Description
This Ronda “Ronda-Matic” selfwindig movement, caliber 4139, was made in the warly 1980ies. It was part of the caliber family 413x/423x/433x/443x, which was produced in different sizes, ranging from 8 3/4 up to 12 lignes, and was available as handwind and selfwindig versions. The calibet 4139 winds in one direction and uses a swiss lever movement, although it is signed as “RL”, which normally stands for Ronda pin-lever movements.
It offers all possible kinds of indications, hour, minute, second, date and weekday (in names as well as in digits from 1 to 7). The date can be quickset by a very unique mechanism: When you set the time backwards, the date advances every 30 minutes.
A big thanks to Mr. Stahl from the Ermano Uhrenwerke GmbH for identifying this movement and providing me very interesting details about it.
Technical data
| Manufacturer: | Ronda |
| Caliber: | 4139 |
| Size: | 8 3/4''' |
| A/h: | 21600 |
| lift angle: | 52° |
| Number of jewels: | 21 |
| Escapement: | Pallet lever |
| Balance types: |
Nickel anular balance |
| Shock protection(s): |
? |
| Balance bearing / direction hairspring: | Counterclockwise |
| Moveable stud: | yes |
| Adjust mechanism: | Hairspring key |
| Features: |
|
| Production period: | 198x |
| Datasheet: |
calibers 4131-3349 |