Citizen Cosmotron Electronic 7803-790553 – Burgundy Dial – April 1975 - freshly serviced

An electronic watch from the brief, technically fascinating phase between the mechanical watch and quartz – and one of the most beautiful dial colors Citizen produced during this era.

The case back is stamped with CITIZEN ELECTRONIC, WATER RESISTANT, STAINLESS STEEL, the model number 7803-790553 TA, the serial number 50401514, and the designation GN-4W-S. The dial bears the signatures CITIZEN ELECTRONIC and COSMOTRON.

Cosmotron – the electronic intermediate stage

Between 1960 and the quartz revolution, the watch industry worldwide sought a way to drive the balance wheel electrically rather than via a mainspring. Citizen’s answer to this challenge was the Cosmotron: a battery-powered movement in which the balance wheel is nudged electromagnetically by a coil. Thus, it still features an oscillating balance wheel and a gear train – only the energy source is different.

For collectors, this very construction is interesting because it documents a technical dead end that was only open for a few years: no sooner had the electromagnetic balance wheel been perfected than the quartz oscillator rendered it obsolete. Cosmotron models were therefore built in manageable numbers and are specifically sought after by collectors of Japanese electronic watches.

The watch features a day and date display with a Japanese day-of-the-week disc, as well as a pusher on the left side of the case for adjusting the calendar.

NOTE:

1. The day of the week does not change with the date.
   
2. Quick-set date by pressing the crown at 3 o'clock
3. Pusher at 8 o'clock sets the second hand to 12. But does not set the date!

Design

The dial is the real reason to buy this watch. It transitions from a deep, almost black edge to a warm wine red in the center – a color gradient executed with this level of saturation only by Japanese manufacturers in the 1970s. Depending on the incidence of light, the bright core moves across the dial and significantly changes the character of the watch. This effect is enhanced by the 9-faceted crystal, which is in excellent condition.

On it sit broad, multi-faceted applied indices that refract light with sharp edges, as well as bold hands with polished surfaces. At 3 o'clock is the framed double window for the day and date, with the day appearing in Japanese characters – a feature of the Japanese domestic market.

The stainless steel case features brushed sides and a polished bezel, measuring 37.2 millimeters without the crown. The watch comes on a new black leather strap by the brand Just Cavalli.

Dating

The serial number 50401514 suggests manufacture in April 1975, according to the standard Citizen system. This corresponds to the known production period of the Cosmotron series.

Condition and Servicing

The watch was serviced in Japan before sale.

The dial is remarkably well preserved: the color gradient is uniform and unbleached; there are no spots, peeling, or traces of moisture. All applied indices are secure, the hands are complete and undamaged, and the day and date sit cleanly in the window.

The 9-faceted crystal is very well preserved. The case shows light signs of polishing and wear on the bezel and sides, as well as a few fine scratches on the lugs. The back is lightly scratched; all stampings, including the serial number, are fully legible. The calendar pusher and crown operate cleanly.

The actual condition is shown unretouched in the product photos.

Technical Data

• Brand: Citizen
• Model: Cosmotron Electronic
• Model number: 7803-790553 TA (GN-4W-S)
• Serial number: 50401514
• Movement: electromagnetically driven balance wheel, battery-powered
• Functions: hour, minute, central second, day of the week (Japanese characters), date, calendar pusher
• Case: stainless steel
• Diameter without crown: 37.2 mm
• Height: 13.1 mm
• Lug-to-lug: 41.6 mm
• Lug width: 18 mm
• Weight incl. strap: 58 g
• Dial: wine red with color gradient, faceted applied indices
• Strap: new black leather strap by the brand Just Cavalli (not original)
• Dating: April 1975
• Origin: Japan
• Servicing: serviced in Japan before sale

For whom?

For collectors of Japanese electronic watches who want to document the phase before the quartz revolution. For lovers of 1970s colored dials. And for buyers who want to wear a watch on their wrist with a technology that existed for only a few years.

Warranty (used)

This is a used item. The limitation period for claims for defects under the statutory warranty is 12 months from delivery.

Note on water resistance

The original Water Resistant marking refers to the watch's condition when new. Due to its age, no current water resistance is guaranteed. To protect the movement, the watch should not come into contact with water or moisture.