Re: [time-nuts] Measuring the accurcy of a wrist watch
Hi Chris My concern was not the magnetization of the watch movement but the induction of eddy currents into the balance wheel which will cause drag. The act of moving the watch into the field of the pickup could cause the watch to start running more slowly. You will be getting a strong signal but it will be the wrong signal. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Friday, April 18, 2014 08:44 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch On Thu, Apr 17, 2014 at 11:12 PM, Hal Murray hmur...@megapathdsl.netwrote: Steel makes very good springs. Are there any non-magnetic materials that are close? I think they can use some kind of non-magnetic stainless steel Also this might be a moot point because I got a good strong signal by placing the watch on top of the guitar strings. I did not have to restring the guitar. The wall clock works even some inches away. You don't have to get really close to the magnets. If you were building a sensor, just use a plain iron core and 1/4 pound of #40 wire -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
I too tried that and equally failed even with 52dB gain. I suspect that part of the trick is how the piezo is mounted: Quite possibly if mounted in a circular form held only at the edges, with the watch crown touching the centre it might be more sensitive than if the centre is clamped to the watch with the edges free? Regards, David Partridge -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Robert Darlington Sent: 18 April 2014 19:49 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch Commercially they use piezo transducers (bender disks) in direct contact with the watch to hear them tick. I did my best to build one up several weeks ago. I could hear ants walking but my cheap swiss movement was just too quiet. It was amazingly quiet, even going through a preamp and dialing the vertical amp to 11 on the scope. They must have them sized for resonance a little closer to the spectrum given off by the movement. -Bob ___ 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] Measuring the accurcy of a wrist watch
On Fri, Apr 18, 2014 at 10:37 PM, DaveH i...@blackmountainforge.com wrote: Hi Chris My concern was not the magnetization of the watch movement but the induction of eddy currents into the balance wheel which will cause drag. The act of moving the watch into the field of the pickup could cause the watch to start running more slowly. You will be getting a strong signal but it will be the wrong signal. What is the magnitude of this effect? Would anyone know the relationship between field strength and watch speed. For example the strength of the Earth's magnetic field changes over at least a factor of four in different parts of the world. Is this a seconds per day or seconds per decade kind of problem? But yes I agree forsaking serious measurements I'm make a purpose built coil. Or actually like I said two of them wires in anti-phase. But even then, it can't measure a mechanical watch. I think a microphone would be best. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Friday, April 18, 2014 08:44 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch On Thu, Apr 17, 2014 at 11:12 PM, Hal Murray hmur...@megapathdsl.netwrote: Steel makes very good springs. Are there any non-magnetic materials that are close? I think they can use some kind of non-magnetic stainless steel Also this might be a moot point because I got a good strong signal by placing the watch on top of the guitar strings. I did not have to restring the guitar. The wall clock works even some inches away. You don't have to get really close to the magnets. If you were building a sensor, just use a plain iron core and 1/4 pound of #40 wire -- Chris Albertson Redondo Beach, California ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
Industry doesn't use microphones. It's piezo pickups or inductive pickups (coils) for things like tuning fork movements in accutrons. For quartz they use probes. http://forums.watchuseek.com/f6/watch-timing-microphone-646148.html On Sat, Apr 19, 2014 at 11:12 AM, Chris Albertson albertson.ch...@gmail.com wrote: On Fri, Apr 18, 2014 at 10:37 PM, DaveH i...@blackmountainforge.com wrote: Hi Chris My concern was not the magnetization of the watch movement but the induction of eddy currents into the balance wheel which will cause drag. The act of moving the watch into the field of the pickup could cause the watch to start running more slowly. You will be getting a strong signal but it will be the wrong signal. What is the magnitude of this effect? Would anyone know the relationship between field strength and watch speed. For example the strength of the Earth's magnetic field changes over at least a factor of four in different parts of the world. Is this a seconds per day or seconds per decade kind of problem? But yes I agree forsaking serious measurements I'm make a purpose built coil. Or actually like I said two of them wires in anti-phase. But even then, it can't measure a mechanical watch. I think a microphone would be best. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Friday, April 18, 2014 08:44 To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch On Thu, Apr 17, 2014 at 11:12 PM, Hal Murray hmur...@megapathdsl.netwrote: Steel makes very good springs. Are there any non-magnetic materials that are close? I think they can use some kind of non-magnetic stainless steel Also this might be a moot point because I got a good strong signal by placing the watch on top of the guitar strings. I did not have to restring the guitar. The wall clock works even some inches away. You don't have to get really close to the magnets. If you were building a sensor, just use a plain iron core and 1/4 pound of #40 wire -- Chris Albertson Redondo Beach, California ___ 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. -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
Early watches were more susceptible to magnetic influence than were later... this is primarily because the early watches used high carbon steel hairsprings for the balance wheel, and when they got magnetized, the spring coils would stick together... Later watches used elinvar for the hairspring coils because its spring constants were less affected by temperature variations... a nice side benefit is it is not easily magnetized. However, when an elinvar hairspring gets magnetized, it is very difficult to demagnetize it using conventional means. Demagnetizers work by rapidly alternating the polarity of the magnetic field, and slowly decreasing the strength of the field. This causes the magnetic poles of the ferrous atoms to get randomly aligned, which is the demagnetized state... But if the item that is magnetized is so light weight and flexible that it can move with the field, it won't get demagnetized... which is what happens with the hairspring. The only way I know to demagnetize a hairspring of this sort is to immobilize the spring with wax, and then run it through the demagnetizer... then melt the wax, and clean the spring with naptha. Fun times! -Chuck Harris DaveH wrote: I remember growing up (50 years ago) that the good watches were marked as being non-magnetic. I would guess that this is standard now. My concern is that the moving balance wheel could have an eddy current induced into it and the resulting magnetic field might cause it to slow down. http://en.wikipedia.org/wiki/Balance_wheel http://en.wikipedia.org/wiki/Eddy_current The act of measurement should not cause a change in what you are measuring. 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] Measuring the accurcy of a wrist watch
