Dear Ladies and Gents,

Have had my Grandfathers Omega for about 20 years now but never had time to research it until now. As per the serial number I believe it’s a 1935 - 1937 model assembled in England. I would appreciate any guidance into the originality of this timepiece as I have searched the forum and although there are watches similar there is nothing identical. Thanks for your time!

 

You're absolutely correct in your assessment

Finding out the reference number will be near impossible unless someone would happen to have a period dealer advert or the like - very few ressources cover these.

A nice watch with an unusual dial configuration - very interesting

 

As it is a Dennisson cased watch, there is no reference number like in the Swiss cased Omega. But as far as I can tell, it is fully genuine. The caliber is a 26,5 and the dial and hands are correct for this caliber and this period. But, as ConelPueblo said, the dial has also some unusual features - the gold indices for instance, which are rather rare in watches with a 26,5.

Nice watch! I like a lot the 26,5 and this is a good example.

 

It's lovely. Don't run it without getting it serviced (grinds it up - think of a gearbox minus oil), but don't send it to Omega! A good vintage specialist watchmaker should do that for not too much north of £100. And don't touch that dial!

 

Welcome, nice watch and good Research

 

I echo what they all said.

The fully retarded regulator indicates that the movement is badly in need of a service so that must be your first priority.

As the Squirrel would say, "NFW!".

 

Sorry my friend but you are wrong - it is a cal. 23.7

 

Thank you Edward53, can you recommend a vintage watch specials in the UK. “Don’t touch that dial” you mean leave as is and don’t attempt to clean?

 

Thanks JiminOz, how can you tell the regulator is retarded? What should I be looking at in the mechanism photo?

Thanks for the response Francois, I was a little sceptical to the authenticity as the gold indices look a bit unusual.

 

Hi Mac, how can you be so sure it’s a 23.7 and not a 26.5 and what do these numbers even mean? Thanks for your reply!

 

?

 

Because I know the difference

These numbers mean the type of movement. Movements have a calibre number - some sort of "name" for the movement.

If you take a loupe and have a look below the balance wheel you will find the calibre number - give it a try...

 

The numbers are designations that Omega assigned after it stopped using Lignes (e.g.: 17''' or 17 ligne) to identify calibers. 23.7 equates closely to a caliber diameter of 23.7mm.

 

Thanks ... this it turning out to be quite an education!

 

The regulator is the little arm between the A/R or F/S markings on the balance cock.



As the energy from the mainspring through to the escape wheel deteriorates due to lack of lubrication, dirt, magnetism etc the impulse to the balance wheel decreases, leading to shorter, thus faster beats of the wheel, moving the regulator to slow it down helps keep time, but it's an indication that all is not well with the watch.

 

So since the arm is pretty near the S (I assume S = Slow) that means that the lack of lubrication, dirt, magnetism, that you mentioned have built up to the point where the regulatory arm has reached it limit? Very interesting.

 

Thank you very much for the detailed explanation, my grandfather died 35 years ago and I have no idea when he last serviced it so probably not been serviced in +40 years. Fortunately I have only worn it once for my Brothers wedding 25 years ago. Based on the comments on this forum I shall get it serviced as soon as I find a reputable vintage watch specialist!

 

You are right - again! I looked too fast.

By the way, a clue is the fact there is no visible click. The 26,5 usually has one. But I have owned and serviced an old 26,5 with a spring click under the balance, like in the 23,7. It seems that I miss this movement - not so much the watch - and want to see it everywhere!

 

Both calibers have invisible clicks (and both have visible ones according to AJTT), and they are both very similar movements.

I think Erich identified which one it was by this.

Calling @mac_omega, please explain?

 

Well,

for those who are not collecting the very early Omega watches it might be a bit confusing...

There have been various variants of both calibres, the 23.7 and the 26.5 with different features and "adornment" grinding

First of all, how can we identify both calibres?
This is not too difficult as the bridge is different



This is the first version 23.7 with visible click

see the end of the barrel bridge (arrow) - it is more pointed with a slightly cut off at the end (only with the first version!!)

For comparison the cal 26.5 :



also with visible click but the end of the barrel bridge looks very different - this is the best feauture to distinguish - you cannot mix up these 2 calibres.

From the variant 23.7 T2 onward the barrel bridge is very pointed (means without the cut off at the end) and the click is somewhat hidden but it is still partly visible:



The "decoration" of the variants can widely differ, above a movement with perlage grinding

Here is a T2 with Geneva stripes:



And here a T3 with smooth surface:



Also the finish of ratchet and crown wheels varies...

Enjoy