Abstract: A cable converter box is a capable of receiving a cable signal that includes both NTSC and digital television (DTV) formatted signals. When the converter box is tuned to a channel, the converter box determines whether the channel carries an NTSC or DTV signal. If the signal is NTSC, the signal passes through an up/down converter, is demodulated in a conventional manner, and is remodulated in order to be provided to the TV on a pre-selected channel. If the signal is DTV, the signal passes through the up/down converter, but not through the demodulator, prior to being output to a DTV-compatible TV on the same pre-selected channel as the NTSC signal. This prevents the user from having to change the tuner on the TV when the cable converter is changed to a DTV channel.

Abstract: A television system having sync suppression scrambling and descrambling which includes in band and out of band signaling methods. The in band signaling method modulates the IF sound carrier of a premium video channel with timing and data pulses while the out of band signaling method modulates the previously modulated IF sound on a separate carrier onto a separate out of band data carrier. The in band signaling method uses a descrambler which tunes a channel before demodulating the timing and data pulses from the sound carrier while the out of band signaling method tunes a selected data carrier to demodulate the timing and data pulses. In both methods, the timing pulses are used to restore the levels of the synchronization pulses in the sync suppressed video signal, and thus descramble the signal, while the data pulses are used for addressable messaging to the descrambler including authorization.