[time-nuts] Re: QM10 Quartz chronometer
Good morning, Thank you to everyone who has replied both on and off list - much appreciated and as usual a wealth of information. My apologies for the late acknowledgement but storm damage had taken out the phone and internet for nearly a week. Regards Peter UK ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: QM10 Quartz chronometer
Yes, I placed Don's QM10 photos and IC pin analysis here: http://leapsecond.com/u/couch/ FYI: the link below is badly mangled due to his email client or ISP or Outlook. It is not a time-nuts server problem. Please do not click on links like that. /tvb On 12/3/2021 3:45 PM, Don Couch wrote: Here is signal data and some pictures from one of my QM-10 chronometers. Curiously, the oscillator only produces 8 Hz. Obviously, it must have a high frequency crystal inside the can somewhere. I set this clock to the correct time on May 23, 2020. It is now five seconds fast! Tom van Baak kindly noted the pictures are too large for email, so he moved them to http://leapsecond.com/u/couch/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fleapsecond.com%2Fu%2Fcouch%2F=04%7C01%7C%7Cee0742a79f1e4d8842fe08d9b6abba73%7C84df9e7fe9f640afb435%7C1%7C0%7C637741670943146640%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000=nNiqsRRttsNVzs88XyMCfeOsqCkRObPymRRRXSw%2BJ0g%3D=0> The picture of the top of the board shows the original backup battery, which I disconnected. I added the round blue-edged supercapacitor (0.047 F with the red and black wires) so the main battery can be replaced without stopping the clock. Let me know if there are more questions. Don Couch Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows From: Don Couch<mailto:couchclo...@hotmail.com> Sent: Friday, November 26, 2021 9:00 AM To: Discussion of precise time and frequency measurement<mailto:time-nuts@lists.febo.com> Subject: [time-nuts] Re: QM10 Quartz chronometer I have two of these. They are very nice precision chronometers. If I remember correctly, the frequency is 4194304. The oscillator is a TCXO usually in a small round 8-legged can. I have never seen a bad one. The most common problem is the backup battery. If it is still there, it is very old and often shorted. There is a diode in series so if the battery is shorted, it does no harm, but I have seen the diode shorted as well. I do not have schematics, but you can trace the battery circuit. Don Couch ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: QM10 Quartz chronometer
Here is signal data and some pictures from one of my QM-10 chronometers. Curiously, the oscillator only produces 8 Hz. Obviously, it must have a high frequency crystal inside the can somewhere. I set this clock to the correct time on May 23, 2020. It is now five seconds fast! Tom van Baak kindly noted the pictures are too large for email, so he moved them to http://leapsecond.com/u/couch/<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fleapsecond.com%2Fu%2Fcouch%2F=04%7C01%7C%7Cee0742a79f1e4d8842fe08d9b6abba73%7C84df9e7fe9f640afb435%7C1%7C0%7C637741670943146640%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000=nNiqsRRttsNVzs88XyMCfeOsqCkRObPymRRRXSw%2BJ0g%3D=0> The picture of the top of the board shows the original backup battery, which I disconnected. I added the round blue-edged supercapacitor (0.047 F with the red and black wires) so the main battery can be replaced without stopping the clock. Let me know if there are more questions. Don Couch Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows From: Don Couch<mailto:couchclo...@hotmail.com> Sent: Friday, November 26, 2021 9:00 AM To: Discussion of precise time and frequency measurement<mailto:time-nuts@lists.febo.com> Subject: [time-nuts] Re: QM10 Quartz chronometer I have two of these. They are very nice precision chronometers. If I remember correctly, the frequency is 4194304. The oscillator is a TCXO usually in a small round 8-legged can. I have never seen a bad one. The most common problem is the backup battery. If it is still there, it is very old and often shorted. There is a diode in series so if the battery is shorted, it does no harm, but I have seen the diode shorted as well. I do not have schematics, but you can trace the battery circuit. Don Couch Sent from Mail<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgo.microsoft.com%2Ffwlink%2F%3FLinkId%3D550986data=04%7C01%7C%7C8d751e8121534ab444d108d9b0f5e39b%7C84df9e7fe9f640afb435%7C1%7C0%7C637735392399899177%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000sdata=FEO%2FS%2FYmwMp28mghhfOq5L9W2J1HA%2FL%2Bz6sEgQW%2BTro%3Dreserved=0> for Windows From: Scott McGrath Sent: Friday, November 26, 2021 7:14:04 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Re: QM10 Quartz chronometer Usually in analog quartz clocks oscillator frequency is around 32khz Content by Scott Typos by Siri On Nov 26, 2021, at 9:09 AM, Peter Torry via time-nuts wrote: Hello list, I am restoring a Seiko Quartz QM10 Marine Chronometer that is currently inoperative. Preliminary investigations would indicate that the oscillator (TO5 header) isn't functioning therefore I am seeking any information as to its nominal frequency and whether it is just a crystal or an oscillator. I can follow the cmos dividers OK but a schematic diagram would be most useful. Any help or pointers much appreciated. Kind regards Peter UK ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: QM10 Quartz chronometer
