Abstract: An automatic equalizer has a transversal filter circuit for equalizing an input signal to be equalized and providing an equalized output according to the value of tap coefficients thereof. The transversal filter circuit includes a low-pass filter (LPF) at its output stage. The equalized output is subjected to a phase shift by the LPF. The equalized output is applied to a sign circuit as well as a wave integration circuit. The sign circuit generates a sign signal indicating a rate of change of the equalized output to time. The wave integration circuit generates a differentiated wave signal indicating the change of wave form or the change of amplitude information of the equalized output. The sign and wave signals are applied to a correlator which performs the correlation operation of the sign and wave signals and providing a tap coefficient control signal. This control signal is used for determining the tap coefficients of the transversal filter circuit.

Abstract: An automatic frequency control circuit comprising two switching transistors with the emitter-collector paths thereof connected in series with each other between a power source and a reference voltage source, a horizontal synchronizing signal being commonly coupled to the bases of the switching transistors, an integrating circuit having an input terminal receiving a horizontal pulse signal and an output terminal connected to the emitter-collector juncture between said two switching transistors, a smoothing circuit to convert the output voltage of said integrating circuit into a d-c voltage, and a voltage controlled oscillator to produce a frequency output in accordance with the d-c output voltage of the smoothing circuit, the output of said oscillator being fed back to the input terminal of said integrating circuit.