JLC 630

Calibre 630 was a compact quartz watch movement with a mechanical chronograph developed by Jaeger-LeCoultre and also used by IWC.

Introduced in 1987, Calibre 630 was the first member in the Jaeger-LeCoultre Mechaquartz family. It was a complicated movement, with 25 jewels. At the time, it was advertised as a revolutionary thin chronograph, measuring just 23.30 mm diameter and 3.70 mm thick. This made it 1/3 the volume of most contemporary chronograph movements and 40% smaller than the smallest equivalent movement on the market.

There are two motors in the calibre

• One powers the main timekeeping hands at a frequency of 1 Hz
• A second powers the mechanical chronograph at 4 Hz

Since the chronograph is mechanical, it has the same feel as a conventional chronograph movement, including mechanical zero reset. Yet the Mechaquartz was much more compact than a conventional automatic chronograph movement.

Calibre 630 differed from Calibre 631 in that it included a moon phase indicator.

Note There is conflicting information on the quartz frequency, with some sources claiming dual 1 KHz and 4 KHz crystals and others claiming 32 KHz. It is likely this confusion comes from the 1 and 4 Hz motors.

Calibre 630 was used in chronograph watches in the 1980's and 1990's, though not as widely as Calibre 631

• Jaeger-LeCoultre Ladies Odysseus Chronograph
• IWC Porsche Design Titan Moonphase Chronograph
• IWC Ladies Da Vinci Moonphase Chronograph
• IWC Pilot's Watch Chronograph Mechaquartz

• Mechaquartz Chronographs

• Frédéric Piguet Meca-Quartz
• Seiko 7A "Mecha-Quartz"