This 4-tube counter was found in Radio Electronics magazine from December 1959. The circuit uses a coil as a sensor to detect the passage of metallic parts or magnets.
120 degree lagged signals can be obtained with the simple configuration shown in the figure....
This circuit was obtained from a Popular Electronics of the 80's. It is set to a certain pulse...
In the figure we have an application of ON Semiconductor's own semiconductor manual from the 80's....