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Brand: | Landeron | 
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|---|---|---|---|
| Family: | |||
| Height: | 6.2 mm | ||
| Jewels: | 17 | ||
| Reserve: | 41 hours | ||
| Frequency: | 18,000 A/h | ||
| Winding: | Hand winding | ||
| Diameter: | 31 mm (13.75 ligne) | ||
| Landeron Cal. 48 | Complications: | 2-Button, Cam Switching Chronograph, Chronograph, Oscillating Pinion Chronograph | |
| Hands: | 30 Minute Chronograph Hand at 3:00, Central 60 Second Chronograph Hand, Central Hour Hand, Central Minute Hand, Small Seconds Hand at 9:00 | ||
| Distinguishing Technical Characteristics | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
 Hand-Winding  Clockwise Balance Cock  Screwed Balance  Indexed Regulator |
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| Production: 1937 – 1970 | |||||||||||
| 1910s | 1920s | 1930s | 1940s | 1950s | 1960s | 1970s | 1980s | 1990s | 2000s | 2010s | 2020s |
Cal. 48 is one of a family of chronograph movements produced by Landeron from 1937 through the 1970s. In all, over 3.5 million examples were produced.
Landeron Cal. 48 is a 13.75 ligne movement with a cam switching chronograph system. A variety of 14 ligne variants were produced, as well as complicated versions with calendars, moon phase, and hour counters. Like all movements in the family it uses Heuer-style oscillating pinion rather than a traditional horizontal clutch to activate the chronograph function.
The preceding Landeron 47 movement (the first cam-actuated chronograph) featured three buttons Start, stop, and reset. Cal. 48 switched to two-button operation.
Landeron Calibre 48 Chronograph Operation
Unlike many 2-button chronograph movements, the stop function shares the reset button rather than the start button. Therefore, on many Cal. 48 family movements from Landeron, the buttons function as follows:
- 2:00 – Start
- 4:00 – Stop/Reset
The later Cal. 149, Cal. 189, Cal. 349, and later movements have a conventional start/stop button at 2:00.
The original Landeron 48 featured a deep, curving hammer, a feature carried on to the 54, 56, and 58. The Landeron 51/151 features a conventional “boot” hammer, as does the 55, 57, 59/159, 80/180, and 81/181. The Landeron 148 moved to a distinct “JI” hammer shape, a feature shared by the 149/189/349, 154, 185, 186, and 187/248. Finally, the Landeron 152/352 moved to a deeply bowed hammer, a feature shared by the 153/353.
