# Just the data in Moleman's Hunt for the Milliseconds



## Hans Moleman (Sep 24, 2007)

How well does my Longines VHP perform?

Not an easy question actually.
In my quest to get its exact rate I measured how much it differs from a reference clock.
I took 1000 measurements and none of them is the same!

Plotted against time, it gives an interesting picture:

I took one measurement every 2 seconds. Each one is shown as a blue dot.
The x-axis is the time passed. Almost half an hour worth of measurements.
The y-axis is the difference with the reference clock. The grid is in 10 milliseconds.

You can see the difference steadily increase until after 8 minutes when the thermo compensation correction kicks in.

Without it, the watch would be a very poor performer indeed.

ETA states an inhibition period of 8 minutes for rate measurements. Makes perfect sense now.

Its done on my computer, which is not a real time computer. Some times its too busy with other things, and the measurements are way off. It shows as noise in the picture.


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## Eeeb (Jul 12, 2007)

*Re: My hunt for the milliseconds continues.*

Very interesting. Have you collected similar data on other watches?

My suspicion is your fine detail (which is finer than any detail we have seen before) may be showing how Eta quartz watches work in general. Even non-thermocompensated watches have an 'inhibition period' I believe.

I'm going to have to dig through your past posts... I think somewhere you discussed how you collect data on this level. I can't find a decent timing machine for quartz and you may have the answer!?! 

Again, Very Interesting :thanks


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

You're right!

I did the same for my Tag Heuer with the lesser ETA 955.114.










It has similar jumps. Its inhibition period is one minute.
Only 960 measurements here, so that works out to 32 jumps. 
Bit more of a 'lean' this one. 

I am just happy that it explains why I was getting so wildly varying measurements.
The only way I knew to get around that was doing lots of them and average them out.

Now we all know what 'inhibition period' means. 
It matters *when* you look at your watch; it might be a few ms out!


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

Anyone can pretend to understand everything. You won't learn anything new that way though. Good for you to be honest about it!

Computers are easily distracted. They always find an excuse to leave what they're doing and start off on something else. 
And when they finally come back to the job that really mattered they're too late. 
Those are the non real time computers.

You can tell the computer not to run off to something else. And to start a certain job straight away. Not the 'I'll look into it when I've got time'.
Those computers are the real time ones. They'll finish the job. Everything else will have to wait.

Mostly you'll get away with the non real time ones, since they are not too busy anyway. And when they're late, its easy to spot.

My computer was not very busy doing that. But I am sure it hopped off now and then to wipe a bit of disk or whatever it thought was needed, but easily could have waited a bit.

My Mac is a real time computer and I did similar measurements there, and it did not display that noise.

I display the difference between a reference clock and my watch. That difference seems to vary over time. Seems to vary very regularly over time. So regular in fact that ETA advices people who measure the difference by machine to take only measurements every 8 minutes or multiple of 8 minutes.

I am intrigued to know why. The watch 'knows' its off by 10 ms but can't be bothered to display that. It only corrects the display every 8 minutes.
Sure, not of importance to a casual observer, but very important if I measure it every day and want to calculate the rate with that.

I am sure we'll discover more sooner or later.


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

Thanks Pedro!
I am surprised myself.

Try this for an afternoon science experiment: 
Do you still have one of those radios that gets its signals from the ether? 
Put it next to a quartz kitchen clock. The signals from the stepper motor are so strong that they can be picked up on the radio. FM reception works best for me. Try fiddling with the tuning a bit.

Picking up the stepper motor electromagnetic noise works much better than picking up the audible noise from the second hand movements.

That noise is fed into my computer where it is compared with a reference clock.

My reference clock is the computer clock that has been synchronized with NTP ( http://en.wikipedia.org/wiki/Network_Time_Protocol ). NTP can be compared with using time.gov. Only NTP adjusts the computer clock for you and uses more tricks to get the synchronization very accurate. That is my only reference clock. The COSC uses two atom clocks to do its stuff. One reference is never enough. One day I'll get a GPS receiver with time output. That will have an atom clock accuracy to use as a second reference.

Simple enough in hardware also: A coil to pick up the stepper motor noise. All the rest is done in software, including the reference clock.

Here is the thread that started it off:
https://www.watchuseek.com/showthread.php?t=95310


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## highvista (Feb 19, 2008)

*Re: My hunt for the milliseconds continues.*

Here are some pictures of the stepper motor pulses from the HEQ watches I have hanging around.

ETA 255.561 (Omega SMP 200M):










ETA 955.652 (Breitling Colt Quartz II):










Citizen E510 (Citizen Exceed):










Seiko 8F35 (Seiko SBCM023):










Pulsar Y301A (Pulsar PSR-10):


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## Eeeb (Jul 12, 2007)

*Re: My hunt for the milliseconds continues.*

As I understand it, what we are recording are changes in the magnet flux around the watch... is that correct? (Or is this sound vibrations?)

And the x-axis is milliseconds?


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## highvista (Feb 19, 2008)

*Re: My hunt for the milliseconds continues.*



Eeeb said:


> As I understand it, what we are recording are changes in the magnet flux around the watch... is that correct? (Or is this sound vibrations?)
> 
> And the x-axis is milliseconds?


The x-axis is in milliseconds. The visual scale is a bit different in each picture, since I tried to cut an entire pulse for each and the pulse width varied, especially for the 255.561, where the pulse was much wider.

Yup, this is a record of the electromagnetic flux around the watch. The stepper motor coil gets a shot of electrical current each second. This produces an electromagnetic flux from the watch's coil (more or less a radio wave) that induces a corresponding electrical current in the coil sitting next to the watch. This current is fed into the microphone input of the sound card, which doesn't care that it is a spike from a coil rather than a microphone and treats it like a sound pulse. This pulse is then visualized using a software package intended for doing sound analysis. Also, the induced flux is the greatest when the outside coil is placed parallel and close to the coil inside the watch.

The software I'm using also allows you to play back the "sound" that is recorded. Each watch's pulses are definitely distinct. A bit of time and you can easily distinguish between the movements by the sound.

The whole process is pretty much the same as a radio station's broadcast signal being picked up by the antenna in a radio and being used to produce a sound output from the radio's speaker. Very neat stuff!


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## highvista (Feb 19, 2008)

*Re: My hunt for the milliseconds continues.*

I've just acquired a refurbished GPS-disciplined OCXO clock that outputs a 1 PPS signal that I'm feeding into my computer's microphone input along with my stepper motor pulses. The 1 PPS pulse is precise to within around 20ns according to the docs, so I've got a very stable reference to observe the drift of my watches via eye-balling the waveforms from the pulses--down to the millisecond. I don't yet have a way to automatically gather data points, but I've been able to use observation to see the inhibition periods for a couple watches so far.

My Omega SMP 200M with the ETA 255.561 is showing the same 8 minute inhibition period as noted by Hans for his Longines VHP. My Breitling Colt Quartz II with the ETA 955.652 is showing a 4 minute period--I would have thought it would be the same, having "evolved" from the older ETA line.

Tomorrow I'm going to set up the Citizen Exceed with its E510 movement and see what I get.


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

Sorry, that was a bit too cryptic.

Only every other pulse looks the same.
If you compare the graphs from for instance 11:02:01 and 11:02:03 and 11:02:05 etc, you see that they look the same.
Similarly you can match up 11:02:02, 11:02:04, 11:02:06 etc.

I was wondering if the timings differ as well for the pulses in the two sequences.
That would point to a different way they get triggered.

Not that it matters off course! :-d


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## highvista (Feb 19, 2008)

*Re: My hunt for the milliseconds continues.*



Hans Moleman said:


> Sorry, that was a bit too cryptic.
> 
> Only every other pulse looks the same.
> If you compare the graphs from for instance 11:02:01 and 11:02:03 and 11:02:05 etc, you see that they look the same.
> ...


Hans, from what I can tell, sequential even and odd pulses have the same delta from the current time. It's a consistent slide from the top of the inhibition period to the bottom, at least for the ETA 255.561, which is my favorite test case right now.


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## highvista (Feb 19, 2008)

*Re: My hunt for the milliseconds continues.*

I spent some time last night trying to figure out how the Citizen E510 1 second pulses behaved when compared against the accurate 1 PPS signal from my GPS clock. I expected to see some sort of easily observable inhibition period such as is obvious with the ETA movements. But, just by eyeballing the waveforms, I couldn't find one. When examining the pulses second-by-second, the watch pulse would alternate back and forth between two time values about 11ms apart. Over a 15 minute period, measuring every 30 seconds showed a similar behavior. This is where being able to automatically collect and graph the data points over a half-hour period would be ideal.

Hopefully, when Hans has a chance to characterize a Citizen A660 with detailed graphed data, we'll see what's going on--since I'm guessing the E510 and A660 will behave similarly. In the meantime, as time allows, I'll try to do some manual data collection and graphing and see what can be found


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

This is what the 9F62A movement graph looks like.
Using Jim's movements. Thanks Jim!

One thousand measurements over a period of 41 minutes.

What I can see is a consistent addition of 20 ms every 'now and then'.
How's that for scientific?
Definitely no inhibition period inside the 41 minutes.









What is the significance of this 20 ms?
No idea, but it sure makes it harder for someone to calibrate it.

Don't be confused about all the 'noise' showing up under the graph instead of above it as before.
I've changed my calculation method.


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## Bruce Reding (May 5, 2005)

*Re: My hunt for the milliseconds continues.*

very interesting! Clearly, it's a digital scheme. Apparently for the rate as well as the thermocomp. Looks like a pulse _adding _method, which is the same concept with different execution from inhibition schemes.

Can you show a blow up of the graph showing so that the seconds in which more pulses occured show up individually?


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*










This is a section towards the end where the measurements seem stable.

I'll attach a .csv file as well. So you play around with it in a spreadsheet.
I had to change the file's extension to .txt though.


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## Eeeb (Jul 12, 2007)

*Re: My hunt for the milliseconds continues.*

Glad the movement made it to NZ.

On the text tile, the first number is the time and the second number is the error from the time standard, I assume. (What is the scale of the second number? milliseconds?)

This sure looks to me like the same scheme Highvista was seeing... The Japanese are using an entirely different scheme than the Swiss.

It is almost as if they have a fast rate and a slow rate for the watch and by alternating between the two, and by throwing in an occasional 'wild' correction, they average to the correct rate. But I don't see a pattern to the alternation...

Very strange... gotta sleep on this...

BTW, keep the movement for a while. I don't need it yet and you may be able to extract more data...

I bought two inductance microphones on ebay... but I fear we are going to have to go to a digital scope to get some clean data... and I am lousy on scopes.

Oh well... as Pepys used to say "and so to bed" ...


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

The .txt file indeed has the format , <milliseconds difference from reference>
Positive difference: lagging behind the reference.
Negative difference: running ahead of reference.

Great! I've ordered a GPS clock. Let's see if that clears up the data a bit.
I am not too sure how accurate my reference is.


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## Bruce Reding (May 5, 2005)

*Re: My hunt for the milliseconds continues.*

First, Martien, let me say that this is totally fantastic stuff. I think I speak for the forum when I say "Totally awesome, Dude!!!!!" (and thanks!b-))

Second, I was wondering about the apparently random pattern of 20 millisecond adders. Each data point represents the timing of the "tick" that occurs each second. There are 60X41 = 2460 ticks in 41 minutes. You have a thousand samples. So, it seems that we have subsampling. I'm wondering if this subsampling is obscuring a more regular pattern, either because the subsampling itself is not regular, or because the pattern is high enough in frequency such that the sampling is not above Nyquist. Can you tell us more about the subsampling?

BTW -- I am off to a racquetball tournament today. I _may _not get a chance to check back in until Sunday evening. Bummer, as this thread is "sick". (My teens assure me that this is a good thing. :-d) I'm looking forward to seeing a lot of interesting discussion. b-)


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

Here is another one.
A straight line if displayed in the same scale as before. That made me change the scale.










Again in ms behind the reference.
It has lost 40 ms in a day.


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## Eeeb (Jul 12, 2007)

*Re: My hunt for the milliseconds continues.*

so it is loosing about 15 sec per year...

I have two curiosities...
1) can the movement be adjusted via what appears to be an adjustment point?
2) does the movement change rate when running at a different temperature?

I am actually more curious about the second. We have yet to prove this movement does not change rate due to temperature.

This is fun.

I like the new scaling. I assume the x-axis is minutes of observation. What are the units on the y-axis?


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

Not bad is it?

I wouldn't put too much weight on that 15 seconds value yet.
We're extrapolating a lot. A small measuring difference carries far.
After a few days there should be more certainty.

When the GPS is hooked on I am far more certain about the reference.

The X-axis is the spreadsheet formula "timevalue()" * 1000.
00:00:00 equals to 0
23:59:59 equals to 1000
It makes 41 minutes spread out nicely over one page.

One measurement every 2.5 seconds in average.

The Y-axis is ms behind the reference.

My tweezers are too fat to fit inside. This knob/screw is set deeper than the surroundings too. Seiko knows their stuff!


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## Hans Moleman (Sep 24, 2007)

*Re: My hunt for the milliseconds continues.*

Another graph.
This one taken later in the day.
Only 350 odd measurements. But oddly the top section now has most of the measurements.
Measurements were taken on a real time system this time. It cleaned it up a bit. Not nearly enough!










Explanations anybody?


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## Eeeb (Jul 12, 2007)

Folks, I extracted the 22 posts that are directly concerned with the data from the bigger thread... That thread is getting to be one of the biggest we have ever had and was getting a bit difficult to follow... I left it intact (I think... I've only done this once before) but this thread might be a better one to continue discussions directly concerned with examining the data Highvista and Moleman have collected for us.

Feel free to use the other thread for the other variants of the discussion.


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## Eeeb (Jul 12, 2007)

*Re: My hunt for the milliseconds continues.*

I've slept on this and I still am at a loss to understand why we see such consistent error in the bimodal form -- i.e. the two parallel lines.

The Eta graphs I can understand. They show the movement has an error in normal operation... the error accumulates... then the error is corrected.

I do not see error correction in the Japanese scheme. Nor can I explain the consistent dual error in normal operation.

I suspect the 'outriders' -- the odd data samples that do not follow the two lines -- may be artifacts of the collection scheme.

It has been years since I have done real-time collection of data like this. Maybe our Fearless Leader does this more often in his job and will be able to shed some light (after he recovers from a weekend of handball!)...

As Alice said of her trip to Wonderland, "Curiouser and curiouser..."


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## Hans Moleman (Sep 24, 2007)

Another day, another graph.










Clean as a whistle.
Figured out why the odd and even ticks differ for my VHP.
The pulse shape differs for the odd and even seconds, and my software calculates the start of the pulse wrong.
After that change, I did another test on the 9F62A. Gone is the phantom graph.
Phew!
Calibration should be a breeze. Or at least working out what the calibration should be.

Now I'll dig a bit further why the first method did not work.


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## Hans Moleman (Sep 24, 2007)

The Seiko pulse that drives the stepper motor consists of two parts.
Could this be because it does not have any hands?
I am measuring on a movement without hands.










The second part happens around 20 ms later.
I was measuring the maximum in the graph, but since there is not much difference between the two parts, sometimes the maximum is located on the later part.
Hence the 'random' nature.

Sorry about the confusion folks!


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## Eeeb (Jul 12, 2007)

Ahhh.... good! now things are making more sense.

The parallel lines are explained... 

I think what we are seeing is a stable and consistent rate without any injection of corrections... but we need more data to say that with any conviction.

We know the Eta movements count vibrations of the quartz crystal. Since temperature may cause it to drift off a true 32k, periodically it injects a correction count.

We don't see this with the Seiko (I think). My supposition is somehow Seiko is shaping the quartz crystal's output to make sure it is always a true 32K...

Is that what the data suggests??

Our journey into Wonderland continues 

(I get an oscilloscope next Friday (an old one, a gift) ... hopefully my copy of Oscilloscopes for Dummies arrives before the scope  So we will have some other views inside these beasts.)


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## Bruce Reding (May 5, 2005)

*Re: My hunt for the milliseconds continues.*



Eeeb said:


> I do not see error correction in the Japanese scheme. Nor can I explain the consistent dual error in normal operation.
> 
> I suspect the 'outriders' -- the odd data samples that do not follow the two lines -- may be artifacts of the collection scheme.
> 
> ...


Racquetball -- and the operative word is somewhere between recover and resuscitate. I won three of four matches in my division. (Did not win overall.) My wife won her division. My wife and I had a very enjoyable doubles match. My son got knocked out of his division in the first match, but it was tight, and the fellow he played went on to win overall. My body is one solid ache. (The joys of being fifty!) Enough of the weekend report, though.

Excellent work on discovering the source of the duality, Martien! Jim -- your instinct was dead on. Artifact it was. So, I think what may be revealing is if we subject Jim's 9F movement to a different temperature. (I would suggest lower.) If we see a bit of a slope with periodic corrections, then it proves some sort of inhibition (or "exhibition") scheme. If we don't then I think that it disproves it.

Fantastic work! :-!


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## ppaulusz (Feb 11, 2006)

Eeeb said:


> ...My supposition is somehow Seiko is shaping the quartz crystal's output to make sure it is always a true 32K...
> 
> Is that what the data suggests??...


If that is the case then the Seiko 9F is not thermocompensated but rather _thermoinsensitive_. Interesting...


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## highvista (Feb 19, 2008)

Eeeb said:


> Ahhh.... good! now things are making more sense.
> 
> The parallel lines are explained...


I guess I missed something. What's the explanation? Maybe my coffee just hasn't soaked in yet.


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## Bruce Reding (May 5, 2005)

Hans Moleman said:


> Another day, another graph.


Martien -- what is the time period over which the data in this graph was taken? Also, could you explain the y-axis values a bit more? (80 _whats _vs. _what_?) Also, are you still subsampling every other second/every third second? Could you get every second?

