Caliber 72: Microtor movement with new design, 25 jewels, 21,600 A/h
The cal. 72 with a diameter of 27.0 mm instead of 28.0 mm, is completely different from the aforementioned movements. It has a date and weekday indication at the "3" and a height of 4.6 mm. The frequency increased to 21,600 vibrations per hour (like with the cal. 215-9, cal. 215-97 and cal. 218-9) while the number of jewels was reduced to 25. This is related to the use of a ball bearing for the rotor mekanisme.
The arrangement of the bridges differs very much from the classical microtor movements (cal. 215, cal. 218-2, cal. 69). The cal. 72 was used in all Polerouter models with separate windows for day and date in the late sixties.
The thinner cal. 71 (3.9 mm) without the weekday indication was not used for Polerouter models. The so-called "Super Microtor" cal. 256 (with the ending A, B or C) is not covered here deliberately. The movement has a "normal" central rotor and was produced by Movado (equivalent to cal. 395). It has 28 jewels but is of lower quality and only used in the Polerouter compact. Furthermore, all electrical or Quartz movements are ignored here.
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