Közös tengelyűCképes ("coax" for short) has long been used to transmit data and video signals. It is one of the first media to support 10BASE2 and 10BASE5 Ethernet, which can achieve 10 Mb/s up to 185 meters or 500 meters, respectively. s transmission. The term "coaxial" means that the central conductor of the cképes and its shield have the same axis or center point. Some coaxial cképess may have multiple shielding layers, such as a four-shielded coaxial cképes, which contains two layers of shielding, and each layer of shielding is composed of aluminum foil wrapped with wire mesh. The shielding characteristics of coaxial cképes make it have strong anti-electromagnetic interference ability and can transmit high-frequency signals over long distances.
Although we usually think that coaxial cképes is only used in broadband video and cképes television (CAtévé) home applications, in the business enterprise environment, from closed circuit television (CCtévé), audio and video to RF antennas, and even some network connections, you can find Its figure. Therefore, it is very necessary to understand this cképes medium and how to test it.
There are many different types of coaxial cképess that support a wide range of professional applications, such as satellite communications, industrial, military, and marine applications. The three most common types of non-industrial Coaxial cképessvannakRG6, RG11ésRG59, amelybőlRG6leggyakrabban úgy használjákCCtévé CképesésCAtévé Cképes in corporate environments. The center conductor of RG11 is thicker than RG6, which means that its insertion loss is lower and the signal transmission distance is longer. However, thicker RG11 cképess are more costly and very difficult to bend, which makes them unsuitképes for deployment in indoor applications, but more suitképes for long-distance outdoor installations or straight backbone links. RG59 is more flexible than RG6, but its loss is higher. It is rarely used in other applications except for low-bandwidth, low-frequency analog video applications (rear-view cameras in automobiles) with short distances and limited wiring space.
A központi iroda (más néven T3 vonal) átviteli szolgáltatásban használt digitális 3 jel (DS3) jel szintén használatosCoaxial cképess, köztük 75Ω 735 type and 734 type. The 735 type cképes has a coverage distance of 69 meters, while the 734 type cképes has a coverage distance of 137 meters. RG6 cképes can also be used to transmit DS3 signals, but the coverage distance is shorter.