I'm still noting bimodal stratification in the data. (A histogram of their values would help here.) Also, there's nothing that says that the corrections cannot be distributed rather than being done all at once.


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## Hans Moleman (Sep 24, 2007)

A few more lines of explanation:
Before my last software change I used the 'loudest' part of the sound to time the pulse with.
That worked very well on the ETA's since they have regular shaped pulses. The loudest part is always in the same position.

That strategy did not work for the Seiko. A small variation in the shape of the pulse shifts my timing of it by 20 ms. 

We'll have to put the 9F through more tests.
I can see it slowly drift, but I can't be sure if that drift is caused by the Seiko or my reference clock. 
We need a test that makes its rate drop by a lot.


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## Hans Moleman (Sep 24, 2007)

These measurements were taken over a 16 minutes period. 
The same program is used for the ETA. 
I am taking a measurement every 2 or 3 seconds like before.
The Y-axis is the difference in ms to the reference clock. Positive values denote running behind the reference.
A pulse timed at the beginning of the pulse.

No, I can't measure every second. My computer can't cope with that.

I'll see if I can make a histogram out of the data. Bell curves, that sort of thing?

I agree, a correction could easily be incorporated without sudden jumps.
That's were I wish I had a GPS reference clock. The changes are so subtle that they might come from my reference, not the movement.
The GPS is on its way.


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## ppaulusz (Feb 11, 2006)

Good on you, Hans!:-!
Your test might give us the answer we've been waiting for about the Japanese technology.


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## Hans Moleman (Sep 24, 2007)

Thanks George!
All thanks to you.
Remembering that my ultimate goal was to regulate the VHP to perfection.


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## Bruce Reding (May 5, 2005)

Hans Moleman said:


> Remembering that my ultimate goal was to regulate the VHP to perfection.


With the tools you're developing, you'll be able to knock that one out of the park! b-)


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## Hans Moleman (Sep 24, 2007)

All these tests sure made the observations more consistent.

Here are more tests on the 9F62A:

I put the movement from room temperature into a chilly bin. The temperature in the bin ranged between 10.3 and 10.5 degrees C during the full hour it had to endure.
After that hour it came out again into a 20 degrees C warm room. That' s 68 degrees F to 50 degrees F and back. 
The movement was not encased. It was inside a small plastic zip lock bag.
It should have warmed up and cooled down fairly quickly.

One hour worth of data. Every 2 or three seconds an observation. An observation is represented by a dot in the graph.
During an observation I determine how far the movement is behind the reference.

X-axis: elapsed time.
Y-axis: milliseconds (0.001 seconds) behind reference.

I would trust my reference to 1 ms. But that has not been tested.
And I would trust my reference not to wander by more than one ms during that hour. Again not tested.

No observations were left out.










Above is the cooling down graph.










Above is the warming up graph.

It does not like the cold. It falls further behind in the cold.

Ask me the spreadsheet and I'll gladly mail it.


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## Eeeb (Jul 12, 2007)

I don't see any compensation for the temperature... I think the 'getting cold' graph shows this clearly.

Am I missing something?


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## Hans Moleman (Sep 24, 2007)

Well, there is no complete compensation for temperature.
They try to compensate for temperature. The compensation is not 100% effective.

5 ms in an hour equates to 40 seconds in a year. That is what a garden variety would lose in a month.

And the 5 ms is chosen very conservatively.

An ETA is next.


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## Hans Moleman (Sep 24, 2007)

Bruce, here is the histogram as requested in 
https://www.watchuseek.com/showpost.php?p=1172086&postcount=12










Every forum needs at least one histogram. :-!

An analogue pick up in between two digital systems. Is that all right?


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## highvista (Feb 19, 2008)

I've found a fairly easy-to-use signal analysis program and gathered a bit of data on the E510 movement. I copied the data by hand into Excel for charting , so I only have about 20 seconds graphed. Just with this small amount, it does show an interesting pattern in the sequential pulses.

The first graph shows the deltas between successive pulses:










The second graph shows the same data, but the absolute values of the pulse deltas are used:










Heck if I know what it means, though...


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## Hans Moleman (Sep 24, 2007)

A graph is a graph! :-!

The more graph **** the better.

Too short for an inhibition period.
Do all the pulses in that 20 second period look alike? 

I suspect an even pulse with a 'long tail' and odd pulse with 'short tail'.
Something like that.


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## highvista (Feb 19, 2008)

The pulses all look alike, except that every successive pulse is mirrored about the x-axis relative to the previous, as we've seen before. But I'm measuring from the rising/falling edge of each pulse, so this isn't an issue. I believe it's a real measure of something the movement is doing, given the periodicity.

Man, this stuff is addictive. I have to get to bed!


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## Hans Moleman (Sep 24, 2007)

You keep finding new methods. I am impressed.
Could it drive the minute hand every 4 seconds?


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## ppaulusz (Feb 11, 2006)

highvista said:


> ...Heck if I know what it means, though...


I must admit that I'm not an expert of reading the graphs. If the results are read out to me I might translate it into something useful. That's all about my understanding of the graphs.
As far as I know, in case of the ETA movements you guys need to follow the inhibition periods during these tests. ETA uses either 8 minutes or 4 minutes inhibition periods with its thermocompensated movements.
Citizen and Seiko might use even longer inhibition period (if they use inhibition period at all) so it would be wise to extend the time of your tests (if technically possible) when measuring the Japanese movements. You never know, it might show a different looking graph.
Keep up the good work, Gents!:-!


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## Bruce Reding (May 5, 2005)

Extremely interesting work! Unfortunately, I'm in a rush this AM. There's clue's here, though. I'll be doing a lot of this: :think:

I must admit that I'm surprised by the histogram, because, by eye, I saw clear stratification. I think I may know what's going on there, though. Could you post or send me the raw data for that, Martien?


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## Eeeb (Jul 12, 2007)

*Re: My hunt for the milliseconds continues.*

I did a little research on how stepping motors work and good old(?) Wikipedia has this wonderful article with a number of supplementary links.

The 'pulsing' we are seeing in the electromagnetic flux is an artifact of how stepping motors work! The article answers a lot of questions -- and brings others to mind.

Different designs of stepping motor will produce different pulse patterns. And we can't assume the motor goes through one rotation per second... it could be more... it could be less. The number of rotations of the motor is linked to the gearing on the second hand.

UPDATE:
Here is an animation and explanation of how a stepping motor works in a watch... very interesting...
More information!


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## highvista (Feb 19, 2008)

ppaulusz said:


> I must admit that I'm not an expert of reading the graphs. If the results are read out to me I might translate it into something useful.


I hear you. It's hard to describe in writing what the graphs mean, as well. It's the kind of thing that needs a lot of pointing and hand motions. 



> Citizen and Seiko might use even longer inhibition period (if they use inhibition period at all) so it would be wise to extend the time of your tests (if technically possible) when measuring the Japanese movements.


That's exactly correct. What is needed are highly accurate measurements at the pulse-by-pulse/sub-millisecond level but over a long time period. I've got the highly accurate part, but the data is being displayed as waveforms from a signal analysis program. I can plot out exact data points down to sub-millisecond resolution, but doing it by hand limits the amount of data I'm able to copy into Excel for plotting without going bonkers.

I wanted to show at least a small segment of the pulse-by-pulse data to demonstrate that there is definitely a "bi-model" character to the pulses that is only seen if each successive pulse is examined. Doing a sampling that only catches a pulse every two or three seconds may miss this.

Once Hans gets his GPS clock, I'm hoping he'll be able to give us both high accuracy and plots of a lot of data. Go Hans!


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## Hans Moleman (Sep 24, 2007)

Bruce: Here is a more detailed histogram of the area of interest. I hope that helps. 
The raw data is attached too.

I put the layering down to the digitization of the analogue signal of the coil.










I envy HighVista's sub millisecond accuracy.
Everything I see under 1 ms I just put down to 'noise'. Most likely that is not correct!
The trend is visible though through that 'noise'.
Now where's that GPS? :roll:


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## highvista (Feb 19, 2008)

Hans Moleman said:


> I envy HighVista's sub millisecond accuracy.
> Everything I see under 1 ms I just put down to 'noise'. Most likely that is not correct!
> The trend is visible though through that 'noise'.
> Now where's that GPS? :roll:


Yeah, figuring out how far to carry the precision of the data is a bit hard. There's definitely noise below a certain level. Given what I'm seeing, I think a precision to 1x10e-4 sec (ten-thousands of a second/100 microsecond) +/- a few hundred microseconds is possible. There definitely seems to be a periodicity in the data showing up there for the E510 movement. But I'm ready to be proven wrong, as good science demands.


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## Hans Moleman (Sep 24, 2007)

I am sure you're right.
It must be one of those tricks that the manufacturer thinks they can get away with since no one will ever notice. 
And they should have been right.
What they try to achieve with it, is the interesting part.

Great link from Eeeb about stepper motors too.
It explains why the ETA's have this high frequency pulse. All a matter of design.
Amazing that it all happens on this small scale.


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## Hans Moleman (Sep 24, 2007)

Thanks to Bruce for his persistence!
The white area's in the histogram were my doing.
I introduced a rounding error in my program.

And more thanks for the Citizen for testing!
It arrived in excellent condition.

These watches amaze me for their dogged consistency. They don't stray away very much!










I would not put any weight to the kinks. Could well be caused by my reference getting its act together.

16 minutes worth of measurements.
One measurement every 2 or 3 seconds.
Y-axis: ms ahead of reference.


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## Hans Moleman (Sep 24, 2007)

And its pulse.
Resembles the E510.


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> And its pulse.
> Resembles the E510...


Excellent! It confirms our theory that modern Citizen movements use identical technology to achieve high-accuracy.:-!
Now, the question: how do they do it? By _thermocompensation_ or by _thermoinsensitivity_?:think:
Also, can you guys confirm that the Seiko 9F's pulse resembles of the Citizen E510 and A660?


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## Hans Moleman (Sep 24, 2007)

I've posted the 9F pulse before. It does not resemble anything we have seen before.
It got me into trouble with its two identical parts.

OK with you Bruce if it spends a few hours in the bin?


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> I've posted the 9F pulse before. It does not resemble anything we have seen before...


Does it mean that we have three different pulses:
- the ETA-type pulse (ETA 255.561)
- the Seiko-type pulse (9F62)
- the Citizen-type pulse (A660 and E510) 
according to your test results?


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## Hans Moleman (Sep 24, 2007)

HighVista published a few here:
https://www.watchuseek.com/showpost.php?p=1168982&postcount=6

The 9F62 pulse is here:
https://www.watchuseek.com/showpost.php?p=1170772&postcount=8

I hope the 9F62 pulse is representative since it did not have any hands.


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## Bruce Reding (May 5, 2005)

Fantastic, Martien! My baby's heartbeat. Very interesting! b-)

What did you mean by the following: "The white area's in the histogram were my doing."?

Again, looks to be clearly bimodal. Do the even and odd pulses look the same? Could you show a plot of each alone? Also, the slope is small, but my eyeball says that it's substantially larger than 5 secs/year. Therefore, I suspect thermocomp.



Hans Moleman said:


> OK with you Bruce if it spends a few hours in the bin?


Yes. Not the freezer please, but refrigerator would be fine.


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## mantisman (May 10, 2008)

I was looking for info about multiple stepper motors in the 9F series of movements and stumbled on this page in their newer literature. The really crude translation I have seems to be saying something about adjusting the rate periodically based on 540 sensors measuring temperature ...??

http://www.seiko-watch.co.jp/gs/about/attractive_03.html


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## ppaulusz (Feb 11, 2006)

mantisman said:


> I was looking for info about multiple stepper motors in the 9F series of movements and stumbled on this page in their newer literature. The really crude translation I have seems to be saying something about adjusting the rate periodically based on 540 sensors measuring temperature ...??
> 
> http://www.seiko-watch.co.jp/gs/about/attractive_03.html


:thanks for the link!!! Great stuff!!!:-!
In my interpretation, it says that the temperature is checked in every 160 seconds as it cheks the temperature 540 times a day (160 x 540 = 86400). So using these temperature datas correction can be made to achieve high-accuracy. In other words, it describes a _thermocompensation_ scheme with an inhibition period of 160 seconds!


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## Eeeb (Jul 12, 2007)

mantisman said:


> I was looking for info about multiple stepper motors in the 9F series of movements and stumbled on this page in their newer literature. The really crude translation I have seems to be saying something about adjusting the rate periodically based on 540 sensors measuring temperature ...??
> 
> http://www.seiko-watch.co.jp/gs/about/attractive_03.html


good find!!

Babelfish translates the 3 relevant paragraphs as follows:

_The crystal oscillator which is used with the quartz clock 32,768 times vibrates to 1 seconds. Precision of the quartz clock whether or not it can maintain this frequency, is decided by. But there is an individual difference in the crystal oscillator, in there are also some which cannot maintain the frequency which is stabilized with the change of environment. With the gland SEIKO quartz clock, passing the process, aging which reaches to also 3 months, you adopt just those which finally clear standard._

(Google xlation:
Use quartz crystal oscillator that is 32,768 times per second vibration. クオーツ時計の精度はこの振動数が保てるかどうかにより、決まります。​ The quartz accuracy is whether the frequency is to manage, determined. しかし水晶振動子には個体差があり、中には環境の変化により安定した振動数が保てないものもあります。​ However, individual differences in the crystal oscillator, a change in the environment of stable frequency保てないis made. グランドセイコーのクオーツ時計では、3ヶ月間にも及ぶエージングという工程を経て、最終的に基準をクリアしたものだけを採用しています。​ Seiko's ground quartz, the 3-month-old aging process through the final, only to the standards adopted.)

And it shows the quartz crystal's location in this pic:









*My understanding of this is crystals are aged 3 months and then those that show the needed adherence to a true 32K rate are selected.*

_The crystal oscillator of the quartz clock receives influence to also change of little temperature. 32,768 times calls frequency, is to rise and fall with temperature in 1 seconds. When 32,768 frequencies 1 times change temporarily in 1 seconds, in regard to calculation it is in 1 years to become approximately 16 minute thing errors. Temperature inside the clock on the 1st you measure the quartz which it is on-board onto gland SEIKO, with 540 sensors, revise the error of frequency of the crystal oscillator._

(Google translation: 
 クオーツ時計の水晶振動子は、わずかな温度の変化にも影響を受けます。​ Quartz crystal oscillator is a slight change in temperature are also affected. 1秒間に32,768回という振動数が、温度によって上下してしまうのです。​ 32768 times per second in the number of vibration, temperature up and down the whole thing. 仮に1秒間に32,768回の振動数が1回変わると、計算上では1年間で約16分もの誤差になってしまうのです。​ If 32768 times per second to one-time change in the frequency, calculated on the year, about 16 minutes to become the error. グランドセイコーに搭載しているクオーツは、時計内部の温度を1日に540回センサーで測り、水晶振動子の振動数の誤差を補正しています。​ GURANDOSEIKO equipped with a quartz to the internal clock 540 times a day temperature sensors measure the frequency of the crystal oscillator to correct the error.)

And it shows the thermocomp circuitry's location in this pic:









*My understanding is thermal drift is compensated 540 times a day (i.e. the inhibition period is 160 seconds). *

_The mechanical cable type clock has the mechanism in order fine to adjust precision, but the quartz clock fine control precision generally. But, fine control of precision can do the gland SEIKO 9F quartz with the "gentle urgent switch". Starting using, several years passing, when to advance the tendency such as tend and late tend is clear, it is to be possible to revise precision with this switch. When long years you regularly use, it means that the adjustment where "habit" of that clock understands, adjusts to that "habit" is possible. _

(Google translation: 
 機械式時計は精度を微調整するための機構を持ちますが、一般的にクオーツ時計は精度の微調整ができません。​ Precision mechanical watch is a mechanism for fine-tuning, but, in general, precision quartz clock is fine-tuning. しかし、グランドセイコーの9Fクオーツは「緩急スイッチ」により精度の微調整ができます。​ However, the Grand Seiko quartz 9 F "brake switch," the accuracy of fine-tuning. 使い始めて数年経って、進みがち、遅れがちといった傾向がはっきりしたときにこのスイッチで精度を補正することができるのです。​ A few years after first use, tend to go, dilatory and this trend is not clear when the switch can be corrected for accuracy. 長い年月ご愛用いただくとその時計の「癖」が分かり、その「癖」に合わせた調整ができるのです。​ Over the years, you'll love the clock and the "habit" to understand the "habit" can be adjusted to meet.)

And the 'gentle urgent switch' used to adjust is pictured as:









*I believe this to mean the rate can be adjusted and this was envisioned as being necessary for 'long term' adjustment (which is probably crystal aging) and for the 'habit' of the watch (possibly the variations due to environmental characteristics??)

Well, at least we know the inhibition period!!

*


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## Bruce Reding (May 5, 2005)

Eeeb said:


> good find!!


Second that. :-!

A correction period of 160 seconds implies rate adjustability of 8 seconds per year. Or, one could get the 9F's mean rate adjusted to no worse than 4 seconds per year. (This assumes that inhibition (or exhibition) down to one count in that period is possible, as opposed to ETA's apparent restriction of 2 counts or more.)

We should be able to see this period. The refrigerator work may be key for this. It may be that the corrections are distributed throughout the period, however, obscuring the pattern.

Jim -- I agree with your interpretation of the translation.

*Robert *-- You can read the original. Are we missing anything?


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## ppaulusz (Feb 11, 2006)

Bruce Reding said:


> ...A correction period of 160 seconds implies rate adjustability of 8 seconds per year. Or, one could get the 9F's mean rate adjusted to no worse than 4 seconds per year...


_Dave (dwjquest)_ had similar result when he calibrated his Seiko 9F movement:
Read_post_#6_here!
So the above is confirmed!