i...@blackmountainforge.com said: My concern is that the moving balance wheel could have an eddy current induced into it and the resulting magnetic field might cause it to slow down. If that's a problem, it should be possible to measure it. That assumes the pickup works when near but not in contact. So measure with it near enough to get a clean signal, then nearer. bob91...@yahoo.com said: Yes, magnetic fields mess up mechanical watches. My dad was a watchmaker and found the need to demagnetize all the watches he worked on. The hairspring was the most sensitive part, and the coils would stick together if magnetized, and the watch would run very fast. Steel makes very good springs. Are there any non-magnetic materials that are close? -- These are my opinions. 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] Measuring the accurcy of a wrist watch
On Thu, Apr 17, 2014 at 11:12 PM, Hal Murray hmur...@megapathdsl.netwrote: Steel makes very good springs. Are there any non-magnetic materials that are close? I think they can use some kind of non-magnetic stainless steel Also this might be a moot point because I got a good strong signal by placing the watch on top of the guitar strings. I did not have to restring the guitar. The wall clock works even some inches away. You don't have to get really close to the magnets. If you were building a sensor, just use a plain iron core and 1/4 pound of #40 wire -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
At least for low-end quartz+mechanical watch movements, magnetic fields can cause the watch to stop mechanically ticking or even produce false ticks to cause dial to spin at a furious rate. e.g. By holding my watches at a certain angle in the field of an AC tape degausser, I can make them run many times faster than normal, and I had one mechanical watch where if I held it at the funny angle it would actually run backwards! (Must've been something other than a one-way escapement inside I guess.) This is not the quartz crystal and electronic divider being affected by a magnetic field, this is the stepper motor and mechanics turning in response to magnetic fields. It does not take a magnetized guitar pickup to catch the magnetic field coming from the stepper coil in the watch. Any nearby unshielded coil or AF-range inductor will pick up easy. Tim N3QE On Fri, Apr 18, 2014 at 2:04 AM, Chuck Harris cfhar...@erols.com wrote: Early watches were more susceptible to magnetic influence than were later... this is primarily because the early watches used high carbon steel hairsprings for the balance wheel, and when they got magnetized, the spring coils would stick together... Later watches used elinvar for the hairspring coils because its spring constants were less affected by temperature variations... a nice side benefit is it is not easily magnetized. However, when an elinvar hairspring gets magnetized, it is very difficult to demagnetize it using conventional means. Demagnetizers work by rapidly alternating the polarity of the magnetic field, and slowly decreasing the strength of the field. This causes the magnetic poles of the ferrous atoms to get randomly aligned, which is the demagnetized state... But if the item that is magnetized is so light weight and flexible that it can move with the field, it won't get demagnetized... which is what happens with the hairspring. The only way I know to demagnetize a hairspring of this sort is to immobilize the spring with wax, and then run it through the demagnetizer... then melt the wax, and clean the spring with naptha. Fun times! -Chuck Harris DaveH wrote: I remember growing up (50 years ago) that the good watches were marked as being non-magnetic. I would guess that this is standard now. My concern is that the moving balance wheel could have an eddy current induced into it and the resulting magnetic field might cause it to slow down. http://en.wikipedia.org/wiki/Balance_wheel http://en.wikipedia.org/wiki/Eddy_current The act of measurement should not cause a change in what you are measuring. 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. ___ 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] Measuring the accurcy of a wrist watch
Commercially they use piezo transducers (bender disks) in direct contact with the watch to hear them tick. I did my best to build one up several weeks ago. I could hear ants walking but my cheap swiss movement was just too quiet. It was amazingly quiet, even going through a preamp and dialing the vertical amp to 11 on the scope. They must have them sized for resonance a little closer to the spectrum given off by the movement. -Bob On Fri, Apr 18, 2014 at 9:43 AM, Chris Albertson albertson.ch...@gmail.comwrote: On Thu, Apr 17, 2014 at 11:12 PM, Hal Murray hmur...@megapathdsl.net wrote: Steel makes very good springs. Are there any non-magnetic materials that are close? I think they can use some kind of non-magnetic stainless steel Also this might be a moot point because I got a good strong signal by placing the watch on top of the guitar strings. I did not have to restring the guitar. The wall clock works even some inches away. You don't have to get really close to the magnets. If you were building a sensor, just use a plain iron core and 1/4 pound of #40 wire -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
I have a Timex watch that's probably seven or eight years old. It has an LCD readout. The buttons haven't worked in years. It looses about one second every three or four months. I have to take out the four microscopic screws in the back to get into it to set it. The only reason I hang onto it is that is the most accurate watch I've ever owned. Is there some way to detect its internal frequency inductively? In the past I have used old relay coils as inductive pickups with success, but never with a watch. Al Hang on to that one; that's an unusually accurate watch. I have been unsuccessful at picking up timing signals from a LCD watch. I did try a webcam once but the timing resolution of an LCD display is rather poor, in the 10 to 100 ms millisecond range. If you look a LCD closely you'll notice how slowly the contrast transitions occur. The acoustic, mechanical, electrical, and magnetic methods offer greater resolution, but none of those work on LCD watches. I wonder if a fine (sub-mm) optical sensor that tracks contrast changes in a single segment would work. On a 7-segment display, the 'd' segment is the best one to aim for since it changes 8 times every 10 seconds. If you open it you may see a number of traces from the IC to the LCD with pulse rates tied to the main oscillator. The problem here is that by opening the case and measuring these extremely low current signals you likely introduce a frequency offset. When you say set it do you mean adjust the time or adjust the rate? One idea to reset the time by a few seconds without opening it: raise or lower the temperature by many tens of degrees for some number of hours or days. /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] Measuring the accurcy of a wrist watch
