This is one of the rarest vintage jump hour watches ever made, very hard to find and not many were produced. Several brands produced this same model, so it can also be found under the names: Rodania electronic, Derby Swissonic electronic, Tenor Dorly electronic, maybe there are some less known…
ESA 9159 is the movement that powers this watch, more precisely it is the same movement as the ESA 9157/58 which is upgraded with a mechanical assembly with gears and discs with printed numbers that instead of hands show the time directly in a digital way. This made the movement significantly thicker, so the thickness of the case of this watch is quite large and amounts to 18mm. The specificity of this watch is that it also has a jump minute, so it is very easy and accurate to read the time. It is important to note that this is not a quartz watch, this is an electro-mechanical watch with a balance wheel. The date is displayed on the left while the hours and minutes are on the right, every minute a “click” is heard as the minute number changes in the same way as the hours jump on jump hour watches. So this is Jump Hours and Minutes watch.
The strap on the watch is not original, but it fits perfectly, the watch is quite massive, so it does not fit a thick strap, which I see some people put on, you should put a strap that narrows towards the buckle. The numbers engraved on the battery cover represent the months of the year, so when you put in a new battery, turn the number of the month towards the triangle on the big cover and that’s how you know the month when you put the battery 🙂
This is a very unusual watch that catches the eye, many people stop their gaze at this watch because it is clear that there is something unusual that can rarely or never be seen on the wrist of someone’s hand.
It was produced in 1975.
