All coaxial cables are constructed with a steel, copper, or aluminum conductor core, which is surrounded by a layer of white/black dielectric insulation. This is further covered with a tube-like braid of copper wires, which is wrapped around by a solid polyvinyl chloride insulating cover called a jacket. Some coaxial cables may have a layer of foil between the dielectric and the conducting core. Coaxial cables use the RG system to differentiate between the various kinds of cables. RG stands for an obsolete military term 'Radio Guide'. The numbers are used to distinguish one cable from the other, but they are assigned randomly and carry no specific meaning.
Did You Know?The first closed-circuit transmission of video signals through television by coaxial cables was used in the 1936 Summer Olympics, to send signals from Berlin to Leipzig.
RG-6 and RG-59 are two of the most common varieties of coaxial cables, i.e., cables that conduct electricity to transmit signals of radio frequencies, computer networks, and cable televisions. You may also find these cables designated as RG-6/U or RG-59/U, but there is no difference. Both types differ in their construction, uses, and range of capabilities. We shall now look at how one can tell the difference between RG-6 and RG-59 coax cables, and identify one from the other.
Construction: Ideally, to identify if the cable is RG-59 or RG-6, one only has to look at the jacket/outer covering, where the details of the cable are printed. However, if this printing is not visible, look for the thickness and the flexibility of the cable. Both cables have 75 Ohm resistance. However, the RG-59 cable has a 22 American wire gauge center of multiple strands of wire, while the RG-6 cable has 18 American wire gauge center with a solid copper core. This means that the RG-59 cable is smaller in diameter than the RG-6. Further, RG-6 cables can have additional foil and wire braid shields along with thicker dielectrics, which reduce the flexibility, lessen the degradation of signals, and are able to carry such signals for longer distances.
Selection of Coaxial Cables: RG-59 cables are best used where transmission distances are short, and the frequencies used are lesser than 50 MHz. Therefore, they are ideal for CCTV security camera networks. Using frequencies larger than 50 MHz will cause electromagnetic interference and degradation of the signal. In cases where transmissions are needed for long distances or signal frequencies of up to 1.5GHz, RG-6 cables are the best. Thus, they are ideal for TV antennas, satellite transmissions, and high-speed Internet broadband. Also, RG-6 cables have thicker and more durable jackets, which make them more suitable as compared to RG-59 cables for outdoor use.
Operating Frequencies: RG-59 is made for appliances that require signals of frequencies lower than 50 MHz, such as high-definition plasma televisions or video projectors. However, this cable is unable cope with signal frequencies which run in GHz, because the wiring and shielding is too thin. Therefore, the quality of the signal is lowered, and it cannot be used for satellite and cable transmissions.
RG-6 is a thicker cable with a large conductor, which allows it to process better signal quality through higher frequencies than RG-59 with reduced signal degradation. This also makes it good for satellite, cable, and high-voltage transmissions for TV antennas. On the other hand, RG-6 cannot handle low frequencies below 50 MHZ.
Signal Loss: RG-6 cables generally have better shielding than RG-59. This means that signal loss is lesser. Signal loss for RG-59 cables at 50, 400, and 1,000 MHz per 100 feet is 2.4, 7.0, and 12.0 decibels, respectively. The same for RG-6 cables is 1.5, 4.3, and 7.0 decibels. Higher quality of signals and additional materials make RG-6 slightly more expensive than the RG-59.
As you can see, the RG-6 cable has the edge over the RG-59 cable. With the continuous, rapid advances of communication systems around the world, the use of RG-6 cables will increase significantly over that of RG-59 type.