EEVblog #920 - World's First Transistor Watch!

[Fungus]

But as others have said/implied, that is probably not a good idea.

I never said it was a good idea, just that it isn't particularly difficult to open it (as previously claimed by some).

[Tim T]

Yep, not difficult at all...

[kalleboo]

Opening things is never difficult, it's putting them together again where it gets tricky

[MK14]

Opening things is never difficult, it's putting them together again where it gets tricky

I use to sometimes open up (to repair them), the older type of calculators. With some of them, when you do that (probably after taking the PCB screws out as well), almost all the keys can fall out, all over the place, unexpectedly.
You then have to spend ages, finding them (on the floor), and finding out what button goes where.

[G7PSK]

The"special tool" is nothing other than a pin spanner with square pins the back is threaded all you need to be careful about is cross threading on re assembly.

[Tim T]

You need to be careful about...
- selecting the correct tool and its use for removing the bracelet without scratching either it or the case.
- selecting the correct case clamp/holder for securing the case without scratching it or the crystal, or bending the lugs as a consequence of applying torque while removing the case back.
- selecting the correct tool for removing the particular case back. My understanding is a competent watchmaker will have tools covering many possible options. Some are quite simple - essentially a sticky rubber ball - others are quite elaborate and rigidly hold both the case and wrench in fixed planes to prevent slipping and gouging (e.g Horotec 07.369 for about $2000). Snap back cases are an entirely different world.
- holding the pin type spanner perfectly parallel with the case back while applying torque, not as easy as it sounds. The earlier posted photos are typical examples of when someone failed - actually the damage on one was originally much worse and the picture was taken after some lathe work. I use the American made LG Master wrench on my beater watches but you need to hold it in such a way that pressure can be applied downward evenly across all contact points, and in the intended direction of rotation.
- agree about risk of cross threading but this is relatively easy to avoid with a bit of care since you should screw the back down by hand and only use the wrench for the final 1/4 or so turn.

The point of course is to leave no evidence, even under magnification, that you ever opened the back of the watch.

I doubt many on this site would use a free/$2 DMM to test mains voltage, so why use a cheap Jaxa knock off wrench on a valuable watch?


regards,

tim

[tatus1969]

very impressive, enjoyed that video. How would these have been tuned/adjusted? Can't see anything. Or would they just rely on manufacturing precision of the tuning forks? Did they drill holes to adjust the masses? And does athmospheric pressure have negligible detuning effect?

[rollatorwieltje]

very impressive, enjoyed that video. How would these have been tuned/adjusted? Can't see anything. Or would they just rely on manufacturing precision of the tuning forks? Did they drill holes to adjust the masses? And does athmospheric pressure have negligible detuning effect?

Afaik there's no adjustment for the 214 movement, the tuning fork was factory calibrated by taking notches out out the base. The ESA 9162 movement (used by Omega) was adjustable, it used a different fork design, which was also less sensitive to orientation.

[albert22]

You can find the regulation procedure in  the service manual for the model 214 (page 10). Which was linked by amyk. BTW thanks amyk.
Although the pictures are not very clear to realize what this regulation does.
According to the manual the regulation can be affected by air variations and the vicinity of the needles to the coils.

[Noize]

This guy made mechanical watches by hand that were more accurate than quartz.

http://www.danielslondon.com/

[electr_peter]

I would not try to open this watch because time setting knob (or crown) is on the backside, not on the side. You definitely do not want to mess that up!

[richnormand]

I do not have a Spaceview but the regular model. Marking is M6 making it 1966 vintage. It wakes me up at night if I leave it on the wooden dresser in the room. If it is sideways at the right location the whole resonates like a guitar and you hear it across the room. 

When I got it a while back it had been damaged due to a leaky battery and it had been stored like that for a decade.
Took me a long time to fix and get running properly but I don't remember it being particularly tricky to open.  I did have Omega's dismantling and repair instructions on CD from a while ago to do the repair.

I re-phased it (under binocular microscope) to use  a regular 1.5V button batteries since the original mercury batteries are hard to get. Note that some watches cannot be made to run properly that way as you will end up at the end of adjustment or with double stepping on the index wheel. In that case, your other option is a voltage dropping diode. That would be easy to do nowadays with the availability of ridiculously small SMD diodes!  I also machined (not visible from the outside)  the inside battery hatch button to accommodate the cheap earring aids batteries of the time that were thicker than the original. 

To check its accuracy a simple phone pickup coil (black blob in photo) coupled to an Ithaco low noise preamp is fed to a frequency counter. No need of a microphone.

I still wear it occasionally. A nice piece of history.

[ian.rees]

How would these have been tuned/adjusted?

There are small adjustments on the back of the permanent magnets of the tuning fork for normal regulation.  Also, I think the fingers that drive the index wheel can be manipulated to some extent.

[ian.rees]

How long does the battery last?

Mine seems to last a year and a half, maybe a bit more, on a battery.

[ian.rees]

Here are voltage waveforms at the two terminals of the "cell coil" - from memory, the yellow one is between D1 and D2 in Rob's schematic above and the blue is between F1 and the R+C.

[Stebanoid]

Here is a slow motion video of the mechanism https://youtu.be/CPS7aNCAwAA

[grumpydoc]

My father had one in the 1970's

I think he still wears it

[mikerj]

What happened at 2:43, did Dave power up one of his flux capacitors?