High Accuracy Quartz watches Archives - Page 7 of 7

Citizen’s first TC movement, the caliber 1930

original title: Exceed ENH-205 with caliber 1930
Vintage find with Citizen’s first thermocompensated movement, the cal. 1930. (But not necessarily the inaugural watch model of 1981.)

There is also a darker dial ENH-200. Catalog page shared by @Citizen _collector
[ATTACH type=”full”…

Citizen’s first TC movement, the caliber 1930

High Accuracy Quartz watches

Thermocompensation: Methods and Movements

In Pursuit of Perfection : Thermocompensated Quartz Watches and Their Movements

[NOTE: hedrick has rescued this from the Google cache. He is not the author. The original version was posted by Bruce Reding.]

The purpose of a watch is to correctly mark…

High Accuracy Quartz watches

Junghans AT-cut 4 Mhz movement(s) (and some of what came before)

The Junghans 667.26 is a 4 Mhz caliber that has been discussed here before:
1. When found in Doensen’s book published 2006
2. A dedicated thread in 2014 by @sekunde
3. A…

Junghans AT-cut 4 Mhz movement(s) (and some of what came before)

High Accuracy Quartz watches

Enjoying my Longines V.H.P 36mm L3.316.4

Recently purchased new off of eBay. Some great deals there at the moment.

Now looking into my next HAQ. Citizen or vintage Omega

I’d love to find a NOS Omega Constellation 1252.30.00.

High Accuracy Quartz watches

Glad to join here and share my The CITIZEN AQ4091-56M.

I’m from China. It was difficult for me to join this forum. Because we can’t visit Google.com and thus I can’t pass the reCAPTCHA verification.
Recently, I’ve been choosing a HAQ watch.Because I’m tired of the errors of mechanical watches.
I’ve learned a lot of knowledge about HAQ from this forum, such as the principles of the movement, the mechanism of thermal compensation, etc. I’ve also seen many sharing posts from friends.
In return, I will also share my watch to everyone.

I bought…

Glad to join here and share my The CITIZEN AQ4091-56M.

High Accuracy Quartz watches News from the Watch Industry rk watch service

Seiko HAQ wristwatch with a cesium atomic oscillator (chip-scale atomic clock)

As I discussed in below quote, Seiko has patented a new HAQ method with dual oscillators (likely based on an older Citizen method for which the patent has expired).

CitizenPromaster said:
———— NEW SEIKO PATENT WARNING ————–

What is also jumping out at me this time, is that JPS57116287A recently got cited by none other than Seiko Epson.

View attachment 18861739

The Japanse characters don’t give anything away to us…

Seiko HAQ wristwatch with a cesium atomic oscillator (chip-scale atomic clock)

High Accuracy Quartz watches News from the Watch Industry rk watch service

What HAQ watch are you sporting today?

My 1st and only at the moment. I am loving this thing.

High Accuracy Quartz watches News from the Watch Industry rk watch service

Citizen frequency correction patents

This thread is a discussion of three Citizen patents highlighted by @CitizenPromaster in the pinned TC thread.

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…

Citizen frequency correction patents

High Accuracy Quartz watches

Citizen cal. 1730

This thread is to collect and organize all information on the Citizen ‘4 Mega’ cal. 1730 launched in 1981, as existing information is scattered such as in the TC thread.

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.

[ATTACH type=”full”…

Citizen cal. 1730

High Accuracy Quartz watches

Table of Contents