In case of a short-circuit between two wires of a dc line, a sustained arc may occur and propagate along the wires through pyrolization of the insulation. This phenomenon, known as arc tracking, is quite critical from a safety point of view since it can cause fire or explosion, depending on its close environment. In addition, the arc generates conducted electromagnetic noise in a wide frequency range which can couple to other wires situated either in the same cable bundle or in its vicinity and disturb control/command devices. In this paper, only this last point is considered, the objective being to characterize the spectral density of the voltage and current generated by such an arc tracking in a high-frequency band extending from 300 kHz to 30 MHz. First, the measurement set up is described, emphasizing the key points to deduce the intrinsic characteristics of the arc from the measured values. A Thevenin generator equivalent to the arc is proposed in order to be able, in a further step, to predict disturbing noise at any point of the cable network.