The Eterna 1408U is a 11 1⁄2 ligne manual wind movent, which was launched in the early 1960ies. The specimen displayed here dates from 1962.
The base plate with its perlage below the regulating staff (balance, lever and escapement wheel) reveals its value.
The gear train design is very modern for its time. The minute wheel is indirectly driven on the dial side by the large driving wheel, resulting in plenty of space for a large mainsprng barrel and a large Glucydur balance. The latter one still beats slowly with 18000 A/h, but is beared in two inhouse shock protections of type Eterna U.
This construction with indirectly driven minute wheel and directly driven center second is still used today in the ubiquitous ETA movements, such as the ETA 2824 and its relatives and replicas.
An interesting detail is the ratchet, which is a very simple and modern construction, consisting of only two parts, a simple spring and a lever. Both are not fixed and located below the ratchet wheel.
If you ever saw a modern ETA movement from its dial side, you’ll immediately notice the similarities to the Eterna 1408U, especially the minute wheel with its slipping clutch on the cannon pinion, which is driven by the large driving wheel at a 8 clock.
Of course, this movements uses a yoke winding system.
It’s noteable, that this movement still has got a partial minute dial, which was used for adjusting without a timegrapher.
In the lab
The specimen shown here dates from 1962 and must have suffered from a terrible accident. The plates were bent(!), the screws partially blown away and the movement was heavily covered by rust. Because of this, no further service was made.
One detail is very interesting: The large Gluydur balance was not harmed at all and still beats strong like on the first day. Big compliments to the inhouse Eterna shock protections!
|Number of jewels:||17|
Glucydur anular balance|
|Balance bearing / direction hairspring:||Clockwise|
|Adjust mechanism:||Long regulator arm|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Setting lever spring:||2 hole(s)|
|Functions:||hour, minute, second|
|Size:||11 1/2''' (measured: 25,6mm)|
Flume: K2 -|