Timex introduced the SSQ series in 1975. This was their first LCD module and was managed by a single control knob. In 1976 the SSQ had two push buttons that had different functions depending on their orientation. The module now also had a mini bulb to light the display. In 1978 the name SSQ was dropped and the series became known as Marathon. The use of an LCD module is still very much present today. So incredible to think it all began 50 years back.
What makes these fun to work on is how quickly they can be taken apart, cleaned, polished, fresh battery and back on the wrist. But please don't take this as an invitation to go try one for yourself. Reason is like all vintage Timex parts are no longer available and you will have to either find NOS or donor parts.
It is known that Timex was working on a Mil-Spec back in the mid to early 60's. Although they never went full production there were several models that came out for civilian use. The first was the 1966 24 hr black dial Sprite. That was the model at J Crew turned into a reissue. Other models were the Funtimer's from 1967 which used the plastic case. The final model was the Camper which is model copied for the MK1. Here is the Sprite
rare is a difficult word to apply but, since the 400 series was only produced for two years there are certainly less of them. The 21 ran for well over 12 years or more so lots them out there.
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