The Beta 21 movement was the fruit of a collaborative effort, named the Centre Electronique Horloger, which got underway in 1962 and was sponsored by over 20 leading Swiss watch brands. The prototype movement debuted in 1967. In 1968, a consortium of Swiss manufacturers pooled their resources and manufacturing capabilities to mass produce the calibers. The first watches containing the Beta 21 movement arrived on the market in 1970.
The Beta 21 is an electronic caliber. The movement features a quartz crystal and interestingly, while the natural oscillation rate of the quartz crystal is 8192 Hz, Patek reduced the oscillation rate to 256 Hz by means of a proprietary frequency reducer. The seconds hand sweeps (versus the usual ticking of quartz regulated movements), and the caliber has 13 jewels. A date is provided at the 6 o’clock position.
This reference 3587 2 Patek has a cushion shaped 18k case which measures 42mm long and wide by 11.8mm thick. Bezel is stepped. The crystal is sapphire and the case construction is two part. The screw down back on this case is practically a manhole cover!
Original two-tone gold dial with applied golden hour markers, date window at 3 o’clock framed in gold, original golden baton hands and center sweep seconds hand. Dial is mint as are the hands.
Bracelet is massive and fixed to the case. Bracelet is two layers of gold and is thick. Patek must have designed the bracelet with holes in order to reduce the weight of the watch. Bracelet and watch will fit up to a 7.75 inch wrist.
Both the bracelet and the case have their original factory finish and this watch is in mint condition.