Comparisons have been made between 2.66-MHz and 40.92-MHz radar signals simultaneously scattered from the mesosphere. Echoes were generally received from the same height ranges, indicating that the same scattering mechanism operates at both radar frequencies. A comparison of the observed radar cross sections was made for data obtained during the spring of 1984. Indications are that these echoes are due to scattering from turbulent irregularities in the refractive index. It has been possible to estimate the inner scale of turbulence from these data. The inner scale was found to be close to that estimated from turbulence theory. A comparison of the reflection coefficients indicates that a specular reflection process cannot account for the relative signal strength observed in these data.