How to choose an antenna for DVB-T2 television for home and garden

Recommendation points

• Briefly about digital television technology
• Antenna types
• Can I use analog antennas
• Do I need to preamplify the signal
• Antennas for individual and collective use
• By trial and error

With the introduction of the digital standard DVB-T2, the first generation receivers turned out to be irrelevant: the architecture of the receiving station became more complicated, the problem of choosing the right antenna became more acute. In areas where the transmitting source is close, signal reception is also possible on a nail, but what about those who have a weak signal?

Briefly about digital television technology

In less than 10 years, the second generation DVB standard has firmly established itself and developed in the CIS radio air. Users now have access to not only sound and image, but also interactive functions of digital television: TV guide, subtitles and others like them. Unlike a more primitive method of processing an analog signal, digital TV requires a radically different element base.

In contrast to the more stable analog radio signal, digital is more susceptible to interference. The digital code includes not only information about the picture, but also check blocks that allow you to recover the signal if it was received with an error. Because of this feature, the signal receiver should not be exposed to all kinds of noise, therefore, excessive antenna size and amplifier power are not always desirable. In receiving a T2 signal, the correct positioning of the antenna and the compliance of its type with the conditions of use is much more important. Compliance with some general rules and recommendations of the manufacturer will help to achieve a clear and stable signal level, to reduce the influence of atmospheric phenomena on the quality of reception.

Antenna types

All antennas for digital television can be divided into internal and external. In the first case, everything is simple: the antenna has a minimum distance from the TV or receiver and is located on the nearest windowsill. This boring picture from a DVB-T2 advertisement rarely correlates with reality: for such an antenna location, you need a reliable signal reception and a direct line of sight of the repeater. Therefore, usually only 30–40% of residents of large cities can afford this method of installation. For indoor installation, loop antennas and balanced dipoles are usually chosen..

Indoor antenna “Remo Wave digital”

If the distance from the transmitting station is more than 10-15 km, an external antenna must be installed. The most common antennas for outdoor installations are “wave channel” and log-periodic antennas. They provide reliable reception at a distance of 30-40 km with the correct direction. There are also hybrid receiving devices: for example, several log-periodic vibrators complete with a lattice mirror as a reflector. The most advanced antenna designs can provide reception from a station 50-80 km away in open areas, provided that the direction is carefully verified.

External antenna “SPECTR 100”, designed for maximum distance from the repeater

Can I use analog antennas

Broadcasting on a coded radio signal is carried out in a wider range than analogue television. DVB-T2 receivers must be able to receive, in addition to decimeter waves, the entire rest of the VHF range, and besides this, also microwave waves. In general terms, the range of received frequencies is determined by the linear dimensions of the antenna elements. Thus, old-style antennas can only be used if broadcasting is carried out on the appropriate frequency range. At the same time, the signal level will still be up to 50% lower than in the case of a carefully selected and correctly installed antenna for DVB-T2.

The most common practice is to use analog antennas in urban areas. Suburban areas do not have a confidently high signal level, so antennas require not only outdoor installation, but also an appropriate radiation pattern. Unfortunately, most of the active reflex (Polish) antennas, like ordinary decimeter ones, do not fully correspond to the reception-transmission parameters. Thus, the Polish antenna can be used at a repeater distance of up to 20 km, a normal “traveling wave” – ​​up to 15 km.

Do I need to preamplify the signal

The use of an active antenna for receiving a DVB-T2 signal is extremely preferable, but for country houses it is strictly necessary. Most antennas use familiar SWA amplification schemes, but the operating parameters of the preamplifier require completely different.

The first difference is the power source. The vast majority of SWA amplifiers are designed to supply power over coaxial cable, which requires a corresponding function in the receiver. Thus, the conversion circuit hidden in the plug of a conventional analog antenna must either be absent or be disabled..

General Satellite AV-958 active indoor antenna with 30 dB gain

The second question is the degree of amplification. Due to the low noise immunity, only circuits with a gain of up to 35 are suitable for signal amplification; with a higher gain, problems with signal decoding may occur. This limits the range of active antennas to 60–70 km instead of the usual 80–100 km.

Antennas for individual and collective use

At a great distance from the repeater, a high-quality picture can be obtained only with the use of powerful antennas with a wide radiation pattern. Fortunately, DVB standards support the sharing of radio signals, so installing an expensive antenna can be done by multiple households..

Building such a reception system is a rather complicated undertaking, but there are only two key points:

1. Installation system. If the terrain is changeable or there are forest plantations or urban development at the desired azimuth, an antenna installation height of 12-15 meters or more will be required. This is the main condition for signal reception at a distance of up to 80 km, while not everyone can afford to install a suitable mast.
2. Powerful active circuit or several individual ones. On a common mast, several dozen active antennas of individual connection can be placed at different heights. Another great opportunity is provided by the power reserve of the amplifiers: when 3-4 log-periodic antennas are connected in parallel, directed with overlapping diagrams, several receivers can be connected to them simultaneously. It is also allowed to install a powerful digital station on the antenna, in which the functions of a router and an amplifier are combined.

By trial and error

You should not stop choosing antennas of dubious origin: sold with hands or without a certificate. Although the antenna costs about half the cost of the receiver, its purchase must be accompanied by a warranty of service and replacement.

CIFRA-6

The fact is that when the repeater is removed up to 50 km, the noise content in the radio signal is relatively small, but it increases abruptly at around 55 km. In this regard, the use of active high-power antennas is advisable only outside the zone of reliable reception. In other words, if a budget antenna does not work in the zone of reliable reception, this is not necessarily a consequence of a lack of power. Most likely, the matter is in the wrong directionality, inaccurate adjustment of the gain level or mismatch of the parameters with the signal range. Sometimes a manufacturing defect is the cause of failures. Therefore, it is recommended to use digital TV coverage maps, check the broadcast ranges and, to be sure, try 2-3 models of antennas of different types and with different gains.

Antennas for digital television of the DVB-T2 standard

Name	Antenna type	Approximate working distance to the repeater, km	Gain, dB	Average price, rub.
DIVISAT DVS-Z1	Indoor, active	ten	18	400
Locus L 922.06 ALTA	Indoor, active / passive	zone of confident reception	In passive mode 6-9, in active mode 16-19	600
REMO Wave digital	Indoor, active	ten	18-24	900
GS AV-958	Indoor, active	20	thirty	1000
Alpha H111 DVB-T2	Street, active	thirty	18	500
CIFRA-6	Street, passive	ten	4.5-7 (Antenna power can be increased with an active amplifier.)	1200
REMO Belka BAS-1121	Street, active	40	40	1200
Locus L020.92	Street, passive	60	12-16.5	1600
SPECTRUM 100	Street, active	80	14-35	2000