How Does Omega Thermo Compensation Work in the cal. 1680 (ETA 252.511)

Neagu

Hello!
I bought an Omega Constellation 1552.40 and has a 1680 (ETA 252.511) movement inside
I was curious how this movement actually compensates for temperature
It doesn't seem to have 2 quartz crystals like some Seikos and it cannot be an OCXO or EMXO inside
Do you guys have some papers or explanations?
Thanks in advance!

Mouse_at_Large

Somewhere in here might be the information you are looking for https://watchlords.com/viewtopic.php?t=20767 🤔