A simplified 1-dimensional (1-D) nonlinear model has been developed to study the nonlinear electron trajectories in the virtual cathode oscillator. This model is based on a modified time- dependent soft-spring Duffing potential. The force equation contains the properties of a chaotic system and is believed to be a contributing factor to the random RF output observed in many vircator experiments. A low-voltage (100-kV) test bed has been designed and built for the study of the characteristic nonlinear trajectories of electrons in the device. The system can inject small amplitude microwaves into the potential well as a means of controlling the chaotic dynamics (sensitivity to initial conditions) of the reflexing electrons. In this case, controlling the chaos means confining electrons in the potential well for a longer time, and with more coherent bunching, which has relevance to microwave production.