When there is almost as much talk about the movement of a particular watch as there is about the watch itself, it is clear that the watch has achieved a place in the replica watch collection. When collectors refer to the Omega Speedmaster professional Moonwatch, for example, they often hear caliber figures as often as reference figures. Some sports are more popular because of their scarcity, while others are praised for their technological advances. Let’s take a closer look at two similar omega overlord movements, the 1861-1863 caliber, to highlight their differences and similarities. 
Some of you may already know that the Omega Speedmaster debuted in 1957 as a timing device designed for motor racing. The timing device is driven by the hand-wound lemanibased calibre 321, a cylindrical wheel controlled side clutch timing device that is highly regarded for its beautiful design. Previous generations of speedpost operated on no. 321 (ref. 2915, 2998, 105. 002, 105. 003, 105. 012, and 145. 012), including the speedpost watch that landed on the moon on Apollo 11.
However, when omega introduced ref.145. 022 in 1969, the Caliber 861, based on lemania, was added to the supercar’s case. Unlike the cal. 321, the manual 861 has a cam-controlled timing device, which is much easier to produce because of its simple structure. In conjunction with the debut of the 861 calibre speedpost, the nickname for the watch’s new “moon watch”; However, the 9t is a reference to the. 321 equipment that is actually worn on the surface of the moon.
The caliber 861(and its derivatives) remained the preferred reference for the standard Speedmaster Professional “Moonwatch” until the 1996 introduction of the reference number 3570. 50, whose caliber was 1861. The main difference between 861 and 1861 is that the newer movement features rhodium-plated parts, as opposed to previous copper-plated. To this day, omega still USES calibre 1861 and its derivatives, which are widely available in the “speedpost” professional monthly reference materials currently produced.
The 1861 omega calibre is a hand-wound timekeeper with a frequency of 21,600 cycles per hour (3Hz) and a power reserve of 48 hours. It has 18 gems and its parts are rhodium-plated. Omega has been using it in selected “speedpost” replica watches since 1996; However, no such substance has been found in current production of omega watches. The modern “speedpost” professional monthly chart refers to the house calibre of 1861, including “speedpost” no.311. 30. 42. 30. 01. 005 and “speedpost” no.311. 33. 42. 30. 01. 001. However, this does not match what omega enthusiasts consider the “true descendant” of the 42mm stainless steel moonwatch.
Caliber 1863 is based on caliber 1861 with the same representation, but its movement is reserved for models with transparent cases. Thus, since the 1863 Karl was on display while the 1861 was hidden behind a solid case, the caliber 1863 is the more attractive version, featuring rounded wood grain on the floor, the Geneva stripes of the bridge (also known as the cozde Geneva), and the polished edge of the lever and bridge.