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Historical Background

Community antenna television, or CATV as it is now called, has its roots extending as far back as the late 1940s. It is widely accepted that the first CATV system was constructed in Mahanoy City, Pennsylvania, by an appliance store owner who wanted to enhance the sale of television sets by making programming available to customers that could not get reception of off-air signals since the community was located in a valley in the Appalachian Mountains. A large antenna was erected on top of a utility pole atop New Boston Mountain and was used to feed wires and repeater amplifiers. The system was ''able to provide sufficient reception of television programs so as to not only sell television sets but to obtain subscribers to his cable connection" 1R. From this early attempt to provide cable service, additional systems were constructed with the intent to provide clear reception of locally generated signals to customers unable to receive off-air signals. By the mid-1960s there were over 1,300 cable systems feeding approximately 1.5 million customers.

Architecturally, these early cable systems were merely distribution systems that received and amplified off-air signals without processing and reassigning redistribution frequency. However, the 1970s brought new technological developments. The launching of geostationary satellites, coupled with the allowance by the FCC to make these satellites available for domestic communications, brought about the growth of satellite delivery of programming directly to cable headends. For the first time, television programmers and programming distributors could use satellites to broadcast their programming with complete U.S. coverage. CATV systems could receive and distribute these signals via cable to customers with little incremental investment. Television broadcast stations such as WTBS in Atlanta and WGN in Chicago made use of this technology to create superstations with full continental U.S. coverage of their signals. In addition, FM satellite receivers, large satellite receiving antennas, and video processing equipment provided cable headends with the necessary electronic equipment to receive and distribute these programs over selected channels in the cable system.

How the Analog Cable Set Top Evolved

For the first time, there were more channels available over the CATV system than the normal Channel 2–13 VHF television could tune. This availability of greater channel capacity led to the development of the cable tuner or "set-top converter." These early units, developed in the late 1970s, were capable of tuning up to 36 channels. They did little more than convert the tuned cable channel to a standard Channel 3 or Channel 4 output frequency so that a standard VHF television set could receive the cable signals. In effect, these units were the cable analog of the UHF converter prevalent in the late 1950s. Recognizing the vast market made available by the satellite and cable distribution system in place, content providers such as Home Box Office, Cinemax, Showtime, The Movie Channel, and The Disney Channel as well as ESPN, USA Network, and others sought to use the existing infrastructure to provide "cable only" delivery of premium and "niche" programming content to a growing audience hungry for content variety.

This programming was meant to service only those who purchased it and therefore required means for selectively enabling only those viewers who paid for these special services. To fulfill the requirement, frequency traps were installed in cable drops to nonsubscribing customers. This technique had several drawbacks:


Traps were used to prevent reception, proving to be a costly proposition since the expense was distributed over nonsubcribing customers.


Customers who changed their viewing tastes required a service call by the cable operator to either remove or add traps.


If the cable operator added a new premium service, new traps were needed for each subscriber not desiring the new service.

Scrambling and addressability removed these road blocks and made premium programming a viable business. In the 1980s, scramblers began replacing frequency trap technology. Premium programming content was scrambled before being redistributed over the cable system. Newer set-top converters were provided that

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