The ETA 2789 is a vintage automatic mechanical watch movement renowned for its reliability in mid-20th-century timepieces. Produced primarily from the 1950s to the 1970s by ETA SA, it powered numerous Swiss brands with its self-winding day-date complication. This 11.5 ligne caliber exemplifies robust engineering from the post-war era.
Key Specifications
Dimensions: 25.6mm diameter, 5.9mm height, suitable for men’s watches around 37mm case size.
Jewels: 17 or 25, depending on variant, reducing friction in critical pivots.
Beat Rate: 21,600 vph (3 Hz), with a 52-degree lift angle for smooth operation.
Power Reserve: Approximately 38 hours when fully wound.
Features and Functions
The movement offers central hours, minutes, and sweeping seconds, plus day-date at 3 o’clock with quickset mechanisms. It supports manual winding and bidirectional rotor winding, often with ball-bearing for efficiency in early models. Variants like the 2789-1 include bilingual day displays. Anti-shock Incabloc protection ensures durability. Hacking seconds aid precise time-setting.
History and Variants
Introduced around 1956, the ETA 2789 evolved from earlier designs like Eterna influences, featuring an indirect minute drive for a larger balance. Production spanned 1969-1980 for base models, with modifications like T-to-U shock changes creating sub-variants (e.g., TC, UT, UC). It appeared in watches by Rado, Certina, Edox, and others.
Service Considerations
Common in vintage repairs, the 2789 requires careful stem handling due to its keyless works layout. Parts remain available via specialists, though full disassembly checks motion and auto works. Its straightforward design appeals to horologists restoring classics.
For any Watch Spare Parts inquiry, Email us for rate and availability: [email protected]
Watch Parts Enquiry
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Stem, Crown, Hands & Spares might be available for this movement.
Email us for rate and availability: [email protected]
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