In 1966 Citizen launched its first ‘electric’ watch – Japan’s first electronic watch in fact – which incorporated what was then new technology to replace the traditional mainspring to drive the movement. Although such a hybrid approach had been introduced years before, Citizen claims this to be ‘the world’s first genuine electronic wristwatch that has adopted a moving-magnet type balance motor, driven by transistor on the regulating device’. (See this thread for some discussion about this claim: http://www.thewatchforum.co.uk/index.php?showtopic=80316)
And this is what Citizen say are the benefits of this technology in their technical guide:
The X8 / Cosmotron production run was short, about 10 years in all, since the early 1970s saw the quartz revolution, and older technology was quickly rendered obsolete. However, there was significant development of the technology during its brief history, including raising the beat rate from a conventional 18,000bph at the start to 43,200bph at the end, in those using a relatively conventional balance. The quality of the X8 movement was indicated by its achievement of chronometer standards. This reflects the aims of the electronic technology to increase both reliability and accuracy, both of which were overtaken by the advantages of quartz modules.
The technical guide states ‘in comparison to conventional wristwatches, the construction is simplified by far, and the power conduct is applied in reversed direction’ and also that ‘this eliminates troubles originating from worn or damaged parts which occurred due to excessive driving power’. So we can see that this technology offered advantages over traditional mechanical movements. It would have been interesting to see where it might have got to had quartz not arrived on the scene….
Before looking at the different movements and models, please note that all movements have fine adjusters on the balance and all of them ‘hack’, i.e. the watch is stopped when the crown is pulled fully out to the time setting position – this is achieved by the battery power being disconnected so would also be used when the watch is not in use (battery removal is recommended if stored for an extended period).
The First Model, 0801/2:
The very first version of the X8 was named the ‘Electric Watch’ and used the initial 0801 movement with 25 jewels – so many jewels were no doubt technically unnecessary, as can be seen with the later movements in the line, but these were high grade watches with a high price to match, so the jewel count was important to reflect its status. The movement ran at 18,000bph and to reflect its difference from conventional watches, the first X8 was given a unique look:
(Above Image by ‘Martback’)
In 1969 the X8 Electric name was replaced by the X8 Chrono Master, using the second iteration of the original movement, the 0802 – and included a ‘Chronometer’ grade version (although not marked ‘officially certified’). ‘Electronic’ was also added to the dial:
The case back is also unique to this model, with an old style case number (ELCS 51201-Y) and a special tool was made to remove it:
The X8 Chrono Master remained in production at least until 1971, but I guess not for much longer than that (it doesn’t appear in the 1973 catalog) and by that time other movements and models had been developed and launched. In the 1971 catalog these early models are shown on the ‘X8 Chronometer’ page, note the one on the left is marked ‘chronometer’ above the X8 logo:
The 0801/2 movement, powered by 1.55v silver oxide batteries, had a tiny rheostat to regulate the balance amplitude which was not needed in the later movements.
Here is an example of marketing for this model:
The 0840 / 0880:
This was the second generation of the movement, running at either 21,600bph (0840) or 18,000bph (0880), and with 12 jewels. It was launched in 1969, and powered the first models to carry the name ‘Cosmotron’ it also had ‘transistorized’ on the dial together with a new applied Cosmotron logo. They retained ‘X8’ on dial, but this was dropped later in the development of the line. The number of models was beginning to expand significantly, with more conventional cases than the first type, along with the later case number type, on this one it’s 4-810139 Y:
Again powered by a 1.55v silver oxide battery, the movement has 12 jewels:
This diagram points out the differences between the first and second generation movements:
The 0820 – Officially Certified Chronometer
This movement, produced in 1970, was officially certified as meeting the JCA (Japan Chronometer Association) standards and as fas as I know was only used in two models. It has 19 jewels, runs at 21,600bph powered by a 1.55v battery and the movement is uniquely numbered. The first model has an unusual case design, and of course carries the ‘officially certified’ logo:
The second model is particularly interesting, in that it was the world’s first titanium cased watch. I understand that only 2000 models were made in 1970 – note that the case back is marked ‘scratch proof. Citizen say that the case was 99.6% titanium:
(with credit to the Yahoo Japan seller)
With 12 jewels I believe this is the same as the 0840, but for the first time has a date complication and was launched in 1970. Here are some examples from 1971, note the bracelet / strap types and case numbers for the different movements:
Still powered by 1.55v silver oxide batteries, and alongside the 0840 versions, there is now a significant range of models in the line up, and more colourful designs were emerging at the start of the 1970s. First some more 4840s:
And some 0840s:
This scan of marketing material shows examples across the range, and includes a pocket watch version:
Inside the 08 Movement: the architecture of the 08 and 78 movements are different, so they are shown as quite separate lines in the technical manuals. Here are exploded views of the 08 design, which can be compared with the 78 shown further down the page:
The 78xx Series:
1972 saw the launch of new models with both date and day complications, now using the 78 movement. With jewelling reduced to 8, and now powered by 1.3v silver oxide batteries, the movement design has been refined, with more functions. The rate has now increased to 36,000bph, and movements were designated 7801A, 7802A, 7803A, 7804A and 7806A. The X8 name has now been dropped, so dials are marked Cosmotron, Electronic and carry the Cosmotron applied logo.
