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Groups > sci.electronics.design > #446378 > unrolled thread
| Started by | Pimpom <pimpom@invalid.com> |
|---|---|
| First post | 2017-02-06 11:22 +0530 |
| Last post | 2017-02-09 04:57 -0500 |
| Articles | 20 on this page of 119 — 31 participants |
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OT: Current standard for watch precision Pimpom <pimpom@invalid.com> - 2017-02-06 11:22 +0530
Re: OT: Current standard for watch precision Phil Allison <pallison49@gmail.com> - 2017-02-05 22:13 -0800
Re: OT: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-06 17:15 +0530
Re: OT: Current standard for watch precision Phil Allison <pallison49@gmail.com> - 2017-02-06 05:11 -0800
Re: OT: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-06 19:30 +0530
Re: OT: Current standard for watch precision Phil Allison <pallison49@gmail.com> - 2017-02-06 06:33 -0800
Re: OT: Current standard for watch precision nub12 <nub12@null.com> - 2017-02-07 07:57 +0800
Re: OT: Current standard for watch precision Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:06 -0800
Re: OT: Current standard for watch precision Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-02-06 20:16 +0200
Re: OT: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-07 00:12 +0530
Re: OT: Current standard for watch precision Don Y <blockedofcourse@foo.invalid> - 2017-02-06 11:58 -0700
Re: OT: Current standard for watch precision Jasen Betts <jasen@xnet.co.nz> - 2017-02-07 05:50 +0000
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-07 02:43 -0500
Re: OT: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-07 14:53 +0530
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-07 12:32 -0500
Re: OT: Current standard for watch precision Phil Allison <pallison49@gmail.com> - 2017-02-07 02:33 -0800
Re: OT: Current standard for watch precision upsidedown@downunder.com - 2017-02-07 17:56 +0200
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-07 17:32 -0500
Re: OT: Current standard for watch precision Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-07 14:52 -0800
Re: OT: Current standard for watch precision upsidedown@downunder.com - 2017-02-08 10:25 +0200
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-08 03:37 -0500
Re: OT: Current standard for watch precision Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-08 09:01 +0000
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-08 05:24 -0500
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 09:08 -0800
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-08 16:04 -0500
Re: OT: Current standard for watch precision Clifford Heath <no.spam@please.net> - 2017-02-09 08:12 +1100
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-08 17:28 -0500
Re: OT: Current standard for watch precision pcdhobbs@gmail.com - 2017-02-08 16:19 -0800
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 00:36 -0500
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 00:38 -0500
Re: OT: Current standard for watch precision Clifford Heath <no.spam@please.net> - 2017-02-09 18:39 +1100
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 04:16 -0500
Re: OT: Current standard for watch precision Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-09 09:46 +0000
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 05:03 -0500
Re: OT: Current standard for watch precision Jeroen Belleman <jeroen@nospam.please> - 2017-02-09 11:45 +0100
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 07:12 -0500
Re: OT: Current standard for watch precision Jeroen Belleman <jeroen@nospam.please> - 2017-02-09 13:31 +0100
Re: OT: Current standard for watch precision Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-09 12:14 +0000
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 07:25 -0500
Re: OT: Current standard for watch precision Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-10 09:17 +0000
Re: OT: Current standard for watch precision Jeroen Belleman <jeroen@nospam.please> - 2017-02-10 10:45 +0100
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-10 21:56 -0500
Re: OT: Current standard for watch precision Jasen Betts <jasen@xnet.co.nz> - 2017-02-11 02:06 +0000
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-10 22:24 -0500
Re: OT: Current standard for watch precision Jasen Betts <jasen@xnet.co.nz> - 2017-02-11 01:54 +0000
Re: OT: Current standard for watch precision Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-10 18:10 -0800
Re: OT: Current standard for watch precision Cursitor Doom <curd@notformail.com> - 2017-02-08 23:34 +0000
Re: OT: Current standard for watch precision Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-08 15:49 -0800
