Abstract: An electromagnetic test system induces large current pulses in a component of a system under test. The pulse waveform may be selectively varied, and possible waveforms include square wave pulse, double exponential, and damped sinusoid waveforms. In a preferred embodiment, these waveforms are generated by simultaneously triggering a plurality of modular signal injector units having ferrite cores hinged to permit positioning of a system component under test (such as a cable or antenna) along their central axes without disturbing connections of the tested component within its system. The injector units are resonance tuned to induce a particular signal in the component under test when triggered, and the modular construction of the system permits selective connection of different injector units to provide different desired total induced signals.