ETA 2800 calibres
This movement family is derived from the ETA 2750 and ETA 2770, which were themselves evolved from the ETA 2600 and ETA 2620 and originally the ETA 2370 and ETA 2375. Today, the most common members of this family are the ETA 2824 and ETA 2836. Note that the ETA 2892 family is technically unrelated to this, having been derived from an entirely different series of Eterna movements.
The 2800 series movements are extremely similar. Across all of the variants, 27 common parts were used. Nearly all of the parts were common to each of the three complications and sizes, and more than half were shared within each speed.
This entire series uses just six mainplates, each of the following in both 11.5 ligne and 13 ligne sizes:
- No date (later dropped; the date version was used on the no-date calibres)
- Date only
- Day/date (0.5 mm thicker)
With three speeds available, there were also three balance/escape/fourth wheel assemblies. Those with a balance stop also had unique parts.
The family shared four mainsprings, 2 for the manual versions and 2 for the automatics.
(Current movements in bold)
| Winding | Size (ligne) | Speed (bph) | Day/Date | Date Only | No Date |
|---|---|---|---|---|---|
| Manual | 11.5 | 21,600 | ETA 2808 | ETA 2802 | ETA 2800 |
| 28,800 | ETA 2810 ETA 2816 ETA 2816-1 |
ETA 2804 ETA 2804-1 ETA 2804-2 |
ETA 2801 ETA 2801-1 ETA 2801-2 | ||
| 36,000 | ETA 2812 ETA 2817 |
ETA 2806 | ETA 2819 | ||
| 13 | 21,600 | ETA 2809 | ETA 2803 | ||
| 28,800 | ETA 2811 | ETA 2805 | |||
| 36,000 | ETA 2813 | ETA 2807 | |||
| Automatic | 11.5 | 21,600 | ETA 2828 | ETA 2822 | ETA 2820 |
| 28,800 | ETA 2830 ETA 2836 ETA 2836-1 ETA 2836-2 |
ETA 2824 ETA 2824-1 ETA 2824-2 |
ETA 2821 ETA 2821-1 | ||
| 36,000 | ETA 2832 ETA 2837 |
ETA 2826 ETA 2826-2 |
|||
| 13 | 21,600 | ETA 2829 | ETA 2823 | ETA 2839 | |
| 28,800 | ETA 2831 ETA 2838 ETA 2834 ETA 2834-1 ETA 2834-2 |
ETA 2825 | |||
| 36,000 | ETA 2833 | ETA 2827 |
Other variants:
- 1820 - 21,600 bph auto, 11.5 l (w/ or w/o hack)
2840 Series
The 2840 series was closely related to the 2800 series but was cost-reduced for use in Swatch-branded automatic watches. The calibres correspond with similar-numbered 2800 movements. Only the ETA 2846 (and perhaps the ETA 2842) were made available to other manufacturers.
- ETA 2840
- ETA 2841
- ETA 2842 - 21,600 bph auto, date, 11.5 l
- ETA 2846 - 21,600 bph auto, day-date, 11.5 l
2850/2870 Series
These differ from the 2800 series in layout but use many similar parts. They were intended as cost-reduced versions like the 2840 series, but retain dial feet and other features for use in serviceable watches.
| Winding | Size (ligne) | Speed (bph) | Day/Date | Date Only | No Date |
|---|---|---|---|---|---|
| Manual | 11.5 | 21,600 | ETA 2859 | ETA 2853 | ETA 2851 |
| 28,800 | ETA 2858 | ETA 2852 | ETA 2850 | ||
| Automatic | 11.5 | 21,600 | ETA 2879 | ETA 2873 | ETA 2871 |
| 28,800 | ETA 2878 | ETA 2872 | ETA 2870 |