Re: [time-nuts] Handy iPhone app
Thomas A. Frank wrote: On Jul 16, 2010, at 4:08 AM, Peter Monta wrote: Rex r...@sonic.net wrote: I just eyeballed the minute turn-over but it was clearly within about a second. Well, apparently it is a phone issue and not a cell-tower issue. Searching the support forums yields the following trick: disable the automatic time setting, set it manually to a grossly wrong time, then put it back to the automatic setting, causing it to reacquire the time. Now my phone is within 3 seconds of NTP. Didn't fix the problem here in RI. Same 15 second error after the fact... Oh well. I don't really use it as a clock anyway... Tom Frank, KA2CDK Curious if you have any comparison you can make with a non-Apple phone? Seems to me that the problem points there, but we need some non-iPhone comparisons in the far (timing-wise) locales to see if there is a clear pattern. Also, I don't have an iPhone. Is there any other way than this Emerald thing to measure the clock? ___ 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] Handy iPhone app
I have an iPod Touch. It's an iPhone without the cellular radio, the camera, the GPS, or the compass, but it runs most of the same applications. Emerald Time works fine on it. As far as I can tell, Apple refuses to acknowledge any timing precision finer than minutes in their user interface. It displays the time on the top of most windows, but only to 1 minute resolution. You can manually set the date and time, but only to within 1 minute precision. The date and time setting widget doesn't display seconds, and doesn't provide a way to reset seconds to zero, or to temporarily stop the clock until the seconds are synchronized with the correct time. The Touch clearly doesn't get time from a cellular base station. It doesn't seem to get its time set from the computer it syncs to either (at least not from a Windows PC). My PC clock is set pretty accurately by a program called Nixie Clock (it agrees with Emerald Time within 200 ms), while the time on the Touch is 145 seconds off. Doing a sync with the PC does *not* correct the time at all. So I guess the only choice available to the Touch owner is manual time setting. By looking at when the minutes roll over, or running Emerald time and reading the error, you can get within 30 seconds of the correct time, and that's all. The Touch internal clock isn't terribly accurate either. Someday I should measure it to see how bad it is, but a quartz watch is better. Dave ___ 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] Handy iPhone app
I'm on the digest, so excuse me if this is redundant. I just checked my ATT HTC Pure (a Windows Mobile phone). It's time matches my Trimble to within a second. Armand KI7J Southern AZ USA -- Message: 8 Date: Sat, 17 Jul 2010 23:09:15 -0700 From: Rex r...@sonic.net Subject: Re: [time-nuts] Handy iPhone app To: Discussion of precise time and frequency measurement time-nuts@febo.com Message-ID: 4c429a8b.7040...@sonic.net Content-Type: text/plain; charset=ISO-8859-1; format=flowed Thomas A. Frank wrote: On Jul 16, 2010, at 4:08 AM, Peter Monta wrote: Rex r...@sonic.net wrote: I just eyeballed the minute turn-over but it was clearly within about a second. Well, apparently it is a phone issue and not a cell-tower issue. Searching the support forums yields the following trick: disable the automatic time setting, set it manually to a grossly wrong time, then put it back to the automatic setting, causing it to reacquire the time. Now my phone is within 3 seconds of NTP. Didn't fix the problem here in RI. Same 15 second error after the fact... Oh well. I don't really use it as a clock anyway... Tom Frank, KA2CDK Curious if you have any comparison you can make with a non-Apple phone? Seems to me that the problem points there, but we need some non-iPhone comparisons in the far (timing-wise) locales to see if there is a clear pattern. Also, I don't have an iPhone. Is there any other way than this Emerald thing to measure the clock? -- ___ time-nuts mailing list time-nuts@febo.com https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts End of time-nuts Digest, Vol 72, Issue 60 * ___ 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] Handy iPhone app
FWIW, my iphone is presently 15 seconds slow wrt Emerald (which matches my GPS based clock as closely as my eye can judge). Tom Frank, KA2CDK On Jul 15, 2010, at 10:40 AM, Mark Gulbrandsen wrote: Now if only Apple would allow Emerald Time to correct the i- phone's internal clock we'd actually have something. By using Emerald Time my i-phone's internal clock has shown itself to be off by as much as 12.4 seconds. That no longer qualifies as a usable clock to me. If I am out somewhere and want to know what time it is I have to bring Emerald Time up in order to see. You would think the phone would be receiving it's time from ATT's standards... but apparently not. There is no way ATT would be 12.4 seconds off which makes it apparent that Apple does not allow any correction of the phone's internal clock. To others here using the i-Phone... how far off is your i-Phone's internal clock??? ___ 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] Handy iPhone app
