What is a coaxial cable ? Everyone knows what a coaxial cable is , right? It s that fat wire that goes into your cable box, satellite receiver , or into your TV from an antenna. It looks different from an audio cable or headphone cable largely because of its heft. There s a little more to a coaxial cable than that. A coaxial cable carries its voltage on the inside core wire, and is surrounded by layers of shielding that stop any signal leakage . The first layer , the dielectric, provides distance between the core and the outer layers, as well as some insulation . The next layers , collectively called the shield , keep electrical impulses and radio transmissions out and keep any stray impulses in. Finally, a jacket made of flexible plastic or rubber protects the entire cable. Keeping the entire cable the same size , and keeping out stray signals , are important . Another important characteristic is that in a coaxial cable , unlike a headphone or audio cable, the core is used as part of the connector. So , it makes a direct connection . This helps keep the signal as strong as possible . Coaxial cable is perfect for broadcast television and satellite signals , which carry a huge amount of information and are very sensitive to outside interference. A satellite signal cable must carry signals from 2MHz to 3 ,000 MHz . Compare that with an audio cable which just needs to carry signals up to 2 MHz . That s a massive amount of information . Generally , coax cables will be referred to by a code such as RG 6 /U. RG is a very old specification that refers to the Radio Guide , a military guidebook . Any cable marked /U is designed for universal use, as opposed to those cables specifically used for computer data or other specified uses . If your cable is not marked /U that s ok as well . RG 11 Cable Let s start with a quick word about RG11 cable. You re not likely to run into RG11 cable unless youre digging around in the yard . It s designed for long runs and not for in-home use. It looks like all other coax but it s about twice as thick . RG 6 Cable This is Quad Shielded RG6 cable. We ll talk about different types of shields in a later article . RG6 cable is the perfect choice for cable and satellite. It is thin enough that it can be coiled or bend enough to go into a wall or ceiling , but carries enough shielding that it can be used for runs up to 100 meters in the house under the right circumstances . This is largely due to the thickness of the dielectric , 4. 7 mm and the use of a double layer of shielding. RG 59 Cable This is a consumer grade cable that conforms to the RG59 standard RG59 cable was used extensively in homes before cable or satellite. It s well - suited to carrying signals from a terrestrial antenna but not well suited to long runs through the house , especially if you re using all the frequencies that a modern cable or satellite system uses . From the outside , RG59 cable looks very similar to RG6 . A cable made to specs is less than 1mm thinner than an RG6 cable, and can feel similar in its weight and stiffness . However , RG59 cables are only required to have a single outer shield layer , while RG6 must have at least a double layer . Some RG59 cables do have a secondary shield , but like the picture above it can be very thin . RG59 cable is well suited to over - the -air antenna use and is perfect for any case where frequencies don t go above 1000MHz , such as cell phone antennas . Slim RG 59 Occasionally, you ll see a cable that carries the same connectors as an RG59 cable but appears much thinner . Such cables may have some stiffness to them compared to an audio cable but can typically be only 3mm thick . This is referred to in literature as slim coaxial or slim RG59. In truth this is not an actual standard . Such a cable is built to the same general standards as an RG59 cable - - a single shield is generally used -- but the dielectric is just 1mm thick, less than one -third the thickness of a regular RG59 cable . Obviously such cables are very limited in their uses . DIRECTV includes one with their wireless Cinema Connection kit for a temporary connection to a receiver . Wi -Ex s YX545 uses this cable for its antenna , and both Winegard and Mohu use this cable for their flat antennas . For the short distance that they are used, they tend to be just fine .
Posted on: Sun, 23 Nov 2014 02:13:33 +0000
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