Abstract: The invention relates to a method for the determination of the impulse response g(t) of a broad band linear system. The method can be used for the application of high frequency technology. For a test signal, a maximum length binary sequence (MLBS) is employed. The measured signal, obtained by the system, is sampled under maintenance of the sample theorem whereby the sampling clock in accordance with the invention is obtained directly from that high frequency clock pulse which is used for the generation of the MLBS. The digitized measured signal is then subjected to a fast Hadamard-transformation for calculation of the impulse response. The invention furthermore, provides a measuring circuit which carries out this method.