Ebauches SA / ETA 2892, quartz Prototype #2, 1975
Category: proof of concept
Description: Symmetric, stainless steel cased prototype with stainless steel snap back, latter marked with case number. Square, metallic blue dial with rounded edges, raised hour indexes. ‘ETA’ Logo in white under ’12’. Date window at ‘3’. Silver hour and minute hands with white insert as hour markers, silver seconds hand. Steel crown. Acrylic crystal.
Dimensions: 34mm (without crown), lug – lug: 42mm, overall thickness: 8.25mm, lug width: 19mm
Movement: ETA 2892 main plate and partial wheel work, (automatic caliber), modified with the artisanal addition of electronic modules, numbered #2 in different places
Additional info: This is the second, hand made ETA prototype for creating very slim quartz calibers. The modifications include the application of a bought-in ‘Statek’ quartz module (with tuning fork shaped quartz) and an integrated circuit module bought-in from RCA. This IC module was bought before the collaboration with ‘Hughes Microsystems’, which will provide CMOS IC’s starting from late 1975. Confirming the dating is the stamp ‘7514’ on the RCA IC, dating the module to April/May 1975 (1).
Apparently this was the first prototype of the development which was actually working, as number ‘1’ was a mock up built for testing the configuration of electronic elements on the ETA 2892 main plate, but was not built to work. As soon as the localisation of the electronic elements and the battery was clear, engineers adapted the mechanical part, including the hand and date setting mechanism (1).
The movement is set inside a very slim ‘Eterna’ case, the Eterna logo is stamped in the center of the crystal. Eterna was the brand out of which of ETA (ETernA) was outsourced and run as semi-independent caliber manufacturer within the Ebauches SA group and many initial prototypes for internal use were built using cases made for Eterna or parts used in Eterna models. Also some prototypes using Certina elements are known. More sophisticated prototypes, which would be destined for representative purposes, would be preferably cased in Longines cases (1).
The ETA 2892 caliber will become one of the most used and versatile mechanical calibers with optimisations concerning precision (ETA 2892-2, 2892A2, Co-Axial caliber 2500) and also with the application of numerous complications and piggy-back modules for creating chronographs (Dubois-Dépraz DD2000 module), GMT and many other variations. This prototype will pave the way to the ETA ‘Quartz Flatline’ family, which will be used by many manufacturers (also outside the ASUAG-SSIH Group) during the early 1980s with updated versions still in use today. The first caliber which will be developed is the ESA/ETA 940.111, it will have a thickness of 3.7mm and will be marketed upon production with the feature of being the slimmest quartz caliber with date available (1).
Provenance: Ex Estate of André Beyner, former technical director of Ebauches SA
Ref.:
- Personal communication with a former Executive Vice-President of Ebauches SA, in charge of Research & Engineering.
Electric Watch Prototypes 