Time-dependent reactivities of many kinds are useful for the analysis of neutron kinetics, such as the study of reactor parameters, neutron wave propagation, or any other specific evolution of the reactor in the time. This is done by imposing the time function directly on a cadmium rod and measuring the neutron flux. Two experiments were performed: In the first one, the reactivity function required for a sinusoidal output was generated with all its parameters in agreement with the previous calculation. In the second experiment, a parameter was slightly altered. Both cases were analyzed, and their results agreed with calculations based on the point reactor model.