Surely many, at least once asked this question. This, at first glance, a simple matter, in fact turns out to be quite a difficult task. Even an experienced specialist, having assessed the reception conditions, cannot give a 100% accurate conclusion on which equipment should be used in a particular case.

The criterion for choosing an antenna, a complex of antennas and amplifying distribution equipment, consists of many factors:

1. Direct visibility to the TV center;
2. Distance from the television center;
3. The presence of obstacles in the reception area that do not necessarily block the reception, such as chimneys of enterprises, high-rise buildings, power lines, trees;
4. The presence of higher buildings in the opposite direction to the reception;
5. The presence between the television center and the reception point of the lowland;
6. The number of television programs broadcast from the television center, their location in the frequency plan and the ratio of signal levels.

Of great importance is direct visibility to the television center, and if you have the opportunity to move the antenna above all obstacles in the direction of reception, do not even try to put the antenna near the window, hoping that by using an amplifier you can achieve high-quality reception.

In line-of-sight conditions, the Delta H311 antenna and its analogues that have recently appeared have proven themselves well. This is a very commonly used option, but factors such as No. 2, 3, 4, 5, 6 can negate all the advantages of this antenna:

If there are no obstacles in the direction of reception, but the range exceeds 50 kilometers, then no matter how high you raise the antenna, it is very difficult to achieve the desired result. At such a distance, the natural attenuation of the signal in the layers of the atmosphere begins to affect. This is where an amplifier can come in handy. In such cases, a mast amplifier is preferable, located next to the antenna and providing maximum efficiency.

If there are high obstacles in the receiving direction, then the direct and reflected signals will arrive at the receiving point with a time shift. The reflected signal will be viewed as a second, weaker image shifted relative to the main one. Also, if the reflected signal is strong enough, then viewing the image becomes impossible due to a synchronization failure. The whole trouble is in the relative simplicity of the Delta H311 type antenna, its radiation pattern is very wide and it is very rare to detune from the reflected signals. In this case, it is necessary to use a complex of antennas with a high gain and a narrow radiation pattern.

The same problems as in paragraph 3 may arise if there are high obstacles in the opposite direction of reception and the reflected signal, with an even greater delay, will be received C3adi. An antenna of the Delta H311 type has a protective coefficient only in the UHF, the image on the meter channels will be spoiled by reflected signals. In such cases, it is necessary to use antennas with a good protective effect. Or, if possible, hide the antenna behind a natural screen, for example, behind an elevator booth. Naturally, there should be a direct line of sight in the direction of the television center.

The lowland located between the television center and the receiving point is also a good source of reflected signals. The Delta H311 antenna is not able to deal with such interference, as well as in the horizontal plane in the vertical it has a very wide radiation pattern. It will help only if the front part is raised higher, but the useful signal is significantly weakened. Again, a complex of antennas with a narrow radiation pattern will come to the rescue in this situation.

Up to 30 km away. The Delta H311 antenna is able to provide a good signal to up to three TVs, provided that a high-quality cable is used. If you need to connect more than three TVs, you can’t do without an amplifier. From the Delta H311 antenna, it is really possible to power up to 10 TVs when using an apartment amplifier such as IKUSI ATB122 or a mast IKUSI JMB222. If you need to connect more than 10 TVs or higher quality requirements when connecting large-screen TVs, it is better to use a set of three antennas that will equalize the levels across the ranges and thereby facilitate the operation of the amplifier and get a better picture.

Publication: cxem.net

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