Chris, I do not own a guitar with single coil pickups but I will surely give it a try to find out whether the humbuckers of my Gibson Firebird SG Standard will also do the trick! Best regards Ulrich -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Chris Albertson Gesendet: Mittwoch, 16. April 2014 20:56 An: Tom Van Baak; Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Measuring the accurcy of a wrist watch I just did an experiment. Place a simple quartz movement wrist watch on top of a Fender Stratocaster guitar. I get a very strong and easy to detect signal. A loud and sharpt ping once per second. More then 1 volt peak to peak. I can cancel almost all the background hum and hiss in the normal way by using the selector switch on the guitar. The guitar has a pickup coil with many thousands of turns of #40 wire. With the selector with at #2 position there is a second coil some inches away that is wound in the opposite direction and the two are added canceling any field that is filing the room. I tried the same with a wall clock and all I had to do was hold the clock an inch away. The wrist watch was placed on top of the strings a few mm above the bridge PU. These is likely about 3 oz of #40 magnet wire on a guitar PU. If I were building a sensor I'd do it just like the guitar. one coil to pick up the signal and another identical coil some inches away to to pick up ambient noise and then wire the two in parallel but in anti-phase. If yu happen to have a guitar around, you have a watch sensor. On Wed, Apr 16, 2014 at 10:43 AM, Tom Van Baak t...@leapsecond.com wrote: Tom, can you explain what exactly you understand by a large coil of wire? Sorry, by large I meant a large number of turns; the coil itself is quite small. Rather the winding one myself I just used the pickup coil from an old cheap plastic self-impulsed pendulum clock. The wire is extremely fine and there must be thousands of turns since the spool diameter is only 15-20mm and the net resistance is 3.5k. Here are some iPhone photos I just took: http://leapsecond.com/pages/Junghans/coil.htm Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? Both. The commercial ones sold by Bryan Mumford are excellent; his instrument includes signal conditioning, adjustable high gain, and other useful features. It's meant for watchmaker types with no electronics background. It works perfectly out of the box. The Junghans wristwatch is extremely well engineered for long-life and the leaked magnetic signal is the weakest of any watch I've measured. Still, it can be measured. The placement of the pickup coil on the watch face needs to be optimized for best reception, or any reception at all for that matter. By contrast, a typical AAA-battery desk/wall quartz clock movement generates a huge magnetic signal. It is so clean that you can clearly see both the start (+) of the impulse and the end (-) of the impulse about 30 ms later. In fact I suspect it's actually 31.25 ms, or 1/32 s, since that's 1024 cycles of a 32.768 kHz oscillator. See: sensor placement: http://leapsecond.com/pages/Junghans/quartz-clock.jpg output to scope: http://leapsecond.com/pages/Junghans/coil-aa.gif I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. I suspect your 1.3 ohms means the number of turns is far too low. I don't see any RF here, nor even very much 50/60 Hz. /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. -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
Tom, many thanks for your help. Will give it a new try over Eastern! Best regards -Ursprüngliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Tom Van Baak Gesendet: Mittwoch, 16. April 2014 19:44 An: 'Discussion of precise time and frequency measurement' Betreff: Re: [time-nuts] Measuring the accurcy of a wrist watch Tom, can you explain what exactly you understand by a large coil of wire? Sorry, by large I meant a large number of turns; the coil itself is quite small. Rather the winding one myself I just used the pickup coil from an old cheap plastic self-impulsed pendulum clock. The wire is extremely fine and there must be thousands of turns since the spool diameter is only 15-20mm and the net resistance is 3.5k. Here are some iPhone photos I just took: http://leapsecond.com/pages/Junghans/coil.htm Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? Both. The commercial ones sold by Bryan Mumford are excellent; his instrument includes signal conditioning, adjustable high gain, and other useful features. It's meant for watchmaker types with no electronics background. It works perfectly out of the box. The Junghans wristwatch is extremely well engineered for long-life and the leaked magnetic signal is the weakest of any watch I've measured. Still, it can be measured. The placement of the pickup coil on the watch face needs to be optimized for best reception, or any reception at all for that matter. By contrast, a typical AAA-battery desk/wall quartz clock movement generates a huge magnetic signal. It is so clean that you can clearly see both the start (+) of the impulse and the end (-) of the impulse about 30 ms later. In fact I suspect it's actually 31.25 ms, or 1/32 s, since that's 1024 cycles of a 32.768 kHz oscillator. See: sensor placement: http://leapsecond.com/pages/Junghans/quartz-clock.jpg output to scope: http://leapsecond.com/pages/Junghans/coil-aa.gif I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. I suspect your 1.3 ohms means the number of turns is far too low. I don't see any RF here, nor even very much 50/60 Hz. /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] Measuring the accurcy of a wrist watch
Mark, is wrist watch not the common English word for a clock that you wear at your wrist? In my case it is a BREITLING Aerospace chronometer. Best regards Ulrich -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Mark Sims Gesendet: Donnerstag, 17. April 2014 00:06 An: time-nuts@febo.com Betreff: [time-nuts] Measuring the accurcy of a wrist watch What are these wrist watches of which you speak? I saw some old geezer wearing some sort of clock bracelet a few years ago. Are they similar? ;-) ___ 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] Measuring the accurcy of a wrist watch
