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ETA 2788
Automatic · 11.5‴ · Switzerland · 1969
Dimensions
26 mm
Height
5.90mm
Jewels
25
Power reserve
47h
Timegrapher
Beat rate
21,600bph
Frequency
3Hz
Lift angle
52°
Reference: healthy amplitude ≈ 270–315° fully wound (>200° at 24 h); beat error ideally < 0.5 ms.
Movement
| Movement type |
Automatic
Mechanical movements fitted with an oscillating rotor that winds the mainspring through the wearer's natural motion. Invented by Abraham-Louis Perrelet around 1777 for pocket watches and adapted to the wristwatch by John Harwood in 1923, it combines traditional craftsmanship with everyday convenience.
|
|---|---|
| Winding type |
Automatic (Rotor-Driven)
Self-winding via a rotor whose motion winds the mainspring through a transmission gear train. The specific rotor configuration (central, micro, peripheral, bumper) is catalogued separately under Rotor Type. Standard on the vast majority of mechanical wristwatches since the mid-20th century.
|
| Setting type |
Stem Set (Crown Pull)
The dominant modern system: pulling the crown out to a setting position engages the hand-setting mechanism. Introduced in the late 19th century and refined into multi-position crowns (date, time, GMT). Used in virtually all modern wristwatches and most 20th-century pocket watches.
|
| Escapement type |
Swiss Lever
The undisputed standard of modern mechanical watchmaking. Through an elegant interplay between escape wheel, pallet fork, and balance, it delivers reliable impulses with the safety of 'draw' to keep the lever locked. Refined since the 18th century, it powers almost every quality mechanical wristwatch made today.
|
| Control type |
Balance Wheel
The heart of mechanical timepieces, the balance wheel is an oscillating component that, together with the hairspring, forms a harmonic oscillator regulating the gear train's pace. Its steady back-and-forth motion ensures the even release of energy from the mainspring, governing the watch's accuracy.
|
| Regulator type |
Pinned Regulator (or Index Regulator)
The most traditional regulator, consisting of a movable index pointer fitted with two curb pins (or a pin and a boot) that embrace the hairspring. Sliding the index along its scale changes the spring's active length, adjusting the rate. Simple, reliable, and easy to service, it remains the workhorse standard across countless mechanical movements.
|
| Rotor type |
Central Rotor
The most common automatic winding rotor, mounted on the central axis of the movement and rotating a full 360°. Industrialized by Rolex with the Perpetual system in 1931 and refined throughout the 20th century, it offers excellent winding efficiency and remains the de facto standard for automatic wristwatches, whether winding in one or both directions.
|
| Shock protection |
Incabloc
The most famous and widely used shock protection system in horology. Invented in 1934 by Georges Braunschweig and Fritz Marti at Universal Escapements (La Chaux-de-Fonds), it employs a lyre-shaped spring holding the jewel setting, allowing it to shift under impact and return to position. Adopted by countless Swiss makers across the 20th century.
|
Specifications
| Lignes | 11.5‴ |
|---|---|
| Shape |
Round
It is the most common form that we can find.
|
| Complications |
Sweep Second
Contrary to the ticking motion of quartz watches, the sweep second hand in mechanical watches moves smoothly around the dial, offering a visual representation of time flowing continuously. This has become synonymous with the precision and craft of mechanical horology.
,
Day
Beyond hours and minutes, the day complication anchors wearers to their weekly schedule, providing context to our cyclical routine.
,
Date
An essential for many, the date display reminds wearers of their daily commitments, connecting the abstract concept of time to tangible daily events.
,
Chronograph Stopwatch
Functionality meets style as this feature allows wearers to measure specific time intervals, embodying the blend of everyday utility with sophisticated design.
|
| Hand count | 3 |
| Hand sizes | 1.50 x 0.90 x 0.25mm |
| Further measures | Mounting Diameter (Dm): 25.6mm Two-part Dial Spacer: 0.1mm Stem height (T): 2.6mm Mounting Height (F): 2.05mm |
Origin & References
| Manufacturer | ETA |
|---|---|
| Country | Switzerland |
| Launch year | 1969 |
| COSC certified | No |
| Signature | ca. 1970: BN, K, 71/1, ETA 2788 - Patented; Incabloc |
| US import codes |
|
Notes
Remarks: 1969-1982, >25000000 (all automatics of the family)
Other data: balance staff: U3337 stem: W3275 mainspring / battery: 1.45 x 10.5 x 0.12 x 368mm stem ronda: 1815 (11,5) Mainspring: 1.450 x 11.000 x 0.125 x 400.000 mm
Ranfft mentioned about this caliber: There are variants with this quantity of jewels 17, 21, 25
Other data: balance staff: U3337 stem: W3275 mainspring / battery: 1.45 x 10.5 x 0.12 x 368mm stem ronda: 1815 (11,5) Mainspring: 1.450 x 11.000 x 0.125 x 400.000 mm
Ranfft mentioned about this caliber: There are variants with this quantity of jewels 17, 21, 25
Family
Series 2750 - 2791
manual / automatic respectively
21600 A/h:
2750 / 2770, 2776: no date
2752 / 2772: date
2753 / 2773: date, precision regulator
2758 / 2778: day, date
2759 / 2779: day, date, precision regulator
2761 / 2781: quick set date, high
2762 / 2782: quick set date
2763 / 2783: quick set date
2763-F6 / 2783-F6: quick set date, digital
2768 / 2788: day, quick set date
2769 / 2789: quick set day and date
2769-1 / 2789-1: quick set day and date, double-language
28800 A/h:
2751 / 2771: no date
2754 / 2774: date
2760 / 2780: day, date
2764 / 2784: quick set date
- / 2790 : quick set day and date
- / 2790-1: quick set day and date, double-language
- / 2791: quick set date, high
21600 A/h:
2750 / 2770, 2776: no date
2752 / 2772: date
2753 / 2773: date, precision regulator
2758 / 2778: day, date
2759 / 2779: day, date, precision regulator
2761 / 2781: quick set date, high
2762 / 2782: quick set date
2763 / 2783: quick set date
2763-F6 / 2783-F6: quick set date, digital
2768 / 2788: day, quick set date
2769 / 2789: quick set day and date
2769-1 / 2789-1: quick set day and date, double-language
28800 A/h:
2751 / 2771: no date
2754 / 2774: date
2760 / 2780: day, date
2764 / 2784: quick set date
- / 2790 : quick set day and date
- / 2790-1: quick set day and date, double-language
- / 2791: quick set date, high
Related calibers
ETA 2750
ETA 2751
ETA 2752
ETA 2753
ETA 2754
ETA 2758
ETA 2759
ETA 2760
ETA 2761
ETA 2762
ETA 2763
ETA 2763-F6
ETA 2764
ETA 2768
ETA 2769
ETA 2769-1
ETA 2770
ETA 2771
ETA 2772
ETA 2773
ETA 2774
ETA 2776
ETA 2778
ETA 2779
ETA 2780
ETA 2781
ETA 2782
ETA 2783
ETA 2783-F6
ETA 2784
ETA 2788
ETA 2789
ETA 2789-1
ETA 2790
ETA 2790-1
ETA 2791
Compatible Parts
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