Re: OT: Current standard for watch precision pcdhobbs@gmail.com - 2017-02-08 15:55 -0800
Re: OT: Current standard for watch precision Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-08 16:08 -0800
Re: OT: Current standard for watch precision Ralph Barone <ralph@invalid.com> - 2017-02-09 03:24 +0000
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 20:34 -0800
Re: OT: Current standard for watch precision Tim Wescott <tim@seemywebsite.com> - 2017-02-08 23:26 -0600
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 23:28 -0800
Re: OT: Current standard for watch precision Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-02-09 00:48 -0500
Re: OT: Current standard for watch precision George Herold <gherold@teachspin.com> - 2017-02-09 06:52 -0800
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-09 20:37 -0500
Re: OT: Current standard for watch precision Cursitor Doom <curd@notformail.com> - 2017-02-10 17:11 +0000
Re: OT: Current standard for watch precision upsidedown@downunder.com - 2017-02-09 23:13 +0200
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-08 20:17 -0500
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 19:29 -0800
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 20:16 -0800
Re: OT: Current standard for watch precision Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-08 17:13 +0000
Re: OT: Current standard for watch precision kevin93 <kevin@whitedigs.com> - 2017-02-08 12:54 -0800
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-08 12:35 -0500
Re: OT: Current standard for watch precision Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-08 09:50 -0800
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-08 13:14 -0500
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-08 11:35 -0800
Re: OT: Current standard for watch precision upsidedown@downunder.com - 2017-02-08 23:16 +0200
Re: OT: Current standard for watch precision Jeroen Belleman <jeroen@nospam.please> - 2017-02-09 09:59 +0100
Re: OT: Current standard for watch precision Lasse Langwadt Christensen <langwadt@fonz.dk> - 2017-02-08 09:41 -0800
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-08 13:15 -0500
Re: OT: Current standard for watch precision Jasen Betts <jasen@xnet.co.nz> - 2017-02-11 01:46 +0000
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-10 22:12 -0500
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-09 15:25 -0800
Re: OT: Current standard for watch precision Clifford Heath <no.spam@please.net> - 2017-02-10 10:38 +1100
Re: OT: Current standard for watch precision bill.sloman@ieee.org - 2017-02-09 17:42 -0800
Re: OT: Current standard for watch precision Jeroen Belleman <jeroen@nospam.please> - 2017-02-08 11:01 +0100
Re: OT: Current standard for watch precision Jasen Betts <jasen@xnet.co.nz> - 2017-02-11 04:06 +0000
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-07 21:02 -0500
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-07 10:24 -0800
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-07 10:48 -0800
Re: OT: Current standard for watch precision George Herold <gherold@teachspin.com> - 2017-02-07 11:12 -0800
Re: OT: Current standard for watch precision Mikko OH2HVJ <mikko.syrjalahti@nospam.fi> - 2017-02-08 09:33 +0200
Re: OT: Current standard for watch precision George Herold <gherold@teachspin.com> - 2017-02-08 06:31 -0800
Re: OT: Current standard for watch precision Martin Brown <|||newspam|||@nezumi.demon.co.uk> - 2017-02-07 09:58 +0000
Re: OT: Current standard for watch precision Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:00 -0800
Re: OT: Current standard for watch precision Jeff Liebermann <jeffl@cruzio.com> - 2017-02-05 23:01 -0800
Re: OT: Current standard for watch precision mike <ham789@netzero.net> - 2017-02-06 03:21 -0800
Re: OT: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-06 17:25 +0530
Re: Current standard for watch precision "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-06 06:57 -0600
Re: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-06 19:10 +0530
Re: Current standard for watch precision "Tim Williams" <tiwill@seventransistorlabs.com> - 2017-02-06 08:13 -0600
Re: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-06 21:04 +0530
Re: Current standard for watch precision Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-02-06 09:30 -0500
Re: Current standard for watch precision George Herold <gherold@teachspin.com> - 2017-02-06 06:56 -0800
Re: Current standard for watch precision Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:11 -0800
Re: Current standard for watch precision Don Y <blockedofcourse@foo.invalid> - 2017-02-06 12:04 -0700
Re: Current standard for watch precision Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 14:58 -0700
