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Discussion Starter · #1 ·
Does anyone manufacture a quartz watch in which the speed can be adjusted?

I have $11 Casio digital watch which I have observed weekly for the past three months. I then ran the 12 observations through a linear regression which showed that the watch gained four seconds every week. While the watch is now 53 seconds in error, the error is extremely consistent. If I could get the watch to pause for 24 milliseconds every hour, all 12 observations would have been within one second of the correct time. (Note: 11 of the 12 observations would have been within one quarter second of the correct time, so it may have been the observation itself that was in error.)
 

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What do you mean by "speed" ? The frequency of the crystal cannot be changed because it is a resonance frequency that depends on the shape of the crystal and the electronic components of the circuit (and also the temperature of the watch). The only thing that could be adjusted is the count of the cycles needed to make a second. A "standard" quartz is built with a resonance frequency of 32768 Hz so you can count 32768 cycles to make a second. You can change this constant adding or subtracting 1 or more virtual cycles to speed up or slow down the rate. Now the problem is that very few watches give the final user the possibility to change the rate and the more recent the watch is the less you have a chance to get it. Seiko 9F calibers (which is anyway already thermocompensated that is it has already a self correction algorythm based on the temperature) has a trimmer that is user adjustable. Old Longines VHP (also thermocompensated) had such a trimmer. 30 or 40 years ago it was a lot more common to put a trimmer inside the movement but honestly nowadays I don't remember a recent watch with a trimmer (or a similar device) to give the user the possibility to adjust the rate. A lot of modern calibers have a digital interface that can be used to do a lot of things but the use of this interface is mainly restricted to the manufacturer...
 

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What do you mean by "speed" ? The frequency of the crystal cannot be changed because it is a resonance frequency that depends on the shape of the crystal and the electronic components of the circuit (and also the temperature of the watch). The only thing that could be adjusted is the count of the cycles needed to make a second.
Actually by using a capacitance trimmer it is possible to 'pull' the frequency of a crystal oscillator slightly and thus regulate a reference frequency. I have an old casio with a screw trimmer which I assume is turning a small variable capacitor. Whether a digital watch uses a capacitor trimmer or a digital approach (e.g. counters and clock pulse inhibit) or has no service adjustment provision at all is down to individual implementation. Some casio g-shock models have trimmer screws accessible when you take the case back off, others do not.
 

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The Russians have been producing cheap, Casioesque watches with digital rate trimmers accessible via an on-screen menu since the Soviet era.

My Elektronika 53 is currently trimmed to near enough +/-0.0 seconds per day (unworn).

IMG_20180525_195637.jpg

The Elektronika 53 is shown, here, on a Casio bracelet.
 

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The Russians have been producing cheap, Casioesque watches with digital rate trimmers accessible via an on-screen menu since the Soviet era.

My Elektronika 53 is currently trimmed to near enough +/-0.0 seconds per day (unworn).

View attachment 13331975

The Elektronika 53 is shown, here, on a Casio bracelet.
Tom what module is in that one. Have to look mine up.
 

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I have a Technocras CHN-01 that was -5 a month ago, set it yesterday four weeks later and it was -2, so it's doing something to itself. Favourite watch of the self-regulating variety is the Xonix digital, https://www.youtube.com/watch?v=fZNME5wNA90, that seems to be consistently accurate. Both, I would worry about banging against an inert object. Not G-shockish.

EDIT: Don't bother with the Xonix self-calibrating analogues as they are rubbish accuracy, as quite a few of us have found out.
 

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EDIT: Don't bother with the Xonix self-calibrating analogues as they are rubbish accuracy, as quite a few of us have found out.
I think we have data from at least one forum regular on this board somewhere that suggests the opposite - that the analogues perform better than the digitals. At least in the case of the Telstar-branded analogue variant. Not sure if there are any material differences between the Telstar watch and its Xonix counterpart but I suspect there aren't.
 

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I think we have data from at least one forum regular on this board somewhere that suggests the opposite - that the analogues perform better than the digitals. At least in the case of the Telstar-branded analogue variant. Not sure if there are any material differences between the Telstar watch and its Xonix counterpart but I suspect there aren't.
Based on my current sample of two I have changed my mind.:-d Who's currently got one and can note accuracy? I just reset my analogue (steel) and it was 25s slow. It had the right hour setting so was last set during standard time, probably the beginning, first Sunday in April. Digital was -1, just. To be honest they are so easy to set with the phone it's easy to forgive them for not being super accurate. They just look cheap. If Xonix had refined their technology and made them look better, they were on a winner.
 

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Discussion Starter · #15 ·
O.P. here. Let me rephrase. I don't want to adjust the speed of the timing crystal, I just want to pause the watch every hour or so. I want to have the watch self-correct periodically.

In my example ... My watch gains 0.57 seconds (570 milliseconds) every day. If I could just get the watch to pause for 24 milliseconds every hour, then it would become extremely accurate. If, for example, the crystal resonates 32768 times per second, pause the watch for 786 cycles every hour.
 

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O.P. here. Let me rephrase. I don't want to adjust the speed of the timing crystal, I just want to pause the watch every hour or so. I want to have the watch self-correct periodically.

In my example ... My watch gains 0.57 seconds (570 milliseconds) every day. If I could just get the watch to pause for 24 milliseconds every hour, then it would become extremely accurate. If, for example, the crystal resonates 32768 times per second, pause the watch for 786 cycles every hour.
You've reinvented inhibition. Modern Swiss watches use it to periodically correct the offset.

Your problem is calibration. The speed the watch runs at.

Accuracy is defined as the consistency of that speed.

But, no. You can't re-engineer your watch to do the inhibition thing. Unless you're willing to spend an awful lot. Really awful.
 

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O.P. here. Let me rephrase. I don't want to adjust the speed of the timing crystal, I just want to pause the watch every hour or so. I want to have the watch self-correct periodically.

In my example ... My watch gains 0.57 seconds (570 milliseconds) every day. If I could just get the watch to pause for 24 milliseconds every hour, then it would become extremely accurate. If, for example, the crystal resonates 32768 times per second, pause the watch for 786 cycles every hour.
I wish more quartz watches had that sort of capability (to user program this) but very few seem to.

I posed a similar question in a thread a few months back - you may find some of the responses relevant:

https://www.watchuseek.com/f2/drift-rate-adjustment-why-not-provided-every-quartz-watch-4691005.html
 

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I think we have data from at least one forum regular on this board somewhere that suggests the opposite - that the analogues perform better than the digitals. At least in the case of the Telstar-branded analogue variant. Not sure if there are any material differences between the Telstar watch and its Xonix counterpart but I suspect there aren't.
My Telstar analogue was astonishingly accurate over a period of 23 months without regulation or resetting: -0.6 SPY. Since then I've had to replace the battery and I'm back to the reset/wait/reset cycle, currently at +24 SPY. The two Xonix digitals have never responded to the reset process, beyond setting the current time accurately. They then run at around +65 for one, and either +100 or -100 for the other, with random swapping between the rates. Considering that the modules at least are all probably from the same source, it's surprising that the digitals are so useless. Has anybody had a respectable result with one?
 

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The Yes Watch Equilibrium allows trimming in +/- 1s/month increments as part of the normal time setting. I can't post links yet, but a quick google for yeswatch will give more info.
 
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