ETA F03.11A – Technical Overview

The ETA F03.11A is a high-precision Swiss quartz movement designed and manufactured by ETA SA Manufacture Horlogère Suisse. It belongs to the 7¾´´´ family and features compact dimensions with a movement diameter of 17.20 mm and a height of 2.50 mm. When fitted with batteries, the total height can vary—2.65 mm with a No. 364 battery or 3.10 mm with a No. 377 battery.

Movement Specifications

• Caliber: ETA F03.11A

• Size: 7¾´´´ (17.20 mm diameter)

• Height: 2.50 mm (movement only)

• Jewels: 3

• Frequency: 32,768 Hz (standard for quartz timekeeping)

This movement is engineered for accuracy and reliability. It includes three jewels, which minimize friction and wear on key components, helping to ensure longevity.

Assembly and Components

The ETA F03.11A is composed of a base movement and an electronic module. The technical document outlines a detailed list of over 40 components, including:

• Main plate, train wheel bridge, intermediate and third wheels

• Calendar mechanisms including the date indicator and jumper

• Rotor, stator, and electronic control module

• Battery components and contact insulators

Assembly instructions are clearly specified in logical sequences, with torque values provided for key screws (typically 0.6–0.7 Ncm). Lubrication points are marked, indicating use of Moebius oils such as 9014, 9034, HP-1300, and D5 for different parts.

Environmental and Safety Requirements

ETA stresses strict adherence to safety and environmental standards:

• Eye protection is mandatory during all work on the movement.

• Harmful lubricants and cleaning agents must be disposed of properly.

• Any materials posing a risk to water contamination must be handled in sealed, appropriate containers and must not enter the sewage system.

ETA disclaims responsibility for any damage caused by failure to comply with these guidelines.

Electrical Testing and EOL Function

The movement is equipped with an End-of-Life (EOL) indication feature. When the battery voltage falls below 1.30 V, the second hand begins to jump in 4-second intervals—alerting the user that the battery needs replacement.

ETA provides specific testing guidelines, which must be performed in an ambient temperature of 20–25°C. Key electrical tests include:

• Battery voltage check at 1.55 V

• EOL response check

• Motor function check with varying pulse rates (8 steps/sec or 32 steps/sec based on voltage)

• Current consumption verification (≤1.10 µA operational, ≤0.5 µA in stop mode)

Technicians must use extremely fine probes to make contact with coil terminals for precise pulse detection.

Notes on Repairs and Maintenance

ETA strictly advises that only properly trained professionals perform any service, repair, or inspection work. The movement’s intricate design, paired with its environmental and safety protocols, makes it suitable only for experienced horological technicians.

Summary

The ETA F03.11A is a compact, efficient quartz movement built with Swiss engineering precision. With features such as an EOL indicator, low energy consumption, and well-documented assembly guidelines, it is a dependable choice for manufacturers and watchmakers. However, proper handling, lubrication, and environmental responsibility are vital to ensuring optimal performance and durability.