A method of adjusting and readjusting an automatic corrector for a data signal transmission system, the corrector serving to restore pulse-amplitude-modulated signals which have suffered linear distortions in a transmission channel. A transversal filter of the corrector receives during a first adjustment phase a reference signal sequence transmitted over the transmission channel and an identical reference signal produced at the receiving end to produce error signals which serve to adjust the transversal filter coefficients stored in the corrector. The filter coefficients are subdivided into at least two groups and during the first phase one group of filter coefficients is calculated with a more attenuated error signal than the filter coefficients of the other group. In a second adjustment phase the filter coefficients of the transversal filter are readjusted in respect of alterations of the properties of the transmission channel, the error signal formed from the output signal of the transversal filter and the reference values for the latter signal being correlated with the data signal arriving at the input of the transversal filter.