JLC 916

Calibre 916 (branded "Speedbeat") was an automatic alarm movement from Jaeger-LeCoultre.

Introduced in 1969, Calibres 916 replaced Calibres 815 and 825 in the Jaeger-LeCoultre Memovox range. This calibre went out of production in 1978 but was eventually replaced by Calibre 919, introduced in 1994. A total of 7,731 watches were produced with Calibre 916.

There were two notable features of Calibre 916:

• It was the first Jaeger-LeCoultre alarm calibre to use a high-speed 28,800 A/h balance, giving improved precision.
• It was the first ever automatic alarm watch with a free-rotating rotor, as opposed to the bumper movements produced previously.

As in other Jaeger-LeCoultre alarm calibres, the alarm hammer struck a protuberance on the back plate, making a distinctive buzzing sound. Even if the alarm was not wound, the hammer rattled freely against the protuberance. In Calibre 916, this protuberance fits through an extra-wide hole in the center of the rotor.

Variants

The Jaeger-LeCoultre Calibre 916 was used as an ebauche by Girard Perregaux, becoming the GP 080 Gyromatic alarm.

Specifications

• 13 lignes in diameter
• Glucydur balance, automatically compensating flat hairspring
• 28,800 A/h
• Double barrel (time and alarm)
  • Bidirectional automatic winding for time
  • Manual winding for alarm
• Direct sweep central seconds
• 27 jewels
• Alarm hammer inside case back

External Links

• A Little Potted History Of The Memovox & My Recently Acquired Cal 911
• Three Cheers for Memovox!