The Model DB-2 is a pulse generator which accurately simulates the random and pile-up characteristics of pulses from a radiation detector. It provides pulses which are mono-energetic over a broad range of average count rates. Under high count rate conditions, the pulses will pile up as shown in the diagram below. This characteristics is useful in determining pile-up or count-rate effects and in measuring the resolution of high count rate spectroscopy systems. Besides random pulse, the Model DB-2 also provides mono energetic repetitive pulses. In this mode, the DB-2 is an excellent general purpose pulser. When the EXT REF input is used with an external ramp, the DB-2 provides sliding pulses to quickly check system or component linearity.