New Addition: Omega Electroquartz Desk Clock

Took a gamble and bought this uncommon Omega Electroquartz desk clock in nonworking condition (not the one from ebay). Based on what I've found online and from other similar posts here from other members (paging @Tom Dick ) Very few of these are still out there out of the 1000 that were originally made.





Anyways. Cleaned up some corrosion on the battery terminals, put in some fresh batteries and.... it fired up! ... Sort of. 😵‍💫

Seems the stepper motor is on its last legs. It ticks on the second without issue, so at the very least the quartz system is good. But the hand staggers or will stay in one spot just ticking.

Took it apart (Modular sandwich), checked the geartrain for interference, cleaned the grounds, etc and took a look at the stepper. Everything is clean, but it seems like it has more front to back play than it should. When face down, it'll tick better, so I'm betting either a bushing in the motor is bad or some other interference between the coils and the rotor. It's pretty well contained, and not obviously serviceable. But there is probably a way.

Marking on the motor plate say it's made by Portescap, and they still make other steppers, but nothing even close to this. I'll be reaching out to them to see if they have any service centers who might be able to figure it out.

But otherwise, anyone have a friend who has a collection of Caliber 1390 parts laying around somewhere? Maybe some old clockmakers in Switzerland?

Or more realistically, any recommendations on someone who can service unique quartz clocks?

Otherwise, I have a nice sounding display piece 😟

Interesting clock ! Have never seen one. So, if you take off the weight of this clock in face down, it works or the hand is still not ok? If so, could it be that the weight of the plates have something to do with a missing contact? If you support the mainplate of the clock / step motor with something like piece of timber / styrofoam as a test , is the clock running better like in face down position? Kind regards. Achim

I confirmed it was the stepper motor when it was disassembled. Just the motor (with no contact on the geartrain) will mis-step/catch in a few different positions. And do better in others. So it ruled out something else causing the resistance. It really seems like the coil/magnet isn't providing enough kick. I'm also going to check power and resistance at the motor to make sure it's getting all the juice it should.

Portescap wrote me back and told me I'm on my own and to "contact the OEM for service". Not sure Bienne would service this. 🤔

I'll post more photos of the components when i'm back in there for anyone who stumbles on this in the future.

Was there a model number on the stepper motor? I wonder if it could be swapped for a replacement one?

Just a sticker that says 542. The motor has no stampings on its casing. In fact, if it was removed from the plate, you'd never know what the heck it was for.

Not sure if that is a batch number or what. I haven't been able to find any motor that is even close. The 12 "steps" of the rotation seems unique to a motor that would be for a clock. And the shaft is a specific size for the gear that's pressed on (cannon pinion style).

I'll post photos so it's more clear.

Edit: I'll assume 201003 was the part number for the motor. Looking through Portescap's catalog I don't see anything that would have 30 degree steps or 12 steps per rotation. Maybe I can get one with correct voltage and dimensions and the quartz driver will do most of the stepping? But I think the detents in the motor act as anti-backlash. Maybe I could retrofit a tension spring either on the shaft or gear to help???

Photos to give some insight into these things.

Also, when I first got into this thing, some of the screws had obviously been attacked. And there are signs of test equipment (scratches on the board when someone was use a multimeter). So it's led a long life it would seem.



Each notch on the back side of the stepper motor corresponds with a "stop" or tick. Also note the 3 holes for a spanner wrench. I think that's the way in to get to the coil.


Penny for scale. This thing is small.

Sorry, cannot help with parts or anything, other than to say kudos to your engineering courage and skills - I am suitably impressed

You are a brave and curious person, indeed !

Beautiful pictures ! Hope you can get it working again.

Good afternoon i also bought one a few days ago but in working condition what do you think

Looks great! Glad yours works!

Nice, how much did you pay for it ?

Around € 750 / USD 900 but i don't see many around at sale so i think it was a reasonable price😟

Good price indeed, TBH these clocks are priceless if you want one ;-)

Update on mine:

Trouble shooting lead me to buy an adjustable DC power supply. Thinking I could run some voltage to the stepper motor to see what it is rated for and maybe buy a similar motor even without the indexing detents that it has.

Turns out, the motor gets switched signals from the board for each pulse. Which makes sense since it would need a North/South polarity for each step. So a simple DC power source wouldn't allow the motor to move. Bummer...

Decided to clean up every speck of battery-leak related corrosion that I could find on the PCB in case there was a voltage drain somewhere. Found out the voltage is (on purpose) massively stepped down at the motor (going from 6v at the battery to only about .8v at the motor, checked while running....duh 😗). So I wanted to be sure it was getting all the juice it needed. Lots of vinegar solution, Deoxit, and time, and it's nice and clean.

Also decided to adjust the front to back play on the rotor inside the stepper. When I received it, some previous clockmaker decided that glueing the shaft running through the center of the rotor was the best solution for some problem. (Glue is never the answer)

Took a little slack out with the staking set and it was too tight. So I backed it off a hair and it seems like it's running strong.

It's kept perfect time over the last 4 days.

So, it's not perfect like some of the other examples out there. But at least it's alive.

And to think, all of that to run an analog clock.

Can't imagine how many resistors were in the Apollo modules. 😲

Great news, keep us posted ! Here's mine BTW, the guy I got it from explained that the grey had faded and looked messy to he gave it a paint job ;-)

Awesome! Seems like we have a good concentration of these things on here!

I bet you could easily strip that with a plastic safe paint stripper. They sell stuff meant for spray paint that is very forgiving on plastic. Traditional strippers can be too caustic.

Something like this:

Thanks for the suggestion. I think I quite like it this way and it must not have looked great if he'd spray painted it ;-)