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## Hans Moleman (Sep 24, 2007)

The odd and even seconds difference on the A660 can't be explained by a different shape of the pulse. The pulses are similar. Other watches don't show that habit, so for now, I must assume its genuine. Another one for the 'as yet unexplained' box.

Where's that GPS? I can't see 0.5 ms corrections.


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## Eeeb (Jul 12, 2007)

one additional point... the second pulse seems to be the mirror of the first... hummmm


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## Hans Moleman (Sep 24, 2007)

I wouldn't trust it either.
I bet it is going twice as fast without hands.
Oops. Let me rephrase that: 
I bet the spindle that holds the second hand turns twice as fast than normal.

Would it affect our accuracy tests though?


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## Eeeb (Jul 12, 2007)

I dug through all of the data posts again looking for the 160 second inhibition correction.

The data at room temperature might not show it as there might not be much correction.

But one would have thought the 'cold' data would have... but I don't see it.

Martien, feel free to put the movement in the freezer if you wish. Such temperatures might cause it to not function properly... but I can't see any way it would cause any long term damage. -20 C is even within operating temperature for some quartz movements...

If we can not see any compensation at that end of the spectrum we are either looking in the wrong places or it isn't happening...

(I got my Oscilloscopes for Dummies book today... I hope to add to our confusion in a few weeks!)


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## Hans Moleman (Sep 24, 2007)

I was going to wait till my GPS turns up.

If you look at the 'cold' tests:
It loses 10 ms in one hour.
That would be 0.5 ms per period. I can't see that sort of detail right now.


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## Eeeb (Jul 12, 2007)

Great! no dead ends yet! WUS HEQ proceeds onward.... 

Actually when Berners-Lee invented the World Wide Web, this is exactly what he envisioned -- people all over the word doing cooperative research! :-!


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## Hans Moleman (Sep 24, 2007)

Well actually I am just lazy.
The fridge is on one end of the house and the computer on the other.
I don't want to shift either.

I'll see if I can put the software on a laptop. 

Never at a dead end. Just going round in circles!
b-)


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## Eeeb (Jul 12, 2007)

Well, I'd pop over and give you a hand... but we are literally at opposite ends of the Earth :-d

I do have a friend who is wintering over at the Pole... In about 5 months he gets off the Ice and will be stopping over in NZ for R&R... He considers NZ a vacation paradise! But I could get him to help. He is a very curious type too.


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## Hans Moleman (Sep 24, 2007)

Thanks for the offer!
It will just have to wait a bit. Too much effort for too little return.
The GPS 'should' give us a 0.001 ms resolution.
Many more riddles to come.
We'll have to factor in the moon's gravitational pull. Jupiter's moon.

An inquisitive mind is a real asset! I hope it never stops.

If I can hold on to the watches, that would be great.


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## Hans Moleman (Sep 24, 2007)

With the the white areas I meant that the histogram showed that some results have no hits booked against them.
And these white areas were regularly spaced. So I figured rounding was effecting the results.
After I corrected the rounding error this layering disappeared.

Are you seeing something else Bruce?


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## ronalddheld (May 5, 2005)

Good ongoing research. Now if someone could get the software to dump/program the ROMS...


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## Hans Moleman (Sep 24, 2007)

Thanks Ronald!
Do you know anyone who could do just that?
Did you just volunteer?
|>  :-!


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## Bruce Reding (May 5, 2005)

Hans Moleman said:


> With the the white areas I meant that the histogram showed that some results have no hits booked against them.
> And these white areas were regularly spaced. So I figured rounding was effecting the results.
> After I corrected the rounding error this layering disappeared.
> 
> Are you seeing something else Bruce?


My leading theory right now is that both the 9F and the A660 has a digital count adjust scheme (inhibition or exhibition), but that the adjustment is distributed rather than being done all at once at the end of the adjustment period. It would work like this: at the end of the period, the software determines that 127 counts need to be added (or subtracted) from the next period. It does so not at the beginning, but rather evenly spaced, one or a few counts at a time, throughout the next period. Such a scheme could look bimodal.

And btw, yes I'm okay if you keep my watch for further testing. Anything for science! Will you do a refrigerator test for it? That could be revealing.


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## ppaulusz (Feb 11, 2006)

Bruce Reding said:


> My leading theory right now is that both the 9F and the A660 has a digital count adjust scheme (inhibition or exhibition), but that the adjustment is distributed rather than being done all at once at the end of the adjustment period. It would work like this: at the end of the period, the software determines that 127 counts need to be added (or subtracted) from the next period. It does so not at the beginning, but rather evenly spaced, one or a few counts at a time, throughout the next period. Such a scheme could look bimodal...


Bruce, your theory could be the explanation for the tests results!|> 
Also, if things work the way you described then the Japanese scheme would be the perfect camouflage: _Thermocompensation_ without a spectacular "_bang_"!;-)


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## Eeeb (Jul 12, 2007)

We need more data to draw any conclusions... Martien said he lacks sufficient resolution to distinguish the correction at the level the correction would currently be (it is in one of our exchanges yesterday. Or at least, that's how I understood our exchange...)

If it was easy, we would not feel a strong sense of accomplishment when we succeed... remember we are delving into modes of observation and analysis that we have never done before. And none of us seem to be expert lab rats so it is all the more amazing we have gotten as far as we have so quickly.

Right now, I don't feel the distributed compensation theory will work out. We'll see.

There are two things we can say for sure, I feel.

1) different watches can have radically different stepping motor implementations.
2) the Swiss and the Japanese have different modes of accomplishing accuracy.

The Japanese cherry pick their crystals and aim for a maximum accuracy without any correction. (so far every Japanese xtl didn't need much correction.) The Swiss apparently take any crystal and just use their scheme to make it accurate.

Are we having fun yet?


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## ppaulusz (Feb 11, 2006)

Eeeb said:


> ...The Japanese cherry pick their crystals and aim for a maximum accuracy without any correction. (so far every Japanese xtl didn't need much correction.)...


Jim, unless you explain _how they do it with 32kHz quartz crystals_, it's rather difficult to digest the above theory.
The thermocompensation theory (described by Bruce) is more in-line with our knowledge about thermocompensation (in general) and the known limitations of 32kHz quartz crystals when exposed to temperature changes, in my opinion.
You just cannot cherry pick 32kHz quartz crystals and expect them high-accuracy performance when exposed to temperature changes. 
You have to somehow:
prepare them to be insensitive for temperature changes
or alternatively:
introduce a thermocompensation circuit in the movement's electronic module.
Did I leave something out?


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## Eeeb (Jul 12, 2007)

Read what I said carefully George. I said no more than the Japanese "cherry pick" their crystals. This means they take only the ones that, at the selection temperature, already hit 32K with little or no correction.

I did not say there is no thermocompensation. But I will assert there is currently no evidence of thermocompensation. I too assume there is thermocompensation. We just have not yet seen it in the data.

What I did say was I do not think we will find 'distributed' corrections. I just do not see systems being engineered that way in real life. I believe we will find any corrections being applied at the 160 second inhibition calculation point (for the 9F). But I am willing to let that conjecture stand the crucible of experimental data.


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## ppaulusz (Feb 11, 2006)

Eeeb said:


> Read what I said carefully George. I said no more than the Japanese "cherry pick" their crystals...


OK, Jim, I read it _very carefully_ this time and guess what?! You _did say more_:

_"the Swiss and the Japanese have different modes of accomplishing accuracy._

_The Japanese cherry pick their crystals and aim for a maximum accuracy without any correction. (so far every Japanese xtl didn't need much correction.) The Swiss apparently take any crystal and just use their scheme to make it accurate."_

Jim, I understand your late explanation however it was not evident from your earlier post that I replied to. Furthermore, without your late explanation it still has a _different_ meaning regardless how carefully I read it again and again...
I agree that the reader should take care... I'm sure that we both agree that the same rule applies to the writer as well!;-)


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## Eeeb (Jul 12, 2007)

Point well taken George... Point well taken... It is not sufficiently clear what I meant.


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## Hans Moleman (Sep 24, 2007)

More graphs! We need more graphs!

How good is my reference?
And how can I tell without any other reference?

I am using NTP. A computer program that compares my computer clock with other clocks. One of them is an atomic clock.
The hardest part for NTP is not knowing how much variation is in the network delays.

I measured my VHP once with NTP running and once without.










Top graph: NTP on.
Bottom: NTP off.

What I can see in it is that those 'sudden drops' happen a lot ofter when NTP is not running. I really need it to have it running.

Since we know the behavior of the ETA, we know these 'sudden drops' are not caused by it. They came about because of my clock or recording software.
They are annoying since they could obscure something more subtle.
The 0.5 ms temperature correction steps for instance. If they exist. I think they do.

Lets hope these 'sudden drops' disappear when a GPS is connected. I expect they will.

I'll do a chilly bin test with the Citizen later on.


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## Bruce Reding (May 5, 2005)

Excellent work in ferreting out noise sources, Martien. :-! Do I understand that you are proceeding with the GPS adder? If so, it should make your setup a true discovery engine.

Just in case our appreciation isn't already abundantly clear, I want to extend mid course kudos now. I'm sure I speak for the forum in saying that your work is excellent, and we _greatly _appreciate your applied time and talent. We had a discussion recently about what the core of this forum is. I think we've got the best possible illustration right here.


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## Bruce Reding (May 5, 2005)

Eeeb said:


> ... If it was easy, we would not feel a strong sense of accomplishment when we succeed...


Hey! You stole the line I use on my kids! :-d



Eeeb said:


> ... Right now, I don't feel the distributed compensation theory will work out. We'll see.


Agreed, Jim. I give it less than fifty-fifty myself. It's just that the other theories I have feel even less probable. The problem with the distributed correction theory, of course, is why would they do the correction in a more complex way for no apparent reason? One possibility is that it's a patent workaround. This is pure speculation, but do we know what patents exist for inhibition methods? A technical reason for gradual, distributed corrections would be that they want to use this or very similar hardware for applications beyond timekeeping where constant frequency is important. (An FFT of the ETA movement's output would be pretty messy looking. As such, their hardware would work poorly for frequency based applications.) This is a stretch at best.



Eeeb said:


> ... Are we having fun yet?


Yes indeed. :-!


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## Bruce Reding (May 5, 2005)

Hans Moleman said:


> ... I'll do a chilly bin test with the Citizen later on.


This may be a very illuminating test for the 9F or the A660. (Again, for my A660, I'd appreciate it if you kept the temp above freezing.) As Jim stated, it's _looking _like both Citizen and Seiko took care to tune the underlying crystals more closely to nominal. (I italicize "looking" because distributed correction, if finely enough grained, would look like excellent nominal frequency at the granularity of the tests so far.) As George stated, however, physics is physics. Those crystals _will _change their frequency if their temp. changes. As such, if they use a lump correction at the end of the time cycle, then, even if things look very flat at room temp., we should see something more ETA like at different temps.


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## Hans Moleman (Sep 24, 2007)

Thanks Bruce!
Glad that I can help. And I find it fascinating myself.

GPS is on its way. That should make the whole play 1000 times more obvious.
And I guess we'll see the tiny jumps at the 160 sec intervals.
Far too much hassle carrying the correction forward all the time. My guess.

No freezing here. Too much hassle.

Now, what is a bimodal scheme? Does that explain the even and odd seconds?


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## Hans Moleman (Sep 24, 2007)

A test with the Citizen A660.
I decided to wear it for a while before putting it in the bin.
All in the name of science!
That must have been a drop from 100 F to 50 F.

The first scale is in the same scale as the Seiko.










And magnified a bit more:










Looks like the reference clock has some good periods in between the bad.
But nothing as good as to see 0.5 ms.

Whole period spans 16 minutes.
Y-axis: ms before the reference. Poor reference, it tries so hard!


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## Bruce Reding (May 5, 2005)

Are these plots of the performance while it was at 50F? A very clear bimodality. Can this be explained away as an artifact like the apparent bimodality of the 9F was? If not, then this is a clue for sure.


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## Hans Moleman (Sep 24, 2007)

I started recording as soon as it was in the bin.
Dropping from 100 to 50.
What is bimodality?


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## ppaulusz (Feb 11, 2006)

Bruce Reding said:


> ...The problem with the distributed correction theory, of course, is why would they do the correction in a more complex way for no apparent reason? One possibility is that it's a patent workaround. This is pure speculation, but do we know what patents exist for inhibition methods?...


Funny, you mention the patent issue, Bruce, because that was my only explanation for it when I tried to reason it.
(Slightly off topic but did you know that the main reason for Sony inventing the Trinitron tube was patent workaround?)

Now back to watches! The other day I suggested to do these measuring tests on a Seiko Twin-Quartz. Why? Because - in theory - that could be the only movement that used the "inhibition" scheme before ETA. I too would be interested to see who introduced and when the technology that is still the 'winner' in these days.

Just a quick historical reminder:

- Before 1977 manufacturer used high-frequency (MHz-range) oscillator to achieve high-accuracy.

- In 1977 Rolex used the first thermocompensation scheme: an analogue method that directly modified the frequency of the 32kHz oscillator as the temperature changed (it even had an analogue trimmer capacitor for rate adjustment). So that scheme was fundamentally different to modern digital inhibition technology.

- In 1978 Seiko introduced the Twin-Quartz thermocompensation design. It had an analogue trimmer capacitor for rate adjustment. The big question is whether it used digital inhibition for thermocompensation?! If it did then Seiko should be credited for introducing and implementing the scheme the very first time.

- In 1984 ETA (in collaboration with Longines and AsuLab) introduced the ETA 255.561 dual-oscillator movement with full digital inhibition technology (Couple of years later ETA modified the hardware and replaced the second oscillator with a thermistor on the IC. That movement was called the ETA 255.563 and it was introduced sometime before 1995 as the last non-perpetual VHP watches were made around that time and those watches towards the end where fitted with the new hardware). It had a digital rate adjustment terminal. Current ETA Thermolines are still using the same digital inhibition technology.

- In 1993 Seiko introduced the 9F movements with fully digital inhibition technology (with digital rate adjustment terminal). They have a 32kHz oscillator and thermister on the IC.

- In 1995 Citizen introduced the A660 thermocompensated movement. Most probably it uses a digital inhibition scheme. (As far as I know, it does not have calibration terminal!) It has a 32kHz oscillator and (most probably) a thermister on the IC.


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## ronalddheld (May 5, 2005)

Unfortunately, no I do not. Any here with extreme "pull" at ETA(or Seiko or Citizen)?


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## Eeeb (Jul 12, 2007)

ronalddheld said:


> Unfortunately, no I do not. Any here with extreme "pull" at ETA(or Seiko or Citizen)?


I don't but I just emailed an old friend who is one of the world's experts on embedded systems. He may have sold to them or might help... worth a try!


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## Bruce Reding (May 5, 2005)

Hans Moleman said:


> I started recording as soon as it was in the bin.
> Dropping from 100 to 50.


So it was actually changing temperature signficantly during the time period of this graph? Interesting! I do not see an obvious change of pulse timing behaviour over the sixteen minutes.



Hans Moleman said:


> What is bimodality?


Just a fancy way of saying that the histogram has two humps. Do you think that this can be explained as an odd/even pulse thing? I know that you don't have sufficient computer power to record all the pulses. Can you record only every other one (or every fourth one) rather than doing the two then three scheme?


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## Hans Moleman (Sep 24, 2007)

I recorded every other second on the A660. 11:01:02, 11:01:04 ...
And every forth second. 11:01:02, 11:01:06 ...
In two separate recordings.

The two humps remained. No explanation from me as yet!

A recording with the 9F did not show that pattern. I am a bit dubious about that one since it has no hands though.
A recording of the ETA 252.611 does not show it either.

Is there an equivalent of 'allowance' in electronic components? As if it shakes between two extremes. If you can call that extremes!

So that's where we are at:

The 9F has a definite slope when cooling down. The A660 has not.
The A660 varies between two values. That should not have any effect on its accuracy though.

We are getting a clearer view on things. I am adjusting my VHP using the knowledge gained and I can see the effect of each 0.33 sec/mths correction.
With a GPS I should be able to see that effect in 16 minutes instead of days.
It's paying off.


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## Eeeb (Jul 12, 2007)

By two humps do you mean the parallel lines?

I suspect using a bare movement instead of one cased with hands would make much difference in the timing of the watch.... but you never know.

The guy forgot to bring the scope to lunch so I'm just going to buy one off the Bay... They are cheaper than Invictas


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## Hans Moleman (Sep 24, 2007)

Yes, the two parallel lines turn into two humps in a histogram.
Who started all this about histograms?

It helped with finding a bug though.

I do believe there must be some feed back from the second hand; it must be more work for the stepper motor to move the hand around but the timing as to when the pulse should start must be the same.

You've got the book, now do the real thing!
Start your own SF movie?


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## Eeeb (Jul 12, 2007)

Hans Moleman said:


> ...
> Start your own SF movie?


Actually, this is all an episode of The Outer Limits :-d

... I'm just waiting for the Aliens to pop up...


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## ronalddheld (May 5, 2005)

It sounds like a good idea? I think it is going to have to come from one of their design/programming engineers.


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## Hans Moleman (Sep 24, 2007)

One more test on the A660.










One dot shows how far ahead the watch is. The scale is in milliseconds.
The dots are grouped in groups of five. Five in the low band followed by five in the high band followed by five in the low band ...
One dot each and every second.

The whole graph took 8 minutes.

Please note the scale.

The test was done without GPS. The pattern can be seen without it, I think.

Magnified a bit:


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## Eeeb (Jul 12, 2007)

If the graph is about 500 seconds then it appears to be about one second per reading...

So we see definite drift for 5 seconds then a correction - which is a over correction - then 5 seconds of drift, then a correction - which is another over correction, etc.

How strange that the over corrections never converge... As long as they average to the correct time, no harm.

