Citizen Cosmotron Special

This is the Citizen Cosmotron Special. It's an electro-mechanical watch from the 70's. It has a special movement that is battery powered, but regulated by a balance wheel instead of a quartz crystal. While Seiko went on to develop the quartz movement around the same time, Citizen was dishing out these unique watches that, as far as I can tell, no other watch manufacturer made.

Citizen Cosmotron Special. Circa 1972

At first glance, it looks like your typical automatic watch. Steel case, thick crystal, unassuming dial and hands combination, day and date complication. Even the ticking of the second hand is the same as an automatic - sweeping second hand instead of the 1-tick per second of quartz watches.

The particular example in the image above is quite old. It's all beat up. Crystal is all scratched. Original bracelet is gone. The watch is on an aftermarket nylon strap.

Back of the Cosmotron Special. There are 2 screws at the back. Under the larger one is the battery compartment. Behind the smaller one is the balance wheel adjustment screw.

This watch has a monocoque case. The case is one piece and cannot be opened from the back. I suspect the movement can be accessed via removal of the crystal and that is something I don't want to attempt yet given that I haven't found anyone online who has done it.

Judging from the serial number, it may have been made in November of 1972 and it may be the 5,475th watch in the batch.

Movement

The movement in this watch is the 7803. It's one of the many variants used in Cosmotrons. This one features a high beat at 36,000bph. and it has a button at the 8 o'clock position that resets the second hand back to zero.

The second hand reset button.

Unsigned crown at the 3 o'clock position.

Crown

The crown also has a special function. Pull the crown and that is the time setting position. However, when you press on the crown when it is set to its original position, you can set the date or day depending in the position of the watch.

To set the date, hold the watch vertically with the 6 o'clock position down. Press the crown and the date will move forward.

Hold vertically, right side up, press the crown (at 3 o'clock) to set the date.

To set the day, hold the watch vertically with the 12 o'clock position down. Press the crown and the day will move forward.

Hold vertically, up side down, press the crown (at 3 o'clock) to set the day.

 The quick set day and date functions are unique and very useful in setting the day and date without changing the time.

Caseback

There are different casebacks for the Cosmotron. So far, I have seen the monocoque case which essentially has no caseback. There are Cosmotrons with the regular solid caseback. There is however another type. It is a 2-piece caseback which can be seen in the photo below.

Caseback is a solid round plate held in place by a separate screw down ring.

In the above photo, the caseback text remains aligned horizontaly since the caseback plate doesn't rotate when the screw down ring is tightened or loosened.

Monocoque Caseback.

 

Common screw-down caseback.

Case, Crystal, Dial

The Cosmotron line came in different case, crystal, and dial shapes and styles.

Rounded square blue dial. Squared flat crystal. Square case.

Another Cosmotron with a monocoque case, but with a thick, faceted crystal.

Watch crystal viewed from the side. It has 5 facets on the top of the crystal.

Angular case with flat crystal.

 

Octagonal shaped case. Domed crystal. Sectioned gradient green dial.

Some examples that can be seen online have irridescent dials and funky designs and colors and I hope to get my hands on one of the more funky ones someday.

Dials have applied markers, applied brand and logo,

Battery

I did mention that the Cosmotron is battery powered. The examples I have shown so far all use the LR44 size battery. There is one minor issue though in regard to availability of the batteries. While LR44 size batteries are still plentiful and easy to obtain, they all have a rating of 1.55V. The Cosmotron with 7803 movement, on the other hand, was designed to use batteries rated at 1.3V. Unfortunately, 1.3V button cells are no longer made. Modern button cells rated at 1.55V will work, but the watch will operate slightly faster that usual. It is possible to regulate the watch, but I think the life of the watch might be shortened with prolonged use of 1.55V batteries. This remains to be seen though as there is not much info on the long term effects of higher voltages to the internal circuitry of the Cosmotron.

 

There is a solution and that is to purchase a battery voltage converter. It has the exact size of the LR44, but uses SR41W batteries which are slightly smaller. The converter/adapter functions as a jacket with a built in voltage regulator that drops the output from 1.55V to 1.35V. Unfortunately, they are quite expensive in comparison to one LR44 Battery and were primarily designed for use in vintage cameras. You can find the converter in the link --> Look for MR44(H-C) Battery Adapter.

Bracelet

The Cosmotron 7803 always came with a stainless steel bracelet with solid links. Almost all examples of cosmotrons I have seen, whether in person or on the internet, always featured as solid link bracelet. Something that is no longer common place today where most affordable watches have bracelets with folded links.

While the clasps and some end links are pressed and folded steel they feature the Citizen branding and the Cosmotron logo.

So far, all my Cosmotrons feature 18mm lug width and aftermarket bracelets and straps can easily be had to replace watches with defective or missing bracelets.

A lot of the times when buying Cosmotrons online, they have aftermarket bracelets or bracelets that came from other Cosmotron models. At this point in time there is no way to know if the bracelet is the original that came with the watch. Personally, I don't mind as long as it is a Cosmotron bracelet. Replacement, original Cosmotron bracelets will be hard to find though. I doubt there are any new ones being made by Citizen today.

Cosmotron clasp with Citizen brand and Cosmotron Logo. This one has a clasp extension (aftermarket) to fit larger wrists.

In a time where mechanical and automatic watches are favored by enthusiasts and battery powered watches are seen as cheap and inferior, the Citizen Cosmotron will remain a hidden gem for those who know about it and its unique quirks and functions. I surmize some languish in old forgotten places waiting to be rediscovered and hopefully get the recognition that these unique, battery powered, non-quartz, mechanical watches deserve.

Enjoy!