 The 500 television channels of a typical system are transmitted from the satellite to subscribers in the Ku microwave band, in two subbands of 10.7 - 11.7 and 11.7 - 12.75 GHz.The downlink signal is received by a satellite dish.In the box at the focus of the dish, called a low-noise block downconverter (LNB), each block of frequencies is converted to the IF range of 950 - 2150 MHz by two fixed frequency local oscillators at 9.75 and 10.6 GHz.