RADO DiaStar 539.0377.3 - Swiss Hybrid Chronograph!
The perfect combination of sapphire crystal clarity, tungsten case durability, and 23-jewel Swiss engineering.
Produced by RADO in the late 1980s, this "DiaStar" hybrid chronograph reflects the brand's technological vision with its both analog and digital displays.
This model combines Rado's legendary scratchproof tungsten-carbide case with a high-quality 23-jewel Swiss quartz chronograph movement.
A timeless engineering achievement and a rare, collectible hybrid chronograph.
Production and Technical Specifications
Brand/Model: RADO DiaStar 539.0377.3
Origin: Switzerland
Year of Manufacture: 1987 (Rado internal serial and caliber code 257.784 → ETA 251.264 variant, production 1987 Q4)
Caliber: ESA / ETA 257.784 (23 Jewel Quartz Chronograph)
Movement Type: Hybrid - Analog & Digital Chronograph
Number of Jewels: 23 Jewels
Battery Type: 395 / SR927SW – Approximately 3-year battery life
Accuracy: ±10 sec / month
Functions:
Chronograph (1/100-second measurement)
Digital time display (dual time)
Alarm function
Calendar (day/date on digital display)
12/24-hour format
Case and Crystal
Case Diameter: 41 mm (excluding crown)
Thickness: 10 mm
Case Material: Tungsten-carbide (scratch-resistant, Rado special alloy)
Case Back: Screw-down, stainless steel – with reference engravings (539.0377.3 / 02388020)
Glass: Sapphire crystal – high light transmission, anti-glare coating
Water Resistance: Water-Sealed – superior insulation standard for the time
Dial and Design
The cobalt-blue dial creates an elegant contrast with the gold-toned indices and red chrono-second hand.
The dual digital displays reflect the "Space Age" design language of the time, while the central analog dials maintain the classic Rado line.
Details:
Gold-tone baton indices and hands
Two digital windows (symmetrically placed at the 6 and 12 o'clock positions)
Slim red chronograph seconds hand
Embossed "RADO Diastar" text
Strap and Buckle
Strap: Original RADO leather strap (blue-toned, with integrated lugs)
Buckle: Steel-gold-plated deployant buckle with original RADO logo
Strap Condition: Excellent - stitching and form integrity preserved
Condition Report
Case: Flawless - no scratches or tarnishing on tungsten surface
Glass: Sapphire - flawless, optically clear
Dial: Original, no oxidation or discoloration
Movement: ETA 257.784 - in perfect working order
Strap/Buckle: Original, with light traces of use
Collectible Value and Historical Background
This RADO DiaStar 539.0377.3 is a RADO DiaStar 539.0377.3, a model of the brand It was one of the last pure "metal hybrid" chronograph series before the transition to the "ceramic & tungsten" era.
In the late 1980s, RADO not only proved its "scratch-proof case" claim with this model but also represented the advanced engineering vision of the era with its analog-digital integration.
The 23-jewel quartz chronograph movement is crafted to a much higher level than conventional quartz movements, as the 23-jewel structure is specifically designed to ensure the mechanical dial gears work in harmony with the quartz system.
Therefore, the DiaStar Chronograph with caliber 257.784 is one of the concrete embodiments of the term "Swiss Quartz Engineering."
Engravings and Codes
Case Back: RADO DIASTAR SWISS / 539.0377.3 / WATERSEALED / SCRATCHPROOF
Movement: ETA 257.784 - “23 JEWELS TWENTY-THREE”
Serial Number: 02388020
Final Word
Combining the hardness of a tungsten case with the clarity of sapphire crystal, this RADO DiaStar is one of the most advanced hybrid watches of its time, both technically and aesthetically.
This timeless design is why it remains a rock solid timepiece.
“RADO DiaStar - the Swiss miracle that even time hasn’t scratched.”
The item you are viewing was manufactured in 1987.
Professionally overhauled and FULLY SERVICED (the movement is completely disassembled, its components cleaned, oiled, and adjusted), your watch will function flawlessly without any surprises. (Maintenance-free for 3 years unless exposed to direct water or high humidity for extended periods.)
Product Condition: Tested, fully functional, and in working order.
