Noncontact eddy‐current techniques for characterizing superconductors between 5 MHz and 1 GHz are described. Both a transmission and a frequency‐modulation technique rely on modification of the mutual inductance between a pair of coupled inductors. The sample is placed between the inductive sensors; the magnitude of eddy currents induced in the sample, a function of conductivity, modifies the mutual inductance. The frequency‐modulation method (where the sensors are the inductive section of a series‐resonantLCcircuit in an oscillator) is particularly useful for determining the critical temperature (Tc) and transition width for superconducting samples.