Swiss 7750 17j VS 25j

[Bll]

Hey guys,

Noob question as stated in the topic. Can somebody clarify the difference b/w 17j and 25j swiss 7750 besides the very obvious difference such as jewels...etc.

Thanks,

Bll

[Logan]

As I understand it the only difference is the extra jewels which I think are all in the chronograph mechanism. Otherwise they are both parts compatible. The extra jewels won't really make any difference unless you run the chrono all the time.

[Watchmeister]

ETA swapped over to the 25j format in the mid to late 80's. As Logan said the incremental jewels are for the chrono mechanism. I prefer them for a different reason. To the best of my knowledge ETA had not set up plants outside of Switzerland prior to the switch over so you are getting a true Swiss movement. It is more likely that they will need servicing though given the age.