CATV distribution system, especially adapted for o

专利名称：CATV distribution system, especially

adapted for off-premises premium channelinterdiction

发明人：Michael Harney,Mark Doremus,Steve

Nussrallah,Roy Lowcock,Lamar West, Jr.

申请号：US07/445316申请日：19891204公开号：US04963966A公开日：19901016

摘要：Equipment for use in CATV lines and a system for distribution of CATV signalsand for power to operate CATV line equipment having active devices which require poweris described. The system distributes CATV signals to subscribers who have ordereddifferent levels of service (basic service without premium channels or different groups ofpremium channels). Housings are located in proximity to the premises of both actualsubscribers and potential subscribers, and have like covers which contain tappingelectronics (a directional coupler, line equalizers and power bypassing circuit). The coverhas ports at opposite ends and an additional port at one end. The tapping electronics islocated on a seizure board having seizure blocks spaced from each other along one edgeof the board. The seizure board is rotatable ninety degrees (90°) so that the blocks arealigned with the ports at the opposite ends of the cover when the cover and housing unitare aerial mounted or with the ports at one end of the cover to receive the cable whenthe housing is pedestal mounted. Different enclosure units are attached to the cover andare configured and equipped with different types of electronics depending upon the

level of service and/or the technology used to control the transmission of the CATVsignals in accordance with the level of service for particular subscribers. A largerenclosure unit contains interdiction electronics which is addressable by signals from thehead end of the CATV system to control frequency agile oscillators which generate thesignals for jamming selected premium channels. A smaller enclosure unit contains thesplitting electronics and may contain band reject filter(s) which block transmission ofpremium channels not ordered by the subscribers. The housing in proximity to potentialsubscriber premises has an enclosure unit provided by a plate and the tapping circuits areterminated with loads simulating the subscriber loads. If desired a circuit board having asplitter may be located in the housing and connectors attached to the plate. Externalband reject filters may be mounted on the plate at the connectors. Power distributionalong the cable is controlled by bypass circuits, containing an RF choke and switchingmeans (a jumper) which is connected across a capacitor which blocks power (60 Hz AC) sothat the power bypass circuit does not adversely affect the transmission of the RF CATVsignals.

申请人：SCIENTIFIC ATLANTA, INC.

代理人：Martin Lukacher

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