The LD7272 Series from NEC Network and Sensor Systems is a Traveling Wave Tube with Frequency 5.85 to 6.65 GHz, Power 400 W, Gain 52.7 dB, Collector Voltage 2.88 to 4.5 kV, Cathode Voltage 9 kV. Tags: Helix. More details for LD7272 Series can be seen below.