A method and apparatus are provided for calibrating an information-signal transmission line that includes elements for generating a control signal and transmitting information signals controlled by the control signals, and an amplifier of the information signals. The amplifier can be configured according to at least a first gain configuration associated with a first gain value, and a second gain configuration associated with a second gain value. The method includes obtaining, for each of the first and second gain configurations, first and second sets of initial values of the control signal, that correspond to first and second sets of measured power that overlap, and selecting, for each power-recovery setpoint value to which corresponds a first measured-power value of the first set and a second measured-power value of the second set, from the first and second calibrated values of the control signal, the calibrated value that meets a predetermined criterion.