Tom, Thank you for your response. I don't think I could improve on the accuracy of this old watch much by trying to regulate it. I was more curious to see if there was any way to determine what was going on in side it with out actually opening it. The buttons on the side have long ceased to function their being clogged with sweat and other detritus. Now even with it opened up the little switch contacts inside seem to do nothing. It is set to DST so is useful most of the year here. I tried to set it to standard time last Fall but gave up. It was thirteen seconds fast then and now down to eleven seconds fast. I think I will not mess with it any more till the battery dies. I have several other toys to play with if I really need to know what time it is. Al I have a Timex watch that's probably seven or eight years old. It has an LCD readout. The buttons haven't worked in years. It looses about one second every three or four months. I have to take out the four microscopic screws in the back to get into it to set it. The only reason I hang onto it is that is the most accurate watch I've ever owned. Is there some way to detect its internal frequency inductively? In the past I have used old relay coils as inductive pickups with success, but never with a watch. Al Hang on to that one; that's an unusually accurate watch. I have been unsuccessful at picking up timing signals from a LCD watch. I did try a webcam once but the timing resolution of an LCD display is rather poor, in the 10 to 100 ms millisecond range. If you look a LCD closely you'll notice how slowly the contrast transitions occur. The acoustic, mechanical, electrical, and magnetic methods offer greater resolution, but none of those work on LCD watches. I wonder if a fine (sub-mm) optical sensor that tracks contrast changes in a single segment would work. On a 7-segment display, the 'd' segment is the best one to aim for since it changes 8 times every 10 seconds. If you open it you may see a number of traces from the IC to the LCD with pulse rates tied to the main oscillator. The problem here is that by opening the case and measuring these extremely low current signals you likely introduce a frequency offset. When you say set it do you mean adjust the time or adjust the rate? One idea to reset the time by a few seconds without opening it: raise or lower the temperature by many tens of degrees for some number of hours or days. /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] Measuring the accurcy of a wrist watch
Something to consider is that most pickups are biased with a fairly strong magnetic field. Don't know if this would cause any damage or changes in operation of a mechanical watch but something to consider... http://www.guitarnuts.com/wiring/pickups.php Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ulrich Bangert Sent: Thursday, April 17, 2014 01:15 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch Chris, I do not own a guitar with single coil pickups but I will surely give it a try to find out whether the humbuckers of my Gibson Firebird SG Standard will also do the trick! Best regards Ulrich -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Chris Albertson Gesendet: Mittwoch, 16. April 2014 20:56 An: Tom Van Baak; Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Measuring the accurcy of a wrist watch I just did an experiment. Place a simple quartz movement wrist watch on top of a Fender Stratocaster guitar. I get a very strong and easy to detect signal. A loud and sharpt ping once per second. More then 1 volt peak to peak. I can cancel almost all the background hum and hiss in the normal way by using the selector switch on the guitar. The guitar has a pickup coil with many thousands of turns of #40 wire. With the selector with at #2 position there is a second coil some inches away that is wound in the opposite direction and the two are added canceling any field that is filing the room. I tried the same with a wall clock and all I had to do was hold the clock an inch away. The wrist watch was placed on top of the strings a few mm above the bridge PU. These is likely about 3 oz of #40 magnet wire on a guitar PU. If I were building a sensor I'd do it just like the guitar. one coil to pick up the signal and another identical coil some inches away to to pick up ambient noise and then wire the two in parallel but in anti-phase. If yu happen to have a guitar around, you have a watch sensor. On Wed, Apr 16, 2014 at 10:43 AM, Tom Van Baak t...@leapsecond.com wrote: Tom, can you explain what exactly you understand by a large coil of wire? Sorry, by large I meant a large number of turns; the coil itself is quite small. Rather the winding one myself I just used the pickup coil from an old cheap plastic self-impulsed pendulum clock. The wire is extremely fine and there must be thousands of turns since the spool diameter is only 15-20mm and the net resistance is 3.5k. Here are some iPhone photos I just took: http://leapsecond.com/pages/Junghans/coil.htm Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? Both. The commercial ones sold by Bryan Mumford are excellent; his instrument includes signal conditioning, adjustable high gain, and other useful features. It's meant for watchmaker types with no electronics background. It works perfectly out of the box. The Junghans wristwatch is extremely well engineered for long-life and the leaked magnetic signal is the weakest of any watch I've measured. Still, it can be measured. The placement of the pickup coil on the watch face needs to be optimized for best reception, or any reception at all for that matter. By contrast, a typical AAA-battery desk/wall quartz clock movement generates a huge magnetic signal. It is so clean that you can clearly see both the start (+) of the impulse and the end (-) of the impulse about 30 ms later. In fact I suspect it's actually 31.25 ms, or 1/32 s, since that's 1024 cycles of a 32.768 kHz oscillator. See: sensor placement: http://leapsecond.com/pages/Junghans/quartz-clock.jpg output to scope: http://leapsecond.com/pages/Junghans/coil-aa.gif I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. I suspect your 1.3 ohms means the number of turns is far too low. I don't see any RF here, nor even very much 50/60 Hz. /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. -- Chris Albertson Redondo Beach, California ___ time-nuts mailing list
Re: [time-nuts] Measuring the accurcy of a wrist watch
