TK Twin Quartz Seiko 1978

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Merk en model: Seiko Grand Quartz 9940-8010
Diameter: 36mm
Leeftijd: 1978
Datum waarop het in mijn bezit is gekomen: 2015
Factuur en/of certificaat: geen
Originele doos en/of eventuele accessoires: Seiko doosje
Verzendkosten of afgehaald: beide
Conditie (krassen, werking etc): gebruikt, wat piterosie aan de onderzijde. Met nieuwe batterij.
Soort uurwerk en kaliber: eerste uitvoering van de Twin Quartz
Vraagprijs: 100 euro

When quartz was well established, at the end of the Seventies, the Seiko 1978 JDM catalogue showed the twin quartz caliber for the first time, however there were (eventually) at least three different design technologies behind the Seiko twin quartz models.

While quartz based watches are extremely accurate compared to mechanical watches, they are still not perfect. One of the main reasons for the inaccuracy in a quartz model is because as the temperature changes the oscillation of the quartz crystal varies slightly. This change in oscillation will cause the slight drift in timing. To compensate for these changes quartz watches will employ some kind of temperature compensation to maintain a steady oscillation.

Seikos with the two oscillators are very interesting watches. Very accurate as you might expect from two time sources (crystals) and thermocompensation. In this small and rather inexpensive group of high end quartz models the oldest (probably before 1978) thermocompensation method is the one present in the King Quartz caliber - the method is based on having two quartz crystals both around 32 kHz and using the difference from them as a way to indirectly measure temperature - and from that the number of quartz ticks that need to be skipped in order to achieve a better accuracy

Hierna volgt een aantal recente foto’s van het daadwerkelijke object. Indien u interesse heeft, klik dan linksboven op mijn gebruikersnaam en stuur mij een bericht. Reageren als antwoord op deze advertentie is helaas niet toegestaan (en mag ik zelf ook slechts om de andere dag).

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Up: voor de liefhebber 50 euro