An April 1979 vintage Seiko Grand Twin Quartz 9940-7000 in great original condition and on its original bracelet. This Seiko Grand Twin Quartz has a stunning textured dial with no date and a sleek circular case. It is powered by the Seiko Grand Twin Quartz Cal. 9940 that had an accuracy of ±10 seconds per year when it was released, and that has two twin oscillators; a second that controls for temperature for even more accuracy. The case measures 34 mm in diameter, with the watch being in great condition, despite the dial having some marks on it. We offer a flat rate for shipping on every order and 30-day free returns. We also offer a 2-month mechanical warranty for every purchase. All prices are in CAD.
Seiko Grand Quartz History
The first Seiko Grand Quartz was released in 1975 and was the Cal. 4843 which had an accuracy of ±5 seconds per month and a day/date display. The Grand Twin Quartz, however, that had a ridiculous accuracy of ±10 seconds per year, was only released in 1978 - and just like the first GQs positioned right under the Superior Twin Quartz line. While the Grand Quartz line was discontinued by 1980, it was continued by the Grand Seiko quartz watches of the late 1980s!
Seiko was founded as a watch store in 1881 by Kintaro Hattori in Tokyo. By the 1890s it was producing both clocks and pocket watches as Seikosha. And in 1913 Seiko produced Japan's first wristwatch, the Seiko Laurel. Seiko had beat out several other Japanese companies, including other Tokyo clock companies like Tokyo Clock Co. and Japan Pocket Watch Manufacturing Co. By the mid-20th century Seiko produced some of its most important wristwatches that set the stage for its future. In the early 1950s Seiko produced the Seiko Super which then became the Marvel. And in 1960 Seiko released the first Grand Seiko. This marked the beginning of not only the Grand Seiko but also the King Seiko and Lord Matic lines to follow.
Then, in 1969, Seiko released the Astron, the watch that would upend the Swiss watchmaking industry. Throughout the 1970s and 1980s Seiko continues to produce extraordinary quartz watches, along with many legendary vintage Seiko dive watches. In modern times Seiko continues to innovate, especially through its Grand Seiko brand.