Coaxial cables consist of a solid copper core surrounded by an insulator mainly made up of poly vinyl chloride (PVC) or Teflon. PVC is a plastic made from the chemical vinyl chloride. It is surrounded by a mesh like ground wire called the braiding or shielding and an outer cover known as a sheath. the insulator acts as a barrier between the braiding and inner core. If the insulator is absent , the shield and the core may come in contact and cause a short circuit. The braiding protects the cable from external interfaces such as Electro magnetic Interference (EMI) And Radio Frequency Interference (RFI).
The Various parts of coaxial cable are :-
- Outer insulation or jacket :- It is made up of plenum (Teflon) or non-plenum (Polyethylene Or polyvinyl chloride)
- Copper mesh or shields :- Some coaxial cable have a braid shield, some have a foil shield, and other have both a braid and foil shields. These shields and supply ground for the carrier wire (Copper) and help protect the copper wire from EMI and RFI.
- Insulation :- It is a non-conductor (Dielectric) around the carrier wir. It is usually made up of polyethylene or Teflon.
- Copper wire or carrier wire :- It is wire conductor at the center of the cable and is made of copper and may be either solid or stranded.
Advantage of coaxial cables
- Secured data transmission.
- Protect from cross talk.
- Protection From EMI RFI.
Disadvantages Of coaxial cable
- Most expensive of all types of cables.
- Difficult to install.
Types Of coaxial cable
- RG-58 Cable (Thinnet, Thinwire, Cheapernet) :- This cable is approximately 0.64 centimeter in diameter and mainly used in networks in which the device are frequently added or removed. It become easy to add or remove devices from the network using RG-58 cable. Coaxial cables specifications are governed by radio Government (RG) in collaboration with U.S. Military. Thinwire falls in the category of RG-58. The thinwire Ethernet is also known as 10Base2 where 2 denotes the maximum segment length of 200 meter (Practically 185 meter) which is a backbone cable. The center conductor of the coax must be sanded.
- RG-8 (Thickwire Ethernet, Thicnet) :-
- This cable is type of coaxial cable that is approximately 1 centimeter in diameter and mainly used as a backbone cable in thicknet. It has a solid center conductor and is physically much thicker than thinnet cable. Thickwire provides better protection from external and internal interference. It can also carry signals at great distances. The only disadvantage is rigidness due to which it is only used as a backbone cable to carry signal over long distances. Thickwire falls mainly in the category of RG-8. The thickwire Ethernet is also known as 10-Base2 where 5 denotes the maximum segment length of 500 m.a maximum of 100 nodes can be attached to each 10-Base2 segment.
This type of wire is a stiff cable with a solid center core covered by a foam insulator, a shielding braid and an outer sheath. The outer sheath is mostly yellow in color.