Seiko Caliber 8M26

The Seiko caliber 8M26 (8M26A) is a vintage multi-function quartz movement with an alarm and chronograph. This movement is a 2-hander with no seconds hand and no date.

This calibre was introduced in the late 1980s (circa 1988).

Multi-Functional:

Notable features are that the hour and minute hands are controlled independently by two different motors, allowing for them to be used in various capacities beyond traditional time-telling.

The crown is used as a controller to select the mode, simply by rotating it forwards and backwards.

The mode indicator is at 6:00. The modes are listed below:

• TIME mode (Alarm disengaged) – Time display, alarm off
• TIME mode (Alarm engaged) – Time display, alarm on
• ALARM SETTING mode – Set the alarm time
• TIMER mode – Up to 60 minutes countdown timer
• Mode for adjusting the hand position – Set the time on the watch
• STOPWATCH mode – 60 minutes chronograph

Alarm Test:

To check if the alarm is working in your watch, there is an alarm test feature.

To test it, turn the crown until the mode is in TIME mode with the alarm activated. Press both the top and bottom buttons at the same time. The alarm sound should be audible while the buttons are pressed in together.

AC Circuit Reset:

The 8M26 is equipped with an electronic circuit reset switch. After a new battery is installed in the movement, you may have to perform a system reset aka short-circuit the movement to clear the information that was last stored in the integrated circuit. Do this will ensure that all functions work properly.

Additional Technical Information:

According to official technical documentation, the 8M26 is always consuming battery power, even when the hands are not moving. In Seiko’s own words:

“An extremely small amount of electricity is always supplied to the electronic circuit in order to make the watch start moving immediately and correctly after it is stopped and the battery itself discharges electricity.” -Source: Official Instruction Manual, Notes on the Battery

• Current consumption of the movement is less than 2.5 uA
• Current consumption of the circuit block is less than 1.6 uA

Additional Resources:

• Official 8M26 instruction manual (pdf)