A method and apparatus for providing periodic subscription television services comprises a way for subscribers who cannot afford the fees for full time television services such as a regular cable television...
A off-premises CATV system includes a compensation control including a picture carrier controlled automatic gain control and an automatic slope control. A broadband television signal output from a variable...
Frequency control of multiple oscillators using a single frequency locked loop is accomplished by a single frequency-control device that is time-shared with a plurality of voltage-controlled oscillators...
A gate circuit for use in switching an interference signal in a CATV system whereby the output impedance of the gate circuit is constant, independent of the switching state of the gate circuit. The inventive...
A scrambled TV signal is provided by adding thereto a signal having an amplitude which changes pseudorandomly in successive increments of time, the duration of each of which is much less than the horizontal...
A head-end apparatus for a CATV system is provided for facilitating identification of unauthorized or defective converter/decoder boxes in the system. According to the invention, an IF audio signal, representing...
A secure cable television distribution system is disclosed for controlling subscriber access to preferred channel information in accordance with the teachings of the instant invention. Premium channel...
A video clamping circuit adapted for satellite communication includes an operational amplifier for detecting the current flowing into a diode connected to the input terminal of the buffer amplifier of...
The present invention provides a method and apparatus for scrambling and unscrambling television signals to prevent reception of acceptable signals by an unauthorized television receiver while maintaining...
Subscriber access to the television transmissions of a cable TV system or other wired program transmission is governed by switching means in the remotely controlled unit to which the subscriber's receiver...
A method and apparatus for blocking the reception of a subscription television program while substituting a replacement program at a blocked receiver, provide security against detuning an unauthorized...
A method and apparatus are provided for blocking the reception of a subscription television program signal while substituting for the blocked signal a replacement program signal which is received by the...
A cable television signal distribution system provides a plurality of television programs and radio programs which are transmitted in frequency multiplex to a plurality of subscriber drop lines. A data...