This must be an artifact of the way corrections are calculated... I can't imagine that anyone could write software this way... hummmm.... possibly this is the result of some kind of state change in the temperature detection? Maybe there is some physical reason for this...?? 

Ok, lets start at the beginning... you have a crystal vibration... that gives you a count... you have a temperature measurement... do you then have a table lookup to know how to correct the count? I suspect Eta does... but this, no. 

Aaah! One possible explaination... corrections can only be applied with a large quanta... so this means they are always too large... 

That does explain the data... I don't like it. I can not see why it would be that way... but it does fit what we are seeing. 

(It has been my experience engineers write AWFUL software... maybe they got something that worked and then walked away from it ?!?!?!??)


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## Hans Moleman (Sep 24, 2007)

One thing is certain:
The Seiko and Citizen are very different.

The extra second resolution did not reveal anything new on the Seiko front.

Could there be two crystals involved?


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## ronalddheld (May 5, 2005)

Some people set their watches ahead knowing it will slow down. Maybe this is an example of that. I also could go with less than optimal engineering and programming(for that price bracket).


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## Bruce Reding (May 5, 2005)

So this is showing every second, now? (As opposed to every second or third second?) Very intersting! Also, the noise now appears to be on the order of a tenth millisecond. Did you do something to improve it? Finally, what were the conditions? Room temp.? Chilled? Transitioning between the two?


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## Hans Moleman (Sep 24, 2007)

Yes, a measurement every second this time. 
I had to rethink the way I do measurements. And presto! Every second could be done.
First gut reaction: Can't be done. But the doubt lingers.

And I've removed another source of noise.
Getting closer every time, don't we?

The watch was at room temperature all the time.

I am stumped with ideas on this one. Nice tire tracks!

But at least it is consistent with previous revelations!
b-)

The ETA is one solid line these days, with the odd breaks. 0.5 ms breaks here and there.
I hope the GPS will clear those up.

I'll do another on the 9F and blow it up more. See the detail reveals the same pattern.


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## Bruce Reding (May 5, 2005)

Hans Moleman said:


> Yes, a measurement every second this time.
> I had to rethink the way I do measurements. And presto! Every second could be done.
> First gut reaction: Can't be done. But the doubt lingers.
> 
> ...


Indeed you are! :-! This new level of ability is quite revealing. To my mind, there is a digital count adjusment scheme in play. Just can't fathom the logic yet. Are you going to get your better time base soon? If so, then I would wait for it, then run the A660 through two to three different constant temps. (and one or two where the temp. is changing). If it's going to be a while before you get the better time base, and if you have the patience, trying some runs at different temps. with this setup might be quite revealing.


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## Eeeb (Jul 12, 2007)

For the record Martien, I would again like to thank you for all your efforts. And the truly anon highvista deserves a tip of the hat too! You two have given us great insights into these devices. :thanks


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## highvista (Feb 19, 2008)

Eeeb said:


> And the truly anon highvista deserves a tip of the hat too! You two have given us great insights into these devices. :thanks


Thanks for the kind words. I wish I had more time to devote to programming, data gathering, and analysis so I could contribute more info on the watches I have access to. This summer has been a bit crazy. I'm going back to school for a Ph.D. in Computer Science and have been using the summer to prepare. I've been out of school for many years, so the self-imposed refresher course is mandatory. 

-- Keith


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## Hans Moleman (Sep 24, 2007)

Thanks Jim! 
Lets hope the insight facilitates the understanding.


Good luck HighVista! I am sure you'll get them brains all fired up.

Focus can be more important than speed.


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## Eeeb (Jul 12, 2007)

I did that once, going back to school for a Masters... It's easier than you think. It is a big advantage to have a more mature outlook. You have perspective and, as Martien says, know where to put your time. Good Luck!!


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## ronalddheld (May 5, 2005)

It is good work. Can we take this to someone at ETA and get the full explanation and dat out of them, without a NDA?


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## Hans Moleman (Sep 24, 2007)

If they would explain how their watches work, that would be great!
I don't think they will explain it to anyone who wants to know though. 

You're welcome to try! Give them a ring.


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## martback (Feb 11, 2006)

What happened to Thomas Polgar, who posted here for a few weeks at the beginning of the summer. He seemed to have both the technical knowledge and the contacts within the watch industry to help us answer these types of questions.

/ martin


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> One thing is certain:
> The Seiko and Citizen are very different.
> 
> The extra second resolution did not reveal anything new on the Seiko front.
> ...


Great stuff, Hans!:-! 
As far as I know, currently every manufacturers use single-oscillator designs.


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## ronalddheld (May 5, 2005)

If I had the contacts(and influence to get the data), I would have done it a while ago.


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## Eeeb (Jul 12, 2007)

Hans Moleman said:


> The Seiko pulse that drives the stepper motor consists of two parts.
> Could this be because it does not have any hands?
> I am measuring on a movement without hands.
> 
> ...


I ran across this on a time zone post:
_"The current backbone of the GS Quartz collection are the 9F calibres (shown above right) first introduced in 1993, which are rated to ± 10 seconds/year and feature a host of refinements including instant date change (1/2000th second). The heart of the 9 jewel module is its unique twin pulse control high-torque stepper motor, which makes each 1 second step of the seconds hand in two fluid pulses to reduce energy consumption._"

So the two step pulse is normal operation!

More data |>


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## Hans Moleman (Sep 24, 2007)

Well spotted!
It sure gives it a unique pulse fingerprint that way. Love to see it in action one day. See its "fluid pulses". 

I am still baffled by the Citizen.
Its pulses are very consistent and uniform. I can't imagine I am picking up different parts of the pulse. 
Good thing I can compare it with other movements. If they work, why not the Citizen?


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## ppaulusz (Feb 11, 2006)

Eeeb said:


> ...So the two step pulse is normal operation!
> 
> More data |>


Good one, Jim!:-!


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## Bruce Reding (May 5, 2005)

ppaulusz said:


> Good one, Jim!:-!


Second that! We're circling in on 'em. b-)


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## mantisman (May 10, 2008)

Last week someone kindly posted information and an animation about stepper motor control, and I (a biologist not an engineer) was trying to understand the relationship between the pulses you've recorded and the stepper motor action for the 9F movements. The comment above goes along with what the info and animation seemed to be saying: it looks like a square pulse moves the rotor 180° and then an identical pulse but of opposite polarity, moves the rotor the final 180° to give one full rotation. The pulse pattern recorded for the 9F seems to go along with this (but capacitor-coupled so the square pulses don't look square). Is that interpretation on the right track? If so, maybe the other watch movements are using more steps of less than 180° per pulse to get a full rotation? (But then, why is the twin pulse a better method?)
Thanks for helping - and for an amazing thread!!
David


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## Eeeb (Jul 12, 2007)

mantisman said:


> Last week someone kindly posted information and an animation about stepper motor control, and I (a biologist not an engineer) was trying to understand the relationship between the pulses you've recorded and the stepper motor action for the 9F movements. The comment above goes along with what the info and animation seemed to be saying: it looks like a square pulse moves the rotor 180° and then an identical pulse but of opposite polarity, moves the rotor the final 180° to give one full rotation. The pulse pattern recorded for the 9F seems to go along with this (but capacitor-coupled so the square pulses don't look square). Is that interpretation on the right track? If so, maybe the other watch movements are using more steps of less than 180° per pulse to get a full rotation? (But then, why is the twin pulse a better method?)
> Thanks for helping - and for an amazing thread!!
> David


I think your interpretation is accurate. I suspect your observation about the capacitance changing the square wave into what we see may be correct... if not the capacitance, then inductance or the like. I wish we had some stepper motors to observe so we could get a better idea of why the magnetic flux takes on the shape it does...

As to how many steps (pulses) of the stepper motor it takes to advance the second hand one second, that could vary on the gearing of the watch...

The "twin pulse is better" may just be marketing hooey... 'hooey' is a polite term which I as a moderator am obligated to use :-d


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## Hans Moleman (Sep 24, 2007)

Wild guess time:
My guess is that there are two oscillators in the A660.
They each take a turn every 5 seconds.
And they correct each other at the end of the 5 seconds.
If the correction is wrong. Then the same correction will turn up when the other oscillator turn comes. Only negative this time.
Sort of like the lame leading the blind. Zigzagging away, but over the long term accurate.


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## ronalddheld (May 5, 2005)

Interesting. Who would sacrifice ther A660 movement for dissection?


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> Wild guess time:
> My guess is that there are two oscillators in the A660...


According to _Citizen_ (as per the _Owner's Manual_) the _A660_ has single 32kHz crystal.
Hans, can you see any difference between the _E510_ and the _A660_ when you compare the graphs?


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## Eeeb (Jul 12, 2007)

When you have multiple CPUs for redundancy, you always have an odd number and use simple voting to decide who is right otherwise you never know who do you trust?

Dual xtls would give us the same problem. And I see no assurance we would converge to an assured time... Or, to put it another way, tying two drunks together does not mean they will walk a straight line. :-d


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## robert11 (Jun 15, 2008)

Sorry for jumping in so late. I was looking into getting my very own atomic clock a few months ago. I thought I had escaped to HEQ.. I think not.

Anyway having read the fantastic thread I thought I would show you what I found when I was looking for my atomic clock.. May be useful. may not.

Using the NTP system won't really give us the accuracy at the level needed here. These sort of measurement need some seriously geeky gear.. Setting to geographically close Starum 0 ntp servers will help, but the blips you are seeing may be ntpd drift correction in your reference clock.
http://www.febo.com/time-freq/ntp/stats/

Going further in to the labyrinth. Most GPS units can not be trusted to give us sub 20 nanosecond accuracy either. Shocking I know. We all be late for tea.. 
http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

Once you go down this track you end up with one of these in the garage.


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## Eeeb (Jul 12, 2007)

I love this quote "_The engineers who designed the GPS system included these relativistic effects when they designed and deployed the system. For example, to counteract the General Relativistic effect once on orbit, they slowed down the ticking frequency of the atomic clocks before they were launched so that once they were in their proper orbit stations their clocks would appear to tick at the correct rate as compared to the reference atomic clocks at the GPS ground stations. Further, each GPS receiver has built into it a microcomputer that (among other things) performs the necessary relativistic calculations when determining the user's location_." - _Richard Pogge

_And all this because Moleman wanted to calibrate his VHP :-dI am going to try and use the radio signals from WWV as my standard... short wave shouldn't have too many relativistic effects ...I got the oscilloscope from friends... a big old HP which they tell me was way too expensive for home use when it was built. It was claimed it came from CERN in .ch land.... but it came from a US Navy lab for sure. Lots of stickers... I'm hoping the ones claiming it is radioactive are someone's attempt at humor :-(


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## robert11 (Jun 15, 2008)

Eeeb said:


> I am going to try and use the radio signals from WWV as my standard... short wave shouldn't have too many relativistic effects ...


I had forgotten all about short wave. we can't use it here! Don;t you love surplus.. I am seriously considering an atomic clock. Customs may have something to say about radioactive stickers though.



Eeeb said:


> I'm hoping the ones claiming it is radioactive are someone's attempt at humor :-(


Maybe only a little bit radioactive?


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## Eeeb (Jul 12, 2007)

robert11 said:


> I had forgotten all about short wave. we can't use it here! ...


I bet you can... but only at night... (I used to listen to Radio Australia as a kid all the time in the 41 meter band.) They have an xmitter in Hawaii so you should have a clear shot.

According to their website:
"WWVH operates in the high frequency (HF) portion of the radio spectrum and radiates 10,000 W on 5, 10, and 15 MHz, and 5000 W on 2.5 MHz."

A good shortwave radio with an external antenna should be able to pick up the metronome... But I warn you, the programming is as boring as it is precise ;-)


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## Hans Moleman (Sep 24, 2007)

Thanks George!
That's the second time you're saying that. Only one crystal.
:-!
I should pay more attention.

That would be a good test. See what an E510 does. Send me one and I'll have a look. 

I suppose that's part of the fun here. What is a measurement error and what is genuine? And how can one prove it? Until it's all explained everything is possible.


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> ...That would be a good test. See what an E510 does. Send me one and I'll have a look...


Hans, I've just read back a bit and found on page_3 of this thread that you compared the _A660_ and the _E510_ (tested by highvista) graphs and concluded that the pulses were similar on both.


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## Hans Moleman (Sep 24, 2007)

The electromagnetic signature from the stepper motor was similar for both.
Apart from that, I don't know anything else about the E510.


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## Bruce Reding (May 5, 2005)

Eeeb said:


> I love this quote "_The engineers who designed the GPS system included these relativistic effects when they designed and deployed the system. For example, to counteract the General Relativistic effect once on orbit, they slowed down the ticking frequency of the atomic clocks before they were launched so that once they were in their proper orbit stations their clocks would appear to tick at the correct rate as compared to the reference atomic clocks at the GPS ground stations. Further, each GPS receiver has built into it a microcomputer that (among other things) performs the necessary relativistic calculations when determining the user's location_." - _Richard Pogge_


_

Yep. Impressive to say the least._


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## Bruce Reding (May 5, 2005)

ppaulusz said:


> According to _Citizen_ (as per the _Owner's Manual_) the _A660_ has single 32kHz crystal.


Yep. Also, I just can't see the benefit of the method you mentioned, Martien. My money is that it's some sort of count manipulation scheme. ("Inhibition" is too confining a term.)


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## Hans Moleman (Sep 24, 2007)

Great links!
Around a millisecond is possible with NTP. That's what I thought. Very hard to come by those exact figures!

I've heard that "relative time on the satellites" differently:

The "powers that be" demanded that the time systems in the satellites be build in two ways:
The first where a "potato is a potato". Without that relativity science nonsense.
The second where the latest science was taken into account.

After a few days it had to be acknowledged that the switch had to be set to position two. Without that the satellites were totally useless.
The proof of the pudding...


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## robert11 (Jun 15, 2008)

Eeeb said:


> A good shortwave radio with an external antenna should be able to pick up the metronome... But I warn you, the programming is as boring as it is precise ;-)


I might try that, if not for that spoilsport at febo.com 
You forgot all about, wait for it...

"ionospheric conditions affect the WWVB signals as they propagate from Boulder, Colorado to my house. 
It often wanders by a few milliseconds, and when the signal momentarily disappears completely, it can spike 20 or 30 milliseconds before recovering. "

Sigh.. Slippery slope


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## Eeeb (Jul 12, 2007)

robert11 said:


> I might try that, if not for that spoilsport at febo.com
> You forgot all about, wait for it...
> 
> "ionospheric conditions affect the WWVB signals as they propagate from Boulder, Colorado to my house.
> ...


Depending on what you are measuring, the right time may not be as important as an assurance your timing marker is one second apart.

As long as the atmospheric delays are consistent while the signal is being used short wave metronomes may still be useful.

Aside- Febo is in Dayton ;-) A short hop for me .... hummmm


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## Hans Moleman (Sep 24, 2007)

Excellent detective work George!

My VHP is back 'in the zone' thanks to your instructions.
It is 50 milliseconds fast for the last week now. 
b-)

I average over exactly 8 minutes to get to that value.
And the watch is worn 23/7.

These are this morning's measurements:










I need to make the dots smaller to see deviations easier.
I think early morning my reference is more reliable since it has the internet to itself, making for a tighter graph.


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> ...My VHP is back 'in the zone'...
> It is 50 milliseconds fast for the last week now...


Indeed, it's _in the zone_!:-!


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## ppaulusz (Feb 11, 2006)

ppaulusz said:


> Thanks to an _ebay_ ad we have more info about the release date of the _ETA 255.563_ (_L234_):
> 
> "_Technical Information: L1.613.3 Conquest II Caliber L234. _
> _This watch was manufactured in 1992 and had a suggested retail price of $2,790.00 Swiss Francs and $2,500.00 US dollars. __If you like, I can email you the price documentation prior to any bidding. It has pictures as well as the 1992 prices."_
> ...


Sorry, Gents, forget it, it's _crap_! What happened is that I got a bit uncomfortable because of the caliber ID in the ad (L234). That is not a VHP caliber! Caliber L174 or L237 are VHP (non-perpetual calendar) calibers so I thought it might be a typo (from the seller). I contacted the seller. He did not have a clue how he ended with L234 as his watch has an L174 movement. Now, I did not quote his whole ad but the point is that he described a single crystal thermocompensation scheme with built-in thermometer, in his ad. That is why I thought we have some useful info. Anyhow, the L174 (ETA 255.561) is the early dual-oscillator design so we still don't have info about the release date of the later L237 (ETA 255.563) caliber.:-(
Sorry for the confusion. I've deleted my original post about it to avoid confusion.

PS: I contacted the seller and pointed out his mistake. He made the necessary correction to his ad.


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## Bruce Reding (May 5, 2005)

No problems, George. All detective work is full of false leads and dead ends. No shame in occasionally hitting one. It's actually a sign of persistence, which is the only really necessary trait for eventually cracking the case.


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## Hans Moleman (Sep 24, 2007)

Every day now, I create a few of these graphs and there always seem to be these small "breaks" in the graph.

If there are two in one graph they are 4 minutes apart.

NTP, my reference, promises not to make any "breaks". Only gradual adjustments by frequency manipulation.


Mmmm. :think:


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## Eeeb (Jul 12, 2007)

hummmm.... I missed these posts.

I assume this is the VHP and shows the periodic adjustment made to account for the drift... no?


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## Hans Moleman (Sep 24, 2007)

Well, its a guess until I have a sub millisecond reference, but I would not be surprised if this is a genuine correction. A few tens of a millisecond each time, if at all.
I was under the impression that the calibration correction and temperature correction were added together and put into effect at the end of a 8 minute period resulting in THE BIG JUMP. 

Looks like these two corrections are administered separately. 

Suits me fine. That will make it easier to see how well the temperature correction works.

The GPS turns up next week. All will be revealed.


