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 that Citizen released 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 code 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 via a coil. Thus, there is still a vibrating balance wheel and a gear train – only the energy source is different.

For collectors, this specific 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 made it obsolete. Consequently, Cosmotron models were built in limited numbers and are specifically sought after by collectors of Japanese electronic watches.

The caliber 7803 belongs to the mature 78 series of the Cosmotron and runs as a Hi-Beat 36,000 with 36,000 semi-oscillations per hour. As a so-called "Cosmotron Special," the watch additionally features a pusher at 8 o’clock: it sets the second hand to 12 and, if the watch is within a few minutes of the top of the hour, it also advances the minute hand. If you hold the pusher down, the second hand stops at 12; upon release, it immediately restarts. This allows the watch to be synchronized to the exact second – a function that hardly any other manufacturer offered.

Important note regarding the day of the week

On this watch, the day of the week does not switch automatically at midnight; the date, however, flips over normally. The day of the week can be adjusted easily at any time via the quick-set function of the crown (see Operation). Apart from this, the watch has been fully overhauled and is functioning perfectly.

Operation

The Cosmotron movements of the 78 series feature an unusual quick-set function: the date and day of the week are both adjusted by pressing the crown in – which indicator moves depends on how you hold the watch.

• Date: Leave the crown in the normal running position, hold the watch vertically with 12 o’clock pointing upward, and press the crown in. Each press advances the date by one day.
• Day of the week: Turn the watch so that 6 o’clock is pointing upward and press the crown in the same way.
• Time: Pull the crown out completely to set the hands. The movement will stop as the battery is disconnected.
• Pusher at 8 o’clock: sets the second hand to 12 (zero-reset).

The quick-set function should not be used while the watch is currently performing the date change around midnight.

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 such saturation only by Japanese manufacturers in the 1970s. Depending on how the light hits it, the bright core moves across the dial, significantly changing the character of the watch. This effect is enhanced by the 9-faceted crystal, which is in excellent condition.

On the dial are broad, multi-faceted applied indices that break the light into 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 of the week appearing in Japanese characters – a feature of the Japanese domestic market.

The stainless steel case features brushed flanks 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, according to the standard Citizen system, that it was manufactured in April 1975. This corresponds to the known production period of the Cosmotron series.

Condition and Overhaul

The watch was overhauled in Japan prior to sale.

The dial is exceptionally well preserved: the color gradient is even and unfaded; there are no spots, no peeling, and no traces of moisture. All applied indices are firmly seated, the hands are complete and undamaged, and the day and date are aligned clearly in the window. The day of the week does not switch automatically and is adjusted manually via the crown (see note above).

The 9-faceted crystal is very well preserved. The case shows light signs of polishing and wear on the bezel and flanks, as well as a few fine scratches on the lugs. The case back is slightly scratched; all stamps, including the serial number, are fully legible. The pusher at 8 o’clock and the crown operate smoothly.

The actual condition is shown unretouched in the product photos.

Technical specifications

• Brand: Citizen
• Model: Cosmotron Electronic (Cosmotron Special)
• Model number: 7803-790553 TA (GN-4W-S)
• Serial number: 50401514
• Caliber: Citizen 7803
• Movement: electromagnetically driven balance wheel, battery-powered, Hi-Beat 36,000 (36,000 A/h)
• Functions: hour, minute, central second, day of the week (Japanese characters), date, quick-set for date and day via crown, second hand zero-reset via pusher at 8 o’clock
• Special feature: day of the week does not switch automatically, set manually via crown
• 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
• Crystal: 9-faceted
• Strap: new black leather strap by Just Cavalli (not original)
• Dating: April 1975
• Origin: Japan
• Overhaul: overhauled in Japan prior to 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 with technology on their wrist that existed in this form for only a few years.

Warranty (used)

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

Note on water resistance

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