This movement is one of the most produced japanese movements, which was for example and mainly used in the legendary “Seiko 5”, until it was replaced in the late eighties by its successor, the caliber 7S26.
The 17-jewel equippted movement is pretty simple but efficiently constructed. It cannot be handwound, but on the other hand, it uses a rather elaborated excenter mechanism like for example IWC uses in many of their own movement. The 7009A uses all possible indications, hour, minute, second and day and weekday.
An interesting detail is, that the day is advanced by turning the crown in its second position, but the weekday is advanced by pressing the crown in position one.
|Number of jewels:||17|
Glucydur anular balance|
|Balance bearing / direction hairspring:||Counterclockwise|
|Adjust mechanism:||Hairspring key|
|Winding mechanism:||yoke winding system|