Re: Current standard for watch precision Don Y <blockedofcourse@foo.invalid> - 2017-02-06 15:21 -0700
Re: Current standard for watch precision Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 16:06 -0700
Re: Current standard for watch precision Don Y <blockedofcourse@foo.invalid> - 2017-02-06 17:19 -0700
Re: Current standard for watch precision Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> - 2017-02-06 17:52 -0700
Re: Current standard for watch precision Don Y <blockedofcourse@foo.invalid> - 2017-02-06 17:55 -0700
Re: Current standard for watch precision krw@notreal.com - 2017-02-06 21:44 -0500
Re: Current standard for watch precision Robert Baer <robertbaer@localnet.com> - 2017-02-08 20:04 -0800
Re: OT: Current standard for watch precision Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> - 2017-02-06 09:06 -0500
Re: OT: Current standard for watch precision Pimpom <Pimpom@invalid.com> - 2017-02-06 21:04 +0530
Re: OT: Current standard for watch precision TTman <pcw1.cad@ntlworld.com> - 2017-02-06 14:31 +0000
Re: OT: Current standard for watch precision Clifford Heath <no.spam@please.net> - 2017-02-07 08:54 +1100
Re: OT: Current standard for watch precision Tim Wescott <seemywebsite@myfooter.really> - 2017-02-06 17:33 -0600
Re: OT: Current standard for watch precision krw@notreal.com - 2017-02-06 21:23 -0500
Re: OT: Current standard for watch precision prairiesky <outgoing.server@mozilla.com> - 2017-02-06 23:00 -0800
Re: OT: Current standard for watch precision Cursitor Doom <curd@notformail.com> - 2017-02-07 18:29 +0000
Re: OT: Current standard for watch precision Robert Baer <robertbaer@localnet.com> - 2017-02-08 19:59 -0800
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 00:48 -0500
Re: OT: Current standard for watch precision Tim Wescott <tim@seemywebsite.com> - 2017-02-08 23:54 -0600
Re: OT: Current standard for watch precision Tim Wescott <tim@seemywebsite.com> - 2017-02-09 00:00 -0600
Re: OT: Current standard for watch precision rickman <gnuarm@gmail.com> - 2017-02-09 04:57 -0500
Page 5 of 6 — ← Prev page 1 2 3 4 [5] 6 Next page →
| From | Jeff Liebermann <jeffl@cruzio.com> |
|---|---|
| Date | 2017-02-07 10:24 -0800 |
| Message-ID | <6o2k9cphegqckitsh1ldjeqgndg0c7ps55@4ax.com> |
| In reply to | #446610 |
On Tue, 7 Feb 2017 02:43:33 -0500, rickman <gnuarm@gmail.com> wrote: >I also remember building a clock with a vacuum florescent display with a >trimmer. I was adjusting it by beating a 60 Hz output against the power >line. I could get it very, very close, but then ten or fifteen minutes >later it would drift again! It took me awhile before I realized that >wasn't the clock, it was the power line. lol I built one of those clocks long ago and found that the higher frequency noise motor noise and power supply trash on the power line would mangle the 60 Hz clock waveform. If the clock you built ran fast no matter what you did to the actual clock frequency, that's your problem. A simple 60Hz low-pass solved the problem for me. >Does the power line still drift like that? Is there a reason why it >would in this day with the many sources of accurate timing available? >I'd expect the many generators could do a much better job of not running >up and down in frequency so much, or is this an inherent aspect of a >widely distributed network? Some numbers and graphs from Europe: <https://wwwhome.ewi.utwente.nl/~ptdeboer/misc/mains.html> I couldn't find anything for Trumpland. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
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| From | Jeff Liebermann <jeffl@cruzio.com> |
|---|---|
| Date | 2017-02-07 10:48 -0800 |
| Message-ID | <ch5k9cd6ok9uh0cgemg85fbbvbdr1kkta2@4ax.com> |
| In reply to | #446663 |
On Tue, 07 Feb 2017 10:24:26 -0800, Jeff Liebermann <jeffl@cruzio.com> wrote: >Some numbers and graphs from Europe: ><https://wwwhome.ewi.utwente.nl/~ptdeboer/misc/mains.html> >I couldn't find anything for Trumpland. Found a USA test in the above web page: <http://www.leapsecond.com/pages/mains/> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
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| From | George Herold <gherold@teachspin.com> |
|---|---|
| Date | 2017-02-07 11:12 -0800 |
| Message-ID | <67b98130-de10-4dfd-b92d-3664f9f14079@googlegroups.com> |
| In reply to | #446667 |
