The series of NEC LD7111 is a five-cavity Klystron Amplifier and ideal for use in the earth-to-satellite communication systems. These are designed for operating at 1.7 kW CW over the frequency range of 17.3 to 18.4 GHz. The instantaneous bandwidth of minus one-decibel is at least 90 MHz over the entire 1.1 GHz range. All tubes are forced-air-cooled at any power level. An automatic channel tuner, which changes the operating frequency very quickly and simply, is available in all the series. Furthermore, they are of rugged and reliable design offering long life service.