Abstract: A tracking filter for tracking the frequency component of highest intensity of an input signal is disclosed in a hand held FM radar device. The tracking filter includes circuitry for providing a high pass signal, a bandpass signal and a low pass signal, all of which are representative of the frequency components of the input signal. An error signal generating circuit utilizes the high pass and low pass signals to control the characteristic frequency associated with the high pass, low pass and bandpass signals. The radar device further includes circuitry for displaying a distance output on an LED display and circuitry for providing an audio signal indicative of target distance.