Ronda 4139

 
Ronda 4139

Ronda 4139

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 34 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
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:SC?,QG,JG,RDR,AUT
Functions:hour, minute, second, day, week day, selfwinding
A/h:21600
Size:8 3/4'''
Production period:198x

Usage gallery

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Pomar Automatic ladies' watch