Based on the measured impedance of the inductors based on a toroidal core wound from a thin (18 m) nanocrystalline tape, with a different number of winding turns, an equivalent high frequency (0 Hz - 500 MHz) circuit model was built. The equivalent circuit model was built taking into account the physical processes occurring in the inductor: effect of wire resistance, effect of core material, mutual effect of wire and core material. The attempt explaining why the frequency characteristics (modulus and phase) of the inductor complex impedance have such a character in a wide frequency band (up to 500 MHz) was made. It was shown that for constructing an equivalent circuit model (structure and parameters), measuring only the inductors resistance modulus is not enough. It is also necessary to measure the phase of the inductor complex resistance, which is ignored in many works on the synthesis of an e inductor equivalent circuit. The fundamental difference between the operation of a nanocrystalline core and a ferrite core as applied to high-frequency filters is shown.