How Does a Cable Box Receiver Work?

By Jared Paventi

What Does the Cable Receiver Do?

Cable companies wire homes specifically to deliver programming to televisions. Cable lines run to homes, entering the house and connecting to a splitter which distributes a signal to different points of the house. The cable line carries programming to the television, where it plugs into the converter box.The converter reads the signal. Cable providers encode signals to prevent theft. In the past, different levels of service would be scrambled to ensure that the customer received the channels for which he paid. During the 1980s and 1990s, this was relegated to premium movie channels like HBO or Cinemax. The advent of digital cable in the late 1990s allowed cable companies to protect each channel equally. The cable box receives the signals which are paid for and blocks access to channels which are not subscribed to or are pay per view.

Technical Detail

Cable signals enter the receiver box through coaxial cable--a thick black cable with either gold or stainless steel fittings. The coaxial cable plugs directly into the receiver, which decodes the incoming signal and prepares it for display. The user chooses channels using a remote control, and the receiver box decodes the correct incoming signal to provide an on-screen display. Video enters the receiver in a compressed format, which allows for 300 to 400 channels to be transmitted at once. Video and audio information leave the receiver in one of two manners. A second coaxial cable connects the television and receiver, transmitting the signal. The other method is through the use of component cables. This provides the clearest and highest quality audio and video. Yellow, red and white cables can be connected to the receiver and hook into the television. Each plug carries separate video and stereo signals.Newer televisions may have the option to connect with five-plug component cables, as opposed to the previously mentioned three-plug connection. This allows for each video channel of color to be transmitted separately, insuring the highest quality color. High-definition receivers will also have HDMI (high-definition multimedia interface) ports which transmit data to the television.

A Home Theatre Accessory

Cable companies have gone to great lengths to improve features of their digital product. Most cable systems offer receivers with personal video recorders (PVRs), which allow viewers to record and view programming without using video tape, or pause and/or rewind live television. Larger cable companies now provide on-demand programming, which permits users to call up movies or television shows at their convenience and watch them outside of the programs typical broadcast schedule. In addition, companies offer specific services through their cable boxes. In many markets, Time Warner Cable offers users the ability to pay bills using their remote control.