On Jul 16, 2010, at 4:08 AM, Peter Monta wrote: Rex r...@sonic.net wrote: I just eyeballed the minute turn-over but it was clearly within about a second. Well, apparently it is a phone issue and not a cell-tower issue. Searching the support forums yields the following trick: disable the automatic time setting, set it manually to a grossly wrong time, then put it back to the automatic setting, causing it to reacquire the time. Now my phone is within 3 seconds of NTP. Didn't fix the problem here in RI. Same 15 second error after the fact... Oh well. I don't really use it as a clock anyway... Tom Frank, KA2CDK ___ 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] Handy iPhone app
li...@ozindfw.net said: I used to work in the cell infra business. While it's less true today, there are still a number of operators that do not sync system clocks. The time supplied to users can be **minutes** off. Most newer operational standards can't tolerate this and accurate time (better than a ms) is important. WiMAX requires TDD base stations to base station alignment to be better than 1 microsecond. Most telecom operators want to avoid GPS at every site. It's a logistical PITA. Does that mean that the time has to match UTC or that all the clocks in the system have to be screwed up by close to the same amount? -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] Handy iPhone app
I'm in San Jose. (Same Bay you are talking about?) I am on ATT but I have a Motoroloa Razr that's at least a couple years old. I just checked the phone's displayed time vs the internet and also my GPS receiver. I just eyeballed the minute turn-over but it was clearly within about a second. Good enough for me on my phone. So, at least here where I am, ATT time is not off by even a couple seconds. Maybe the issue is another iPhone problem. Do you have any friends on ATT with Motorola phones you can compare? -Rex Peter Monta wrote: Here in the Bay Area, ATT/iPhone time has gotten noticeably worse recently. The error used to be around 4 seconds; now it's 49 seconds (!). Emerald Time is fine for interactive use, but what I find very impolite is that ATT's bad timestamps are written into the EXIF headers on photos. Sometimes I take pictures of sundials, for example, and a 49-second error is not negligible for a carefully made dial. It would be amusing to arrange for a long-term record of the offset of one's phone (which can of course change across multiple providers during travel), say by using a background process to take a sample every few hours against NTP sources or against GPS if the phone has it (or both). Then any photos can be batch-corrected later if desired. Apple, give me control over the time on my own phone, and please don't force me to resort to these schemes :-). Cheers, Peter Monta ___ 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] Handy iPhone app
pmo...@gmail.com said: It would be amusing to arrange for a long-term record of the offset of one's phone (which can of course change across multiple providers during travel), say by using a background process to take a sample every few hours against NTP sources or against GPS if the phone has it (or both). Then any photos can be batch-corrected later if desired. Apple, give me control over the time on my own phone, and please don't force me to resort to these schemes :-). I know nothing about developing apps for an iPhone, but I have real dumb/simple code that talks to ntpd. If anybody is serious about tracking their iPhone clock, contact me off-list. -- These are my opinions, not necessarily my employer's. I hate spam. ___ 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] Handy iPhone app
Rex r...@sonic.net wrote: I just eyeballed the minute turn-over but it was clearly within about a second. Well, apparently it is a phone issue and not a cell-tower issue. Searching the support forums yields the following trick: disable the automatic time setting, set it manually to a grossly wrong time, then put it back to the automatic setting, causing it to reacquire the time. Now my phone is within 3 seconds of NTP. Could there be some huge hysteresis/dead zone within which the iPhone doesn't bother to trim its clock to the cell tower? Sigh. Cheers, Peter Monta ___ 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] Handy iPhone app
In Tampa bay ATT is about 17 seconds off -- Mike On Jul 16, 2010, at 1:00, Peter Monta pmo...