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Choosing the right TV antenna – general considerations
Choosing the right antenna is a key issue in any TV system. When looking for the right model consider the following factors:
1) Gain.
The basic and measurable parameter to consider when choosing an antenna is its energy gain, usually given in dBi. In simple terms, it means how much "better" a given antenna is in relation to a theoretical isotropic antenna – an omnidirectional, lossless one having zero physical dimensions. The greater the gain, the better. Some antennas have amplifiers in the antenna box, which, when supplied with voltage (usually 12 VDC), further increases the received signal level. However, this should not be confused with the nominal gain of the antenna itself. Is use of the amplifier always desirable? Not always.
The basic and measurable parameter to consider when choosing an antenna is its energy gain, usually given in dBi. In simple terms, it means how much "better" a given antenna is in relation to a theoretical isotropic antenna – an omnidirectional, lossless one having zero physical dimensions. The greater the gain, the better. Some antennas have amplifiers in the antenna box, which, when supplied with voltage (usually 12 VDC), further increases the received signal level. However, this should not be confused with the nominal gain of the antenna itself. Is use of the amplifier always desirable? Not always.
2) Directivity.
The ability of an antenna to absorb energy from one direction at the expense of other directions. In the case of directional antennas, this parameter is related to gain – the greater the gain, the higher directivity. This often desirable feature may turn out to be a disadvantage when trying to receive reflected signal, which usually happens in the city. In digital TV transmission technology it is possible to use reflections of the signal to the advantage of the receiver – in a sense, the reflections add up generating higher signal power. Strongly directional antenna with high gain is therefore not always the best solution.
The ability of an antenna to absorb energy from one direction at the expense of other directions. In the case of directional antennas, this parameter is related to gain – the greater the gain, the higher directivity. This often desirable feature may turn out to be a disadvantage when trying to receive reflected signal, which usually happens in the city. In digital TV transmission technology it is possible to use reflections of the signal to the advantage of the receiver – in a sense, the reflections add up generating higher signal power. Strongly directional antenna with high gain is therefore not always the best solution.
3) Location, aesthetics.
Big antennas usually do not fit on balconies or in window recesses. For most of us, especially in cities, it is important that the antenna does not take up much space and is not conspicuous. The size of the antenna, as well as its directivity, is connected with its gain; as a rule, the larger the antenna, the higher the gain. So is the ideal solution to mount a small antenna with an amplifier? Not always.
Big antennas usually do not fit on balconies or in window recesses. For most of us, especially in cities, it is important that the antenna does not take up much space and is not conspicuous. The size of the antenna, as well as its directivity, is connected with its gain; as a rule, the larger the antenna, the higher the gain. So is the ideal solution to mount a small antenna with an amplifier? Not always.
4) Signal amplifiers.
Regardless of the antenna installation place, you should always check the reception possibilities without using amplifiers or preamplifiers. If reception without extra support is sufficient, the problem power supply to the antenna is avoided, and so are the malfunctions and possible overdrive problems that cause unstable reception.
Regardless of the antenna installation place, you should always check the reception possibilities without using amplifiers or preamplifiers. If reception without extra support is sufficient, the problem power supply to the antenna is avoided, and so are the malfunctions and possible overdrive problems that cause unstable reception.
An ideal antenna is the one that has high gain, optimal directivity, relatively small size, and will not require additional power supply. However, every installer knows that such a model does not exist. The choice of an antenna is largely a matter of making appropriate compromises.
Professionals working in unknown regions often have several antenna models to choose from – the ones with combiners and preamplifiers installed in antenna boxes, if needed. Taking appropriate measurements with a special meter the optimum antenna for the location can be selected.
What about customers wishing to choose and install TV antennas themselves? Unfortunately, they have to take the risk – to buy a passive version of the antenna and, if necessary, buy a preamplifier. Both in the case of the installer and the customer buying the antenna themselves, it is far from ideal solution.
To meet the needs of consumers and installers, DIPOL has introduced SMART antennas that significantly facilitate solving the above mentioned problems.
DIPOL SMART – choosing an antenna is no longer an issue!
DIPOL has solved most of the above problems by offering 2 models of DVB-T2 antennas of SMART series, which are suitable for almost any installation scenario.
These antennas have a number of advantages, with the versatility being the most important. The bypass used in the antenna box makes it possible to work in two modes:
- passive – the antenna works with its nominal gain (max. 14 dBi for HORIZON models and max. 10 dBi for CITY models),
- active – after applying 12 VDC through the coaxial cable (from the power supply (not included), multiswitch, amplifier, etc.), the signal is amplified by additional 20 dB.
So, using these antennas, the installer avoids troublesome replacement of the combiner for preamplifier and testing reception in different configurations. For SMART antennas, testing of various options is performed by switching on and off the power supply of the preamplifier at the meter. The installer can immediately verify whether additional boosting of signal level is needed in a specific location, and the final signal parameters offered by the antenna.
Which model to choose?
For those who wonder which model of SMART antenna to choose, we present a simple algorithm to help make the decision. Note that receiving of terrestrial television depends on a number of external factors and choosing an antenna according to the above instructions cannot guarantee 100% success. If your location is known to have problems with DVB-T2 signal reception you should use the services of a professional installer, who, if possible, will select an appropriate antenna, add extra components, if necessary, and provide complete information about the reception parameters for individual channels.
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SMART antenna and TV connection diagrams depending on the operating mode. In the active mode use the 12 VDC power supply, while in the passive mode, it is sufficient to connect the antenna directly to a TV set using an antenna cable terminated with F-connector (antenna) and IEC-connector (TV/receiver).
