Coaxial Cable

A single insulated inner wire is surrounded by cylindrical conductor which is covered with a shield; it transmits electromagnetic signals. Coaxial cable is classified into two categories:

• Base Band (uses digital signals)
• Broad Band (uses analog signals) coaxial cable.

1. Advantages of coaxial cable (Round Insulated Wire):
   • Not susceptible to interference
   • Transmits faster.
2. Disadvantages of coaxial cable (Round Insulated Wire):
   • Heavy and bulky
   • Needs booster over distance

1. Base band Coaxial Cable

It has been used for many years in the telephone network in applications with requirements similar to those of a LAN. Both base band and broadband coaxial cable are available. Although their structure is same, their installation and applications differ.

In base band coaxial cable, a central carrier wire is surrounded by a fine woven mesh of copper which forms an outer shell. The space between the wire and the outer shell is insulated to separate the two conductors and to maintain the electrical properties. The entire cable is covered by protective insulation to minimize electrical emissions. The cable is usually approximately 3/8 inch in diameter.

2. Broadband Coaxial Cable

This comes in several different diameters with varying amounts of insulation. The cable may have the same construction as base band coaxial. The central carrier may be surrounded by an aluminium sleeve. The space between the core and the shell is filled with insulation and the whole is enclosed in a protective coat of insulation. Broadband coaxial cable can carry 50 to 100 television channels or thousands of voice and low speed data channels at the rates of 9.2 to 50 Kpbs.