Citizen Cosmotron Electronic 4-790138 Y from November 1974 with blue sunburst dial and original bracelet

This Citizen Cosmotron Electronic from November 1974 is a technically and aesthetically outstanding example of Japanese watchmaking from the early 1970s. Particularly noteworthy is the rare combination of the striking case design, the intense blue sunburst dial, and the original Citizen steel bracelet with a signed clasp – a configuration that is increasingly difficult to find today.

The Cosmotron series represents a highly exciting transitional phase in watch history: electronic watches with a classic balance wheel, but already transistor-controlled. Citizen was one of the pioneers in this field, developing the Cosmotron as an independent technical solution between mechanical watches and the later dominant quartz movements.

Inside, the Citizen Caliber 7804, an electronic movement from the advanced Cosmotron generation, is at work. It is characterized by a high frequency of 36,000 semi-oscillations per hour and a typically smooth second hand for this type of construction. Power is supplied by a battery, but without quartz regulation – a technical concept that has become rare today. Particularly characteristic is the intelligent quick-set feature: depending on the watch's orientation, either the date or the weekday can be adjusted via the crown – an unusually well-thought-out solution for its time.

Aesthetically, this model impresses with a strong presence on the wrist. The angular stainless steel case reflects the clear design language of the 1970s, while the dial shimmers from cool blue to deep petrol depending on the light. The applied indices, the framed day-date window, and the Cosmotron logo give the watch a high-quality, almost futuristic appearance.

The present catalog excerpt shows this model under the designation 0723-77 with a selling price at the time of ¥18,000, which underlines its positioning in the upscale segment of Citizen's collection at the time.

Condition

The watch is in very good used condition. The dial is particularly well preserved and shows an attractive color effect. The case shows age-appropriate, overall moderate signs of wear, but retains its clear geometry. The original Citizen steel bracelet is a significant added value and perfectly matches the watch.

Technical Data

Brand: Citizen
Model: Cosmotron Electronic
Reference: 4-790138 Y
Year of Manufacture: November 1974
Caliber: Citizen 7804
Movement: electronic movement with balance wheel and transistor control
Functions: hour, minute, central second, Day-Date
Case Material: Stainless Steel
Bracelet: original Citizen steel bracelet
Weight including bracelet: 81 g
Case Diameter: approx. 38.2 mm without crown
Lug-to-Lug: approx. 41.4 mm
Height: approx. 12.3 mm
Lug Width: 18 mm

Classification for Collectors

The Cosmotron models are among the most technically interesting Citizen watches ever. They mark an independent stage of development that is gaining increasing attention today. Particularly well-preserved examples with original bracelets and attractive dials – like this one – have gained significant collector interest in recent years. The combination of technical history, design, and originality makes this model a convincing piece for any discerning collection of Japanese vintage watches.

Warranty (used)
This is a used item. The limitation period for claims for defects (statutory warranty) is 12 months from delivery.

Note
As this is a used watch, no water resistance can be guaranteed. To protect the movement, the watch should not come into contact with water or moisture.