Cable boosters, also known as cable amplifiers or distribution amplifiers, are small devices that look similar to cable splitters. When cable signals travel through long lengths of coaxial wiring and through splitters, they may experience degradation that can affect the quality of the video and audio or cause channels to be completely unwatchable. A booster attaches to the entry point of a home’s coaxial cable and increases the strength of the signal before it reaches the cable box or television. Specific types of cable amplifiers are available for both audiovisual signals and data signals, such as those used for Internet service.
Cable Booster Basics
Most cable amplifiers are small, metallic boxes with two or more fittings for the connection of coaxial cables. Without looking closely, they may be mistaken for cable splitters, and some boosters are both amplifiers and splitters. In many cases, the only way to tell that a unit is an amplifier is to read the label. Cable amplifiers may also include surge-protection components and grounding ports, and some include additional coaxial connections that can be used to connect multiple amplifiers together to boost particularly weak signals.
Cable amplifiers are made to boost signals in a wide range of frequencies because cable signals may vary from 5 MHz to 1,000 MHz. However, the adaptation that allows the units to boost such a wide range also limits how much the signals can be amplified. Most cable amplifiers can only boost signals by about 4 dB, which is just over two times the input power. This amount of power is not always adequate but may be enough to send a strong signal to one or two TVs.
In some cases, when the cable company knows that a signal will degrade and adversely affect reception by customers, technicians may install cable amplifiers outside of a home. This preemptive measure can prevent signal problems from occurring. Some of these amplifiers have remote controls built into them that allow cable technicians to fine tune the signals from their control stations.
Inline Cable Boosters Vs. Powered Boosters
Cable amplifiers are available in two basic varieties: inline boosters and powered boosters. Inline boosters are the simpler of the two, but they may not always work well enough for some homes. Inline boosters typically only have one input connection and one output connection. This type of amplifier uses small amounts of residual electricity flowing through the cable to boost signals.
Inline boosters are perfect for attaching long cable extensions to the input cable. Signals can degrade when travelling through long lengths of cable or when travelling through the seam created by a standard coupler. Instead of using a coupler to attach an additional length of cable, an inline booster can be used to avoid signal degradation.
Powered cable amplifiers can boost signals more efficiently than inline amplifiers because they use external power sources instead of the miniscule amount of power flowing through the input cables. Most boosters that are also cable splitters are powered boosters, and they may be able to split a signal up to eight ways. Subscribers using splitter boosters must be careful to cover any connections not being used with special caps that prevent outside interference in the signals.
Powered boosters suffer from one major drawback: They require a stable source of electricity. If the electricity is interrupted, the signal will not go through the amplifier to the output connections. However, this is not usually a problem because it is uncommon for electricity to be cut to the amplifier but not to the devices that use the signal. As a precautionary measure, some powered amplifiers include passive ports, which are mostly used for data signals. Passive ports allow a signal to pass through the amplifier even if it is not receiving power.
Bidirectional Cable Boosters
While most cable amplifiers only boost incoming signals, bidirectional amplifiers can boost both incoming and outgoing signals. These boosters work especially well in homes that have cable Internet. If outgoing data signals degrade before reaching an Internet hub, the data could be lost or become corrupted. Like unidirectional boosters, bidirectional boosters can amplify incoming signals ranging in frequency from 5 MHz to 1,000 MHz, but the only outgoing signals that can be boosted are those with a frequency of 40 MHz. These amplifiers may also have ports dedicated to data lines. This prevents excess degradation of data signals when connecting a modem and multiple televisions to the primary input cable.
Installing Cable Boosters
The installation of cable boosters is simple, and most cable subscribers can install them without the assistance of a technician. Manufacturers of boosters can provide instructions, and these instructions should always be followed because each model may work a little differently than other models. The biggest problem experienced by most people when installing a cable amplifier is that it must be connected to the primary input cable. The input cable is often located in a garage, attic or other inconvenient location, and a power source may not be nearby.