Recent research efforts at Texas Tech University on impulse antenna phased array has necessitated the need to develop a reliable high voltage, high repetition rate switch that will operate with ultra low jitter. An ideal jitter of a small fraction of the rise-time is required to accurately synchronize the array to steer and preserve the rise-time of the radiated pulse. In , we showed the initial test system with sub-ns results for operations in different gases and gas mixtures. This paper presents the impact gases and gas mixtures have on switch performance which includes recovery rate and in particular jitter. A 50 Ω, 1 nF pulse forming line is charged to 50 kV and provides the low inductance voltage source to test the different gases. Triggering is provided by a solid state opening switch voltage source that supplies ∼150 kV, 10 ns rise-time pulses at a rep rate up to 100 Hz in burst mode. A hermetically sealed spark gap with a Kel-F lining is used to house the switch and high pressure gas. This paper discusses in detail 50 kV, 100 Hz switch operations with different gases, in particular, mixtures of Kr85. Switch jitter as a function of operation time and gas temperature is also evaluated.