Among the many cables that electronic devices can use, there are coaxial cables , widely used in the industry and well known for example because they are the ones we use to connect the television signal. In this article we are going to tell you what they are, what their characteristics are and, especially, what they are used for .
Surely, at some point you have used a coaxial cable even without knowing it, since its use is very common even today, although it is true that in the past they had many more practical applications than today. In any case, let’s see what they are and what they are used for.
What are coaxial cables and what are they for
Coaxial cables are also known as coaxcable or just coax . They were created in the 1930s to transport high-frequency electrical signals, and have the peculiarity that they have two concentric conductors: a central one called the nucleus (D), in charge of transporting the information, and another exterior with a tubular appearance called mesh, shielding. or braid (B), which serves as grounding and current return.
The center conductor can be made of a single copper wire (this is common) or of several twisted wires, while the outer conductor can be a braided mesh, a rolled sheet or even a corrugated tube. Sometimes it is made of copper, but it is usually made of aluminum because it is cheaper.
Between the two conductors there is an insulating layer (C), and the whole set is in turn covered with another insulating layer (called the outer jacket) to protect the whole set (A).
This cable is especially useful for transmitting video or audio signals, since the insulators and shields make it especially good at avoiding electrical noise and signal interference, and for that reason its use is widespread in radio and television systems, as well. as in professional audio systems. For this reason, many sound cards incorporate coaxial connectors, especially those that are oriented for the professional environment.
Thus, coaxial cables are much more resistant to interference and signal attenuation than twisted pair cables; the wire mesh absorbs the lost electronic signals, so that the data transmitted over the central cable is never lost. For this reason, this is also a type of cable that is widely used to cover large distances and to reliably support large volumes of data.
In the image above you can see a high voltage coaxial cable, used to transport large amounts of power but not data, since they also represent the ideal type of cable for this purpose.
Types of cables
Although there are more than a dozen types of coaxial cables, only three are used today and they are the ones we are going to see next. The difference between the three types has to do simply with the width and gauge of the copper center conductor, and generally speaking the larger the gauge, the less the degradation in signal quality with respect to distance or length of the copper. cable.
- RG59 : it is the thinnest, and therefore the most malleable. It is ideal for closed circuit TV (CCTV), but its bandwidth does not allow high definition video transmission. It only supports a few tens of meters before the signal starts to degrade.
- RG6 : it is the best known and most widespread, as it is the type used for high definition television. Supports a distance of up to 600 meters without signal loss.
- RG11 : It is the best of all and also the most expensive, and supports lengths of up to 1,100 meters.
By the way, generally coaxial cables have two types of connector: either the “antenna” that we all know from TV, or the infinite thread, more used in professional and / or audio systems.
What are coaxial cables used for?
We have already mentioned that they are the most common type of cable for television, and it is the one that we will generally use to connect the antenna socket to the TV. They are also widely used in CCTV systems (and a PC can come in here) and professional audio, as well as to transmit even electrical power without data.
In PC they are used with TV capture cards, but also with some sound cards that, as we have mentioned before, are more oriented to the professional environment.