Citizen Cosmotron 7802 – Electronic – Original bracelet (August 1973)

Technically sophisticated and visually striking Citizen Cosmotron Electronic with caliber 7802 , manufactured in Japan in 1973 .
This watch represents the transition between mechanical and quartz movements – an early hybrid concept that impressively demonstrates Citizen's innovative power in the 1970s.

Historical background

The Citizen Cosmotron was the first Japanese fully electronic watch with a classic balance wheel movement, powered by a battery, in 1966.
The model shown here , Ref. 4-870387 Y / Cal. 7802, belongs to the later generation of this line and combines an electronically controlled manual/automatic winding system with traditional mechanics.
The Cosmotron series was advertised in the Japanese market as a high-tech watch of the future – durable, shockproof and precise.
The original catalog shown (price ¥ 22,000) documents the company's positioning at that time in the upper middle segment.

Technical features

• Model: Citizen Electronic Cosmotron
• Reference: 4-870387 Y
• Caliber: 7802 (electromechanical, transistor control)
• Origin: Japan, August 1973
• Housing: Stainless steel, brushed/polished
• Dimensions: 39 × 42 mm
• Lug-to-lug: 42 mm
• Height: 12.1 mm
• Lug width: 18 mm
• Weight: 95 g (including original strap)
• Dial: two-tone “Smoky Gradient Dial” (anthracite-gold), applied gold indices
• Hands: gold-colored, rectangular with black central axis
• Display: Day of the week and date (bilingual, English/Japanese)
• Battery: new cell installed in October 2025
• Glass: Mineral with scratches
• Waterproof rating: “Water Resistant” (originally, now without guarantee)
• Condition: authentic vintage condition, unpolished, functional

bracelet

Original Citizen stainless steel bracelet with folded link structure and classic Citizen folding clasp with embossed Cosmotron logo.
The bracelet is fully functional and suitable for wrist circumferences up to approximately 18 cm.
It emphasizes the distinctive, angular case shape and the futuristic style of the 1970s.

Description

The Cosmotron 7802 is a key watch in the history of Japanese electronic watches.
It combines mechanical watchmaking architecture with electronic control – a concept that Citizen pioneered.
The distinctive gradient dial and the solid case shape reflect the design philosophy of the early 1970s: technical, confident, modern.
Collector's value and significance

The models with caliber 7802 are considered the most sophisticated generation of the Cosmotron series and are valued by collectors for their hybrid technology and robust construction.
Examples with original straps and documented catalog entries like this one are particularly sought after.
They document a crucial chapter in Japanese watchmaking technology – the transition from mechanics to electronics.

Warranty (used)

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

Notice

Since this is a used watch, water resistance cannot be guaranteed.
To protect the clock mechanism, the clock should not come into contact with water or moisture.