The VTU-6398D9C from Communications & Power Industries is a Traveling Wave Tube with Frequency 17.3 to 18.4 GHz, Power 625 W, Peak Output Power 1.25 kW, Gain 52 dB, Collector Voltage 57 to 59 kV (DC). Tags: Helix. More details for VTU-6398D9C can be seen below.