Manufacturer | Seiko Time Corp. |
Caliber Number | 7548, 7548A |
Movement Type | Quartz, battery-powered |
Display | Analog |
Diameter | 27mm |
Height | 4.6mm |
Jewel Count | 5 jewels |
Frequency | 32,768 Hz |
Accuracy Rating | Less than 15 seconds/month (less than 3 minutes/year) |
Battery Cell # | SR43SW (aka 386/301) / silver oxide / 1.55 V |
Battery Life | ~3 years |
Driving System | 2 pole step motor |
Regulator? | Trimmer condenser |
Hand Count | 3 |
Functions | Central hours; central minutes; central seconds; day of the week at 3:00; date at 3:00 |
Hacking Seconds? | Yes |
Quickset Date? | Yes |
Other Features | Bilingual day, AC reset, low battery indicator (EOL) |
Plastic Parts? | Yes |
Country of Manufacture | Made in Japan |
Known Models | Seiko Series 75 Diver 150m, PYH011, PYH018 (Add your watch to the comments below…) |
The Seiko caliber 7548A is a vintage quartz movement from the 1980s (originally introduced in 1979?).
Note: This calibre is sometimes misspelled as 7S48 or 7S48A.
Some of the topics covered in this caliber listing:
Cal. 7548 VS 7546:
There is a similar caliber 7546A sharing most of the same specs (dimensions, accuracy, etc.) with a few notable differences:
7548A | 7546A | |
Jewels | 5 | 4 |
Battery Life | 3 years | 5 years |
The 7548 is also said to have a higher torque rating than the 7546.
Note: Some components (particularly calendar parts) are also interchangeable with the caliber 63 series.
Video – Seiko 7548-700B Disassembly:
Video – Seiko 7548-700B Assembly:
Video – Why you don’t want to leave an old battery in your watch:
Additional Resources:
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