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## robert11 (Jun 15, 2008)

Hans Moleman said:


> The GPS turns up next week. All will be revealed.


Which GPS clock are you getting? Has it arrived?


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## Hans Moleman (Sep 24, 2007)

I am trying to get hold of one of these:
https://buy.garmin.com/shop/shop.do?cID=158&pID=223
The LVC version has a wire that pulses every UTC second with an accuracy of 1 millionth of a second. 
Not quite an atom clock, but close.

It needs to be connected to a computer to be useful.

And no, I am still waiting for it to turn up. 
According to FedEx, it has arrived in this hemisphere.
|>


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## ronalddheld (May 5, 2005)

Hans:
Maybe for some help join the time-nuts listserve.


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## Hans Moleman (Sep 24, 2007)

Fortunately it has been done before. I would never have tried otherwise!
It connects to the serial port. 

The little blob has arrived. Now some time, to connect it all up.

Great pointer. It shows you can always sink deeper.


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## Hans Moleman (Sep 24, 2007)

My clock reference now includes the GPS.

The Longines graph now clearly shows breaks 2 minutes before and after the start of a period.
Why these breaks are there is another question.










This graph shows how much the watch is ahead (in milliseconds) when compared with an accurate time reference.
And it shows how this varies over time.

One measurement each second. Each measurement is represented by a red dot.


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> ...The Longines graph now clearly shows breaks 2 minutes before and after the start of a period.
> Why these breaks are there is another question...


Thanks, Hans!|> Any explanation for those _breaks_?


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## Hans Moleman (Sep 24, 2007)

Welcome!
No, no explanation yet. 
Its a bit one step forward, three back.
I forgot though. The temperature of the watch went from body temperature to room temperature. 
In the next test I try to drop its temperature a bit more. 
See if that makes a change.
I was speculating the smaller breaks were the temperature corrections. 
We'll see.


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## Bruce Reding (May 5, 2005)

Great, Martien! :-! This setup should allow us to really begin to figure things out. 

Let me suggest that, at first, you keep the various movements at constant temperatures throughout the test, as opposed to letting the temp change. That way, we'll get a feel for the underlying pattern. Then, if we see how this pattern changes at various different (but constant) temps, this should clue us in on the compensation scheme. (Easy for me to say. You're doing all the work. :-d)

I'm excited!


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## Hans Moleman (Sep 24, 2007)

That is a good approach.
I'll need to think of a setup that keeps a watch or movement at a constant body temperature while being measured. 

Please tell me when you want your watch back! It won't be a very quick process.


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## Bruce Reding (May 5, 2005)

No hurry on returning the watch. Knowledge is the goal. On the temps., start easy. I have no problem with you immersing the watch in ice water (a very known temp.), and at a measured room temp. (maybe with a bit of insulation on it to damp any temperature transients).


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## Hans Moleman (Sep 24, 2007)

I've put the watch under a lamp.
It roughly kept its temperature after it came from my wrist. Not a very good way though, I'll need to find something better.
What it does show is that having these breaks seems to be the default behavior.

My guess is that it 'breaks upward' in colder conditions.


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## Bruce Reding (May 5, 2005)

Martien, I've lost track. (My apologies.) Which watch is this? Also, are you still collecting every second, or is this sampled?


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## robert11 (Jun 15, 2008)

Hans Moleman said:


> I've put the watch under a lamp.
> It roughly kept its temperature after it came from my wrist.


Uh oh. Now you need an accurate thermometer..
http://www.allqa.com/aqa1417.htm

joking. I hope.


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## Hans Moleman (Sep 24, 2007)

A thermometer with only three decimals? Thanks for the suggestion Robert!

The setup was the same as in:
https://www.watchuseek.com/showpost.php?p=1225730&postcount=9
In the setup that this link points to, the watch went from my wrist to my desk. Its temperature was allowed to drop.

In the setup in:
https://www.watchuseek.com/showpost.php?p=1228397&postcount=15
the watch went from my wrist to under one of those energy wasting 75 W light bulbs.
I estimate its temperature at the end of the measurements at 40 degrees Celsius. Slightly more than intended.

Longines VHP, one measurement each and every second.


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## robert11 (Jun 15, 2008)

Hans Moleman said:


> A thermometer with only three decimals?
> .


:-d LMAO

This is indeed a slippery slope.

I would like to try and duplicate the test conditions and attempt this with a Citizen Exceed. Unfortunately there is quiet a long wait for the GPS unit from Garmin... Did you buy the serial Unit? 
In the meantime would you mind posting lab setup instructions?

As a matter of interest. Have you noticed a marked difference in the NTP versus GPS reference timing?


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## Hans Moleman (Sep 24, 2007)

Slippery slope indeed!

I need to make a conscious decision to leave it at this.
The reference is good enough!
No need to get into the nano seconds.
Other work commitments limit my time on it too.

It turns out that the atom clock in the neighborhood that I was connecting to via NTP, gave me a 3 ms accuracy. I was hoping for less obviously and it made me adjust my watch far too often. One way to learn...

Anyhoo, the GPS changed the offset from 3 ms to 0.030 ms. That's not as good as Garmin says it could be, but still 100 times better than before. It makes the reference a lot more stable at that.

I did get the LVC model. Its the only model that has a time output, accurate to the millionth of a second. Pretty basic thing. No manual, no CD, no nothing. User friendliness you'll find with other models. You could not expect anything more from an OEM model.

I got the idea from:http://time.qnan.org/
Soldering iron and serial port (!) required.

For the long term accuracy, the GPS is invaluable. Great if you regulate your watch and need to make ridiculous extrapolations on the basis of a few milliseconds.


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## Hans Moleman (Sep 24, 2007)

Here is a graph of the Seiko's 9F drift.
0.1 ms over 8 minutes is equal to 6 sec/yr. 
I believe this drift is genuine since the reference's drift is so little.

During this time it was at a constant temperature of 17 degrees Celsius.









This graph shows how much the watch is ahead (in milliseconds) when compared with an accurate time reference.
And it shows how this varies over time.

One measurement each second. Each measurement is represented by a red dot.


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## ppaulusz (Feb 11, 2006)

Hans Moleman said:


> Here is a graph of the Seiko's 9F drift.
> 0.1 ms over 8 minutes is equal to 6 sec/yr...


Thanks, Hans!|>
The inhibition period of the Seiko 9F movements is 160 seconds (according to Seiko). It means that during the 8 minutes or 480 seconds (the period of your measurements) the 9F had to have 3 adjustments. Is there any indication of that in the graph? (Remember that I am not very good at reading those graphs!;-))


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## Hans Moleman (Sep 24, 2007)

Forgot about the Seiko's inhibition period!
I am sure you would have found them, if they were that obvious.
I guess we're looking for breaks in the graph or kinks where the graph changes its direction.

Nothing I can see here. If ever there was a nice gradual consistent slope, this is it.
They might show up when the temperature is a bit more extreme.
Or when the temperature changes violently.

:think:


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## Eeeb (Jul 12, 2007)

Well, this does answer at least one question - Was the 9F movement I bought a genuine one or just a dud for display... looks pretty good!


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## Eeeb (Jul 12, 2007)

Martien, go ahead and freeze and roast that 9F! Just don't use any temps so extreme you couldn't hold the unit... it's all in the interests of science! :think: :-d


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## ronalddheld (May 5, 2005)

Maybe the alledged breaks will be more obvious at a much higher or much lower temperature?


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## Hans Moleman (Sep 24, 2007)

Definitely no dud dude!
This is after I fiddled with the +/- button with my (filed down) tweezers.
This button can easily be turned with a pair of tweezers. Not in stops, but continuously.
That is something else we need to test later.


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## Bruce Reding (May 5, 2005)

Extremely interesting! Clearly the base rate at 17C is very close to perfect. No corrections necessary (although they may be occurring, since a single count correction would be be 0.03 msec). I'm thinking that we may need to see a different temperature to more clearly see the corrections.


----------



## Don_Wallbaum (Dec 17, 2007)

I have been looking at this thread for a while, and I am still confused...

Is the ideal situation to have all the dots line up in a straight line, with no deviation up or down? Would this indicate no deviation from the standard source?

Thx for your assistance in graph reading for dummies...


----------



## Eeeb (Jul 12, 2007)

Don_Wallbaum said:


> I have been looking at this thread for a while, and I am still confused...
> 
> Is the ideal situation to have all the dots line up in a straight line, with no deviation up or down? Would this indicate no deviation from the standard source?
> 
> Thx for your assistance in graph reading for dummies...


Well, yes that would. However, we don't expect that. Quartz crystals do vary due to temperature. We are trying to observe how the watches handle that variation and make corrections.


----------



## Don_Wallbaum (Dec 17, 2007)

Eeeb said:


> Well, yes that would. However, we don't expect that. Quartz crystals do vary due to temperature. We are trying to observe how the watches handle that variation and make corrections.


Thanks, Eeb..that helps a lot!

So, in earlier captures in which the data points trend down or up, then snap back to the center line, this is an autocorrection scheme kicking in, right? And the 9F here appears to not have one kicking in? Am I getting the basic elements?

OK, back to lurking.


----------



## Eeeb (Jul 12, 2007)

Don_Wallbaum said:


> Thanks, Eeb..that helps a lot!
> 
> So, in earlier captures in which the data points trend down or up, then snap back to the center line, this is an autocorrection scheme kicking in, right? And the 9F here appears to not have one kicking in? Am I getting the basic elements?
> 
> OK, back to lurking.


Don't go back! We like posters!

There are lots of graphs kicking around but I think I am correct in saying to the question about snap back, yes, we think that represents some sort of error correction. And that the 9F is flat and appears to have none may well be that at MNT (Moleman Normal Temperature) it requires no correction. It is, withing measuring limits, exactly correct.

Now we expect at lower and higher temperatures we will see correction... but the data will show what ever the data will show. Best not anticipate too much...


----------



## Hans Moleman (Sep 24, 2007)

Keep asking those questions Don!
And since I am a smart ass, I've got something to add to Eeeb's perfect explanation:

When you see a graph, look at the scale. A graph without a scale and what it represents is useless.
I sometimes forget to add the scale. Sorry!

The vertical scale is in milliseconds. That allows us to show variations that would otherwise be invisible to the human eye.
And why?
Because if we used seconds as the scale, the graph would have to span a year to see any deviations.
I don't like to measure a watch for over a year: It takes too long.

If we use milliseconds we can extrapolate the short time span to a year, and work out what the watch would gain in a year.

MNT is quite low this time of year. Its still winter in New Zealand!


----------



## Hans Moleman (Sep 24, 2007)

Here is the base mark graph for the Citizen A660:










This graph shows how much the watch is ahead (in milliseconds) when compared with an accurate time reference.
And it shows how this varies over time.

One measurement each second. Each measurement is represented by a red dot.

Temperature over the 8 minutes: a constant chilly 16 degrees Celsius (61 F).
Sorry guys it's early over here.

Not much change from previous graphs. The long term drift is more obvious now, and genuine since the reference does not have any drift.
b-) :-!

That's all the base graphs done. Now the change of temperature graphs ...

I am struggling inventing a cheap (!) device that cooks and freezes a watch at a moments notice. 
Chilly bin is as far as I got. Suggestions anybody?


----------



## Hans Moleman (Sep 24, 2007)

The Citizen A660 going from 17 degrees Celsius to 10 degrees Celsius.
(63 F to 50 F).


































These graphs shows how much the watch is ahead (in milliseconds) when compared with an accurate time reference.
And it shows how this varies over time.

One measurement each second. Each measurement is represented by a red dot.

The slope of the entire pattern becomes more pronounced as the watch gets colder. 
The watch is still warm in the first graph and cold in the last.
In the first graph, this pattern stays on the same height. In the last, the pattern dips by 0.4 milliseconds in 8 minutes.
That means: as the watch gets colder, its rate changes.

The rate of the watch goes from near perfect when warm, to losing 0.4 milliseconds over 8 minutes when cold.
Losing 0.0004 seconds in 8 minutes corresponds to losing 26 seconds in a year.

This graphically explains why some manufacturers require that the watch be worn to meet their specified accuracy.

On how and when temperature changes are compensated:
No new insights were gained by this experiment.
:think:
I don't see any difference between the graphs apart from the slope. No indication of a temperature correction becoming more pronounced.


----------



## ronalddheld (May 5, 2005)

At the 'end' all of this data needs some organizing and archiving.


----------



## robert11 (Jun 15, 2008)

Hans Moleman said:


> I am struggling inventing a cheap (!) device that cooks and freezes a watch at a moments notice.
> Chilly bin is as far as I got. Suggestions anybody?


You could use the "OMG I need a cold beer method"
10 mins in the freezer and then straight into the ice.[$2].

This may be a little hard on the beastie. So, 1/2 an hour in between 2 bags of ice? [$4]

Moleman's Results?
Priceless


----------



## Bruce Reding (May 5, 2005)

Excellent Martien. An outstanding look into the secret heart of the A660. :-! Now, the challenge is to figure out their scheme. :think: First, a few observations.

First, I feel that this must be a digital, count adjust compensation scheme. There's no way this intricate correction dance (four second intervals shifting high then low between each) could be done with an analogue circuit.

Second, unlike the ETA movements, which have their crystals deliberately set fast, the crystal here is set slow. (The slope in the four second intervals indicates a rate which is over 2000 seconds per year slow.) As such, whatever the digital correction scheme is, the term "inhibition", which implies a fast rate with periodic stepdowns, is inappropriate.

Third, correction is clearly happening over the 32 minute interval. Assuming that the rate of the reference clock is perfect (do you know how good it is?), the A660 lost 0.9 msec over the 32 minutes. This is equivalent to 12 seconds per year. Not quite its typical performance, but the thermocomp scheme probably assumes a slow change in temperature over the correction period, which assumption is not good here.

Fourth, the interval between the upper sets of four and the lower sets of four appear to have diminished by 0.1 ish msecs over the 32 minutes. (I assume, btw, that the occasional dropouts are just measurement error due to noise. Do you think that is true?)

I posit that the correction takes place via shifting the step size between the two groupings. Difficult to say, though.

Martien, I know you've sunk a huge amount of time into this. It would be great if we could get two more sets of data as your time allows. Basically, can you record 32 or more minutes at each of two constant temperatures? (Say 32 minutes at room temp. and then 32 minutes sitting in a closed tupperware bowl floating in ice water.) I'm trying to see if we can catch discreet corrections.

I think that this excellent work is beginning to crack the correction scheme. The fundamental mystery remains, however, as to _why_ they chose a scheme that is so much less straightforward than the ETA inhibition scheme. Suggests hidden depths not yet grasped.


----------



## Hans Moleman (Sep 24, 2007)

Thanks for the specific test suggestions Bruce!
If I dip your watch just in the freezing water the coil can sit nice and dry above it.
You don't mind your watch getting wet?

A rate of 27 seconds per year sound like a lot to me too. That is at fridge temperatures though. Not a very realistic day to day storage environment. I was wrong about the 10 degrees Celsius (50 F) in the chilly bin. It's just above freezing (33 F).

I have to rely on Garmin's specifications. They go well beyond what we are doing here. 
Garmin guarantees the time to 1 millionth of a second. Connection software uses that to adjust my clock.
That software is not entirely successful though.
At any time, my computer with the GPS hanging off it, is at most 0.060 ms off the actual time. Sometimes it gets to 0.001 ms. 
Silly figures.

I did a test and used the GPS as input, not as reference.
Pretending the GPS was a watch, and I was checking it.
Just to see if my computer was adding some strange pattern.

That showed a near horizontal graph with a slight dip since NTP was correcting the reference now. Noise was under 0.05 ms. That looked fine to me. No phantom pattern!

We should not forget that the input is analogue. 
The coil, the wire and the sound card are. The spots around the graph I put down to just that. Noise in the sound that is picked up. 
To get more detail we need to connect wires somehow. I certainly don't want to go there!

I don't believe you'll see anything new in a 32 minute test, but its easy enough to do. I'll do one later on.


----------



## Bruce Reding (May 5, 2005)

I have no problem with you half immersing the watch. Also, that was a good test on the Garmin.



Hans Moleman said:


> ... A rate of 27 seconds per year sound like a lot to me too. That is at fridge temperatures though. Not a very realistic day to day storage environment.


What is the 27 seconds per year you're referring to? Per my calcs., the rate of the A660 is 12 seconds per year slow over the 32 minutes of your test.


----------



## ppaulusz (Feb 11, 2006)

Bruce Reding said:


> ...The fundamental mystery remains, however, as to _why_ they chose a scheme that is so much less straightforward than the ETA inhibition scheme...


I think, Bruce, you have already answered the above question:
"_One possibility is that it's a patent workaround_." (you have wrote this earlier in this thread)
That would make sense and would nicely fit into the timeline (the release dates of the digitally thermocompensated movements of Citizen, ETA and Seiko).


----------



## Bruce Reding (May 5, 2005)

ppaulusz said:


> I think, Bruce, you have already answered the above question:
> "_One possibility is that it's a patent workaround_." (you have wrote this earlier in this thread)
> That would make sense and would nicely fit into the timeline (the release dates of the digitally thermocompensated movements of Citizen, ETA and Seiko).


Thanks for the reminder, George! This is indeed quite possible. I cannot come up with a rational explanation for the _technical_ driver for such an apparently complex digital count correction scheme.


----------



## Haqnut (Nov 13, 2006)

*8F35 data*

Hey Hans,

Did you manage to get any tests on the above? I'd be interested.


----------



## Hans Moleman (Sep 24, 2007)

*Re: 8F35 data*

Hi Overlandr!
Unfortunately I don't have a 8F35 to test.

Dwjquest worked out just how temperature insensitive such a movement is.
https://www.watchuseek.com/showthread.php?t=272143

Is that what you're after?


