Comments:
Four generations of IWC Ingenieur. From left to right:
The ref. 666, the ref. 866 (special version: believed to have been a "military dial" prototype), the ref. 1832 "Jumbo" and the ref. 3508 (special version: 500'000 A/m).
Cheers, HSTE
IWC made a small batch of a-magnetic versions (coping with up to 500'000 Ampere per Meter).
To make the movement a-magnetic, they used rubies as rotor ball bearings (like in the compass watch). And for the balance spring they used a new alloy which could not be magnetized. However, the alloy was an issue in terms of accuracy and production and individual testing (and the high number of "fails") led IWC to stop this project quickly. So, the number of "500'000 A/m" models is very limited.
Cheers, HSTE
Cheers, HSTE
For me it would be the ref. 1832 "Jumbo" and the ref. 3508
I actually prefer those to the latest releases.
Marc