outputted by the rssi circuit 42 is applied to an antenna controller circuit 44 the antenna control circuit 44 contains an analog to digital converter 46 which converts the analog rssi signal into digital format suitable for processing by a dedicated asic microprocessor the antenna controller 44 contains an asic microprocessor based control circuit which executes a computer program contained in a rom in the asic circuit the asic circuit functions to produce a wobble signal which is outputted as a variable digital value which is applied to digital to analog converter 48 to produce the antenna tuning signal having a variable analog value which causes the antenna circuit 14 to be tuned variably through a frequency band for the purpose of continually locking on the point of maximum gain as a channel is being received the variation in signal amplitude caused by the wobbling of the tuning frequency of the antenna circuit 14 is detected by the rssi circuit 42 so that the antenna controller circuit 44 continually outputs an antenna tuning signal which tunes the antenna circuit 14 to achieve maximum gain for the antenna 12 the antenna tuning signal compensates for environmental factors which change the gain of the antenna.