Discrete electric sparks at high frequency are employed in electrical discharge machining (EDM) for machining electrically conductive materials. A reliable evaluation of pulse trains is essential for applying control techniques to achieve stable and efficient machining performance. In this work powder metallurgy (PM) tool electrodes are employed and the effect of electrode manufacturing variables on process stability is evaluated through pulse train analysis. PM provides a means of combining desirable characteristics of different electrode materials. In addition, PM manufacturing variables control the level of many of the properties of tool electrodes and hence their performance in actual machining. The voltage and current pulses have been recorded simultaneously using a dual trace storage oscilloscope connected to an X-Y plotter. Quantitative analysis of the pulses is considered in this paper.