seiko_38
Differences
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+ | ====== Seiko 38 ====== | ||
+ | Seiko' | ||
+ | |||
+ | ===== History ===== | ||
+ | [[Seiko]] was quietly racing to develop a [[quartz watch]] movement in the 1960s, and delivered their first [[Seiko 35|Cal. 35]] movement to the [[Neuchatel Observatory]] in late [[1967]], just a few months after the [[CEH]] delivered their [[Beta 21|" | ||
+ | |||
+ | Suwa Seikosha developed Cal. 38 as a full-production midrange to high-end quartz movement, and it incorporates many features that now seem commonplace but were groundbreaking at the time. The quartz crystal oscillated at 16,384 Hz and it used a [[CMOS]] [[integrated circuit]] to reduce battery consumption, | ||
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+ | Early examples of Cal. 3823 use a large 16 KHz quartz tube and unusual "step variable condenser" | ||
+ | |||
+ | Cal. 380x were the lower-end movements but were still accurate to 2 minutes per year. However these movements lacked any adjustment beyond replacement of the condenser block. Cal. 382x included a [[thermocompensation]] circuit and was accurate to 1 minute per year. It could be regulated using a step variable condenser. All basic movements used 7 jewels: Two each on the third wheel, sweep second wheel, and step rotor, and another used on the seconds hand finger. | ||
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+ | All 38x3 movements were branded " | ||
+ | |||
+ | These movements were produced in larger volume but were still quite high-end compared to mass-market quartz watches later in the 1970s. | ||
+ | |||
+ | The **38SQ " | ||
+ | |||
+ | ===== Variants ===== | ||
+ | * 3800/ | ||
+ | * 3800 - 38QT - time-only | ||
+ | * 3802 - 38QTC - date | ||
+ | * 3803 - 38QTW - day/date | ||
+ | * 3819 - 38DQC - "Duo Time" - Central [[GMT]] hand and date (part of the " | ||
+ | * 3820/3823A (1971) - "Seiko VFA" line - Step variable condenser; temperature compensation; | ||
+ | * 3820 - 38SQ - time-only | ||
+ | * 3823 - 38SQW - day/date | ||
+ | * 3862/3863 - "Seiko QR" line - Oscillation regulation condenser or trimmer condenser | ||
+ | * 3862 - 38QRC - date | ||
+ | * 3863 - 38QRW - day/date | ||
+ | * 3870 | ||
+ | * 3882/3883 G.F.A. - "Seiko Superior" | ||
+ | * 3882 | ||
+ | * 3883 | ||
+ | |||
+ | |||
+ | <WRAP ud ud_mov> | ||
+ | |||
+ | **Description: | ||
+ | * [[Quartz]] movement with [[stepper motor]] | ||
+ | |||
+ | **Functions: | ||
+ | * Hours, minutes, central seconds | ||
+ | * Optional [[date]] | ||
+ | |||
+ | **Data:** | ||
+ | * 7 [[jewels]] | ||
+ | * 16,384 Hz | ||
+ | * [[CMOS]] [[integrated circuit]] | ||
+ | * [[Stepper motor]] | ||
+ | * Diameter 25.6 mm | ||
+ | * Height 5.3 mm | ||
+ | |||
+ | **Production period:** | ||
+ | * [[1971]]-[[1976]] | ||
+ | * Predecessor [[Seiko 35|Seiko 35]], [[Seiko 36|Seiko 36]] | ||
+ | * Successor [[Seiko 48|Seiko 48]] | ||
+ | </ | ||
+ | |||
+ | {{tag> | ||
seiko_38.txt · Last modified: 02.12.2022 20:38 by 127.0.0.1