Conn - ST11 Tuner

The strobometer (strobotuner) bases its operation on a visual phenomenon called the stroboscopic effect: have you ever seen a car that, while moving forward, seems to have its wheels turning backward? or in cinema or on TV, the wheel (the disk) of a car that seems to rotate opposite to the direction of travel? In all these cases, the culprit is the stroboscopic effect.
This apparent reverse rotation is due to the difference between the object's rotation frequency and the shutter speed of the camera (in the case of television or cinematic images) or the persistence of vision frequency of the eye (in the case of real images).
The strobotuner bases its operation precisely on this concept.
Still used today by McCartney, Gilmour, Page, etc.
An item for discerning collectors and musicians.