----------



## Haqnut (Nov 13, 2006)

*Re: 8F35 data*



Hans Moleman said:


> Hi Overlandr!
> Unfortunately I don't have a 8F35 to test.
> 
> Dwjquest worked out just how temperature insensitive such a movement is.
> ...


You had one listed in your collection but perhaps you no longer have it. Yes i was after accuracy vs temp info similar to that discussed in this thread earlier. But that link has a lot of info in it which is interesting so thank you for that! I am assuming that 86F is the nominal temperature that is taken to be a constant on a 24/7 worn watch?


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## Hans Moleman (Sep 24, 2007)

*Re: 8F35 data*

I never had a 8F35. 
No, not because I am not too ashamed to admit it.


The only time I came close to a movement with a name that had an 'F" in it was with the 9F62A.
That was a loaner. I have only two watches. One for the dirty work and the other to keep accurate.

Good question that.
I don't know what an average temperature would be for a watch that is continuously worn.
I do notice that a strap that is tight enough in summer is suddenly too loose in winter. 
Should we start a thread on how tight a strap should be?
;-)


----------



## Haqnut (Nov 13, 2006)

*Re: 8F35 data*



Hans Moleman said:


> I never had a 8F35.
> No, not because I am not too ashamed to admit it.
> 
> 
> ...


My apologies! I got you first post confused with a later one here. Re yr last point, I've been thinking about the whole strap degree of looseness subject for some time! Perhaps we should start a thread to see what technical fixes are out there to provide intra day strap length adjustments in the 1-2mm range?b-)


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## Hans Moleman (Sep 24, 2007)

*Re: 8F35 data*

Jim has a super duper thermometer!
I saw it in his video. 
What is a nominal watch temperature Jim?

Glad to see you're working on the strapping issue.


----------



## Eeeb (Jul 12, 2007)

*Re: 8F35 data*



Hans Moleman said:


> Jim has a super duper thermometer!
> I saw it in his video.
> What is a nominal watch temperature Jim?
> 
> Glad to see you're working on the strapping issue.


The thermometer is a Fluke Infrared Thermometer. I needed it for the temp vs timing data I am collecting sporadically. There is really no other way of getting the 'instant' temperature of a watch. (Shiny casebacks sometimes confuse it though so all readings have to be via the dial...:-s)

Watches on a wrist are normally 2-3 degrees F cooler than the wrist skin temperature. This means they are normally 90-92 degrees F (in the Midwest US in the summer... probably different in the winter but probably not much difference).


----------



## dwjquest (Jul 22, 2006)

*Re: 8F35 data*



Eeeb said:


> The thermometer is a Fluke Infrared Thermometer. I needed it for the temp vs timing data I am collecting sporadically. There is really no other way of getting the 'instant' temperature of a watch. (Shiny casebacks sometimes confuse it though so all readings have to be via the dial...:-s)
> 
> Watches on a wrist are normally 2-3 degrees F cooler than the wrist skin temperature. This means they are normally 90-92 degrees F (in the Midwest US in the summer... probably different in the winter but probably not much difference).


I have been taking some readings via infrared thermometer on the dial of some of my watches. I typically get readings in the 86-90 deg. F range. When the watches are at room temperature, the infrared readings from the dial agree with the current room temperature.


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## Eeeb (Jul 12, 2007)

*Re: 8F35 data*



dwjquest said:


> I have been taking some readings via infrared thermometer on the dial of some of my watches. I typically get readings in the 86-90 deg. F range. When the watches are at room temperature, the infrared readings from the dial agree with the current room temperature.


Does this mean you are cool? b-)

Conversely, does this mean I'm Hot! Hot! Hot! :-d


----------



## dwjquest (Jul 22, 2006)

*Re: 8F35 data*



Eeeb said:


> Does this mean you are cool? b-)
> 
> Conversely, does this mean I'm Hot! Hot! Hot! :-d


I suspect that it is the converse!


----------



## webvan (Dec 11, 2008)

*Re: 8F35 data*

Having just got my grubby hands on a Greiner "Quartz Timer" I'm trying to figure out the best way to see when the inhibition kicks in in my Omega 1680 (same movement as the VHP)....The longest timespan it can measure is 600 seconds so I first thought I'd see it zero out over that period since the inhibition is 480 seconds, but of course that's not the way it works, hehe...so I'll probably be measuring 1 minute periods to hone in on when the inhibition kicks in. Any thoughts?


----------



## dwjquest (Jul 22, 2006)

*Re: 8F35 data*



webvan said:


> Having just got my grubby hands on a Greiner "Quartz Timer" I'm trying to figure out the best way to see when the inhibition kicks in in my Omega 1680 (same movement as the VHP)....The longest timespan it can measure is 600 seconds so I first thought I'd see it zero out over that period since the inhibition is 480 seconds, but of course that's not the way it works, hehe...so I'll probably be measuring 1 minute periods to hone in on when the inhibition kicks in. Any thoughts?


Don't know how to do it with the Greiner, but if you had a Microset Timer you could produce a graph like this one.


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## Hans Moleman (Sep 24, 2007)

*Re: 8F35 data*



webvan said:


> Having just got my grubby hands on a Greiner "Quartz Timer" I'm trying to figure out the best way to see when the inhibition kicks in in my Omega 1680 (same movement as the VHP)....The longest timespan it can measure is 600 seconds so I first thought I'd see it zero out over that period since the inhibition is 480 seconds, but of course that's not the way it works, hehe...so I'll probably be measuring 1 minute periods to hone in on when the inhibition kicks in. Any thoughts?


600 seconds is the longest averaging period?
It gets one rate measurement over a (fixed) one minute period?

Does it show a running average while its averaging over that 600 seconds?
I guess not. That would be too confusing. A user who glances at the machine might think it has finished already.

Remove the watch after 8 minutes?


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## webvan (Dec 11, 2008)

Thanks for the suggestions, the timer averages over 2/3/4/5/10 and all the multiples, 2x10, 2x4x5, etc...

There is an audio out so maybe I could plug it into my PC, not sure what comes out, will have to check with my earphones!


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## dwjquest (Jul 22, 2006)

*Re: 8F35 data*



Hans Moleman said:


> 600 seconds is the longest averaging period?
> It gets one rate measurement over a (fixed) one minute period?
> 
> Does it show a running average while its averaging over that 600 seconds?
> ...


The longest averaging period is whatever you want it to be. It takes a reading every 10 seconds. What you get from the instrument is an offset in seconds from the GPS time. This offset is accurate to 1x10-6 seconds. What you see on the graph is this offset plotted versus time over two inhibition periods. To get the rate, you would average over the inhibition period (480 seconds) and then find the slope of that plot. This value times the number of seconds in a year will give you the yearly rate. The more data points that are included in the analysis, the better the results. Two points will define a line and give you a rate value, but 500 points will statistically give you a better result. I generally try to use at least two hours worth of data (720 points) for a calculation.

The included software allows the computation of a running average. You select the time period to average. For this movement, I would select 480 seconds as this is the inhibition period. For other movements, an inhibition period of 60 seconds, 520 seconds or some other value would be appropriate. The inhibition period can be found by looking at the raw data that is shown graphically by the software.

What I intended to show in the graph is the ability of the Microset to produce data that can be used to investigate how the inhibition period and the corrections built into the watch's firmware are implemented. The Microset is an extremely accurate device, but it only provides the raw data. There is a function in the included software that will take the data and convert to a yearly rate. You can specify the period of time (ie, number of data points) that each rate calculation will use. If you select some multiple of the overall inhibition period as the rate calculation period, then the results will give an accurate rate reading.

A previous thread shows how the information from the Microset can be used to further investigate the inhibition period: 
https://www.watchuseek.com/f9/eta-2...rature-correction-method-unveiled-300533.html
And a correction: 
https://www.watchuseek.com/f9/updat...rature-correction-method-unveiled-364695.html

The correction involved in the second post was due to the incorrect calculation of the primary inhibition correction. This lead to the conclusion that the primary correction was a very weak function of temperature. Further review of the calculations revealed the mistake and the primary inhibition correction was shown to be temperature insensitive.


----------



## Hans Moleman (Sep 24, 2007)

*Re: 8F35 data*

Rate measurements by machine can go wrong in so many ways.

How do you know for sure what the inhibition period is?

Better go with the raw data.


----------



## Hans Moleman (Sep 24, 2007)

*Re: 8F35 data*

I can think of a very convoluted way:

Split the 8 minute period up in 4 measuring periods of 2 minutes each.
Measure the rate four times and average them.

First period: 
start: 11:30:40 until 11:32:40

Second period:
start 11:40:40 until 11:42:40

Third period:
start 11:50:40 until 11:52:40

Fourth period:
start 12:00:40 until 12:02:40

Because you can't start a new period right after closing another, just do one 8 minutes later.

Mmmm.

NB: Do not start a measure period on the full minute.
The major correction always happens on the full minute I believe.
You want to make sure you include that one.

As an image:







The teeth are 8 minutes apart: The inhibition period.


----------



## igna (Nov 6, 2014)

Hans Moleman said:


> The Seiko pulse that drives the stepper motor consists of two parts.
> Could this be because it does not have any hands?
> I am measuring on a movement without hands.
> 
> ...


I was reading this old thread for several days now ... great information.

The second pulse :



> At first glance, Caliber 9F looks like a mechanical watch, because the hands extend right to the edge of the dial, something that is not possible in a normal quartz watch. Caliber 9F has greater torque and therefore can use longer hands, thanks to a twin pulse motor that delivers more power, while still delivering a three year battery life.


(Quote from 9F Quartz | Grand Seiko )

What the plot shows is the second pulse shape exactly the same first pulse, but Y mirrored. 
Can this help (or is related) to minimize vibration?

Regards.


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## Hans Moleman (Sep 24, 2007)

igna said:


> I was reading this old thread for several days now ... great information.
> 
> The second pulse :
> 
> ...


It was good fun doing too. Lots of guesswork in it, but that goes with discovering things.









One pulse makes a rotor turn 180 degrees.
Most movements are geared so that that moves the second hand by one second.

The Grand Seiko is geared for the second hand to move half a second. It needs two pulses for a whole.

The polarity of the pulse changes for each subsequent pulse because of the position of the rotor. It is now upside down and it needs an upside down pulse.

The low gearing of the Seiko gives it more torque, so that it can move larger hands.


----------



## igna (Nov 6, 2014)

Hans Moleman said:


> It was good fun doing too. Lots of guesswork in it, but that goes with discovering things.
> 
> One pulse makes a rotor turn 180 degrees.
> Most movements are geared so that that moves the second hand by one second.
> ...


Nice to see the explanation, Always learning...

There was a link to a page with animation and explanation on step motors working, but the page is missing.
(Post is here Page 5 and web page was: http://www.infolytica.com/en/coolstuff/ex0101/ )

EDIT/UPDATE: found a new link to there!! : http://www.infolytica.com/en/applications/ex0101/index.aspx

Now, I was playing a bit by recording pulses of my GS and other several non TC quartz and here are some thoughts:

1) For every watch, the pulse looks very similar, to the point it can be like a fingerprint. But probably will change in long term because voltage variation, friction change because wear, and so on...

2) By recording at same time watch pulses and a NTP signal then is easy to measure time difference. (the fraction part of the second). After some testing I find much more easy (and precise) to do this than the stopwatch method to perform accuracy tracking.

There are several details in how is performed, and I dont know why this method is not in the *Sticky: Methods of Determining the Accuracy of a Watch*

Regards.


----------



## Hans Moleman (Sep 24, 2007)

igna said:


> Nice to see the explanation, Always learning...
> 
> There was a link to a page with animation and explanation on step motors working, but the page is missing.
> (Post is here Page 5 and web page was: http://www.infolytica.com/en/coolstuff/ex0101/ )
> ...


Thanks for the links. I can't remember seeing the animations.

You definitely recognise the ETA movements from their stepper pulse. They all have these regular spikes.

ETA uses an additional complication with their fancier movements:

A computer gradually reduces the energy supplied to the stepper, while monitoring the second hand.
If it notices that it failed to move, it sends out an additional high energy pulse a few ms later.

Slowly starving the stepper of energy just to conserve power.

Picking up the stepper noise is the way the timing machines work: Place the watch on a receiver that holds an antenna. That picks up the electromagnetic field from the stepper even with the back still in place.

You can get measurements accurate to a few ms that way.


----------



## igna (Nov 6, 2014)

Hans Moleman said:


> Thanks for the links. I can't remember seeing the animations.


The animations videos are in the updated link, on left side of page. They are mostly to show the magnetic flux , the rotor position and the relation on magnetic and mechanical torque. Probably not very interesting for HAQ, but good to understand what moves the second hand on quartz.



Hans Moleman said:


> You definitely recognise the ETA movements from their stepper pulse. They all have these regular spikes.
> 
> ETA uses an additional complication with their fancier movements:
> 
> ...


That ETA trick for energy saving is very smart. And with your setup you can see this in action!

I always thought more duration is because big batteries and maybe some passive actions as a mechanical efficient gear movement, low friction, etc... Do you know how much more will a bettary last comparing a ETA with this trick and other without? (with similar or equal battery both movements)

Seiko 9F has a expected 3 Years life battery and hast to give 2 pulses for every second, not bad... but would be better a 5 Year, as The Citizen.



Hans Moleman said:


> Picking up the stepper noise is the way the timing machines work: Place the watch on a receiver that holds an antenna. That picks up the electromagnetic field from the stepper even with the back still in place.
> 
> You can get measurements accurate to a few ms that way.


Sure, that is what i'm doing. Getting a source of regular beeps/pulses at zero milliseconds reference time is not so easy, I'm using the sound option offered by Time.is. There is a little delay but seems always equal. I record both signals and then, do measurements (manually) in the saved sound file.

What I dont know is how to automatize the measurements, so I can analyze big amount of pulses, as you done. Maybe one day you can tell better witch programs you use to record, file formats, and software to measure (I understand is your own code).

Regards.


----------



## Hans Moleman (Sep 24, 2007)

igna said:


> The animations videos are in the updated link, on left side of page. They are mostly to show the magnetic flux , the rotor position and the relation on magnetic and mechanical torque. Probably not very interesting for HAQ, but good to understand what moves the second hand on quartz.
> 
> That ETA trick for energy saving is very smart. And with your setup you can see this in action!
> 
> ...


I don't know how much energy is saved by throttling the stepper. It is a trick that other movement manufacturers use too. The computer that is doing the throttling needs energy as well, but I guess, it must pay off.

The trick to use the sound output from time.is is a clever trick!
You're doing in effect the same thing as me. I record a GPS pulse instead of a beep from time.is, but the principle is the same.

The telephone pick up coil is the same thing as the inductive sensor from  the MicroSet sensors

MicroSet makes a watch timer that allows a very deep insight in what is going on.

Although: Making is more fun than buying.
I am still impressed with Loki's inventiveness.









Shine a laser pointer on the dial and when the seconds hand moves under it, it reflects the beam. Record the the time when you see the reflection.


----------



## igna (Nov 6, 2014)

Hans Moleman said:


> I don't know how much energy is saved by throttling the stepper. It is a trick that other movement manufacturers use too. The computer that is doing the throttling needs energy as well, but I guess, it must pay off.
> 
> The trick to use the sound output from time.is is a clever trick!
> You're doing in effect the same thing as me. I record a GPS pulse instead of a beep from time.is, but the principle is the same.
> ...


Loki setup its very clever!

The 1 PPS GPS maybe is the best source, but I don't know GPS or how I can get that 1PPS in a easy and not expensive way. So I'm limited to NTP.

Agree, making its better than buying. I was unlucky to make a coil sensible enough. Pulses where too small.

The telephone pickup I use was around at home for years, now finally find a good use. Its a good finding because cost 2$ (vs the MicroSet 40$) , it is available at any electronic store close to anyone home and maybe it's sensible as MicroSet induction sensor.

The final setup I made has to meet some requeriments: Easy to everyone, this means no building fancy devices, no soldering, not programming, no expensive hardware, not even asking a linux box, neither a NTP service or a GPS 1PPS. Here is why time.is sound is a simple solution.

I done some measures against NTP and the time.is sound signal is recorded with a lag of ~110ms ± 10ms. Then, a watch holding exact time will have a EM-Pulse about that amount ahead.


----------



## Hans Moleman (Sep 24, 2007)

If you keep the time beep on the left stereo channel and the watch pulse on the right, they won't step on each others' toes when they are close together. Makes it easier to work out the time delay between both.

That may take opening the plug of the pick-up and microphone. 
Be brave! It can be done without explosions.


----------



## Tom-HK (Jan 6, 2015)

Forgive my ignorance, but in all the above testing, was the offset rate of the computer's clock taken into account? To my mind, not knowing how far the computer's clock drifts in the interval between PPS inputs would seem to suggest that there is an error margin that cannot be quantified. I might have this all backwards and inside out, so let me set out my train of thought and I'll happily let people box my ears if I'm barking up the wrong tree or mixing too many metaphors.

I am assuming that the clock on a computer is less than perfect (otherwise we wouldn't need any other reference point). Would I also be right in speculating that the accuracy (or lack thereof) of a computer's clock is no less likely to vary according to changes in circumstances (current, temperature, gremlins etc.) than that of a HAQ (otherwise there wouldn't be much of a market for OCXO or atomic oscillators)? I am also assuming that a GPS PPS is a pulse delivered once ever second and that it serves to reset (or discipline) the computer's clock every second (otherwise we're saying that the computer's clock is inherently accurate and just needs to be zeroed against an atomic time source once). So wouldn't this mean that the computer's clock becomes increasingly inaccurate throughout the entire PPS interval, and at an unknown rate? I know the interval is 'only' a second, but when you're timing pulses to the millisecond it must be assumed to be significant (otherwise a reset period of longer than a second could be tolerated).

