|Reserve:||48, 52 hours|
|Diameter:||30.00 mm (13.25 ligne)|
|© ETA||Complications:||2-Button, Cam Switching Chronograph, Chronograph, Date, Hand Winding, Quick Date Correction|
|Hands:||30 Minute Chronograph Hand at 12:00, Central 60 Second Chronograph Hand, Central Hour Hand, Central Minute Hand, Date Window at 3:00, Small Seconds Hand at 9:00|
|Distinguishing Technical Characteristics|
Clockwise Balance Cock
|Production: 1983 – 1998|
Cal. 7765 is a hand-winding cam-switching chronograph movement with date from ETA. It is closely related to the automatic ETA Cal. 7750 and the hand-winding Cal. 7760.
Cal. 7765 is quite unusual in the subdial layout: It has small seconds at 9:00 and a 30 minute counter at 12:00 but no subdial at 6:00. The date window at 3:00 gives it an “upside down” look.
ETA 7750 Family Overview
The ETA (formerly Valjoux) 7750 is a robust and reliable automatic movement with an integrated cam-operated chronograph function. It has spawned a family of chronograph and time-only movements and is used as a base for many complications and third-party watch movements.
Introduced in 1974, the Valjoux 7750 was soon retired but returned in the 1980s. It has come to dominate the industry and remains popular today. Most versions of Cal. 7750 feature small seconds at 9:00 and chronograph hours and minutes subdials at 12:00 and 6:00, respectively. This “6-9-12” subdial arrangement is instantly recognizable to watch enthusiasts.
Distinguishing features of the ETA 7750 family include a smaller balance wheel than many historic movements and a small rotor hub with a slotted screw and five visible bearings. The balance is located at 1:30 when viewed from the back with the crown at 9:00, and is located by a clockwise cock. The distinctive Valjoux regulator was used on most 7750 variants until the 2010s, with a clamp-shaped arm and “dagger” pointer. The chronograph functions use cams rather than the levers and column wheel found on many other movements.Images are taken from official publications and are used here for commentary and educational purposes. Copyright is held by the original owner as noted.