Automatic equalizer

An automatic equalizer comprising a transversal filter connected to receive an input signal to be equalized and having tap gains adjustable by control voltages supplied from outside;

• a circuit connected to receive an output signal from the transversal filter and the input signal to be equalized to produce an equalized output signal;
• a distortion detect circuit connected to receive the equalized output signal to detect a distortion component contained in the output signal and to produce a distortion detect signal in correspondence with the distortion component;
• a tap gain correct circuit responsive to the distortion detect circuit to produce tap gain correct signals;
• and a tap gain hold circuit responsive to the tap gain correct circuit to correct the control voltages supplied to the transversal filter based on the tap gain correct signals and hold the corrected control voltages;
• characterized by further comprising polarity inverting means for synchronously and periodically inverting the polarity of a signal component included in the distortion detect signal produced at the output of the distortion detect circuit and the polarity of the correct signals.