A precision of distance measurement of mobile radio-range station with the interference is considered. When radio-range station designs based on the optimal filtering theory the parameters optimal evaluation obtains by a priori information about the specific levels of signal and noise, as well as the range of values of the filter elements. However, the realized filter has parameters that deviate from the design because of the elements tolerances, components deterioration, etc. Optimal radio devices, in particular the mobile radio-range stations, which have the best accuracy specifications without of deviation of device parameters from the nominal values, do not guarantee their preservation with the appearance of such deviations in the operation. We show that there is a nonlinearly increasing dynamic error if the optimal filter of radio-range station was constructed without taking into consideration of the elements imperfection.