Investigation of the dynamic character of EBR-II has been done with rod-drop and rotary rod-oscillator experiments. Both of these experiments provide linear feedback transfer functions in the complex domain; the rod-oscillator experiment gives this information directly, whereas modeling procedures must be done for the rod-drop experiment. Comparisons of results show good qualitative agreement. Quantitatively, the rod-drop experiment appears to predict less feedback than the rod-oscillator experiment.