North American Philips Corporation

Jeffrey L Cox

Aravanan Gurusami

Victor J Jacek

Thomas P Strong

Robert J Chamberlin

Mark Chapman

Douglas J Hatch

A subscriber control system designed to be placed outside of the subscriber's home, for controlling access to cable television signals provided by a cable television headend. The system is modular in design containing a single control module and a single RF distribution module both shared by a number of jammer modules. The jammer modules contain a plurality of frequency agile oscillators, the frequencies of which can be changed in time-multiplex fashion. The outputs of the jammer modules can be shared amongst a number of subscribers using space division switching. The system features switching utilizing a plurality of series connected diodes to form a transmission line switch and also utilizes filters having inductive elements which are configured by etching processes

Expandable cable television subscriber control system

A device is disclosed for controlling access to cable television signals. Jamming oscillators are shifted in frequency, jamming multiple services each. The oscillators are shared between multiple subscriber ports, providing a cost effective, high security control system. A modular approach allows security to be added as additional capacity is required.

Cable subscriber control device using shared jamming modules

A phase-locked loop capable of generating a plurality of stable frequncy signals. This loop includes a plurality of voltage controlled oscillators which are sequentially coupled to the output of a phase sensitive detector by a multiplexer. RF switches then sequentially couple, in synchronism with the multiplexer, the oscillator outputs to a programmable divider which, in turn, is coupled to an input of the phase sensitive detector, the other input thereto being coupled to a reference oscillator. The dividing factors for the programmable divider are inputted thereto, in synchronism with the multiplexer, from a memory.

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Camillus, NY, United States of America

Jeffrey L Cox