In 1952, the ETA launched one of their most modern and successful ladies' selfwindig movements.
With a diameter of only 7 3/4 lignes, it was really tiny, but offered lots of features, such as a selfwindig mechamisn, center second hand and date indication. Not many manufacturers could offer such a large set of features. That amound led to a minor disadvantage: The height was with 5.6mm quite big, so the watches, which used that movement looked a bit clumsy.
The ETA 2369 was produced for one and a half decades, until it was superseded in 1966 by the only marginally modified caliber 2551. How modern the 2369 was constructed can be seen on the fact, that all following movements, starting with caliber 2551 up to the still produced caliber ETA 2671, use the same basic construction and only changed details such as the balance beating rate. The design with directly driven center second hand and indirectly driven minute hand was never changed.
So, this construction of the early fifties was a really genious one!
In the 14 years, while this movement was produced, it was slightly modernized with the not really required "fashion" jewels on the pawl winding wheels were omitted and the balance with screws was superseded by a screwless balance, which also featured a modern moveable hairspring stud instead of the old static one.
The gear construction was done by most modern knowledge. The center second hand was directly driven, while the minute hand was driven by the decentral driving wheel. The cannon pinion however used the typical ETA construction with the large moveable gear.
Of course, all bearings contained synthetic rubis and the balance was beared in two Incabloc shock protection systems. The moveable regulator contained a short regulation arm and was movemed directly at the place, where it looked out below the selfwindig plate.
The selfwinding mechanism used the common ETA pawl winding wheels plus two following gears.
On manual winding, the clicks of the pawl winding wheels detatch the rotor.
On the dial side, there's of course a yoke winding system.
The date ring slowly advances and can be corrected semi-fast by turning the time back and forth - this was a common correction mechanism in these times.