On Tuesday, February 7, 2017 at 1:48:32 PM UTC-5, Jeff Liebermann wrote: > On Tue, 07 Feb 2017 10:24:26 -0800, Jeff Liebermann <jeffl@cruzio.com> > wrote: > > >Some numbers and graphs from Europe: > ><https://wwwhome.ewi.utwente.nl/~ptdeboer/misc/mains.html> > >I couldn't find anything for Trumpland. > > Found a USA test in the above web page: > <http://www.leapsecond.com/pages/mains/> If you've got a modern x-tal controlled function generator and a 'scope, it's pretty easy to watch the 60 Hz fluctuations. (Trigger off the AC, set FG to 60.000000 Hz and watch the waveform crawl.) George H. > > -- > Jeff Liebermann jeffl@cruzio.com > 150 Felker St #D http://www.LearnByDestroying.com > Santa Cruz CA 95060 http://802.11junk.com > Skype: JeffLiebermann AE6KS 831-336-2558
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| From | Mikko OH2HVJ <mikko.syrjalahti@nospam.fi> |
|---|---|
| Date | 2017-02-08 09:33 +0200 |
| Message-ID | <m2r339dtms.fsf@nospam.fi> |
| In reply to | #446672 |
George Herold <gherold@teachspin.com> writes: > If you've got a modern x-tal controlled function generator > and a 'scope, it's pretty easy to watch the 60 Hz fluctuations. > (Trigger off the AC, set FG to 60.000000 Hz and watch the waveform > crawl.) XY mode with line + n*line is also nice for following this. -- mikko
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| From | George Herold <gherold@teachspin.com> |
|---|---|
| Date | 2017-02-08 06:31 -0800 |
| Message-ID | <ea6c8e92-0468-482c-97b8-f3f02b408060@googlegroups.com> |
| In reply to | #446755 |
On Wednesday, February 8, 2017 at 2:29:32 AM UTC-5, Mikko OH2HVJ wrote: > George Herold <gherold@teachspin.com> writes: > > > If you've got a modern x-tal controlled function generator > > and a 'scope, it's pretty easy to watch the 60 Hz fluctuations. > > (Trigger off the AC, set FG to 60.000000 Hz and watch the waveform > > crawl.) > > XY mode with line + n*line is also nice for following this. Huh, OK I'll have to give it a try some day. George H. > > -- > mikko
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| From | Martin Brown <|||newspam|||@nezumi.demon.co.uk> |
|---|---|
| Date | 2017-02-07 09:58 +0000 |
| Message-ID | <o7c5o7$10pc$2@gioia.aioe.org> |
| In reply to | #446391 |
On 06/02/2017 11:45, Pimpom wrote: > On 2/6/2017 11:43 AM, Phil Allison wrote: >> Pimpom wrote: >>> >>> >>> What would be considered a "good" wristwatch today in terms of >>> timekeeping precision? Forget about build quality, price, shock- >>> and waterproofing, etc. >>> >>> Half a century ago, a wristwatch with a-minute-a-month accuracy >>> might have been labelled a chronometer. What standard would you >>> apply now? >>> >> >> ** The Quartz standard, of course. >> >> Goolge has heaps of info on this topic: >> >> http://www.chronocentric.com/watches/accuracy.shtml >> > Perhaps I should rephrase the question. I meant to ask what level of > accuracy would be considered good for a consumer wristwatch nowadays. Its possible to get stuff as bad as 15s/day untrimmed if they don't get the load capacitor network round the crystal right. Older Meade LX200 telescopes suffer from this fault on their realtime clock :( They solved it by adding a GPS function so it resets the clock on newer ones! > For example, I bought a Chinese analog-digital wristwatch from > www.aliexpress.com last month and have been monitoring its accuracy. I > do this by comparing it to a freshly synced computer clock. It's now > exactly one month since I synced it to the computer clock. The analog > section is ahead by 6 seconds and the digital one is behind by 35 secs. > The errors may not be linearly cumulative but I think it's pretty good > for a US$7 watch. It depends on the cut of the crystal and whether or not it is being thermally stabilised by being worn on the wrist for some of the time. (or worn outside in extreme conditions) It isn't hard to get a couple of seconds a month or better with a simple temperature compensation scheme. I made a direct drive LCD chronometer which keeps time free running very nicely 2s/month after being trimmed against MSF Rugby for a couple of days. Not fully temperature compensated or it would be even better. Its actually used as a sidereal clock by flicking a switch after it has been calibrated. -- Regards, Martin Brown
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| From | Robert Baer <robertbaer@localnet.com> |
|---|---|
| Date | 2017-02-08 20:00 -0800 |
| Message-ID | <QPRmA.867$YA7.459@fx03.iad> |
| In reply to | #446379 |
Phil Allison wrote: > Pimpom wrote: >> >> >> What would be considered a "good" wristwatch today in terms of >> timekeeping precision? Forget about build quality, price, shock- >> and waterproofing, etc. >> >> Half a century ago, a wristwatch with a-minute-a-month accuracy >> might have been labelled a chronometer. What standard would you >> apply now? >> > > ** The Quartz standard, of course. > > Goolge has heaps of info on this topic: > > http://www.chronocentric.com/watches/accuracy.shtml > > > > ..... Phil Well, maybe. They are all over the map.
