Abstract: A television converter includes a circuit for detecting scrambled signals and enabling the descrambler in response thereto. Scrambled signals are detected by sensing amplitude modulated digital tag information on the audio carrier. The descrambler is enabled if amplitude modulation is detected on the audio carrier during the portion of a horizontal line where digital information is expected, and also if no amplitude modulation is detected during a portion of the horizontal line where no data is expected. The scrambled signal detector of the present invention reduces the tendency for noise and other influences to enable the scrambler when viewing a clear, i.e. unscrambled, signal.