@gmail.com wrote: Oz-in-DFW writes: ... There is no way ATT would be 12.4 seconds off ... I used to work in the cell infra business. While it's less true today, there are still a number of operators that do not sync system clocks. The time supplied to users can be **minutes** off. Most newer operational standards can't tolerate this and accurate time (better than a ms) is important. WiMAX requires TDD base stations to base station alignment to be better than 1 microsecond. Most telecom operators want to avoid GPS at every site. It's a logistical PITA. Here in the Bay Area, ATT/iPhone time has gotten noticeably worse recently. The error used to be around 4 seconds; now it's 49 seconds (!). Emerald Time is fine for interactive use, but what I find very impolite is that ATT's bad timestamps are written into the EXIF headers on photos. Sometimes I take pictures of sundials, for example, and a 49-second error is not negligible for a carefully made dial. It would be amusing to arrange for a long-term record of the offset of one's phone (which can of course change across multiple providers during travel), say by using a background process to take a sample every few hours against NTP sources or against GPS if the phone has it (or both). Then any photos can be batch-corrected later if desired. Apple, give me control over the time on my own phone, and please don't force me to resort to these schemes :-). Cheers, Peter Monta ___ 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] Handy iPhone app
On 7/16/2010 1:57 AM, Hal Murray wrote: li...@ozindfw.net said: Most newer operational standards can't tolerate this and accurate time (better than a ms) is important. WiMAX requires TDD base stations to base station alignment to be better than 1 microsecond. Most telecom operators want to avoid GPS at every site. It's a logistical PITA. Does that mean that the time has to match UTC or that all the clocks in the system have to be screwed up by close to the same amount? The spec is only relative, that is base station to base station not absolute. The only practical way to accomplish this is GPS, so as a practical matter it's GPS time. There are a lot of problems with GPS in this application. Urban canyons, interference, logistics, indoor use, and politics are all issues. Oddly enough Iran, China, and even many European countries don't want critical infrastructure referenced to a US controlled system. Telecom systems are increasing moving indoors and this includes cellular. It would seem that bolting an antenna outside is no big deal, but often that is the dominant cost in a low cost application like femto base stations (those access point sized things that Verizon, ATT, and others are selling.) -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Handy iPhone app
On 7/16/2010 12:00 AM, Peter Monta wrote: Here in the Bay Area, ATT/iPhone time has gotten noticeably worse recently. The error used to be around 4 seconds; now it's 49 seconds (!). Emerald Time is fine for interactive use, but what I find very impolite is that ATT's bad timestamps are written into the EXIF headers on photos. Sometimes I take pictures of sundials, for example, and a 49-second error is not negligible for a carefully made dial. It would be amusing to arrange for a long-term record of the offset of one's phone (which can of course change across multiple providers during The problem is more challenging than this. It can depend on: 1. What air interface your phone is using (2G,3G, 0.0005g) 2. Where in the system you are. The time messages provided to a phone is usually referenced to some element of the billing system - not over the air operation. 3. The phone make, model, and internal settings. While the standards usually specify how this is to be done,not all manufacturers worry about this much. Apple is one of the worst, but not by much. It's further complicated by multiple standards which can have inconsistent requirements. Most phones don't do step corrections and instead use some sort of correction filter to gradually correct to the reference. For various values of gradual. So you'll need to record a lot more information to get anything really useful, though just average error would be interesting. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Handy iPhone app
Hi Here in Carlisle PA the same check shows the iPhone 3G within a second. That's running 3G, with no odd settings on the phone. Bob On Jul 16, 2010, at 3:06 AM, Rex wrote: I'm in San Jose. (Same Bay you are talking about?) I am on ATT but I have a Motoroloa Razr that's at least a couple years old. I just checked the phone's displayed time vs the internet and also my GPS receiver. I just eyeballed the minute turn-over but it was clearly within about a second. Good enough for me on my phone. So, at least here where I am, ATT time is not off by even a couple seconds. Maybe the issue is another iPhone problem. Do you have any friends on ATT with Motorola phones you can compare? -Rex Peter Monta wrote: Here in the Bay Area, ATT/iPhone time has gotten noticeably worse recently. The error used to be around 4 seconds; now it's 49 seconds (!). Emerald Time is fine for interactive use, but what I find very impolite is that ATT's bad timestamps are written into the EXIF headers on photos. Sometimes I take pictures of sundials, for example, and a 49-second error is not negligible for a carefully made dial. It would be amusing to arrange for a long-term record of the offset of one's phone (which can of course change across multiple providers during travel), say by using a background process to take a sample every few hours against NTP sources or against GPS if the phone has it (or both). Then any photos can be batch-corrected later if desired. Apple, give me control over the time on my own phone, and please don't force me to resort to these schemes :-). Cheers, Peter Monta ___ 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] Handy iPhone app
