Citizen Crystron: 88XX and 86XX series

Online there is a scarcity of information about vintage Citizen's quartz watches, so for this reason I decided to write this post to put together some pieces of the very broad Citizen quartz production. Initially, I'm going to talk about the very interesting story of the first quartz made by Citizen, and then I'm going to illustrate all the different movements and models of the watch in my possession.

First generation, the electromechanical quartzes

88XX series (8810 (E.F.A), 8811 (day/date) e 8821 (day)

In September 1973 Citizen launched its first family of quartz watches, the 88XX, constituted by the 8810, 8811 and 8821 movements. The first of the list was fitted in the extremely rare Citizen E.F.A  (extra fine accuracy) starting from October 1973, and it is featured by an higher precision than the other two movements (+/- 5 sec/month compared to +/- 10 sec/month). 

It is worth noticing the price difference between the EFA model (the first to the left) and the other models.

These movements operate quite differently from traditional quartz watches, as they still strongly derive from electromechanical watches. In a few words, the balance wheel's oscillation frequency (at a whopping 16Hz) is regulated electromagnetically by two coils connected to a quartz crystal, which oscillate constantly at 16kHz.

The production of these so-called "quartz-controlled balance wheel movements" lasted about 6 months, and was later replaced by the traditional "step-motor quartzes" with the release of the 8600 movement in October 1974.

Step-motor quartz watches

8600 series (8600A (day/date), 8600E (EFA), 8610A (date)

Also called "blinker" because of the LED dot at 12 o'clock that blink every minute, all the watches fitting this movement have a button at 8 o'clock that, when pressed, stops the watch for the number of seconds indicated by the second hand when the button is pressed. This allows synchronization of the time with an external source, such as a radio. In this case, the quartz crystal vibrates at 36kHz and the precision is +/- 15 sec/month.

The sign "Crystron" appeared on all Citizen quartz watches only from October 1974 onwards.

8650 series  (8650A, 8650B)

In April 1975, the Crystron Mega was released. The very high quartz's oscillation frequency (4MHz) makes the crystal less supcettible to temperature variations, thereby allowing it to reach the incredible precision of +/- 3 sec/year in the 8650A version and +/- 10 sec/year in the 8650B version. This is at the expense of the battery, whose reserve charge is only 1 year. The 8650A was housed only in gold cases (from 1000 to 3000 were produced) at the price of 4.500.000 yen, whereas the 8650B was housed in stainless steel cases.

Citizen 8629A

In 1974, Citizen developed the first prototype of the Crystron Solar, but the cadmium battery used to power the watch was too expensive to be mass-produced, so the commercialization of the first solar-powered watch was postponed until September 1976.

This watch was registered as a Future Technology Heritage, an important material for the history of science and technology in 2019, selected by the National Museum of Nature and Science.

Regarding the production period of these movements, there aren't official dates. However, from my research, all 8600 variants and the 8620 movement went out of production at the end of 1976 (September is the latest caseback I have found), whereas the 8629 ceased production at the beginning of 1977 (January is the latest caseback I have found). As for the high-frequency 8650 movement, due to the scarcity of specimens on the internet, it is trickier to exactly identify the production end. Despite that, commercialization probably ceased in 1979, since another high-frequency movement, the 7370, was introduced in that year.

Now let's talk about my watch. It was made in August 1975, during the early period of Citizen's step-motor quartz watches, when they were still very expansive (43.000 yen for this watch).

It is fitted with the 8620A movement, featuring a regulation trimmer (an innovation for the time) and day/date mechanism. It still works very well, with a precision far below the +/- 15 sec/month range.

The shape of the case is a blend between round and rectangular, which is what I like the most about this watch. It is frontally satinated and polished on the sides. The crown is marked with the CQ (Citizen quartz) logo.

Another beautiful detail is the arrow-like shape of the second hand. 

Here there are some vintage adverts