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I have compiled a rather large "profiles.ini" file for e-timer with lift angles for many hundreds of watch movements, much of the VBH data is also correct.  It is a work in progress, If anyone is interested I will be happy to share it.

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Here is a cheap and easy way to calibrate the sound-card clock. The $13 GPS receiver/antenna just needs 5 V power and it outputs a 1 pps signal. There is no setup procedure or software required. The output goes to a 3.5-mm-plug audio cable and is plugged into the line input of the sound card. The power comes from a USB cable plugged into the computer. I took an old A-B USB cable and cut off and stripped the B end and used the red and black wires to create this "power supply."
GPS-PPS-1564.thumb.jpg.c1c9ee8537cbedb31386219c58ca9ebd.jpg

 

The first time I turned this on it would not work (generate the 1 pps pulses) until I brought it near a window. After that first turn-on, it starts up in a few seconds on my desk and it doesn't matter which side of the unit is up. Here is what it looks like on Watch-O-Scope:

gps-scope.PNG.51e972f4a46de930e0e7142da482794a.PNG

My Focusrite Scarlett Solo (3rd gen) audio interface (external sound card) reads +2.1 s/d fast. This compares to the 1.9 s/d I was getting using a quartz watch.

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18 hours ago, wlysenko said:

My Focusrite Scarlett Solo (3rd gen) audio interface (external sound card) reads +2.1 s/d fast. This compares to the 1.9 s/d I was getting using a quartz watch.

Depending on how it's designed, a USB sound card might be sourcing its clock from the host system.  So it could be that your computer's USB interface has a frame clock that is +2.1 s/d fast.

Unless either one has a TCXO, and they probably don't, this will change over temperature.  Even NTP can detect a computer clock's temperature coefficient.  With a GPS you should be even better than that.  The limitation is likely the coursesness of the 48 kHz (or other) audio clock's ability to precisely capture the GPS PPS.

At 48 kHz, the sampling resolution is 20.8 µs.  An error of 20.8 µs/s is 1.8 s/d.  Or course, by increasing our averaging interval we can measure more accurately than that.

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On 5/8/2021 at 9:47 PM, LittleWatchShop said:

Anxious to know how you will construct an experiment to give an unbiased measurement of the performance of each.  So many variables at play.

I was planning to drop my tools for the first sight of any signal and consider the job done. ? You are right actually, the space i have in my mic does not allow me to try all of the piezos unless i trim them. I could clip them to a watch though and compare the signal I get.

So far I tried to use my smallest piezo (12 mm) and the bimorph. I started with the bimorph. As the original plate was too wide i created a bone for it so I could properly glue the bimorph to the plate by one end:

IMG_20210509_204458.thumb.jpg.0eee0ccf06a38228582153cff8ce4740.jpg

IMG_20210509_204534.thumb.jpg.45e74dc1cbb27f3b5205792b03c5fd69.jpg

IMG_20210509_204830.thumb.jpg.cd93c059c8d31a7f6109e351b5ebb1d5.jpg

IMG_20210511_214340.thumb.jpg.0a89a347ea558f2824d275bad5a6e6e5.jpg

I mounted it in my mic, placed a noisy pocket watch on the mic and without adding amplification I checked if I could see anything with my oscilloscope, found nothing at all so I added the one transistor amp with a 1M resistor, nothing. I double checked the wiring and my little circuit board, but could not find anything wrong so I added the piezo next and bumm it gave me a nice clear signal not too strong though and I could see the signal with my oscilloscope using the two pins of the piezo. Whats wrong with the bimorph then? Or the way I am using it?

ald_english.PNG.4ca49d94a95a4769a31590db67c22653.PNG

with 10db:

ald_english_10db.PNG.8cefe5fe463a69b33d31e7024ab61d4d.PNG

It has no problem with a noisy timex, but i think it is struggling with an ingersoll 17 jewels ronda 1217-21.

This is how far I could go, i am struggling to find time to spend with this beautiful hobby.

IMG_20210511_215204.thumb.jpg.0b6477351b70af8f1aaa8b962ec6e918.jpg

I need to find a high quality jack connector, i repurposed a cable of a faulty headset for the time being. Forgive me for the quality of wiring and soldering its not final yet. I probably will need to add an extra transistor to the circuit. The good thing with this mic that it was designed for this purpose and it is designed in a way so the noise level would be on a minimum.