Hello, I've seen that on a forum (in french sorry) : http://www.forum-mdp.com/t16731-un-chronocomparateur-pour-petit-budget It's an application for iPhone called Kello, look at the picture and you will understand. The most difficult part seems to find the right position of the microphone. Claude On Thursday, 17 April 2014, 19:55, DaveH i...@blackmountainforge.com wrote: Something to consider is that most pickups are biased with a fairly strong magnetic field. Don't know if this would cause any damage or changes in operation of a mechanical watch but something to consider... http://www.guitarnuts.com/wiring/pickups.php Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Ulrich Bangert Sent: Thursday, April 17, 2014 01:15 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch Chris, I do not own a guitar with single coil pickups but I will surely give it a try to find out whether the humbuckers of my Gibson Firebird SG Standard will also do the trick! Best regards Ulrich -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Chris Albertson Gesendet: Mittwoch, 16. April 2014 20:56 An: Tom Van Baak; Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Measuring the accurcy of a wrist watch I just did an experiment. Place a simple quartz movement wrist watch on top of a Fender Stratocaster guitar. I get a very strong and easy to detect signal. A loud and sharpt ping once per second. More then 1 volt peak to peak. I can cancel almost all the background hum and hiss in the normal way by using the selector switch on the guitar. The guitar has a pickup coil with many thousands of turns of #40 wire. With the selector with at #2 position there is a second coil some inches away that is wound in the opposite direction and the two are added canceling any field that is filing the room. I tried the same with a wall clock and all I had to do was hold the clock an inch away. The wrist watch was placed on top of the strings a few mm above the bridge PU. These is likely about 3 oz of #40 magnet wire on a guitar PU. If I were building a sensor I'd do it just like the guitar. one coil to pick up the signal and another identical coil some inches away to to pick up ambient noise and then wire the two in parallel but in anti-phase. If yu happen to have a guitar around, you have a watch sensor. On Wed, Apr 16, 2014 at 10:43 AM, Tom Van Baak t...@leapsecond.com wrote: Tom, can you explain what exactly you understand by a large coil of wire? Sorry, by large I meant a large number of turns; the coil itself is quite small. Rather the winding one myself I just used the pickup coil from an old cheap plastic self-impulsed pendulum clock. The wire is extremely fine and there must be thousands of turns since the spool diameter is only 15-20mm and the net resistance is 3.5k. Here are some iPhone photos I just took: http://leapsecond.com/pages/Junghans/coil.htm Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? Both. The commercial ones sold by Bryan Mumford are excellent; his instrument includes signal conditioning, adjustable high gain, and other useful features. It's meant for watchmaker types with no electronics background. It works perfectly out of the box. The Junghans wristwatch is extremely well engineered for long-life and the leaked magnetic signal is the weakest of any watch I've measured. Still, it can be measured. The placement of the pickup coil on the watch face needs to be optimized for best reception, or any reception at all for that matter. By contrast, a typical AAA-battery desk/wall quartz clock movement generates a huge magnetic signal. It is so clean that you can clearly see both the start (+) of the impulse and the end (-) of the impulse about 30 ms later. In fact I suspect it's actually 31.25 ms, or 1/32 s, since that's 1024 cycles of a 32.768 kHz oscillator. See: sensor placement: http://leapsecond.com/pages/Junghans/quartz-clock.jpg output to scope: http://leapsecond.com/pages/Junghans/coil-aa.gif I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. I suspect your 1.3 ohms means the number of turns is far too low. I don't see any RF here, nor even very much 50
Re: [time-nuts] Measuring the accurcy of a wrist watch
Hi: Somewhere here I have a page from a magazine showing a resonant tank circuit at 32768 Hz where the coil is maybe a few inches in diameter. You set any watch running at that frequency and it can count the oscillations. Rather than adjusting the rate to be spot on, the suggestion is to know the rate of the watch in normal use over a week and then make a proportional adjustment in the rate. I can see the crystals used in various electronics boxes by attaching their BNC connector to the HP 4395A used as a spectrum analyzer. For example in the drop zone assembly aid system receiver you can see the local oscillator frequency by connecting the receive antenna terminal to the SA. http://www.prc68.com/I/DZAAS_Rx.shtml http://www.prc68.com/I/4395A.shtml This works because the 4395A uses a DSP based IF system including true Resolution Band Width filters down to 1 Hz which makes for a very low noise floor. Have Fun, Brooke Clarke http://www.PRC68.com http://www.end2partygovernment.com/2012Issues.html ___ 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] Measuring the accurcy of a wrist watch
Are watches damaged by magnets? I hope not because magnets are common. Yes a guitar does have some powerful Alnico magnets in the coil. If this were a problem I think we would have heard about it. My guess is that watch parts are non-magnets brass and stainless and glass and so on. Not plain steel or iron. But maybe there are cheap watches made with stamped steel part? I don't know. In any case my experiment of placing the watch nest to the pickup caused no damage. Next time I get a chance I'll haul the guitar over to the HP counter and see if I can't measure the watch tick period. Something to consider is that most pickups are biased with a fairly strong magnetic field. Don't know if this would cause any damage or changes in operation of a mechanical watch but something to consider... -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
I remember growing up (50 years ago) that the good watches were marked as being non-magnetic. I would guess that this is standard now. My concern is that the moving balance wheel could have an eddy current induced into it and the resulting magnetic field might cause it to slow down. http://en.wikipedia.org/wiki/Balance_wheel http://en.wikipedia.org/wiki/Eddy_current The act of measurement should not cause a change in what you are measuring. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Thursday, April 17, 2014 17:12 To: Claude Fender; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch Are watches damaged by magnets? I hope not because magnets are common. Yes a guitar does have some powerful Alnico magnets in the coil. If this were a problem I think we would have heard about it. My guess is that watch parts are non-magnets brass and stainless and glass and so on. Not plain steel or iron. But maybe there are cheap watches made with stamped steel part? I don't know. In any case my experiment of placing the watch nest to the pickup caused no damage. Next time I get a chance I'll haul the guitar over to the HP counter and see if I can't measure the watch tick period. Something to consider is that most pickups are biased with a fairly strong magnetic field. Don't know if this would cause any damage or changes in operation of a mechanical watch but something to consider... -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
