The article presents a methodology for assessing intermodulation interference at the input of one of the receivers of a group of medium-sized radio stations. This technique is based on determining the powers of interfering signals at the terminals of the receiving antenna by calculating the nodal potentials. Nodal potentials differ from ordinary ones in that they are not inside the segments into which the wire is divided, but at the junctions of the conductors, including the load. For calculations, a computational scheme based on the method of moments is used. As an object of study, a group of radio stations consisting of two hardware stations is considered. The authors presented an algorithm for calculating the power of intermodulation interference, counted to the input of the receiver. Using this algorithm, based on the reference data, a numerical simulation of the interference situation in the area of the object is performed. It is proved that the presented method allows us to simplify the task of calculating the power in the load of the receiving antenna, as well as expand the scope of known methods for evaluating the interference environment.