The system described:
Out of respect for possible copyright, I will not (yet) post the entire paper…
First the good news
At the tier of ‘annual accuracy’, the JIS mandates that manufacturers measure three things:
1) Temperature variation Vt
2) Aging variation Va
3) Battery voltage drop variation Ve
These are added together and…
The 1995 Japanese Industrial Standard for HAQ and its fatal flaw
I have mentioned the HIJ a few times before, but my very first was in the cal. 2722 thread when I stumbled onto primary sources for the significance of te Citizen cal. 1930.
"The Horological Institute of Japan is the only academic organization sp…
Continue readingInteresting article:
A History of the Quartz Crystal Industry in the USA | IEEE UFFC
Starting with the discovery of the piezoelectric effect by the Curies, and then the first constructions of quartz oscillators by Nicholson, Cady and Pierce.
In 1926 …
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There is also a darker dial ENH-200. Catalog page shared by @Citizen _collector
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Junghans AT-cut 4 Mhz movement(s) (and some of what came before)
This thread is not so much about this technology’s place in Citizen’s product line, if any, but about the invention on its own merits as an aid to energy-efficient quartz watch accuracy.
Attached as PDF, the US version of these patents are…
The Exceed 4 Mega watches powered by this caliber were the last known Citizen AT-cut wristwatches before the cal. 0100 pocket watch shown at BaselWorld 2018 and First Series wristwatches released to the market in 2019.
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