A TV aerial cable or TV coaxial cable is a type of cable used to transmit television signals from an antenna, cable service provider, or other sources to a television set. It is the most common type of cable used for this purpose. Here are some key features and components of a TV coaxial cable:
- Coaxial Construction: A coaxial cable consists of two main components: the centre conductor and the outer conductor. These two conductors are separated by an insulating layer. The design is called "coaxial" because the centre conductor and the outer conductor share the same axis, with one surrounding the other.
- Centre Conductor: The centre conductor is typically made of copper or aluminium and carries the electrical signals. It is usually a solid wire but can also be stranded.
- Insulating Layer: Surrounding the centre conductor is an insulating layer, usually made of plastic, which prevents electrical contact between the centre conductor and the outer conductor.
- Outer Conductor (Shield): The outer conductor, also known as the shield, is usually made of braided wire or foil. It serves two primary purposes: it provides a path for returning current and acts as a shield to reduce interference from external electrical and radio frequency (RF) signals.
- Dielectric Material: The insulating layer, which separates the centre conductor and the outer conductor, is known as the dielectric material. Common materials used for this purpose include polyethylene or foam.
- Connectors: Coaxial cables have connectors at both ends that are designed to make a secure electrical connection. The most common type of connector for TV coaxial cables is the F-type connector, which is a threaded, screw-on connector.
- Impedance: TV coaxial cables are typically designed with a characteristic impedance of 75 ohms. This value is important for maintaining signal integrity.