New colorway for the SSNAV-D pilot watch with the ETA F06.412 PreciDrive movement
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Continue readingSeiko’s technology for battery-powered clocks with sweeping seconds
From a survey of the literature, Seiko has used two methods:
Continue reading1. In 1996, Seiko published one method involving a spring and a viscous damper:
“we adopted a method in which a third wheel, whose gear and pinion are elastically connected by a coil spring, and a fourth wheel, whose rotational load is applied by the viscous resistance of grease, are installed in the gear train”
The spring…
Seiko’s technology for battery-powered clocks with sweeping seconds
Analog Thermocompensation
Prior to the 1978 appearance of Seiko Twin Quartz, the methods used to achieve high accuracy under varying temperatures were limited thermoinsensitivity via megahertz frequency AT-cut oscillators, and analog thermocompensation (analog TC) via some sort…
Continue readingCatalog of Citizen A660 A010 A060 0100 HAQ models
This is a running catalog of all known watches with Citizen’s caliber 0350, A660, A010, A060 and 0100 high accuracy quartz movements. It is provided in PDF form for offline viewing. The intended audience are those interesting in acquiring one of these watches.
Continue readingPlease jump to post #60 for latest version 2.0 (Mar 2025).
Original text
I have scoured the web for days to build the following list in the Citizen forum. If I have…
Spring Drive caliber 9RB2
New movement, smallest automatic SD ever, with energy density midway between the venerable 9R65 and the mighty 120 hour 9RA2.
Specs per Fratello:
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Continue readingPatek Philippe Cubitus
Said to be print ad in Fortune
Very interested in the details of the new movement.
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Continue readingSpring Drive watches with nicknames
The Grand Seiko Database (GSDB) maintained by @Plus 9Time is great for many projects. I decided to have fun collecting all the modern Grand Seiko models with nicknames.
Spring Drive 3-hand automatics
Using the GSDB search feature, here are the…
Spr…
Continue readingThe specially adjusted 9F models
@BrianBinFL and I have assembled the following list of the 9F watches, which halve the usual 10 seconds a year tolerance to just 5 seconds a year through special adjustment at the factory. Most feature a ‘gold star’ on the dial, but not all.
Continue readingFrom newest to oldest they are:
1. SBGP017 in 2022, the ‘Shinshu Sea of Clouds’ for the 55th anniversary of the 44GS case; with 9F85 and display back
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