Telephone cords/cables connect circuits in a telephone system. They join landline telephones or computers to telecommunications networks. Telephone cords play a vital role in communication by transmitting both sound and data from one location to another.
There are three main types of telephone cords which include internal, external, and internal/external. Telephone cords for external use are thicker and designed to be weatherproof, while internal cabling is more flexible and can be used in a variety of locations. Internal/external cords are the most versatile option and can be used indoors and outdoors.
Below are some of the most common types of telephone cords:
- Coaxial cable – These are the most common telephone cords is. They are coaxial because they have one physical channel, which is an insulated layer that is a woven shield of copper. This inner layer carries the signal and is surrounded by another physical channel that is created out of a plastic sheath. The outer channel is considered the ‘ground’ where many of the pairs of coaxial tubes are placed and transmit information over a great distance.
- Twisted pair cable – This cord contains a pair of copper wires- usually colour coded – that are twisted around each other. These cords have a diameter in the range of 0.4 to 0.8 mm. In each twisted pair cable, the number of twisted pairs can vary. In most cases, the higher the number of wire pairs, the better, because it reduces the risk of cross talk and any external noise. However, it is important to note that although twisted pair cables are incredibly cost-effective when compared to other telephone cables, they have a high attenuation and low bandwidth. There are essentially two types of twisted cables:
- Unshielded twisted pair (UTP) - These cords do not rely on a physical shield to block any connectivity issues or interference. This is the most common type of twisted pair cable used for both business and residential use.
- Shielded twisted pair - Unlike the unshielded twisted pair (UTP), this cords blocks external interference with foil jacket. This cord is used on a larger scale for big enterprises and high-end applications that may be exposed to environmental elements.
- Jelly-filled telecom cable – This cord is filled with petroleum jelly which is water resistant. It is an underground cable that uses the material polythene as insulation on the conductors. The spaces between the conductors is filled with petroleum jelly. This jelly has numerous benefits, for one it prevents the entry of moisture or water from entering the core of the cable in the event that the cable is damaged. They are suitable for both hot and cold climates.
- Ribbon cable - Also known as a flat twin cable or a multi-wire planar cable, this cable is made of numerous insulated wires that are parallel to each other. These cables are beneficial as they allow the transmission of data to occur simultaneously. Ribbon cables are used in interconnected network devices. Telephone lines are connected by numerous cables that come in many different types and each has its own purpose and function. Telephone cables like power cables perform the function of carrying sound signals.