[time-nuts] Re: QM10 Quartz chronometer

[Don Couch]

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

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________________________________
From: Scott McGrath <scmcgrath at gmail.com>
Sent: Friday, November 26, 2021 7:14:04 AM
To: Discussion of precise time and frequency measurement <time-nuts at lists.febo.com>
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 <time-nuts at 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
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