Some years ago, before we had locked LOs for transverters, the Am. Microwave community used clip-on crystal heaters. These were a PTC thermistor with a turnover around 35 - 40C. They were usually used on 5th or 7th overtone crystals around 100MHz designed for 20C operation, so weren't ideal, but could maintain a crystal more on frequency that just open to the the air temp. Perhaps used on a watch crystal thay would work more effectively. Not sure where you'd get them from now, though. Andy www.g4jnt.com On Fri, 26 Nov 2021 at 16:46, David G. McGaw wrote: > But not in a chronometer. They usually use something in the MHz range. > > 32kHz crystals are not very stable over temperature. Watches rely on > you wearing it for much of the day, keeping it at a nearly constant > temperature and putting it on your bed stand at night, also presumably > fairly constant. Unfortunately they have been adopted for computer Real > Time Clocks, which is why most computers do not keep very good time. > > David N1HAC > > On 11/26/21 9:14 AM, Scott McGrath wrote: > > Usually in analog quartz clocks oscillator frequency is around 32khz > > > > Content by Scott > > Typos by Siri > > > > On Nov 26, 2021, at 9:09 AM, Peter Torry via time-nuts < > time-nuts@lists.febo.com> wrote: > > > > Hello list, > > > > I am restoring a Seiko Quartz QM10 Marine Chronometer that is currently > inoperative. Preliminary investigations would indicate that the oscillator > (TO5 header) isn't functioning therefore I am seeking any information as to > its nominal frequency and whether it is just a crystal or an oscillator. I > can follow the cmos dividers OK but a schematic diagram would be most > useful. > > > > Any help or pointers much appreciated. > > > > Kind regards > > > > Peter UK > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > > ___ > > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe > send an email to time-nuts-le...@lists.febo.com > > To unsubscribe, go to and follow the instructions there. > ___ > time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send > an email to time-nuts-le...@lists.febo.com > To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: QM10 Quartz chronometer
But not in a chronometer. They usually use something in the MHz range. 32kHz crystals are not very stable over temperature. Watches rely on you wearing it for much of the day, keeping it at a nearly constant temperature and putting it on your bed stand at night, also presumably fairly constant. Unfortunately they have been adopted for computer Real Time Clocks, which is why most computers do not keep very good time. David N1HAC On 11/26/21 9:14 AM, Scott McGrath wrote: Usually in analog quartz clocks oscillator frequency is around 32khz Content by Scott Typos by Siri On Nov 26, 2021, at 9:09 AM, Peter Torry via time-nuts wrote: Hello list, I am restoring a Seiko Quartz QM10 Marine Chronometer that is currently inoperative. Preliminary investigations would indicate that the oscillator (TO5 header) isn't functioning therefore I am seeking any information as to its nominal frequency and whether it is just a crystal or an oscillator. I can follow the cmos dividers OK but a schematic diagram would be most useful. Any help or pointers much appreciated. Kind regards Peter UK ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: QM10 Quartz chronometer
I have two of these. They are very nice precision chronometers. If I remember correctly, the frequency is 4194304. The oscillator is a TCXO usually in a small round 8-legged can. I have never seen a bad one. The most common problem is the backup battery. If it is still there, it is very old and often shorted. There is a diode in series so if the battery is shorted, it does no harm, but I have seen the diode shorted as well. I do not have schematics, but you can trace the battery circuit. Don Couch Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows From: Scott McGrath Sent: Friday, November 26, 2021 7:14:04 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] Re: QM10 Quartz chronometer Usually in analog quartz clocks oscillator frequency is around 32khz Content by Scott Typos by Siri On Nov 26, 2021, at 9:09 AM, Peter Torry via time-nuts wrote: Hello list, I am restoring a Seiko Quartz QM10 Marine Chronometer that is currently inoperative. Preliminary investigations would indicate that the oscillator (TO5 header) isn't functioning therefore I am seeking any information as to its nominal frequency and whether it is just a crystal or an oscillator. I can follow the cmos dividers OK but a schematic diagram would be most useful. Any help or pointers much appreciated. Kind regards Peter UK ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: QM10 Quartz chronometer
Check this link: https://www.watchuseek.com/threads/seiko-marine-chronometer-qm-10.4913/ It indicates that the QM-10 used a 4.19MHz crystal. John - Original Message - From: "Peter Torry via time-nuts" To: time-nuts@lists.febo.com Cc: "Peter Torry" Sent: Friday, November 26, 2021 9:09:07 AM Subject: [time-nuts] QM10 Quartz chronometer Hello list, I am restoring a Seiko Quartz QM10 Marine Chronometer that is currently inoperative. Preliminary investigations would indicate that the oscillator (TO5 header) isn't functioning therefore I am seeking any information as to its nominal frequency and whether it is just a crystal or an oscillator. I can follow the cmos dividers OK but a schematic diagram would be most useful. Any help or pointers much appreciated. Kind regards Peter UK ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
[time-nuts] Re: QM10 Quartz chronometer
Usually in analog quartz clocks oscillator frequency is around 32khz Content by Scott Typos by Siri On Nov 26, 2021, at 9:09 AM, Peter Torry via time-nuts wrote: Hello list, I am restoring a Seiko Quartz QM10 Marine Chronometer that is currently inoperative. Preliminary investigations would indicate that the oscillator (TO5 header) isn't functioning therefore I am seeking any information as to its nominal frequency and whether it is just a crystal or an oscillator. I can follow the cmos dividers OK but a schematic diagram would be most useful. Any help or pointers much appreciated. Kind regards Peter UK ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there. ___ time-nuts mailing list -- time-nuts@lists.febo.com -- To unsubscribe send an email to time-nuts-le...@lists.febo.com To unsubscribe, go to and follow the instructions there.
