/fa/ - Fashion

>>12850049
It is a Bulova Accutron cal 224. As far as I'm aware Bulova didn't have specific case references so I'm unable to give you one.

The 224 was Bulova's (unsuccessful) answer the quartz crisis. It's basically a standard cal 218 (2nd generation tuning fork movement, the evolution of the original 214 that was in the spaceview), but with a quartz timing circuit driving the tuning fork timing - in other words, the tuning fork does not vibrate at it's natural frequency, but rather the electromagnets force the tuning fork to vibrate at a frequency controlled by the quartz crystal. Bulova took this approach to get a quartz watch going without investing in much r&d - in fact, only one wheel has to be changed out of the 218's gear train (due to the fork running at a different frequency). Ultimately though the 224 was too expensive and went through batteries too quickly compared to the stepper-motor based quartz watches that came to dominate.