Before going into the heart of this guide and seeing how to choose a TV antenna , discovering in detail what are the main features to look at when choosing this type of product, I would like to provide you, in broad terms, with some information on how it works.
The television channels and, consequently, the various programs on the schedule such as films and shows, are radiated into the surrounding space, in the form of amplified signals (radio waves), by repeaters (also called transmitters). These signals are picked up by terrestrial antennas, placed on the roofs of our houses, which then transmit this signal to the television or DTT decoder .
So it goes without saying that, in order for the antenna to receive the TV signal at its best, the first factor to take into consideration is the radio coverage , i.e. your location compared to that of the repeater as well as the signal strength and proximity, without major obstacles (hills, mountains or buildings) between you and the transmitter.
Finally, a last clarification should be made on the transmission frequencies (also called frequency bands ). In fact, broadcasting stations broadcast with the following transmission frequencies.
- VHF (Very High Frequency or, in Italian, Frequency Very High) — the basic frequency that covers from 30 to 300 Megahertz (MHz), however it is being phased out because it is not able to receive all the channels transmitted by digital terrestrial.
- UHF (Ultra High Frequency or, in Italian, Frequency Ultra Elevate) — which supports a wider band, from 300 MHz to 3 GHz, with better quality even on high definition. Most of today’s digital broadcasting channels are in the UHF band.
So, having made these necessary premises, here are the main characteristics that you must take into consideration to find the best antenna capable of fully satisfying your needs.
Typologies
So if you want me to recommend the main types of TV antennas among the most interesting ones currently available on the market, then I’ll settle you right away.
For domestic use, the most used and best performing antennas are certainly the outdoor ones , generally installed on the roof of the apartment, on the facade of the building or on the balcony railings using special clamps and dowels. This type of antenna picks up the transmitter signal even at long distances, even if partially hidden. It is also possible to connect several television sets to the same antenna, using signal splitters or amplifiers to improve reception.
Depending on the coverage and distance from the repeater, there are the following types of outdoor antennas to choose from, which differ from each other in certain characteristics.
- Broadband — have better reception as they cover a very wide range of frequencies, these are the most used antennas in homes. Suitable for both TV channels and radio connections.
- Directives (or Yagi antenna) — suitable in those areas where there is little coverage since they receive a lot of power in a specific area, still managing to take most of the channels well.
- Panel — designed for those situations where the signal comes from different directions even from the farthest distance.
- Logarithmic — consist of two broadband antennas. Thanks to the very wide opening angle, these antennas are used in areas where the signal is clean and strong, even when the repeaters are not perfectly aligned.
Finally, where the distance from the transmitter is very short (less than 5 kilometers as the crow flies) with a total absence of obstacles, you can consider buying an indoor antenna . They are very practical, compact, easy to install and equipped with an integrated amplifier to improve reception. However, it will be possible to connect only one television, placed however in the same room, therefore without carrying out masonry work to pull the antenna cables around the house.
I earn
The main feature of a TV antenna is undoubtedly the gain , i.e. the measurement, expressed in isotropic decibels ( dBi ), which indicates how much electromagnetic signal present in the air the antenna is able to transform into an electrical signal, essential for the proper functioning of the TV. Simply put, gain is the amount of TV signal picked up by an antenna.
The higher the gain of the antenna, the higher the directivity, but this means that an antenna with too high gain will have to be pointed with almost pinpoint accuracy at the repeater, otherwise it will not work well.
As a general rule, 35 dBi gain is a good compromise for your antenna. On the other hand, antennas with a higher value should be avoided.
Forward/reverse ratio
Another feature to consider, when buying an antenna, is the forward / backward ratio , i.e. the shielding that the antenna has towards signals coming from behind.
This ratio, expressed in decibels ( db ), in fact measures the difference between the ability to gain a signal in the maximum reception direction (therefore coming from the front) and its attenuation in the opposite direction at 180°
In a nutshell, it indicates how much the antenna “takes”: the higher this value is, the better the antenna efficiency will be.
Wind resistance
As mentioned before, the installation of outdoor antennas takes place mostly on the roofs of buildings or on the balconies of apartments, very often in open spaces precisely to avoid the interference of obstacles. This means that the antennas are exposed for most of their “life” to atmospheric disturbances such as rain and above all wind.
Therefore, in order to know the resistance of an external TV antenna to bad weather, we need the wind resistance (or wind load ), expressed in kilograms ( Kg ) or in Newton ( N ), i.e. the value calculated in the hypothesis of a wind which has a speed of about 120 Km/h (or 720N/m²).
A good value of wind resistance coefficient is around 18 kg, therefore suitable in the most windy areas. Also remember that wind resistance is also useful for determining the dimensioning of the pole on which the antenna will be mounted, as well as any tie rods for anchoring.
Dimensions and number of elements
An antenna, to pick up the amplified signal of the repeaters, needs a number of elements arranged in a manner appropriate to the reception direction. Each element is normally half the wavelength of the signal to be received, ie the longer the elements, the lower the frequencies they can receive. The shorter elements, in fact, correspond to the UHF frequency range, known as Ultra High Frequency.
Obviously the number of elements also determines the dimensions of the antenna: the more elements it will consist of, the greater the overall dimensions will be and it will also require a more complex installation.
Installation
Unless it’s a replacement (and not always), as far as a new system is concerned, do-it-yourself is always inadvisable, entrusting the installation to a professional antenna installer.
Most of the time, in fact, the antenna is placed on the roof or on a terrace and this certainly makes the operation more difficult, moreover it is often necessary to raise it further to increase the reception of the signal, therefore tying it to a pole or even positioning it on a taller turret.
Finally, and most importantly, it is necessary to know how to direct the antenna as best as possible in favor of the repeaters and check its orientation. Furthermore, in the presence of several antennas, a specialized technician will be able to position them to avoid interference between them.
If you are still interested in learning more about the subject, then I suggest you take a look at my guide in which I explain how to orient a TV antenna.