Hello, everyone!
Today, I will shortly explain coax cables and indoor applications.
Coaxial cables are cables used in telecommunication networks to transmit RF signals. This type of cable has high bandwidth capability. Coax cables are used for high frequency signal transmissions.
The coaxial cable consists of:
an inner conductor,
a dielectric,
an outer conductor – shield, and
a jacket.
In the next figure, we can see coaxial cable construction (type of coax cable – RG6).
Figure 1. RG6
For early LAN networks, coaxial cables were used. These were RG8 and RG58. The impedance of these cables is 50 Ohms. In 10Base-2 networks, hosts were connected to the network by a BNC “T” connector. The architecture of this network was a bus. Today, coaxial cables are not used in LAN networks. They were replaced by UTP cables. And the architecture is a star.
Today, coaxial cables are used in premises networks: data centers, CCTV, satellite TV, and cable TV. In data centers, we can use special coaxial cable for very high speed and very short links. The links must be smaller than 5 m. For 10 Gbps in data centers, we can use coaxial cable CX-4. Figure 2. shows us this type of coaxial cable.
Figure 2. CX-4
Today, coaxial cables are mostly used for satellite and cable television. RG6, RG11 and RG59 are used. The impedance of these cables is 75 ohms. Different connectors are used - BNC, F, P1, P2, etc. The next figure shows us many types of coaxial connectors.
Figure 3. Different types of coaxial connectors
Special tools for coaxial cables are used to install the connectors. And the procedure for mounting the connector is as follows:
stripper for coaxial cable with two blades – it cuts the jacket, outer conductor and dielectric,
the connector on the cable is pushed and then crimp.
We must be very careful during the installation to ensure that the cables are not damaged. Also, the cable must not bend or deform too much. All of these events change the cable impedance and present transmission problems.
There are different instruments for testing coaxial cables, especially for measuring RF parameters. But, generally, we have to check continuity with an ohmmeter or cable tester. The main problems are opens, shorts and kinking of coax cable.
Thank you!
