Movement record · Switzerland
Valjoux/ETA 7750
Partially verifiedAutomatic cam-and-lever chronograph with the chronograph mechanism driven from the going train; deliberately engineered for industrial production rather than traditional column-wheel refinement.
Technical specifications
- Diameter
- Approx. 30 mm (13¼ lignes)
- Height
- Approx. 7.9 mm
- Jewels
- 17 or 25 jewels depending on version
- Frequency
- 28,800 vph (4 Hz)
- Power reserve
- Approx. 42–48 hours
- Winding
- Automatic, unidirectional winding
- Setting
- Stem setting with quickset date
- Escapement
- Swiss lever
- Balance
- Monometallic, Nivarox-type spring
- Complications
- Chronograph, Date, Day-date in some variants
Identification features
- Day-date at 3, small seconds at 9, 12-hour counter at 6, 30-minute counter at 12 in the standard layout
- Cam switching rather than a column wheel
- ETA 7750 or Valjoux signature under the balance or on the main plate
Known variants
- 7753 (different counter layout)
- 7754 (GMT)
- Hand-wound derivatives
Servicing notes
Cleaning, lubrication, mainspring and pivot work belong with a qualified watchmaker working from calibre-specific documentation. Conserve original parts: replacing a worn component with a modern substitute changes the object, and refinishing plates or dials destroys evidence.
General guidance only. Antique movements should be serviced by a qualified watchmaker.
Historical significance
The 7750's 1980s revival made the affordable Swiss automatic chronograph possible again after the quartz crisis; it underpins an enormous share of modern mechanical chronographs and is a benchmark of industrial movement design.
Diagram
Sources & references
- de Carle, D., Watch and Clock Encyclopedia
- Period trade material catalogues and calibre reference compilations (edition-dependent)
- Published manufacturer technical documentation where available
Where sources disagree, the disagreement is stated rather than resolved silently.