|Diameter:||32.45 mm (14.5 ligne)|
|Cal. 39||Complications:||2-Button, 7-Column Chronograph, Chronograph, Column Wheel Chronograph, Horizontal Clutch Chronograph|
|Hands:||45 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|
Clockwise Balance Cock
Cal. 39 is a column wheel chronograph movement produced by Landeron (Charles Hahn & Cie.) in the 1940s. It features a Breguet hairspring, screwed balance, and regulator index. It used a horizontal clutch and column wheel but was plainly finished and utilitarian.
Cal. 42 was similar but used a flat spiral hairspring and added an hour counter register. A new chronograph mechanism was fitted for the derived Cal. 52. Cal. 53 was a more radical departure, with a cam-switching chronograph mechanism from Dèpraz similar to the Landeron/Dèpraz Cal. 48.
Cal. 39 was commonly used by Nicolet watch and Breitling.Images are taken from official publications and are used here for commentary and educational purposes. Copyright is held by the original owner as noted.