Hi, just found a handy free iPhone app called Emerald Time. It uses ntp and visually shows the time to within 100 msec. I've videod the screen and compared it with a real clock and found the claim to be accurate. Certainly not up to nut standard, but for a mobile phone it's great. Jim Palfreyman ___ 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] Handy iPhone app
On 15/07/2010, Jim Palfreyman jim77...@gmail.com wrote: Hi, just found a handy free iPhone app called Emerald Time. It uses ntp and visually shows the time to within 100 msec. I've videod the screen and compared it with a real clock and found the claim to be accurate. You know you can be excommunicated from the list for being off by 1E-1 s :) Steve Certainly not up to nut standard, but for a mobile phone it's great. Jim Palfreyman ___ 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. -- Steve Rooke - ZL3TUV G8KVD The only reason for time is so that everything doesn't happen at once. - Einstein ___ 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] Handy iPhone app
Now if only Apple would allow Emerald Time to correct the i-phone's internal clock we'd actually have something. By using Emerald Time my i-phone's internal clock has shown itself to be off by as much as 12.4 seconds. That no longer qualifies as a usable clock to me. If I am out somewhere and want to know what time it is I have to bring Emerald Time up in order to see. You would think the phone would be receiving it's time from ATT's standards... but apparently not. There is no way ATT would be 12.4 seconds off which makes it apparent that Apple does not allow any correction of the phone's internal clock. To others here using the i-Phone... how far off is your i-Phone's internal clock??? ___ 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] Handy iPhone app
Hate to say it. ATT is wrong and so are the rest of us. Its Apple time on Apple stuff thats the standard. You can have your own reference when you control a particular world. On Thu, Jul 15, 2010 at 10:47 AM, Bob Bownes bow...@gmail.com wrote: I put ntp on mine. :) On Thu, Jul 15, 2010 at 10:40 AM, Mark Gulbrandsen ksa50...@yahoo.com wrote: Now if only Apple would allow Emerald Time to correct the i-phone's internal clock we'd actually have something. By using Emerald Time my i-phone's internal clock has shown itself to be off by as much as 12.4 seconds. That no longer qualifies as a usable clock to me. If I am out somewhere and want to know what time it is I have to bring Emerald Time up in order to see. You would think the phone would be receiving it's time from ATT's standards... but apparently not. There is no way ATT would be 12.4 seconds off which makes it apparent that Apple does not allow any correction of the phone's internal clock. To others here using the i-Phone... how far off is your i-Phone's internal clock??? ___ 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] Handy iPhone app
On 7/15/2010 9:40 AM, Mark Gulbrandsen wrote: ... There is no way ATT would be 12.4 seconds off ... I used to work in the cell infra business. While it's less true today, there are still a number of operators that do not sync system clocks. The time supplied to users can be **minutes** off. Most newer operational standards can't tolerate this and accurate time (better than a ms) is important. WiMAX requires TDD base stations to base station alignment to be better than 1 microsecond. Most telecom operators want to avoid GPS at every site. It's a logistical PITA. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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] Handy iPhone app
Oz-in-DFW writes: ... There is no way ATT would be 12.4 seconds off ... I used to work in the cell infra business. While it's less true today, there are still a number of operators that do not sync system clocks. The time supplied to users can be **minutes** off. Most newer operational standards can't tolerate this and accurate time (better than a ms) is important. WiMAX requires TDD base stations to base station alignment to be better than 1 microsecond. Most telecom operators want to avoid GPS at every site. It's a logistical PITA. Here in the Bay Area, ATT/iPhone time has gotten noticeably worse recently. The error used to be around 4 seconds; now it's 49 seconds (!). Emerald Time is fine for interactive use, but what I find very impolite is that ATT's bad timestamps are written into the EXIF headers on photos. Sometimes I take pictures of sundials, for example, and a 49-second error is not negligible for a carefully made dial. It would be amusing to arrange for a long-term record of the offset of one's phone (which can of course change across multiple providers during travel), say by using a background process to take a sample every few hours against NTP sources or against GPS if the phone has it (or both). Then any photos can be batch-corrected later if desired. Apple, give me control over the time on my own phone, and please don't force me to resort to these schemes :-). Cheers, Peter Monta ___ 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.
