Brief description of the jamming of a signal of the television and apparatus of the corresponding freeview

摘要

Method for scrambling and freeview of a signal of the television and apparatus of the corresponding freeview. / p & & p & the method for scrambling and freeview consists in the transmission is superimposed on a television signal of an interference signal of frequency very close to one of the carriers under - image or of the television signal and, at the reception, to isolate the interference signal by filtering the signal of the television jams and then subtracting the signal insulates the scrambled television signal in order to obtain the signal of the television freed of the signal of jamming. / p & & p & the apparatus of freeview comprises two channels: one comprising a band pass filter - do not pass the signal to interference, the other channel transmitting the signal of the interference signal and the television. Means are provided for equalize the amplitude of the signals of each channel and performing a phase shift of 180 of the said signals. At the output, a coupler superimposed on the signals issued for each channel, canceling the scrambling.