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| From | Jeff Liebermann <jeffl@cruzio.com> |
|---|---|
| Date | 2017-02-05 23:01 -0800 |
| Message-ID | <695g9c58jg4t8277ticn9dmbjghkrup43b@4ax.com> |
| In reply to | #446378 |
On Mon, 6 Feb 2017 11:22:26 +0530, Pimpom <pimpom@invalid.com> wrote: >What would be considered a "good" wristwatch today in terms of >timekeeping precision? Forget about build quality, price, shock- >and waterproofing, etc. > >Half a century ago, a wristwatch with a-minute-a-month accuracy >might have been labelled a chronometer. What standard would you >apply now? "Good" would mean a watch that's updated by a remote frequency standard. The common WWVB "atomic time" watch is one example: <https://en.wikipedia.org/wiki/Casio_Wave_Ceptor> "...one second in three million years" However, they get updated only once per day, so the short term (daily) accuracy is only about 0.5 sec/day. Beyond this point, we're talking fractions of a second accuracy, which is much better than "good", and a good excuse not to lookup the PPM numbers. At that accuracy, you also get into the question of which time scale (UTC, UT1, UT2, LMT, MST, ST, etc) you want to display. Much depends on whether you are into astronomy, navigation, communications, metrology, or racing: <http://www.ucolick.org/~sla/leapsecs/timescales.html> Another accurate clock is the clock in a smartphone or cell phone. The cell phone system time is synchronized to an atomic clock somewhere. Unlike the aforementioned daily atomic time clock updates, the cell phone clock gets its time updated every few minutes. However, watch out for the difference between UTC and GPS time: <http://802.11junk.com/jeffl/crud/GPS-vs-UTC.jpg> <http://www.leapsecond.com/java/gpsclock.htm> You could also use the GPS in your smartphone to display the time. You'll need an app to do that because the phone uses the time provided by the cellular system. Since a smartphone is umm... smart, you could use one of the public NTP (network time protocol) servers to display the time: <https://play.google.com/store/apps/details?id=ru.org.amip.ClockSync&hl=en> However, because there is considerable latency between the NTP server and your phone, there may be some errors if the delays vary or are not sufficiently compensated. Of course, you could carry a GPS around with you. However, they are rather battery hungry. <https://www.amazon.com/Garmin-Foretrex-401-Waterproof-Hiking/dp/B002EOSQII> Then, there's the smart watch, some of which have a built in GPS receiver. However, be careful when buying as some of them (e.g. Pebble) are unable to sync the system time to the GPS time. If you happen to be a prepper, awaiting the zombie apocalypse where civilization and all RF time services will collapse, you could carry around your very own cesium atomic wristwatch: <https://www.kickstarter.com/projects/846511652/the-worlds-first-true-atomic-wristwatch-the-cesium> <http://www.ablogtowatch.com/bathys-hawaii-cesium-133-atomic-wrist-watch-accurate-second-1000-years/> Early models were a bit cumbersome: <http://www.leapsecond.com/pages/atomic-bill/> However, if all you want is something cool in the way of retro tech, I suggest a wrist sundial: <https://www.google.com/search?q=wrist+sundial&tbm=isch> -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
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| From | mike <ham789@netzero.net> |
|---|---|
| Date | 2017-02-06 03:21 -0800 |
| Message-ID | <o79m5j$b6p$2@dont-email.me> |
| In reply to | #446378 |
On 2/5/2017 9:52 PM, Pimpom wrote: > What would be considered a "good" wristwatch today in terms of > timekeeping precision? Forget about build quality, price, shock- and > waterproofing, etc. > > Half a century ago, a wristwatch with a-minute-a-month accuracy might > have been labelled a chronometer. What standard would you apply now? Adopt a policy to always be on time. Show up five minutes early for your appointment and you don't have to worry about the accuracy of your watch. Knowing that you're 5 milliseconds late is of no consequence to your meeting.
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| From | Pimpom <Pimpom@invalid.com> |
|---|---|
| Date | 2017-02-06 17:25 +0530 |
| Message-ID | <o79o78$vgm$1@news.albasani.net> |
| In reply to | #446389 |
On 2/6/2017 4:51 PM, mike wrote: > On 2/5/2017 9:52 PM, Pimpom wrote: >> What would be considered a "good" wristwatch today in terms of >> timekeeping precision? Forget about build quality, price, shock- and >> waterproofing, etc. >> >> Half a century ago, a wristwatch with a-minute-a-month accuracy might >> have been labelled a chronometer. What standard would you apply now? > > Adopt a policy to always be on time. > Show up five minutes early for your appointment and you don't > have to worry about the accuracy of your watch. > Knowing that you're 5 milliseconds late is of no consequence to > your meeting. > How would I know how early/late I am if my watch is not accurate? :-) Anyway, I'm seldom in a position where I have to conform to someone else's timepiece.
