We have developed a pulser that is able to generate a simulated signal from a high-purity germanium (HPGe) detector for various plutonium isotopes. In this paper we describe the development of an 'isotopics' pulser for the simulation of signals that are produced by an HPGe detector. The present pulser generates the waveforms that are produced by an HPGe detector both before and after the preamplifier. These signals have been input into a normal MCA and the result closely simulates a genuine pulse-height distribution. The goal of this project was to show that it is possible to generate electronic signals that can accurately mimic the signals that are produced by a high-purity germanium (HPGe) gamma-ray detector. The underlying reason for the pulser was to develop a method that would allow the production of signals that are produced by a source of plutonium or uranium without the logistical difficulty of measuring actual material.. We believe that this electronic source has at least three immediate applications: 1. development of analysis software; 2. Authentication of measurement systems; and 3. As a training aid. We see other applications of the 'isotopics' pulser; however, all of the applications of the pulser have a common theme. The interrogation of plutonium or uranium is logistically complicated, particularly for low-burnup plutonium and highly enriched uranium, and therefore rather expensive.