Yes, magnetic fields mess up mechanical watches. My dad was a watchmaker and found the need to demagnetize all the watches he worked on. The hairspring was the most sensitive part, and the coils would stick together if magnetized, and the watch would run very fast. Bob On Thursday, April 17, 2014 9:06 PM, DaveH i...@blackmountainforge.com wrote: I remember growing up (50 years ago) that the good watches were marked as being non-magnetic. I would guess that this is standard now. My concern is that the moving balance wheel could have an eddy current induced into it and the resulting magnetic field might cause it to slow down. http://en.wikipedia.org/wiki/Balance_wheel http://en.wikipedia.org/wiki/Eddy_current The act of measurement should not cause a change in what you are measuring. Dave -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Chris Albertson Sent: Thursday, April 17, 2014 17:12 To: Claude Fender; Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch Are watches damaged by magnets? I hope not because magnets are common. Yes a guitar does have some powerful Alnico magnets in the coil. If this were a problem I think we would have heard about it. My guess is that watch parts are non-magnets brass and stainless and glass and so on. Not plain steel or iron. But maybe there are cheap watches made with stamped steel part? I don't know. In any case my experiment of placing the watch nest to the pickup caused no damage. Next time I get a chance I'll haul the guitar over to the HP counter and see if I can't measure the watch tick period. Something to consider is that most pickups are biased with a fairly strong magnetic field. Don't know if this would cause any damage or changes in operation of a mechanical watch but something to consider... -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
Tom, can you explain what exactly you understand by a large coil of wire? Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. Best regards Ulrich -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Tom Van Baak Gesendet: Dienstag, 15. April 2014 15:53 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Measuring the accurcy of a wrist watch Some research has shown that there is an comparable instrument for ANALOG quarz watches. As far as I understand it does not try to detect the quarz frequency but detects magnetic pulses from the step motors that move the hands of the watch. Has anyone of you ever tried to do this in a time nuts laboratory? Ulrich, Yes, this works well, for both those with seconds hands (one magnetic pulse per second) and those with only minute/hour hands (one or two steps per minute). A large coil of wire is all you need. Have a look at the watch timing tools and sensors at http://www.bmumford.com/microset.html or http://www.bmumford.com/mset/modelwatch1.html Here's an example using a magnetic sensor: http://leapsecond.com/pages/Junghans/ /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] Measuring the accurcy of a wrist watch
The first sensor I'd think of if I wanted to measure a wrist watch would be a microphone. Listen for the tick. You'd need a good quality preamplifier. Place the watch directly on top of the microphone then the mic in a closet with a blanket on it. Good quality studio microphones are very, very sensitive. At home with two doors shut my condenser mic picks of the motor in the fridge, wall clock ticks and the nearly silent fan motor in computer 20 feet away.Then in post processing software I can find and identify the frequency components of each of those the remove most of the signal. I'm not by any means an audio pro and I'm using entry level recording gear. I'm making digital recording but for precision timing you'd need to use the analog signal after a pre-amplifier and apply a sharp bandpass analog filter. About using a coil, I'd assume they use one with many thousands of turns, maybe 100x more then a crossover coil. and place the watch, coil and signal conditioning amplifier all in a faraday shield and apply a powerful analog filter. But even if this works it needs a battery powered watch, it couldn't pick up a purely mechanical movement. I was all set to On Wed, Apr 16, 2014 at 6:21 AM, Ulrich Bangert df...@ulrich-bangert.dewrote: Tom, can you explain what exactly you understand by a large coil of wire? Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. Best regards Ulrich -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Tom Van Baak Gesendet: Dienstag, 15. April 2014 15:53 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Measuring the accurcy of a wrist watch Some research has shown that there is an comparable instrument for ANALOG quarz watches. As far as I understand it does not try to detect the quarz frequency but detects magnetic pulses from the step motors that move the hands of the watch. Has anyone of you ever tried to do this in a time nuts laboratory? Ulrich, Yes, this works well, for both those with seconds hands (one magnetic pulse per second) and those with only minute/hour hands (one or two steps per minute). A large coil of wire is all you need. Have a look at the watch timing tools and sensors at http://www.bmumford.com/microset.html or http://www.bmumford.com/mset/modelwatch1.html Here's an example using a magnetic sensor: http://leapsecond.com/pages/Junghans/ /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. -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
I just did an experiment. Place a simple quartz movement wrist watch on top of a Fender Stratocaster guitar. I get a very strong and easy to detect signal. A loud and sharpt ping once per second. More then 1 volt peak to peak. I can cancel almost all the background hum and hiss in the normal way by using the selector switch on the guitar. The guitar has a pickup coil with many thousands of turns of #40 wire. With the selector with at #2 position there is a second coil some inches away that is wound in the opposite direction and the two are added canceling any field that is filing the room. I tried the same with a wall clock and all I had to do was hold the clock an inch away. The wrist watch was placed on top of the strings a few mm above the bridge PU. These is likely about 3 oz of #40 magnet wire on a guitar PU. If I were building a sensor I'd do it just like the guitar. one coil to pick up the signal and another identical coil some inches away to to pick up ambient noise and then wire the two in parallel but in anti-phase. If yu happen to have a guitar around, you have a watch sensor. On Wed, Apr 16, 2014 at 10:43 AM, Tom Van Baak t...