Cable TV amplifiers distribute signals to remote screens, a useful function when you're showing a sporting event at a party, for example. When it's at least 6 inches away from other electronic devices, the amplifier reduces interference while boosting the signal. This amplification accounts for signal losses produced by splitting the signal. Preamps are sometimes needed in weak signal areas.
Coaxial cables connect the amplifier and cable system and sometimes require routing through walls. A coaxial cable contains dual conductors sharing the same axis with the outer conductor protected by a shield. This cable connects an input source such as the TV, cable modem or antenna to the amp's input and terminates with an F-connector in a wall-mounted box.
Cable amplifiers usually have one to eight ports. Each port has equal output strength and the amount of signal boost is related to the number of ports on the amplifier, which has a fixed gain and divides the signal among ports. A unit with eight ports divides the signal eight ways, with 12.5 percent of the full signal at each output.
A variety of cable amplifiers are used for specific purposes. Bidirectional amplifiers allow better communication with the cable company but are not suitable for cable modems. Reverse amplifiers boost the signals returning to Comcast and make cable modems more reliable, but not necessarily faster. Forward-path equalizing amplifiers compensate for weakness from long cables. Cheap systems tend to not solve picture quality issues.