In this paper, some critical issues concerning the measurement of radiated emissions of products in an electromagnetic compatibility test stage are dealt with. In particular, an approach is proposed to evaluate the adequacy of anechoic enclosures that do not fulfil the requirements regarding the normalized site attenuation (NSA) factor. The purpose is to suggest a test method that can be used in order to define a way to know the limits of the chamber in terms of the frequency response over some critical radiations. To this aim, a number of simulation analyses and experiments have been performed for two different elementary types of radiating circuits (electric dipole, magnetic loop). Investigations have also been made by varying the physical size of the antennas.