The modern world is characterized by the rapid development of information technology. Therefore, the means of transmitting information are significantly improved. After all, they should provide higher quality and speed of data processing. One of these areas, which became widespread, was satellite communications. It is used in many fields of human activity: from large industrial developments to small households.
One such development is satellite television. It is now very difficult to find at least one apartment building in which at least several satellite dishes would not be installed . This is not surprising, because for a fairly small fee you can get excellent quality broadcast television channels from around the world.
There are two main types of these devices: direct focus and offset antenna. Their main difference from each other is the location of the received signal. Also, the sizes of the parabolic dish are not the same . So, the offset antenna is small, and the location of the converter (reflection occurs in it) is offset relative to the geometric axis. For a direct-focus antenna, large sizes and, accordingly, reflection to a point placed on the geometric axis are characteristic.
The offset antenna works on the principle of reflection of the signal from the front of the parabola to the converter. In this case, only part of the entire parabola branch is used. A large offset antenna has the full-face appearance of an egg, those of a smaller one - a circle. Large include devices that have a minimum diameter of more than one meter. For small ones - less than a hundred centimeters.
But it is worth noting that the offset antenna cannot be used to receive a professional television signal. This is because when reflected on the converter, an uneven spot is formed.
To install offset satellite dishes, you do not need a significant investment of time and energy, since these devices must be fixed almost vertically, and this greatly simplifies their mounting on a balcony or just on a wall of a house.
This device also has one important advantage: any
precipitation does not linger on a reflective plate. All these parameters contributed to the widespread use of such devices for connecting satellite television.
Offset antennas can be made of different materials: plastic, steel, mesh, aluminum - all this can become the basis for the production of reflective surfaces. Each of these devices has its own disadvantages and advantages. For example, plastic antennas are highly susceptible to temperature, but are much lighter in weight and more convenient to install. Steel, on the contrary, is heavier, but much stronger and more reliable. Although antennas made of this material have one property that negatively affects reception, they rust over time.
The modern market will provide you with a wide range of products, so you can always choose exactly what is suitable in a particular case.