Even if a computer's clock might conceivably not need disciplining for several seconds, not knowing the rate of inaccuracy of a given specimen at a particular point in time would seem to lead to a presumption to discipline the clock every second. But when we're talking about measuring seconds per day to at least three decimal places, is there not a case for erring further on the side of caution and using a GPS-disciplined atomic oscillator? Of course, if a computer's clock is actually a very consistent performer under easily controllable circumstances, then could its offset value be calculated and adjusted for?


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## Hans Moleman (Sep 24, 2007)

There are only two sources of time in this setup:

1. The watch that emits a 'sound' every time the stepper steps.
2. The beep from time.is. Or the plop from the PPS out of a GPS.

These two are recorded and compared.

That's it. The computer clock is not involved. You can ignore it in this setup.


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## Tom-HK (Jan 6, 2015)

Hans Moleman said:


> There are only two sources of time in this setup:
> 
> 1. The watch that emits a 'sound' every time the stepper steps.
> 2. The beep from time.is. Or the plop from the PPS out of a GPS.
> ...


Ok, I am still confused. The GPS emits a pulse (the PPS) every second. At some point after the GPS pulse has been received, the pulse from the stepper is received. Computer software represents this interval as an elapsed period of time. How does the software measure the length of this interval? If it waits for the next GPS signal and then works backwards to divide the preceding period into the proper number of equal segments, then that would ensure that every division of the second that had just past had been recorded accurately. But if it is plotting the stepper pulse in real time and not retrospectively, then it must still rely on some internal mechanism for counting the passage of time from the receipt of one PPS to the next. Is the degree of error in its internal count mechanism assumed to be so small as to be insignificant in the grand (or micro) scheme of things?


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## chris01 (Jan 5, 2011)

Tom-HK said:


> Forgive my ignorance, but in all the above testing, was the offset rate of the computer's clock taken into account? To my mind, not knowing how far the computer's clock drifts in the interval between PPS inputs would seem to suggest that there is an error margin that cannot be quantified. I might have this all backwards and inside out, so let me set out my train of thought and I'll happily let people box my ears if I'm barking up the wrong tree or mixing too many metaphors.
> 
> I am assuming that the clock on a computer is less than perfect (otherwise we wouldn't need any other reference point). Would I also be right in speculating that the accuracy (or lack thereof) of a computer's clock is no less likely to vary according to changes in circumstances (current, temperature, gremlins etc.) than that of a HAQ (otherwise there wouldn't be much of a market for OCXO or atomic oscillators)? I am also assuming that a GPS PPS is a pulse delivered once ever second and that it serves to reset (or discipline) the computer's clock every second (otherwise we're saying that the computer's clock is inherently accurate and just needs to be zeroed against an atomic time source once). So wouldn't this mean that the computer's clock becomes increasingly inaccurate throughout the entire PPS interval, and at an unknown rate? I know the interval is 'only' a second, but when you're timing pulses to the millisecond it must be assumed to be significant (otherwise a reset period of longer than a second could be tolerated).
> 
> Even if a computer's clock might conceivably not need disciplining for several seconds, not knowing the rate of inaccuracy of a given specimen at a particular point in time would seem to lead to a presumption to discipline the clock every second. But when we're talking about measuring seconds per day to at least three decimal places, is there not a case for erring further on the side of caution and using a GPS-disciplined atomic oscillator? Of course, if a computer's clock is actually a very consistent performer under easily controllable circumstances, then could its offset value be calculated and adjusted for?


While the other recent points in this thread, from Hans and igna, deal mostly with measuring independently from a PC's internal clock, it might be worth clarifying how that clock can be properly disciplined to give a reasonably accurate time.

A default setup of a Windows PC uses a process (Win32Time) that runs once per week to retrieve the time from an internet server. This is hopeless for accurate timing, as the local clock can drift wildly in that time. Also, if the server can't be reached, the time will not be corrected for another week. It's not difficult to change the update period to a daily (or even hourly) event, and to choose a better time server, but none of this is good enough for our purposes.

The best simple method is to run an NTP process, called ntpd (available on Windows, Linux, and others I expect). This regularly polls a number of external NTP servers that can be on the local network or via the internet, or even internal to the host PC. It uses some clever processing to determine valid and invalid time sources and then applies corrections to the local clock. This is not done by suddenly jumping the time backwards and forwards every few seconds, but by gradually adjusting the clock rate to bring it into line with the 'correct' time. After a period that could be some minutes, hours, or even days, the clock will be running very accurately. A change of clock rate, due for example to an ambient temperature change, is dealt with by the same process. The PPS signal from a GPS time source is used to discipline the external NTP server, not the local PC clock.

My own PC has an internal NTP server and I have a second, Linux-based, constantly running server on my network. When I start the PC from cold it takes from 30 to 60 minutes to reach a stable rate.


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## igna (Nov 6, 2014)

Tom-HK said:


> Ok, I am still confused. The GPS emits a pulse (the PPS) every second. At some point after the GPS pulse has been received, the pulse from the stepper is received. Computer software represents this interval as an elapsed period of time. How does the software measure the length of this interval? If it waits for the next GPS signal and then works backwards to divide the preceding period into the proper number of equal segments, then that would ensure that every division of the second that had just past had been recorded accurately. But if it is plotting the stepper pulse in real time and not retrospectively, then it must still rely on some internal mechanism for counting the passage of time from the receipt of one PPS to the next. Is the degree of error in its internal count mechanism assumed to be so small as to be insignificant in the grand (or micro) scheme of things?


Tom, is more easy for me to explain with a example.

Let say your citizen is running ahead of reference, by eye, more than 1 second but less than 2 seconds. Later with a stopwatch you determine better: about 1.3 s ahead reference. Over the time the stopwatch will give good results...

If you decide to use the EM-Pulse detection, you will measure the time between EM pulse and reference pulse, from 0 to 999 ms. In your example you will see in the software a EM-pulse ahead of reference pulse about 300 ms. How you measure? Simple, record several seconds into a wav (or other type) file. Then open a sound editor program (maybe the same used to record) and zoom in, select the space between pulses. Software will display in some place the time selection. Repeat several times to confirm values. Once you find that interval, you have to add the whole seconds part, in your case 1 second + measured ms.

Audio editors are easy to use and there is many tutorial videos on youtube, (search for audacity)


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## igna (Nov 6, 2014)

I made a video capture on the process of getting both signals, recording and measuring the difference. Its a 7mb file. I will try to attach, but I'm not sure if it will work.

Update: no luck, i get this error: EM-Pulse.mp4 - Invalid File

I managed to upload here:
www35.zippyshare.com/v/7O43U2Lu/file.html
(If you cant watch, as me, there is a download option)

Video shows:
1) Audacity program, recording till visualizing a good signal, while moving pickup / watch relative position for best signal.
2) loading Time.is and then enabling sound
3) back to audacity and recording (test) to check both signals and volume from beeps.
4)stop and starting a new track with the recording to be measured.
5) stop recording, beeps, watch signal.
6) measuring by selecting space between pulses, zooming in, out, etc and reading the time interval at middle-bottom from screen.

Notes: 
Watch was not a TC (actually a cheap testing one, that runs -0.9 second per day slow !!)
Computer was a little overloaded because video capture.


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## Hans Moleman (Sep 24, 2007)

igna said:


> I made a video capture on the process of getting both signals, recording and measuring the difference. Its a 7mb file. I will try to attach, but I'm not sure if it will work.
> 
> Update: no luck, i get this error:
> 
> ...


Cool! A video is worth a thousand words.

I was looking for that double pulse, but you've explained it: Not a Grand Seiko.


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## svorkoetter (Dec 12, 2012)

Tom-HK said:


> Ok, I am still confused. The GPS emits a pulse (the PPS) every second. At some point after the GPS pulse has been received, the pulse from the stepper is received. Computer software represents this interval as an elapsed period of time. How does the software measure the length of this interval? If it waits for the next GPS signal and then works backwards to divide the preceding period into the proper number of equal segments, then that would ensure that every division of the second that had just past had been recorded accurately. But if it is plotting the stepper pulse in real time and not retrospectively, then it must still rely on some internal mechanism for counting the passage of time from the receipt of one PPS to the next. Is the degree of error in its internal count mechanism assumed to be so small as to be insignificant in the grand (or micro) scheme of things?


I've seen a few responses to your post, but none of them seem to answer what I think you're asking, which is basically, how is the interval between the GPS pulse and watch pulse measured accurately?

If people are using their sound card to record the two pulse streams and compare them, then it is the accuracy of the sound card's sample clock that matters. The computer's CPU oscillator or real-time clock don't enter into the picture at all. Now, sound card sample clocks can be notoriously inaccurate. I've seen supposedly 44100kHz sample clocks running at 44150kHz. For audio work, that's fine, as it represents only about 2 cent (2% of a semitone) pitch difference, which no one can discern. But when used for watch timing, that represents an error of 100 seconds per day.

However, we're using this to measure a very short interval, which in turn is being used to measure an error in a very long interval. With a sound card as bad as the one above, a measurement within a 1 second interval will be off by at most 1.1ms. A 1.1ms error in measuring a day-long interval means a 400ms error for the year. So, even with a crappy sound card, you can measure the accuracy of your watch over that one day period to within 0.4s/year.


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## Hans Moleman (Sep 24, 2007)

svorkoetter said:


> ...
> So, even with a crappy sound card, you can measure the accuracy of your watch over that one day period to within 0.4s/year.
> ...


Too right!

The rate variations over such a small recording period are very little too. Even a crappy crystal is very stable over small periods. More stable even than an atomic clock.


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## ronalddheld (May 5, 2005)

igna said:


> I made a video capture on the process of getting both signals, recording and measuring the difference. Its a 7mb file. I will try to attach, but I'm not sure if it will work.
> 
> Update: no luck, i get this error: EM-Pulse.mp4 - Invalid File
> 
> ...


I will have to try to download it.


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## igna (Nov 6, 2014)

svorkoetter said:


> I've seen a few responses to your post, but none of them seem to answer what I think you're asking, which is basically, how is the interval between the GPS pulse and watch pulse measured accurately?
> 
> If people are using their sound card to record the two pulse streams and compare them, then it is the accuracy of the sound card's sample clock that matters. The computer's CPU oscillator or real-time clock don't enter into the picture at all. Now, sound card sample clocks can be notoriously inaccurate. I've seen supposedly 44100kHz sample clocks running at 44150kHz. For audio work, that's fine, as it represents only about 2 cent (2% of a semitone) pitch difference, which no one can discern. But when used for watch timing, that represents an error of 100 seconds per day.
> 
> However, we're using this to measure a very short interval, which in turn is being used to measure an error in a very long interval. With a sound card as bad as the one above, a measurement within a 1 second interval will be off by at most 1.1ms. A 1.1ms error in measuring a day-long interval means a 400ms error for the year. So, even with a crappy sound card, you can measure the accuracy of your watch over that one day period to within 0.4s/year.


Good points! It can be used a oscilloscope maybe? (I don't have one)

On sound cards, you say 2% of a semitone, but total error its much less 50/44100. Still you are right, will be an error of ~97 second a day in that card. If you record in such card 10 seconds, the total error will (I guess) be evenly divided along the total lenght, so its about those 1.1 ms you said per every second. And that looks ok to use in the [sound card-induction sensor-time.is] and probably also ok if your reference is NTP. Because, as in the stopwatch method, the measuring error form instrument is less compared to other errors. Maybe will be a problem if your reference is 1PPS, as it was the original question.

Its reasonable to worry on such level of accuracy to measure aspects what is the TC mechanism doing. But, do we need to use such accuracy towards an annual figure SPY?

Regards


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## Tom-HK (Jan 6, 2015)

svorkoetter said:


> I've seen a few responses to your post, but none of them seem to answer what I think you're asking, which is basically, how is the interval between the GPS pulse and watch pulse measured accurately?
> 
> If people are using their sound card to record the two pulse streams and compare them, then it is the accuracy of the sound card's sample clock that matters. The computer's CPU oscillator or real-time clock don't enter into the picture at all. Now, sound card sample clocks can be notoriously inaccurate. I've seen supposedly 44100kHz sample clocks running at 44150kHz. For audio work, that's fine, as it represents only about 2 cent (2% of a semitone) pitch difference, which no one can discern. But when used for watch timing, that represents an error of 100 seconds per day.
> 
> However, we're using this to measure a very short interval, which in turn is being used to measure an error in a very long interval. With a sound card as bad as the one above, a measurement within a 1 second interval will be off by at most 1.1ms. A 1.1ms error in measuring a day-long interval means a 400ms error for the year. So, even with a crappy sound card, you can measure the accuracy of your watch over that one day period to within 0.4s/year.


This is the answer I was looking for. Thank you!


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## Tom-HK (Jan 6, 2015)

Hans Moleman said:


> Even a crappy crystal is very stable over small periods.


Though if you're trying to precisely measure the accuracy of a good crystal with TC over a similarly small period, then the crappy crystal's degree of crappiness becomes statistically significant even though it is minuscule in real world terms. That's really the essence of what I was trying to get at (although I know that computers don't use crappy crystals). I was curious to pin down the accuracy of whatever count mechanism is being used in the measurement and comparison process. I think I've got that answer, now, and the sound card's inaccuracy is not a significant issue. Or is it...? Waiting to see how igna's response is resolved...


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## Hans Moleman (Sep 24, 2007)

You're not measuring the accuracy of a TC crystal over a period less than a second.

You're measuring an offset: The difference between a reference and the watch.

An offset is not a rate.


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## Tom-HK (Jan 6, 2015)

Hans Moleman said:


> You're not measuring the accuracy of a TC crystal over a period less than a second.
> 
> You're measuring an offset: The difference between a reference and the watch.
> 
> An offset is not a rate.


True. I stand corrected.


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## Hans Moleman (Sep 24, 2007)

igna said:


> Good points! It can be used a oscilloscope maybe? (I don't have one)
> 
> On sound cards, you say 2% of a semitone, but total error its much less 50/44100. Still you are right, will be an error of ~97 second a day in that card. If you record in such card 10 seconds, the total error will (I guess) be evenly divided along the total lenght, so its about those 1.1 ms you said per every second. And that looks ok to use in the [sound card-induction sensor-time.is] and probably also ok if your reference is NTP. Because, as in the stopwatch method, the measuring error form instrument is less compared to other errors. Maybe will be a problem if your reference is 1PPS, as it was the original question.
> 
> ...


An oscilloscope works very well here:
Connect the PPS to the trigger and capture the stepper noise.
The offset is immediately visible.

An annual SPY value is only part of the whole accuracy picture:

As the temperature varies during the year, so does the rate of your watch. It will speed up during summer and slow down over winter. Your annual SPY value does not include that rise and fall. It is a snapshot only.

As such it is silly to extrapolate a current rate to a year and expect that to be the SPY value. Another season, another temperature will certainly spoil that projection.


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## ronalddheld (May 5, 2005)

Hans Moleman said:


> An oscilloscope works very well here:
> Connect the PPS to the trigger and capture the stepper noise.
> The offset is immediately visible.
> 
> ...


Some of my watches were fairly consistent with yearly samples, and no low batteries.


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## Hans Moleman (Sep 24, 2007)

Consistency is not the issue here.

The issue is the actual current rate in between the yearly snapshots.


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## ronalddheld (May 5, 2005)

Hans Moleman said:


> Consistency is not the issue here.
> 
> The issue is the actual current rate in between the yearly snapshots.


Of course as I am looking at aging more than intrayear variations. Many more skilled people are doing that.


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## igna (Nov 6, 2014)

svorkoetter said:


> [...]
> Now, sound card sample clocks can be notoriously inaccurate. I've seen supposedly 44100kHz sample clocks running at 44150kHz. For audio work, that's fine, as it represents only about 2 cent (2% of a semitone) pitch difference, which no one can discern. But when used for watch timing, that represents an error of 100 seconds per day.
> 
> However, we're using this to measure a very short interval, which in turn is being used to measure an error in a very long interval. With a sound card as bad as the one above, a measurement within a 1 second interval will be off by at most 1.1ms. [...]


Sorry to bring this up again, but those error numbers are too big, and I will defend those audio cards, I find the recording very accurate:

When I record several EM pulses form a quartz watch (not a TC, running +55 SPY) and its enough constant to show any error of the magnitude you mention, if my audio card is so bad. Once record is done, then I measure the time in between pulses at random "distances" of whole seconds apart (15, 10, 12, 9, 5, 11, etc). In most cases the time the difference is 0ms (perfect coincidence), few times 1ms and only once measures 2ms.

So if the card is off by 1.1 ms each second because error sampling, then the software should show it as a 16 ms error in a "15 second distance". This way, the watch proves the sound card is precise enough to the propose of measuring few second intervals.

BTW, I'm using the sound card / EM pulse to study the stopwatch method: I'm doing stopwatch while at same time recording a NTP sound signal, the EM-Pulses and the "start-stop beeps" coming from stopwatch. This way I think I will come with some real numbers on reaction times, difference between NTP signal to Time.is rendering display, and so on. Just collecting data now.

Regards.


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## Hans Moleman (Sep 24, 2007)

That is clever too.
Measure the distance between EM pulses to check the sound card.
|>

All depends on where the sound card, if they are still in use today, gets its pacing from.

I have one that has a crystal on it. I guess it gets its time from that.

Cheapskate sound cards may get the time from the computer. And if that time is disciplined by NTP, it will be spot on.


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## svorkoetter (Dec 12, 2012)

igna said:


> Sorry to bring this up again, but those error numbers are too big, and I will defend those audio cards, I find the recording very accurate:


I didn't say all sound cards are that inaccurate. The one in my desktop PC is off by 3.6s/d, which corresponds to a sample rate of 44101.4Hz. The example I gave was of one really bad sound card I've encountered.



Hans Moleman said:


> Cheapskate sound cards may get the time from the computer. And if that time is disciplined by NTP, it will be spot on.




