A high capacity fluidic valve is disclosed which is useful for creating psure pulses in a drill string for communicating diagnostic information from the bottom of a well bore to the surface during drilling. The device of the present invention comprises essentially a vortex chamber having an element therein which is capable of rapidly changing the flow through the chamber from radial to vortical. Flow throttling action in the valve is produced by the vortical flow in the chamber, thereby producing pressure pulses in the fluid stream flowing through the valve.