecond.com/ten/ /tvb ___ 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] Fake leap second ntp servers
Thanks I'll give that a try. On Jan 31, 2008 7:58 AM, Jeff Mock [EMAIL PROTECTED] wrote: There's probably a good NTP hacker hanging around on this list, but the best place to answer your question is probably the NTP hackers mailing list: https://lists.ntp.org/mailman/listinfo jeff Maciej Żenczykowski wrote: Hey folks, I just joined your email list to inquire about something which some of you may have some knowledge of... I'm developing some code (for linux with an ntp server/client running), for which I would like to verify that it handles positive (and negative) leap seconds correctly (I need good time stamps for cross-machine synchronization). Obviously this is hard to do in practice due to the extreme rarity of these events. (even more so, considering my home servers running ntp apparently for some reason saw leap seconds at the end of 2007...) I've thought about switching to djb's suggestion of keeping a non-posix time zone on the machines in question, but this is not feasible because of existing legacy code... Thus I am curious to know if someone somewhere has perhaps set up fake ntp servers which regularly insert and delete leap seconds (ie. reset their time every couple days and randomly simulate a positive or negative leap second 2-3 days down the line). If not, does anyone know how to go about setting up such a fake ntp server for testing purposes? Also, is there a known good list of ntp servers which are known to provide correct leap second announcements (as mentioned above, the stratum 1s at least 2 of my machines were synched to apparently broadcast a leap second at the end of 2008). I've heard horror stories about time synchronization going haywire the last time there was a leap second and some upstream ntp servers announced leap-seconds and others didn't (the time mis-synchronization brought down the application)... Cheers, Maciej. ___ 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 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] Clock Powers of Ten
Brooke Clarke wrote: Hi Tom: Nice overview. I think in your Powers of Ten you showed a timepiece for which I don't remember any data. Since it's shown on the last page does that mean the hour glass has very good specs? How can it have (as a clock)? It isnt a periodic device by itself. Need to turn it into an oscillator/periodic device first before AVAR etc, can be measured. Bruce ___ 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.