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| From | "Tim Williams" <tiwill@seventransistorlabs.com> |
|---|---|
| Date | 2017-02-06 06:57 -0600 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <o79roj$2c0$1@dont-email.me> |
| In reply to | #446378 |
FWIW, the most accurate clock I have, is in my car. I don't know quite how they managed it, but it runs on battery power (admittedly, it has quite a reserve to draw from!), tolerates wide temperature swings (at least -20 to 60C that I know of), and regularly goes a full year without skipping a minute. (It's within a minute of accuracy, throughout the year, too -- no noticeable seasonal error.) The only reason I have to set it is because of stupid Daylight Savings... If it's a TCXO, that wouldn't be too bad for a watch; an OCXO is also plausible given the available current, but obviously that wouldn't work so well for a watch*. *While worn, the watch temperature is pretty consistent (10-30C?). But if it's taken off regularly, that goes out the window. Anyway, I'd be more than happy with a minute per year. That seems nice and solid. I have no reason to believe my car does WWVB or GPSDO, so it's certainly achievable without that assistance. But personally? As with most people, I just reach for my phone when I need to know the time... Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com "Pimpom" <pimpom@invalid.com> wrote in message news:o792ut$ooh$1@news.albasani.net... > What would be considered a "good" wristwatch today in terms of timekeeping > precision? Forget about build quality, price, shock- and waterproofing, > etc. > > Half a century ago, a wristwatch with a-minute-a-month accuracy might have > been labelled a chronometer. What standard would you apply now?
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| From | Pimpom <Pimpom@invalid.com> |
|---|---|
| Date | 2017-02-06 19:10 +0530 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <o79uch$50n$1@news.albasani.net> |
| In reply to | #446397 |
On 2/6/2017 6:27 PM, Tim Williams wrote: > FWIW, the most accurate clock I have, is in my car. I don't know quite how > they managed it, but it runs on battery power (admittedly, it has quite a > reserve to draw from!), tolerates wide temperature swings (at least -20 to > 60C that I know of), and regularly goes a full year without skipping a > minute. (It's within a minute of accuracy, throughout the year, too -- no > noticeable seasonal error.) My car's clock is in the same class. I set it when I bought the car in Dec '11 and reset it a couple of months ago when it had fallen behind by about 3 minutes. The only reason I have to set it is because of > stupid Daylight Savings... > We don't use DST here and I could never think of any significant benefit to the practice. Thinking that I must be missing something, I posted a question about it in a newsgroup (might have been s.e.d.) several years ago. I was surprised to see that most people think it's a meaningless practice. ........> > But personally? As with most people, I just reach for my phone when I need > to know the time... > Personally, I use a mobile phone only when I go out, which is quite seldom. I must be in a miniscule minority in a technologically enlightened society. Even when I have my phone on my desk, I tend to look at my wristwatch or at the wall clock to tell the time.
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| From | "Tim Williams" <tiwill@seventransistorlabs.com> |
|---|---|
| Date | 2017-02-06 08:13 -0600 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <o7a06i$ic0$1@dont-email.me> |
| In reply to | #446401 |
"Pimpom" <Pimpom@invalid.com> wrote in message news:o79uch$50n$1@news.albasani.net... > Personally, I use a mobile phone only when I go out, which is quite > seldom. I must be in a miniscule minority in a technologically enlightened > society. Even when I have my phone on my desk, I tend to look at my > wristwatch or at the wall clock to tell the time. Yeah, but you live in a technologically backwatered society, so it's okay. :^) (NB: I don't know how the average tech level actually compares, there (northern edge of India, isn't it?). If nothing else, it sounds like you have all the cheap Chinese crap available that we do. :-p ) Tim -- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website: http://seventransistorlabs.com
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| From | Pimpom <Pimpom@invalid.com> |
|---|---|
| Date | 2017-02-06 21:04 +0530 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <o7a51n$t46$1@news.albasani.net> |
| In reply to | #446408 |
On 2/6/2017 7:43 PM, Tim Williams wrote: > "Pimpom" <Pimpom@invalid.com> wrote in message > news:o79uch$50n$1@news.albasani.net... >> Personally, I use a mobile phone only when I go out, which is quite >> seldom. I must be in a miniscule minority in a technologically enlightened >> society. Even when I have my phone on my desk, I tend to look at my >> wristwatch or at the wall clock to tell the time. > > Yeah, but you live in a technologically backwatered society, so it's okay. > :^) Not so "backwatered" as far as consumer products are concerned. Practically every home in towns has a computer or two, microwave and so on. Except for very young and very old people, 99.9% have cellphones. Heck, my live-in maid from a small village has asked me to order a smartphone for her. She's the only one in 15 years who didn't already have one. I give them the password to my WiFi and they enjoy Facebook and Whatsapp in their free time. > > (NB: I don't know how the average tech level actually compares, there > (northern edge of India, isn't it?). Actually the eastern edge, sandwiched between Myanmar (Burma) and Bangladesh. My people have little in common with mainstream Indians. Looks, religion, language, culture, taste, cuisine, mentality..... are all different. My own knowledge of the majority language Hindi is limited to about a couple of dozen words. > If nothing else, it sounds like you > have all the cheap Chinese crap available that we do. :-p ) > That, we do. But some of them are quite OK and cost a fraction of what the major brands are asking for an equivalent product.
