Recent research indicated that eddy current conductivity measurements can be exploited for nondestructive evaluation of subsurface residual stress in surface‐treated components. This technique is based on the so‐called piezoresistive effect, i.e., the stress‐dependence of electric conductivity. Previous experimental studies were conducted on excessively peened (Almen 10–16A peening intensity levels) nickel‐base superalloy specimens that exhibited harmful cold work in excess of 30% plastic strain. The main reason for choosing peening intensities above recommended normal levels was that the eddy current penetration depth could not be decreased below 0.2 mm without conducting accurate measurements above 10 MHz, which is beyond the operational range of most commercially available eddy current instruments. In this paper we report the development of a new high‐frequency eddy current conductivity measuring system that offers an extended inspection frequency range up to 80 MHz with a single probe coil. In addition, the new system offers better reproducibility, accuracy, and measurement speed than the previously used conventional system. © 2007 American Institute of Physics