The Omega Caliber 1665 is a high-precision quartz movement that reflects Omega's significant development in advanced timekeeping during the 1980s. Built as part of the Omega Megaquartz evolution, this caliber was commonly found in models such as the Omega Seamaster 120 Quartz, and it showcased Omega’s focus on durable, reliable, and low-maintenance quartz mechanisms during a period when quartz technology was revolutionizing the watch industry.
Movement Type: Quartz
Caliber Number: Omega 1665
Base Caliber: ESA 9362
Power Supply: Silver oxide battery (originally 1.55V, such as SR1136SW)
Display: Analog
Functions: Hours, minutes, central seconds, date (quickset)
Jewels: 7
Battery Life: Approximately 2–3 years
Accuracy: ±15 seconds/month (factory standard)
The movement included a trimmer capacitor that allowed fine adjustment for timing regulation. As with many early quartz watches, the 1665 uses a stepper motor that advances the seconds hand in one-second intervals, which became the signature look of quartz timekeeping.
The most recognized watch housing this caliber is the Omega Seamaster 120 Quartz (often nicknamed the “Baby Ploprof” due to its bold design). These models featured:
Stainless steel cases with integrated bracelets
Rotating bezels for dive timing
Screw-down crowns
Prominent lume on indices and hands
Water resistance suitable for recreational diving
This placed the 1665-powered watches within Omega’s professional sports watch category, aimed at users who wanted cutting-edge quartz technology with the ruggedness of a diver’s tool.
Omega built the 1665 to be both robust and serviceable, with shock protection and antimagnetic components. Its date function was implemented via a semi-instantaneous changeover mechanism, which is still considered reliable even after decades of use.
While the design leans toward functional rather than luxurious, the casework and dial layout of 1665-equipped watches reflect the brand’s focus on legibility, practicality, and long-term accuracy.
Quartz movements like the 1665 are low-maintenance, but not service-free. Recommended upkeep includes:
Battery replacement every 2–3 years
Lubrication of gear train pivots every 7–10 years
Checking and adjusting the trimmer capacitor if accuracy drifts
Inspection for corrosion or battery leakage
Replacement parts (such as coils, motors, and date disks) can be difficult to source, as Omega no longer manufactures them. However, some NOS (New Old Stock) components may still be found through vintage parts suppliers.
The Omega Caliber 1665 played a vital role in the brand’s history during the quartz revolution. It combined accuracy, functionality, and rugged design into watches that remain appreciated by collectors today. Though not as mechanically complex as Omega’s automatic or tuning fork calibers, the 1665 represents a reliable and noteworthy chapter in the legacy of quartz horology.
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