 

 

IMG_20210511_214740.jpg

Edited by luiazazrambo
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10 hours ago, OneBadWolf said:

Amazon sells these:

Cerrxian-Terminal-Headphone-Converter-Adapter

 

 

phono.jpg

Thank you for this, but I would only consider this as a temporary solution like for testing. The wire in my shielded cable is very delicate, i would have difficulties to attach the wire to this type of connector and even if i could it would not be a long lasting solution, i am looking for a connector where i can solder the wire to the connector and the connector housing would provide physical protection for the cable so it would not break. An additional benefit is that this type of connector is better shielded against noise, only thing is that I need to find a quality one. Cheap ones tend to be imperfect considering their size (would not fit perfectly when you plug it in) and the quality of their surface (conductivity). 

Just an example, and actually a bad one because i cannot see how is the connector providing physical protection. The ones I used earlier had that U shaped metal part where you tightly wrapped the two "legs" of the U around the cable:

jack.thumb.jpg.4b9dca8ed4ad4b263b0295600639a711.jpg

update: found a pic with that U shaped metal part:

proper_jack.jpg.3271c26b557fdd2895f2285d5dee1034.jpg

 

 

Edited by luiazazrambo
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5 hours ago, luiazazrambo said:

Thank you for this, but I would only consider this as a temporary solution like for testing. The wire in my shielded cable is very delicate, i would have difficulties to attach the wire to this type of connector and even if i could it would not be a long lasting solution, i am looking for a connector where i can solder the wire to the connector and the connector housing would provide physical protection for the cable so it would not break. An additional benefit is that this type of connector is better shielded against noise, only thing is that I need to find a quality one. Cheap ones tend to be imperfect considering their size (would not fit perfectly when you plug it in) and the quality of their surface (conductivity). 

Just an example, and actually a bad one because i cannot see how is the connector providing physical protection. The ones I used earlier had that U shaped metal part where you tightly wrapped the two "legs" of the U around the cable:

jack.thumb.jpg.4b9dca8ed4ad4b263b0295600639a711.jpg

update: found a pic with that U shaped metal part:

proper_jack.jpg.3271c26b557fdd2895f2285d5dee1034.jpg

 

 

This is what I use .....

3 pole female XLR receptacle, grounding:

And matching male with good cables.

https://www.neutrik.com/en/product/nc3fbh1

 

image.png.e9e45270cb855f7a28280dbc4e097959.png

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This is my new streamlined prototype amp.  I made a version of this myself using my CNC router and it works very well.  The new board will be using surface mount components for most of the components and the rest I can solder on myself for testing.  It has several test pins/pads and extra places for components.  It also has several POTS/Variable resistors for testing different values.  I'm having several of these made.  I wanted a board that I could use to test different components and values more easily, while keeping the size small enough. (92.0mm X 120.0mm roughly).  Not very inexpensive nor is it simple but it works well.image.thumb.png.e2bda4a41419768bf745d5f3d2a2e95b.png

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1 minute ago, guidovelasquez said:

Thank you, it is an extensive database. The interesting facts are lift angle, number of teeth of the escape wheel and of course BPH or VPH.

The tooth counts are nearly all accurate, the lift angles are all correct as far as I can tell from manufacturer data.  The VPH values are mostly correct but I haven't had time to go over them all yet, many unfortunately cannot be found very easily.  Thankfully the VPH is easy to figure out when needed.  Please share yours...

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1 minute ago, guidovelasquez said:

?

?️?️

Not Huge cost but there are minimum orders for many components.  Making the board yourself is cheap but very time consuming.  A lot of fun, and a wonderful learning experience for sure.

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4 minutes ago, guidovelasquez said:

?

?️?️

In other words you can't build it in 30 minutes, with a home depot soldering set, and 20 bucks....  But it is a very doable project if one has a few decent tools and a bunch of time....

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1 minute ago, guidovelasquez said:

I have to warn that my registration is very rudimentary. I started doing it several years ago as a trial and error. Much of the data is from wall clocks or cuckoo clock. Another 2 are tower clocks with a beat of 3600 BPH. 1 BPS.Profiles_guido.rar

Thank you!

 

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