Engineers who work on survivability of complex infrastructure targets to highpower microwave illumination are careful to understand possible instabilities that can be forced by the threat illumination. Transition to chaos is one indicator of such instability. Engineers who design infrastructure systems are careful to consider the stability of the systems under normal operation, but do not normally consider external threats or stimulants that may contribute to the instability. Stoudt, Gardner, and Kohlberg [1][2][3] show examples of simple electronic systems that go unstable through a combination of pulsed field illumination and misdirected energy from a system power supply. In this paper, we will examine the effects on simple selected oscillators of multi-frequency (chaotic in that the center frequency jumps abruptly from frequency to frequency) and ultra wideband signals. The first case study is based on the Chua Circuit, which is very simple, but known to easily exhibit chaotic behavior. The Chua circuit can be described using only three nonlinear differential equations, so is near the minimum requirements for chaos. This study will use Mathematica© scripts to compare the Chua circuit results to that of a simple oscillator then add complexity to the target circuit so that it is clear where instabilities can be found and exploited.