Around 1975, Ronda launched their second generation of quartz movements, to which the caliber 1175 belongs, which is presented here.
Except a few details, it is still today state of the art, so you can say, that Ronda successfully finished the development of quartz movements in the mid 1975ies.
The base plate is already massive and has got a large diameter, which is due to the electronics parts, which were larger and more power consuming at that time, and additionally, this movement required two batteries in parallel for a longer run time.
The setting lever spring on the movement side steers the hacking lever. When the crown is pulled, it blocks the gears, but does not disconnect the power.
The gear train is still visually appealing with “true” gears. Except the rotor, which is ruby-beared on both side, the gears are only ruby-beared on the movement side, while their pivots on the dial side are beared in metal bearings.
The transmission wheel between rotor and seconds wheel is thicker than the others.
The electronics board shows, that Ronda finished the development of the quartz watch already by 1975. On the main plate, there’s on ly the IC, a tuning fork quartz and an adjustable capcitor. Only the quarz (32768 Hz) is a bit ticker than todays’s quarz’ , but even the shape is the same.
On the dial side there’s the plastic date ring and the Ronda-typical, slowly advancing date mechanism with switching star and covered quickset mechanism. This works pretty unusual: By turning the time backwards, the date is advanced!
The quickset mechanism uses a swimming switching star, which is connected by an intermediate wheel (at 11 o’clock). Depending on the rotation direction, it interferes with the date ring or moves away from it. Its upper axle is pushed towards the date ring with a spring.
Here you see the switching star and how the connection with the date disk (which had just happened before) would look like.
As many early quarz movement of the 1970ies, the specimen shown here does not work any more. A water damage with heavy corrosion (due to the batteries, their current and the water), it resulted on the fragile contacts between electronics board and stepper motor to break away. Additionally, the motor coil is interrupted beyond repair and it’s uncertain whether the IC would still work.
|Number of jewels:||5|
|Adjust mechanism:||Variable capacitor|
|Construction type:||solid construction|
|Winding mechanism:||yoke winding system|
|Functions:||hour, minute, second, day|
|Size:||11 1/2''' (measured: 25,6mm)|