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What Is Coaxial Cable Used For

A coaxial cable connects the antenna to receive a TV signal. The quality of the cable largely depends on the reproduction of TV programs.

Let’s understand what a coaxial cable is and how it is arranged. What antenna cable is suitable for digital television, and what brands are better to choose?

How a TV Cable Works

To transmit the signals the antenna receives, you need not just a wire but a cable of the coaxial type. The term is Latin for “coaxial” and means that two conductors lie on the same axis.

The coaxial cable for TV has the following parts:

  • External insulating jacket. Protects the feeder from mechanical damage and short circuits.
  • Shield. The shield protects the conductor from inductive interference. Without the shield, the feeder becomes one long antenna, receiving not what is needed but everything in a row (e.g., noise from working electrical appliances and even floods from AC networks). The shield works on the “Faraday cage” principle and consists of braid (assembled from thin conductors), aluminum foil, synthetic film, and various combinations.
  • Internal insulation. Its task is to prevent the shielding layer from shorting to the center core. If this occurs, the shielding itself loses its meaning.
  • The central core is used for signal transmission. It is made either of copper (in high-quality but expensive cables) or steel wire covered with a galvanic layer.

Also read:  You must connect two TVs to the same antenna

what is coaxial cable used for

What Is Important When Choosing

The choice of cable for a TV antenna is based on seven main factors:

  • The material of the outer sheath.
    Two options are used to produce feeders: PVC and light-stabilized (that is, resistant to ultraviolet rays) polyethylene. However, nothing better than polyethylene has yet been invented for outdoor installation. An unsuitable coating will damage and break the cable.
  • Strength of the outer layer.
    Enough on a piece of feeder to try the outer PE- or PVC-shell, pulling it on itself. If it moves quickly, the cable should not be used: bending may damage the screen.
  • The length of the route through which the cable duct will run.
    The longer it is, the more signal power is lost due to conductor resistance. Therefore, when a long route (30 feet or more) is necessary, a cable with a copper central core is better than a steel one.
  • The power of the incoming signal.
    The equipment receives sufficiently powerful pulses from terrestrial retransmission television transmissions. However, the power of the satellite signal is small. Therefore, choosing cables with a copper core for dishes is better.
  • Diameter of the central core.
    The thicker the conductor, the less loss there is in the signal’s passage. However, too-thick conductors may require special adapters for standard connectors.
  • Cable thickness.
    Typically, the more influential the feeder, the more shielding layers used, the thicker the center core, and the more reliable the insulation. However, this is only a rough guide. A high-quality, thin cord may be better suited for installation than a thick, low-quality cord.
  • The material of the center core.
    Copper transmits the signal better, while clad steel is more substantial. The core’s material can be easily checked: You need to take a magnet and bring it to the cable. If it attracts, it means steel, not copper.

Also read:  How to boost TV antenna signal

what is coaxial cable used for

Most Used Antenna Cables

The three most common types of coaxial cables are RG-6, RG-59, and RG-11. Each cable serves a different purpose. RG stands for Radio Guide, and the RG number refers to the diameter of the cable.

RG-59

Coaxial cables of this type are used as feeders in television networks and video surveillance systems. The outer sheath is made of foamed PVC, and the inner sheath is made of polyethylene. They are essentially a cheaper alternative to RG-6.

Pros:

  • Excellent shielding, especially when working with HDTV at frequencies below 50 MHz;
  • low price;
  • the small diameter of the center core (0.02-0.023 in) 0,5-0,58 mm and outer sheath (about 0.24 in) 6 mm simplifies installation in cable channels.

Minuses:

  • narrower frequency range than RG-6 – only 2 GHz;
  • Significant signal attenuation is the price to pay for the thin center core. RG-59 cannot be used over long distances (500 feet or more).

RG-6

Signal wire with a diameter of 1.0 mm (0.04 in) is available in two versions: with a copper or copper-plated steel core. The screen is made of triple-ply aluminum foil and tinned copper, and the outer sheath is PVC.

Pros:

  • wide operating range – up to 3 GHz, which allows it to be used for satellite TV;
  • if a steel core is used, the feeder does not sag, and wiring can be done with a small number of fasteners;
  • high shielding factor (80-90 dB).

Minuses:

  • brittleness of the outer jacket;
  • not consistently high-quality braiding. Before buying, check how tightly the wire shield is wound;

RG-11

RG-11 is a coaxial cable for HDTV. It provides more airspace for signal transmission, making it suitable for transmitting powerful HD signals at high speeds. Using low-loss RG-11 cable means better overall signal quality.

Larger-diameter cables, such as RG-11, reduce signal loss over longer distances and provide increased durability and weather resistance, making them ideal for outdoor applications.

Another cable with an impedance of 75 ohms. More durable and with lower loss than RG-6, it is better suited for longer cable runs.

It provides lower attenuation than RG-6 or RG-59.

Also read:  Home cinema is commonly calibrated at 14-16 ft lamberts.

how to choose a coaxial cable

Which brand to choose

When making your choice, consider the following:

  • If long overhangs are used during installation, causing the feeder to stretch under its weight, losses should be ignored, and brands with a steel core should be used. Copper can tear in such cases.
  • A feeder with low signal losses should be used to lay satellite TV networks. In this situation, amplifiers are technically challenging to use.
  • The foil layer, not the braid, is essential in shielding. Therefore, foil cable should be used for satellite or terrestrial networks with low signal strength.

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