It can be divided into two basic types of coaxial cable, baseband coaxial cable and broadband coaxial cable. Currently baseband common cable, which shield is made of copper mesh, the characteristic impedance is 50 OHM (e.g., RG-8, RG-58,RG-213, etc.); broadband coaxial cables commonly used shield is usually stamped aluminum into a characteristic impedance of 75 Ohm (such as RG-59,RG-6,RG-11, etc.).
Thick coaxial and thin coaxial cable coaxial cable refers to the diameter of the large or small. Culan applicable to relatively large local network, its standard long distance, high reliability. Since no cutting cable installation, so you can flexibly adjust the location of the computer network as needed. But the thick cable network must be installed transceiver and transceiver cable, installation is difficult, so the overall cost is high. In contrast, thin cable installation is relatively simple, low cost, but because of the installation process to cut off cable, two shall be fitted with basic network connector (BNC), and then connected to the T-connectors at both ends, so when joint for a long time prone to poor contact risks, which is one of the most common problems is currently running in Ethernet occurred.
In order to maintain the proper electrical characteristics of coaxial cable, cable shield must be grounded. While two have terminal device to weaken the signal reflection.
Whether it is Thick or thin cable are both bus topology, which received more than one cable on the machine, this topology for machine intensive environments. But when a contact failure, failure will affect the series to diagnose and repair all machines, the entire root cable fault on the hassle, therefore, will gradually replace unshielded twisted pair or fiber optic cable.
The most commonly used coaxial cable are the following:
• RG-8 or RG-213 50Ω
• RG-58 50Ω
• RG-59 and RG-6 75Ω
• RG-62 93Ω
Computer networks generally use RG-8 RG-58 Ethernet Culan and Ethernet thin cable. RG-59 for the television system. RG-62 for the ARCnet network and IBM3270 network.