@leapsecond.com wrote: Tom, can you explain what exactly you understand by a large coil of wire? Sorry, by large I meant a large number of turns; the coil itself is quite small. Rather the winding one myself I just used the pickup coil from an old cheap plastic self-impulsed pendulum clock. The wire is extremely fine and there must be thousands of turns since the spool diameter is only 15-20mm and the net resistance is 3.5k. Here are some iPhone photos I just took: http://leapsecond.com/pages/Junghans/coil.htm Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? Both. The commercial ones sold by Bryan Mumford are excellent; his instrument includes signal conditioning, adjustable high gain, and other useful features. It's meant for watchmaker types with no electronics background. It works perfectly out of the box. The Junghans wristwatch is extremely well engineered for long-life and the leaked magnetic signal is the weakest of any watch I've measured. Still, it can be measured. The placement of the pickup coil on the watch face needs to be optimized for best reception, or any reception at all for that matter. By contrast, a typical AAA-battery desk/wall quartz clock movement generates a huge magnetic signal. It is so clean that you can clearly see both the start (+) of the impulse and the end (-) of the impulse about 30 ms later. In fact I suspect it's actually 31.25 ms, or 1/32 s, since that's 1024 cycles of a 32.768 kHz oscillator. See: sensor placement: http://leapsecond.com/pages/Junghans/quartz-clock.jpg output to scope: http://leapsecond.com/pages/Junghans/coil-aa.gif I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. I suspect your 1.3 ohms means the number of turns is far too low. I don't see any RF here, nor even very much 50/60 Hz. /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. -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
What are these wrist watches of which you speak? I saw some old geezer wearing some sort of clock bracelet a few years ago. Are they similar? ;-) ___ 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] Measuring the accurcy of a wrist watch
It does not take a large pickup coil to pick up the magnetic field of a quartz watch movement tick. Radio Shack used to sell suction cup telephone pick up coils but I doubt they have them anymore. These piggybacked on a phone receiver. They are still out there, http://www.elliottelectronicsupply.com/camera-security-equipment/listening/telephone-pickup-coil-suction-cup.html Just as effective is any unshielded mH-range inductor. e.g. http://www.mouser.com/ProductDetail/Murata-Power-Solutions/13R336C/?qs=gLyyx31KZaCXYrPIar3DqA== I work with e.g. Rick Campbell's R2 series receivers, which do AF filtering using inductors and these pick up the tick, tick, tick from my watch clear as day from over a foot away. Back when I had a CRT computer monitor on my desk, they picked up the flyback and deflection frequencies real well. Tim. On Wed, Apr 16, 2014 at 1:51 PM, Chris Albertson albertson.ch...@gmail.comwrote: The first sensor I'd think of if I wanted to measure a wrist watch would be a microphone. Listen for the tick. You'd need a good quality preamplifier. Place the watch directly on top of the microphone then the mic in a closet with a blanket on it. Good quality studio microphones are very, very sensitive. At home with two doors shut my condenser mic picks of the motor in the fridge, wall clock ticks and the nearly silent fan motor in computer 20 feet away.Then in post processing software I can find and identify the frequency components of each of those the remove most of the signal. I'm not by any means an audio pro and I'm using entry level recording gear. I'm making digital recording but for precision timing you'd need to use the analog signal after a pre-amplifier and apply a sharp bandpass analog filter. About using a coil, I'd assume they use one with many thousands of turns, maybe 100x more then a crossover coil. and place the watch, coil and signal conditioning amplifier all in a faraday shield and apply a powerful analog filter. But even if this works it needs a battery powered watch, it couldn't pick up a purely mechanical movement. I was all set to On Wed, Apr 16, 2014 at 6:21 AM, Ulrich Bangert df...@ulrich-bangert.de wrote: Tom, can you explain what exactly you understand by a large coil of wire? Did you make the easurements on the Junghans with a DIY sensor or with one of the commercially available? I have made some basic tests with a coil coming from a loudspeaker's cross over network. It has a few hundred windings, R=1.3 Ohms, 2.3 mH, but the only thing i receive with this coil is a strong 10 Mhz signal...perhaps no real surprise in a time nuts laboratory. Best regards Ulrich -Ursprungliche Nachricht- Von: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] Im Auftrag von Tom Van Baak Gesendet: Dienstag, 15. April 2014 15:53 An: Discussion of precise time and frequency measurement Betreff: Re: [time-nuts] Measuring the accurcy of a wrist watch Some research has shown that there is an comparable instrument for ANALOG quarz watches. As far as I understand it does not try to detect the quarz frequency but detects magnetic pulses from the step motors that move the hands of the watch. Has anyone of you ever tried to do this in a time nuts laboratory? Ulrich, Yes, this works well, for both those with seconds hands (one magnetic pulse per second) and those with only minute/hour hands (one or two steps per minute). A large coil of wire is all you need. Have a look at the watch timing tools and sensors at http://www.bmumford.com/microset.html or http://www.bmumford.com/mset/modelwatch1.html Here's an example using a magnetic sensor: http://leapsecond.com/pages/Junghans/ /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. -- Chris Albertson Redondo Beach, California ___ 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] Measuring the accurcy of a wrist watch
I have a Timex watch that's probably seven or eight years old. It has an LCD readout. The buttons haven't worked in years. It looses about one second every three or four months. I have to take out the four microscopic screws in the back to get into it to set it. The only reason I hang onto it is that is the most accurate watch I've ever owned. Is there some way to detect its internal frequency inductively? In the past I have used old relay coils as inductive pickups with success, but never with a watch. Al ___ 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] Measuring the accurcy of a wrist watch
