Signal filtration in experiments with test fields with little a priori information

The minimal root mean square error is calculated when restoring a useful signal $F_s(t)$ in experiments with test fields with minimal prior information $sup_{-\infty <t<\infty} | F_s | = F_0$. It is shown that the resolution of electromechanical converters based on a nonlinear reactive element in a mode of dynamic damping is limited only by fluctuations in the preamplifier with a known minimal noise temperature. Formulas are acquired for calculating the root mean square error in a minimax criterion.