Zenith movement with plain balance wheel

Posts
33
Likes
8
Hi,

Could anyone tell me what Caliber is this?
And why is the balance wheel plain?

ae6703962888d323e28ed481f31f830f.png


Thank You
 
Posts
3,070
Likes
3,526
It looks like a 106 variant of some description. The serial dates it to around 1937/1938 but I wouldn't expect to see a balance without screws from that date.

I haven't seen all of the 106 variants but I have never seen one with a plain balance, nor that regulator and the balance cock is a slightly different shape from the ones I have seen.

Does it have a seconds sub-dial or is it a central seconds movement? - they made both in the 106.
 
Posts
33
Likes
8
It is subsecond one
Maybe it just a shot while on the move :/ But in that case there should be some blured circle around the wheel
 
Posts
3,070
Likes
3,526
It is definitely stopped (or a very fast shutter speed) You can see the spiral of the hair spring.
 
Posts
221
Likes
161
I think this is the cal. wich 106 with the extension B: cam disc regulator as referenced at bidfun.
I also think the balance wheel is original- i also have a couple of watches of the same cal. and period with exact the same BW(plain).
Yours is very clean wich is rare.
 
Posts
2,912
Likes
6,209
The balance wheel does have screws - you can see them blurred. I think the balance wheel is coming to a stop in one direction, giving the impression that it's not moving. Not sure why the hairspring isn't blurred as much...