In 1951, Jaeger-LeCoultre's first alarm wristwatch was released under the name Memovox.[1] The company Vulcain had already produced the world's first alarm wristwatch named cricket in 1949. These first Memovox models were equipped with the watch calibres K489, K489/1 or K601, which were wound manually.[2] The K601 also referred to a later quartz movement by Jaeger-LeCoultre.[2]

The time and alarm function were separated by constructing two separate barrels which ensured that the power reserve of the clock was not reduced by triggering the alarm function. As a result, Memovox watches had two crowns for winding. Memovox watches were also sold with Logo on the dial and bridge engraving by Cartier, Gübelin (here under the name Ipsovox), Dunhill and Van Cleef & Arpels. From 1955 on, Memovoxes were also available equipped with the caliber K814 which had a date display.

Due to the Smoot-Hawley Tariff Act, the Memovox models for the American market were printed and engraved with LeCoultre instead of Jaeger-LeCoultre until 1980. The calibers for the American market were encased in the USA in watch cases that were locally produced. Accordingly, the dials and case shapes used in the US models differ from the european ones. An exception were the case bottoms made of stainless steel, which were always engraved on the inside with LeCoultre on both European and US Memovox watches. The Memovoxes in North America were distributed by the company Vacheron-Constantin-LeCoultre, a subsidiary of Longines-Wittnauer.