Gentlemen, today I would like to propose a question that may be a bit OOT for the group but I became interested in it: Watchbuilders and juwellers use an instrument to measure the accuracy of mechanical watches. I am not aware of the correct name for this instrument in English but in German it is called a Zeitwaage and my internet translator calls it a timing maschine. For mechanical watches the timing maschine uses a microphone to detect the acustical impulses of the balance spring (correct word?) and compares it to a xtal. Some research has shown that there is an comparable instrument for ANALOG quarz watches. As far as I understand it does not try to detect the quarz frequency but detects magnetic pulses from the step motors that move the hands of the watch. Has anyone of you ever tried to do this in a time nuts laboratory? Best regards and TIA Ulrich Bangert www.ulrich-bangert.de Ortholzer Weg 1 27243 Gross Ippener ___ 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] Measuring the accurcy of a wrist watch
In message 94A06362A4E942EE9EC49A685C099C32@athlon, Ulrich Bangert writes: Has anyone of you ever tried to do this in a time nuts laboratory? Yes. And then I threw my wrist watch away, having documented how shit it was :-) If your smartphone has a magnetometer, you can measure it that way, but you have to get pretty close to the chip in the smartphone. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ___ 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] Measuring the accurcy of a wrist watch
Some research has shown that there is an comparable instrument for ANALOG quarz watches. As far as I understand it does not try to detect the quarz frequency but detects magnetic pulses from the step motors that move the hands of the watch. Has anyone of you ever tried to do this in a time nuts laboratory? Ulrich, Yes, this works well, for both those with seconds hands (one magnetic pulse per second) and those with only minute/hour hands (one or two steps per minute). A large coil of wire is all you need. Have a look at the watch timing tools and sensors at http://www.bmumford.com/microset.html or http://www.bmumford.com/mset/modelwatch1.html Here's an example using a magnetic sensor: http://leapsecond.com/pages/Junghans/ /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] Measuring the accurcy of a wrist watch
In the United States we can buy analog quarts watches from Wal-Mart for under 15 dollars. When the battery dies you don't even bother to replace it you just buy a new watch, unless...the one you have is very good. There is a lot of variation and buying one is the luck of the draw. They can be as bad as 1 minute a month and they always seem to be gaining. Right now I have one that gains about 2 seconds a month. I fully intend to see if it is possible to replace the battery when it runs down. Counting motor pulses seems to be a little impractical because it would take 12 days to get to 1e6 accuracy. Regards. Max. K 4 O DS. Email: m...@maxsmusicplace.com Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Woodworking site http://www.angelfire.com/electronic/funwithtubes/Woodworking/wwindex.html Music site: http://www.maxsmusicplace.com To subscribe to the fun with transistors group send an email to. funwithtransistors-subscr...@yahoogroups.com To subscribe to the fun with tubes group send an email to, funwithtubes-subscr...@yahoogroups.com To subscribe to the fun with wood group send a blank email to funwithwood-subscr...@yahoogroups.com - Original Message - From: Tom Van Baak t...@leapsecond.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Tuesday, April 15, 2014 8:52 AM Subject: Re: [time-nuts] Measuring the accurcy of a wrist watch Some research has shown that there is an comparable instrument for ANALOG quarz watches. As far as I understand it does not try to detect the quarz frequency but detects magnetic pulses from the step motors that move the hands of the watch. Has anyone of you ever tried to do this in a time nuts laboratory? Ulrich, Yes, this works well, for both those with seconds hands (one magnetic pulse per second) and those with only minute/hour hands (one or two steps per minute). A large coil of wire is all you need. Have a look at the watch timing tools and sensors at http://www.bmumford.com/microset.html or http://www.bmumford.com/mset/modelwatch1.html Here's an example using a magnetic sensor: http://leapsecond.com/pages/Junghans/ /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. --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com ___ 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] Measuring the accurcy of a wrist watch
Here is a discussion forum page that shows a commercial quartz watch timing machine in use: http://omegaforums.net/threads/quartz-watches-some-information-some-may-find-interesting.5475/ The machine obviously measures the time of each second tick, either electrically or acoustically, because it can tell you the instantaneous rate over one second based on the time between ticks. In the example shown, the crystal is fast by 4.18 seconds/day (48 PPM) based on the period between most ticks, but every 60th tick has a longer period due to inhibition (oscillator pulse dropping), and the net rate measured over 60 seconds is 0.32 seconds/day (3.7 PPM). There is a bunch of additional information about the motor drive pulses too. The article explains what it means in some detail. It seems to me that calculating the rate information should require nothing more than capturing the leading edge of each motor pulse and time stamping it, at a rate of 1 data point per second. The motor information requires capturing several pulses (at a rate of a few kHz max.) every second. - Dave On 15/04/2014 09:52, Tom Van Baak wrote: Some research has shown that there is an comparable instrument for ANALOG quarz watches. As far as I understand it does not try to detect the quarz frequency but detects magnetic pulses from the step motors that move the hands of the watch. Has anyone of you ever tried to do this in a time nuts laboratory? Ulrich, Yes, this works well, for both those with seconds hands (one magnetic pulse per second) and those with only minute/hour hands (one or two steps per minute). A large coil of wire is all you need. Have a look at the watch timing tools and sensors at http://www.bmumford.com/microset.html or http://www.bmumford.com/mset/modelwatch1.html Here's an example using a magnetic sensor: http://leapsecond.com/pages/Junghans/ /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] Measuring the accurcy of a wrist watch
You don't count the pulses, you measure the separation between the pulses. Just like with the 1PPS output on your C-Beam. -Chuck Harris Max Robinson wrote: In the United States we can buy analog quarts watches from Wal-Mart for under 15 dollars. When the battery dies you don't even bother to replace it you just buy a new watch, unless...the one you have is very good. There is a lot of variation and buying one is the luck of the draw. They can be as bad as 1 minute a month and they always seem to be gaining. Right now I have one that gains about 2 seconds a month. I fully intend to see if it is possible to replace the battery when it runs down. Counting motor pulses seems to be a little impractical because it would take 12 days to get to 1e6 accuracy. Regards. Max. K 4 O DS. ___ 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.