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| From | Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> |
|---|---|
| Date | 2017-02-06 09:30 -0500 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <su1h9c91njslc392dum9lb8ther527d3c5@4ax.com> |
| In reply to | #446401 |
On Mon, 6 Feb 2017 19:10:31 +0530, the renowned Pimpom <Pimpom@invalid.com> wrote: >On 2/6/2017 6:27 PM, Tim Williams wrote: >> FWIW, the most accurate clock I have, is in my car. I don't know quite how >> they managed it, but it runs on battery power (admittedly, it has quite a >> reserve to draw from!), tolerates wide temperature swings (at least -20 to >> 60C that I know of), and regularly goes a full year without skipping a >> minute. (It's within a minute of accuracy, throughout the year, too -- no >> noticeable seasonal error.) > >My car's clock is in the same class. I set it when I bought the >car in Dec '11 and reset it a couple of months ago when it had >fallen behind by about 3 minutes. > Here is a wristwatch for you: http://watchesbysjx.com/2013/05/11 Claimed accuracy 1.5 seconds per 1000 years. My Casio does even better but it depends on an outside atomic clock and there's no guarantee that will physically be there next year let alone 1000 years from now. --sp -- Best regards, Spehro Pefhany
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| From | George Herold <gherold@teachspin.com> |
|---|---|
| Date | 2017-02-06 06:56 -0800 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <4a996cce-ada1-4ad5-b33b-402bbd3e4ca7@googlegroups.com> |
| In reply to | #446410 |
On Monday, February 6, 2017 at 9:30:28 AM UTC-5, Spehro Pefhany wrote: > On Mon, 6 Feb 2017 19:10:31 +0530, the renowned Pimpom > <Pimpom@invalid.com> wrote: > > >On 2/6/2017 6:27 PM, Tim Williams wrote: > >> FWIW, the most accurate clock I have, is in my car. I don't know quite how > >> they managed it, but it runs on battery power (admittedly, it has quite a > >> reserve to draw from!), tolerates wide temperature swings (at least -20 to > >> 60C that I know of), and regularly goes a full year without skipping a > >> minute. (It's within a minute of accuracy, throughout the year, too -- no > >> noticeable seasonal error.) > > > >My car's clock is in the same class. I set it when I bought the > >car in Dec '11 and reset it a couple of months ago when it had > >fallen behind by about 3 minutes. > > > > Here is a wristwatch for you: > > http://watchesbysjx.com/2013/05/11 > > Claimed accuracy 1.5 seconds per 1000 years. My Casio does even better > but it depends on an outside atomic clock and there's no guarantee > that will physically be there next year let alone 1000 years from now. > > --sp > > > -- > Best regards, > Spehro Pefhany Was it really the first? http://leapsecond.com/pages/atomic-bill/ (As long as style isn't important :^) George H.
