DC power supplies of the same polarity (i.e. both positive or both negative polarity) may be used for the Pulse and Bias DC supply inputs of the GRX, PVX-41XX and PVM-41XX pulse generators. However most high voltage DC power supplies cannot regulate voltages of the same polarity from a separate source. To operate with power supplies of common polarity, the bias, or lower voltage (-HV or VLOW) supply must be provided with an additional current flow path to ground. If this path is not provided, the output voltage may not remain at the -HV In potential when the pulse generator is not gated, but can be charged up to the potential of the VHIGH (+HV In) supply. This technical note describes how to install a current path to ground to mitigate this problem.