Abstract: A pulser circuit produces pulses of broadband radio frequency (RF) electromagnetic wave energy that are coupled through a hybrid to a transmit-receive antenna which is contiguous with the ground. If a transmitted pulse is incident on a conductive wire in the ground, a ringing is set up in it. The wire retransmits the electromagnetic wave signal with the energy concentrated at the ringing frequency. Signals received by the antenna are coupled through the hybrid and selectively passed by a gate circuit to a processor. Signals passed by the gate are combined with a local oscillator signal in a mixer to produce an intermediate frequency (IF) signal that is displayed on an oscilloscope. A concentration of energy at a particular frequency on the oscilloscope display is an indication that a wire is in the ground below the antenna. The operation of the pulser and the gate are controlled by timing pulses from a clock circuit.