Every sound card has a crystal on it. A sound card doesn't need the time, it needs a sample clock at one of several common rates (e.g. 44100Hz). The computer's real-time clock won't help with that.


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## igna (Nov 6, 2014)

svorkoetter said:


> I didn't say all sound cards are that inaccurate. The one in my desktop PC is off by 3.6s/d, which corresponds to a sample rate of 44101.4Hz. The example I gave was of one really bad sound card I've encountered.
> 
> Every sound card has a crystal on it. A sound card doesn't need the time, it needs a sample clock at one of several common rates (e.g. 44100Hz). The computer's real-time clock won't help with that.[/COLOR]


Sure, I understand your example was about one specific bad card. I have no idea on electronics or audio cards, and maybe those bad cards are common ... It bugged me, and asked myself how bad my audio card was and if it was a source of extra inaccuracy.

So the idea of posting that test was not to prove you incorrect, all the opposite, I appreciate your comment, telling us to not blind trust the audio card. The conclusion can be: We can use audio cards to time our watches, but before starting a long or complex test, do some checking to be sure we don't have one of those bad cards.

Regards.


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## Hans Moleman (Sep 24, 2007)

The same thing using a scope:









The yellow line is the GPS pulse. Every second on the second. The pulse lasts for 4 * 50 ms.
The green line is the EM pulse from the stepper. Roughly 140 ms early.


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## Ksh (Feb 4, 2013)

We could use a WWVB loopstick antenna instead of time.is (more precise and accurate). And then any systematic error of the sound card ADC doesn't matter as it will affect both signals equally. I believe modern PCs routinely have 192 KHz discretization. It would be interesting to calculate what kind of accuracy we get with two measurements taken a day apart.


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## svorkoetter (Dec 12, 2012)

Ksh said:


> We could use a WWVB loopstick antenna instead of time.is (more precise and accurate). And then any systematic error of the sound card ADC doesn't matter as it will affect both signals equally. I believe modern PCs routinely have 192 KHz discretization. It would be interesting to calculate what kind of accuracy we get with two measurements taken a day apart.


Well, with 192kHz sampling, assuming you could narrow down the beginning of the EM pulse to a particular sample, the most error you could have would be two times the sample interval: 2 * 1/192000 = 10.42 microseconds. So if your samples are a day apart, that works out to a precision of 3.8ms/y. In reality, the start of the EM pulse will be fuzzy, and it will be hard to nail down just exactly where it occurs.


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## jisham (Oct 21, 2015)

I'm trying to climb up to the shoulders of the giants on this thread. Great inspiring work, and I hope I may eventually be able to add to it.

I've got one of the $2 telephone inductive pickups to pick up quartz pulses from the watch (original idea from a forum member - Igna?), and I've got a GPS with PPS out that I can use as a reference. I'm working towards wiring these into and harness that I can plug into a computer soundcard and get 192KHz sampling. I believe this was originally Hans Moleman's idea, correct me if I'm wrong, I'd like to give the credit where it is due. This leads to a low cost, high precision setup that many HAQ'ers should be able to assemble.

The PPS pulse is well defined, I know the rising edge is defined as the reference, and with my particular GPS should be accurate to <20nsec.

I'm a little fuzzier on what constitutes the exact second on the watch. The stepper motor pulses we see are 10-20msec long. I assume the square pulses in the beginning are as the second hand begins to move, and the more sinusoidal damping towards the end is as it settles into position. I think I even saw one on this thread that used two (phase opposed) pulses (a seiko 9F perhaps?). But what is accepted as the true second "event" - when the hand begins to move, or when it lands on the next second mark?

I see others have already done many measurements using this technique, what point of the waveform do you pick ? The leading edge is easy to detect, the sinusoidal damping at the end is a bit more difficult to define precisely. Or should I be looking for a different point in the middle?

Perhaps in the long run it doesn't matter what point is picked, as long as it can be used to get repeatable day to day measurements to track rate. The 10-20msec of error from the width of the stepper motor pulse would only show up in absolute accuracy, but cancel out in rate measurement.

I'm hoping to cobble up a program that can do the analysis easily, and generate data files that could be used to generate plots similar to the ones shown in this thread. I'm comfortable with C-language in Linux, so I am starting there, but if there is interest, I might try Python which should work on both Linux and Windows (unsure about Mac, but probably). My first pass is using a captured wave file for the analysis, but with a little work I can probably siphon the ticks and PPS pulses straight off the soundcard.


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## Hans Moleman (Sep 24, 2007)

jisham said:


> ...
> I'm a little fuzzier on what constitutes the exact second on the watch. The stepper motor pulses we see are 10-20msec long. I assume the square pulses in the beginning are as the second hand begins to move, and the more sinusoidal damping towards the end is as it settles into position. I think I even saw one on this thread that used two (phase opposed) pulses (a seiko 9F perhaps?). But what is accepted as the true second "event" - when the hand begins to move, or when it lands on the next second mark?
> ...


Thanks for the kind words! It has been an enjoyable journey of discoveries. It really annoyed me that I could not work out why I could not perfectly calibrate my VHP.

The movement decided that the next second has started and generates a pulse.
The pulse is applied to the coil which makes the rotor turn. It takes the rotor a while to turn 180 degrees.









Modern movements are cutting back on the pulse as a way to save energy. They slowly starve the stepper of power while monitoring the movement of the rotor. As long as the rotor turns, the starvation hasn't gone too far.

This is called 'asservissement'.

If the rotor fails to move, a second pulse is required, and the starvation needs to be reduced a bit.

The movement measures the voltage over the coil to see if the rotor has moved. The rotor has turned into a generator.

The following is from a previous thread:









The bottom shows normal operation, where the highlighted bump shows that the second hand has landed on the next marker.
The top does not show that bump, and a second pulse follows.

So, it takes a while for the rotor to complete its turn. Longer than the pulse duration actually.

If you define the moment that the second hand lands on the marker as the start of a new second, you open a can of worms. 
It probably overshoots it first anyway, or overshoots some markers and not on others.

Using the movements definition is a lot more clear cut. It has counted to 32768 and it decides to move.


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## wbird (Feb 25, 2015)

I am wondering if you are using sound pulses don't they overlap on really close readings?

For example say the pulse from your reference lasts say 100 ms, and your test watch is 50ms fast, how do you tell which is which? Will the change in amplitude of the spike be discrete enough to see the start?

If I had a two way I would plug in the watchville app (it counts down the 5 seconds to the minute change) from my phone into my computer and compare its chime to the time.is chime. Really clear check of the system response.

It also makes me wonder how fast the second hand moves, does it leave so many ms's early to keep accurate time, and does it vary with different watches.

Just some random thoughts on a late train.


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## jisham (Oct 21, 2015)

Hans Moleman said:


> Thanks for the kind words! It has been an enjoyable journey of discoveries. It really annoyed me that I could not work out why I could not perfectly calibrate my VHP.
> 
> Using the movements definition is a lot more clear cut. It has counted to 32768 and it decides to move.


That's what I was leaning towards. It's much easier to detect the front edge of that pulse train rather than try to pick a point near the tail as it settles into the marker. This may introduce a small error from the "absolute second" but gives a repeatable reference that can be used to accurate estimate rate, since this error would be cancelled by subtracting two points.

Understanding the second pulse is good... but I think it should be ignored for timing purposes - the movement failed to hit its mark and is trying to correct, but the electro/mechanical error has now introduced a timing error (around 10-20msec). Again, picking the leading edge of the pulse train when the movement decides to begin moving the hand I believe will lead to more repeatable measurements. Let's see if the data supports this.


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## jisham (Oct 21, 2015)

wbird said:


> I am wondering if you are using sound pulses don't they overlap on really close readings?


 By using a soundcard, we have two channels available. If the microphone (or GPS PPS line) is on one channel, and the inductive pickup on another, you should be able to resolve both pulses. Cross-talk shouldn't be an issue.


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## wbird (Feb 25, 2015)

So if I understand correctly it's a little different then the schematic in the sticky. In the sticky its two into one input setup. Doesn't appear to be a 2 channel setup. Are using line in and microphone on the sound card? Or do you have other audio inputs? I'm also not sure what software you are going to use to make the measurements either.

But like I said, I'm curious, maybe you can show a dry run. Line out to line in time.is and your nexus running watchville into your mic line and use whatever software to make the measurement. 

Tempted to try it myself just don't know the measurement software, and haven't looked at the sound card on my desktop and it's a pain to get to. My laptops have only one audio input.


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## jisham (Oct 21, 2015)

wbird said:


> So if I understand correctly it's a little different then the schematic in the sticky. In the sticky its two into one input setup. Doesn't appear to be a 2 channel setup. Are using line in and microphone on the sound card? Or do you have other audio inputs? I'm also not sure what software you are going to use to make the measurements either.


I'm aiming at Igna's setup: https://www.watchuseek.com/f9/methods-determining-accuracy-watch-382752-4.html#post13295914 . He uses the mic input to the computer, and he uses a stereo to mono splitter to make two channels out on the stereo mic channel.

I'm keeping his idea of the inductive telephone pickup to capture the quartz stepper drive pulses, but I'm hoping to replace the microphone aimed at time.is beep output with a high accuracy / low latency PPS (pulse per second) output from an inexpensive ( ~$40 USD) hobbyist GPS unit.

I was hoping to have some plots to show, since I feel like I'm hijacking this thread without results to show, but I'm stealing slack time at work and haven't gotten the right wires soldered up yet. The PPS signal is very hot for the mic input, so without serious attenuation or games with the mic amp I get overloading, plus I'm getting a lot of noise and cross talk as I don't think I have the shield wired correct yet. But these should all be fixable and I'll share my lessons and mistakes when I figure it out.

Software is a self-rolled C program for now. Still a work-in-progress as I'm still working out the hardware inputs.

One issue I've notice so far is that my soundcard rate seems to be slightly off - less than 1% (~0.03%), but that's noticeable. Once I get the PPS input usable, I should be able to use that to correct the sound card rate into "true seconds"



wbird said:


> But like I said, I'm curious, maybe you can show a dry run. Line out to line in time.is and your nexus running watchville into your mic line and use whatever software to make the measurement.
> 
> Tempted to try it myself just don't know the measurement software, and haven't looked at the sound card on my desktop and it's a pain to get to. My laptops have only one audio input.


I was hoping to get away from watchville and use the GPS/PPS as a time reference. Does watchville have a beep output as well? If so, I could move the inputs around and do a comparison of time.is or watchville to the GPS to see how suitable they are as a timebase for our measurements.

FWIW, I ran across a program on one of the mechanical forums on this site where they use a similar technique to measure mechanical watches by using a microphone to capture the audible tic-toc of the watch. Their timing requirements are a whole lot less strict than what we need here in HAQ  Soundcard rate / computer clock rate is fine, and they measure things in seconds/day, not spy.


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## jisham (Oct 21, 2015)

Here's a bit of a tease, these plots are from a quick gnuradio mockup:









top: PPS signal. Took a fair bit of attenuation and some fine tweaking of the mic gain, but there's a recognizable pulse. There appears to be a coupling issue I haven't solved yet, that's why the pulse is all curvy. I need to apply some electrical engineering to the problem 

Bottom: The inductive pickup pulse of a Casio Edifice (affordable, non-HAQ, ~60s/y) that I had lying around. It's a familiar shape to others we've seen in this forum, although still a bit noisy, hopefully due to long wires near noisy computers.


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## jisham (Oct 21, 2015)

So I captured a 480sec wav file with PPS on one channel, and the inductive pickup on my Casio Edifice (non-HAQ). Used my primitive C program to detect the peaks and normalize them to the PPS seconds to cancel soundcard drift, dump the data to a file.

A quick plot (via gnuplot) of the data:









x axis is seconds. y axis is partial second offset from PPS second (I think the sign may be flipped, but that shouldn't matter). Shows about 1.2msec drift over 8 minutes, which extrapolates to 79 s/y, which is in the ballpark I expect for this watch.(~60s/y measured previously via stopwatch)

It also displays a behavior similar to others noted on this forum: 5 seconds, then an inhibition jump, 5 more samples, then another inhbition jump. I haven't observed the noisy samples seen in some of the Moleman plots yet.... I don't know if it's just a lucky run, or if the PPS reference is helping to get rid of them

I suspect the ping-ponging back and forth to the two rates is a PLL loop type regulation - runs 5 seconds, notices it's running early, bumps the rate down a notch for 5 seconds, notices its running late, dumps the rate up a notch, repeat...

Now, time to get my new Christopher Ward C7 rapide COSC chronometer (ETA 251.264 TC HAQ) into the test bench....


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## Hans Moleman (Sep 24, 2007)

jisham said:


> So I captured a 480sec wav file with PPS on one channel, and the inductive pickup on my Casio Edifice (non-HAQ). Used my primitive C program to detect the peaks and normalize them to the PPS seconds to cancel soundcard drift, dump the data to a file.
> 
> A quick plot (via gnuplot) of the data:
> 
> ...


Those are very tidy results!
It reminds me of the A660 measurements

I don't understand what was behind that again. They made the quartz switch between two frequencies.

And I don't know if inhibition is something the Swiss have sole rights to. So the Christopher Ward should look more familiar to me.


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## wbird (Feb 25, 2015)

Looks good jisham. I'm still a little confused on your setup but it seems to work for you. I thought about it a little more on lunch, and wanted your thoughts.

Why is the mic input even being used? Why not just use the audio in input? 

Use a sterio input. One input say from your GPS to left and your test watch to right. This will give you the two channels on your sound card.

If you want to test your setup, you can just loop audio out or headphone from time.is into left, and if you want loop time.is from your nexus from the headphone jack into right. Or use the watchville app which gives an audible 5s chime countdown. Or your GPS

Or you could take the stereo signal to mono this would be a single line and the peaks would show time offset or if they are dead on an amplitude doubling.

In the igna setup never understood why he used a mic for his computer sound as opposed to using the headphone or audio out jack.

I've purged these connections from my house a while ago, don't have the measurement software, the time and skills to write it, but you seem have these things.

It's apparent you know before you measure samples you run a bunch of controls as system checks. You could run any of the above to check that your setup. If time.is versus time.is is different or your gps is different then something is going on.

Just some thoughts, what do you think?


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## jisham (Oct 21, 2015)

wbird said:


> Looks good jisham. I'm still a little confused on your setup but it seems to work for you. I thought about it a little more on lunch, and wanted your thoughts.
> 
> Why is the mic input even being used? Why not just use the audio in input?
> 
> Use a sterio input. One input say from your GPS to left and your test watch to right. This will give you the two channels on your sound card.


 I'm using the stereo microphone input. PPS on one channel, watch on the other. No actual microphone in this case, it's been replaced by the PPS line.

I guess I could used the line in as well, but I'm guessing the inductive pickup level would be too low.



wbird said:


> If you want to test your setup, you can just loop audio out or headphone from time.is into left, and if you want loop time.is from your nexus from the headphone jack into right. Or use the watchville app which gives an audible 5s chime countdown. Or your GPS
> 
> Or you could take the stereo signal to mono this would be a single line and the peaks would show time offset or if they are dead on an amplitude doubling.
> 
> ...


 I've gone away from using watchville/time.is/my nexus for the reference and I am using the PPS it should be superior to all of those. For completeness, I should cross check the GPS against them, but that's a test for later.


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## jisham (Oct 21, 2015)

Looks my my newbskillz lost my first post, but the attachment with the C7 rapide graph made it in.

That's for my newly acquired Chr. Ward C7 Rapide COSC / ETA 251.264.

Is that a 240s inhibition, or two lobes of a 480s inhibition?

It's curious that the inhibition is done as a sequence rather than a step. 30s in the first instance, 16 in the next. I will have to explore if that is time related or part of the thermal compensation.

I also need to add some averaging/line-fitting to extract a drift out of the sawtooth inhibition pattern.


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## Hans Moleman (Sep 24, 2007)

jisham said:


> Looks my my newbskillz lost my first post, but the attachment with the C7 rapide graph made it in.
> 
> That's for my newly acquired Chr. Ward C7 Rapide COSC / ETA 251.264.
> 
> ...


ETA mentions both 60 and 960 seconds as inhibition period. The 960 in older documentation.


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## chris01 (Jan 5, 2011)

Hans Moleman said:


> ETA mentions both 60 and 960 seconds as inhibition period. The 960 in older documentation.


For the current 251.264 chrono calibre they give 960 for the PreciDrive (+PowerDrive) version and 60 for the PowerDrive-only version.


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## Hans Moleman (Sep 24, 2007)

Thanks Chris.

My mistake.
Boy, that's confusing.

960 it is then.


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## jisham (Oct 21, 2015)

chris01 said:


> For the current 251.264 chrono calibre they give 960 for the PreciDrive (+PowerDrive) version and 60 for the PowerDrive-only version.


Everything I read on this Chr.Ward says it is an ETA 251.264, but to me it definitely looks to be a 480s inhibition period, not a 960s:








FWIW, seems to be well within HAQ territory, at least in my ideal off-wrist office test bench environment:








I''m prepared to offer some details of my test setup, but I fear I'm hijacking this thread. Should I post them here, or start a new thread?

[EDIT: fixed attachments, and the consensus seem to be to start a new thread, I will do that soon].


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## Hans Moleman (Sep 24, 2007)

Good idea, start another thread.
Makes it easier for searching.

Have a look at the attachments please. I can't open them.

You're using all open source tools! GNUradio is not something you see every day.
And Igna uses Audacity.

Really pleased to see them used.


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## ronalddheld (May 5, 2005)

If another thread is started I can move or delete that list.


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## igna (Nov 6, 2014)

Hans Moleman said:


> Good idea, start another thread. Makes it easier for searching. Have a look at the attachments please. I can't open them. You're using all open source tools! GNUradio is not something you see every day. And Igna uses Audacity. Really pleased to see them used.


 And GNUPLOT ! Can't see attachments.


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