Abstract: An improved automatic test equipment system for testing electronic assemblies wherein such system includes a main cabinet and a test head. Driver and load circuits are partitioned between the test head and main cabinet so that high power dissipating portions of the load circuit and drive circuit are located in the main cabinet and the low power dissipating portions of the load circuit and drive circuit are positioned in the test head. Disclosed is a structure by which the partitioning of the driver and load circuits can be achieved, the structure including a transmission line and a current buffer which permit the transmission of current pulses over long distances without degradation in the current pulse shape. The structure utilizes a common base current buffer stage with collector base clamping.