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| From | Robert Baer <robertbaer@localnet.com> |
|---|---|
| Date | 2017-02-08 20:11 -0800 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <sZRmA.1281$X9.1056@fx28.iad> |
| In reply to | #446401 |
Pimpom wrote: > On 2/6/2017 6:27 PM, Tim Williams wrote: >> FWIW, the most accurate clock I have, is in my car. I don't know quite >> how >> they managed it, but it runs on battery power (admittedly, it has quite a >> reserve to draw from!), tolerates wide temperature swings (at least >> -20 to >> 60C that I know of), and regularly goes a full year without skipping a >> minute. (It's within a minute of accuracy, throughout the year, too -- no >> noticeable seasonal error.) > > My car's clock is in the same class. I set it when I bought the car in > Dec '11 and reset it a couple of months ago when it had fallen behind by > about 3 minutes. > > The only reason I have to set it is because of >> stupid Daylight Savings... >> > We don't use DST here and I could never think of any significant benefit > to the practice. Thinking that I must be missing something, I posted a > question about it in a newsgroup (might have been s.e.d.) several years > ago. I was surprised to see that most people think it's a meaningless > practice. * When that was instigated, it was (politically) meaningless. The idea was to have more daylight hours during an 8-hour work time, "thus" more production of guns from butter... > > ........> >> But personally? As with most people, I just reach for my phone when I >> need >> to know the time... >> > Personally, I use a mobile phone only when I go out, which is quite > seldom. I must be in a miniscule minority in a technologically > enlightened society. Even when I have my phone on my desk, I tend to > look at my wristwatch or at the wall clock to tell the time. >
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| From | Don Y <blockedofcourse@foo.invalid> |
|---|---|
| Date | 2017-02-06 12:04 -0700 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <o7ah9b$kgm$1@dont-email.me> |
| In reply to | #446397 |
On 2/6/2017 5:57 AM, Tim Williams wrote: > FWIW, the most accurate clock I have, is in my car. I don't know quite how > they managed it, but it runs on battery power (admittedly, it has quite a > reserve to draw from!), tolerates wide temperature swings (at least -20 to 60C > that I know of), and regularly goes a full year without skipping a minute. > (It's within a minute of accuracy, throughout the year, too -- no noticeable > seasonal error.) The only reason I have to set it is because of stupid > Daylight Savings... This was always the joke with stated accuracies of clocks -- if you're going to have to reset it every ~6 months, just how far out of sync *can* it get? Here, we don't have that folly so we don't have to keep tweeking clocks. OTOH, we're always asking ourselves if <somebody>, <somewhere> is an hour ahead of us, or two... (etc). So, its almost WORST than having to be consciously aware of the time changes!
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| From | Jim Thompson <To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> |
|---|---|
| Date | 2017-02-06 14:58 -0700 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <rash9cpnqic9dsqvd4rnt7ok9rsa2mmak3@4ax.com> |
| In reply to | #446444 |
On Mon, 6 Feb 2017 12:04:52 -0700, Don Y <blockedofcourse@foo.invalid>
wrote:
>On 2/6/2017 5:57 AM, Tim Williams wrote:
>> FWIW, the most accurate clock I have, is in my car. I don't know quite how
>> they managed it, but it runs on battery power (admittedly, it has quite a
>> reserve to draw from!), tolerates wide temperature swings (at least -20 to 60C
>> that I know of), and regularly goes a full year without skipping a minute.
>> (It's within a minute of accuracy, throughout the year, too -- no noticeable
>> seasonal error.) The only reason I have to set it is because of stupid
>> Daylight Savings...
>
>This was always the joke with stated accuracies of clocks -- if you're going
>to have to reset it every ~6 months, just how far out of sync *can* it get?
>
>Here, we don't have that folly so we don't have to keep tweeking clocks.
>OTOH, we're always asking ourselves if <somebody>, <somewhere> is an hour
>ahead of us, or two... (etc).
>
>So, its almost WORST than having to be consciously aware of the time changes!
Some of us don't have to endure daylight savings time ;-)
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice:(480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
Thinking outside the box... producing elegant solutions.
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| From | Don Y <blockedofcourse@foo.invalid> |
|---|---|
| Date | 2017-02-06 15:21 -0700 |
| Subject | Re: Current standard for watch precision |
| Message-ID | <o7aspi$1mc$2@dont-email.me> |
| In reply to | #446476 |
On 2/6/2017 2:58 PM, Jim Thompson wrote: >> Here, we don't have that folly so we don't have to keep tweeking clocks. >> OTOH, we're always asking ourselves if <somebody>, <somewhere> is an hour >> ahead of us, or two... (etc). >> >> So, its almost WORST than having to be consciously aware of the time changes! > > Some of us don't have to endure daylight savings time ;-) I don't -- but, I have to deal with folks elsewhere in the country who *do*. So, have to consider: it's 11A here. Is it just BEFORE lunch, there? Or, just AFTER? Is DST in effect (for THEM)? Or not? [Even worse to discover it's just a bit before *6*PM when you think it's actually just before *5*!]
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