All these 78 movements have an unusual method for quickly setting the date and day, which I believe no other manufacturer has used. The crown is pushed in to do this when the crown is in the normal running position – to set the date this action is carried out with the watch held vertically, 12 o’clock high. To set the day, the watch is held the other way up, i.e. vertically with 6 o’clock high – with thanks to Noah (SCWF) here are photos which show the lever – sternly marked ‘DON’T OIL’ – which enables the dual function. The day wheel is removed to show the lever. Setting the date – watch is 12 o’clock high (crown on right side of watch):
And now inverted – 6 o’clock high – to change the day, note the tip of the lever is no longer engaged with the date wheel:
The 7803 is perhaps the most interesting of the 78 models, sometimes found in a monocoque case (i.e. single piece, opened via removal of the crystal) with a different case number style – 7800-870xxx. Known as the Cosmotron Special the 7803 models is clearly identifiable by the button it has at the 8 o’clock position:
On this monocoque case (from July 1973) the back has a battery hatch, and a hole covered by a screw down cap (removed in this pic) which gives access to the fine adjuster on the balance:
The ‘special’ nature of this is the action applied by using the button at the 8 o’clock position. This not only zeros the second hand (to 12 o’clock) but also zeros the minute hand when it is within + or – 3 minutes of 12 o’clock. Currently I’m not aware of any other manufacturer that has employed this feature, which I believe is to allow exact synchronisation of the watch. Also, when the button is held in, the second hand is kept at 12 o’clock until the button is released. If the button is pressed and released the hand is zero’d and immediately restarts, as is found in a ‘fly-back‘ chronograph. Citizen also notes that the Cosmotron Special is capable of chronometer grade accuracy.
Here’s a video of the button in action:
Here is an example of the 78 movement, this one is a 7806A:
And the dial side of this 7806A model:
Inside the 78 movement: here are exploded views of the 78 movement, which can be compared with the 08 shown above:
The IC-12 / 5800
In 1970 Citizen launched the IC-12 – meaning Integrated Circuit – 12 beats per second. This was their fastest beating electro-mechanical watch, with an hourly rate of 43,200. Although initially not badged ‘X8’ or ‘Cosmotron’ they later used the movement – designated the 5800 – in Cosmotron models.
The movement is small and was used in both men and women’s watches, it uses a 1.55v battery. Here’s a catalog image of the men’s model which is an ‘Officially Certified Chronometer’– note the price! (although it is a 14k white gold model):
This marketing image shows it alongside a woman’s model:
And here’s the 17 jewel movement, an impressive piece of small scale engineering:
By the mid-1970s the movement was being used in Cosmotron models:
The small movement looks rather lost in what is only a medium sized men’s model:
The final model in the Cosmotron line-up is something of an anomaly, in that it uses a completely different type of movement. It remains a very interesting piece however, since it is a single coil tuning fork watch. Although Citizen made twin coil movements licensed by Bulova as used in the Hisonic, it appears that the GX movement, designated 3701B, was its own design and uses a 1.55v battery. For example the coil is placed on the opposite side to Bulova’s version, and the 11 jewel movement is not stamped as ‘Lic. Bulova’ as is the case with the Hisonic. And, again as in the Hisonic, the battery is positioned with the +ve side away from you as you look at it, unlike all the other Cosmotrons:
The tuning fork movement runs at 360hz – 360 beats per second – which of course gives a very smooth sweep of the second hand, of the sort you might see on a modern day Seiko Spring Drive. Here are two examples, the second of which has an unusual dial colour and finish:
An example of the case back, this one has been engraved:
It’s not clear why Citizen included this model in the Cosmotron line – I can only speculate that it was to preserve the exclusivity of the Hisonic models.
Finally a few scans of marketing material from 1969/1971:
Footnote: I think I’ve covered all the movements and given examples of the related models, but I’m always learning about vintage Citizens so please get in touch if you have information I can add, or which would amend / correct / improve what I have published so far.