Abstract: A logarithmic amplifier calibrator internal to an electronic instrument applies a swept frequency signal via a switch and a single pole resonator to a logarithmic amplifier to be calibrated. The logarithmic amplifier output is digitized and stored as a frequency response for the resonator. The switch is opened and the single pole resonator rings down through the logarithmic amplifier. The ringdown output of the logarithmic amplifier also is digitized and stored as a linear log response. A ripple error look-up table is generated from the linear log response. An approximate bandwidth for the resonator is determined from the frequency response and a ringdown time corresponding to the time the linear log response decreases from the maximum amplitude to a 3 dB down amplitude of the frequency response to determine the exact bandwidth for the resonator.