The ETA 980 was produced for some decades; the oldest versions (probably from the 1940ies) are quite different from the most recent ones, only the basic layout is the same:
The screw balance shown on the old version here was later on replaced by a modern screw-less type, the old 15 jewels later increased to seventeen, by putting one jewel into the minute train bushing and the second one as cap jewel for the escapement wheel.
The base plate shows, that all important bearings contain rubies. The modern version shown here is really eye-pleasant with its red-golden color and perlage decoration.
We have the classical gear train with directly driven center minute wheel, followed by third wheel, decentral second wheel and steel escapement wheel.
This movement has got a diameter of 8 3/4 lignes, a small subsecond hand at "6" and a screw balance without regulator arm. A shock protection was not yet available on the old version, but the decoration was much nicer with angled briged and jewels, which contain a golden tone ring among them and remind of chatons.
The modern versions have got a screw less anular balance, which is beared in two Incabloc shock protections and which beats slowly with 18000 A/h. The hairspring is already connected to a moveable stud, and two additional jewels are used, one for the minute wheel and one as cap jewel for the escapement wheel.
It's noteable, that the lever is not beared below a cock, but under a bridge, secured with two screws.
On the dial side, there is of course a yoke winding system, unfortunately, on the specimen shown here, the yoke spring is broken and missing - a tribute to its age. The partial minute dial on the plate was often found on vintage movements and helped to regulate them when not yet put into a case.
This movement was probably launced in the late 1940ies and was available in two versions: Version I had the opening of the yoke spring head directing to "3", version II directing to "6". Since that spring is missing on my movement, it cannot be 100% properly identified.
The modern version only differs on the dial side in details from the old version, most noteable are the the use of an Incabloc shock protection bearing and the loss of the embossed partial minute dial.
- Otto Frey: ETA Movements (On this overview, you can see the ETA 980 in its latest version)
The movement in its modern version, together with the Fortis gents watch is a kind donation of G.Keilhammer. Thank you very much for the support of the movement archive!