Simple antenna for digital television dvb t2. What is the difference between an antenna for receiving digital television and a regular one? Antenna assembly for DVB-T2

Digital terrestrial television(DVB-Digital Video Broadcasting) is a technology for transmitting television images and sound using digital encoding of video and sound. Digital coding, unlike analogue, ensures signal delivery with minimal losses, since the signal is not affected by external interference. At the time of writing, 20 digital channels are available, and this number should increase in the future. This number of digital channels is not available in all regions; find out more precisely about the possibility of catching digital channels You can visit the website www.rtrs.rf. If your region has digital channels, then you just need to make sure that your TV supports DVB-T2 technology (this can be found in the documentation for the TV) or purchase a DVB-T2 set-top box and connect the antenna. The question arises - Which antenna to use for digital television? or How to make an antenna for digital television? In this article I would like to dwell in more detail on antennas for watching digital television, and in particular I will show how to make your own antenna for digital television.

The first thing I would like to emphasize is that digital television does not require a specialized antenna; analog antenna(the one you used previously to view analog channels). Moreover, only a television cable can be used as an antenna...

In my opinion, the simplest antenna for digital television is a television cable. Everything is extremely simple, take a coaxial cable, put an F connector and an adapter for connecting to a TV on one end, and at the other end the central core of the cable is exposed (a kind of whip antenna). All that remains is to decide how many centimeters to expose the central core, since the quality of reception of digital channels depends on this. To do this, you need to understand at what frequency digital channels broadcast in your region, to do this, go to the website www.rtrs.rf/when/ here on the map, find the tower closest to you and see at what frequency digital channels broadcast.

More detailed information you will get if you click the "More details" button.

Now we need to calculate the wavelength. The formula is very simple:

where, λ (lamda) is the wavelength,

c - speed of light (3-10 8 m/s)

F - frequency in hertz

or simpler λ=300/F (MHz)

In my case, the frequency is 602 MHz and 610 MHz, for the calculation I will use the frequency of 602 MHz

Total: 300/ 602 ≈ 0.5 m = 50 cm.

Leaving half a meter of the central core of a coaxial cable is not beautiful and inconvenient, so I will leave half, or maybe a quarter, of the wavelength.

l=λ*k/2

where l is the length of the antenna (central core)

λ - wavelength (calculated earlier)

k - shortening coefficient, since the length of the entire cable will not be large, this value can be considered equal to 1.

As a result, l=50/2=25 cm.

From these calculations it turned out that for a frequency of 602 MHz I need to expose 25 cm of coaxial cable.

Here is the result of the work done

This is what the antenna looks like when installed.

View of the antenna when watching TV.

Digital terrestrial television is a good budget alternative to satellite TV. Its main advantages are perfect quality pictures and sound and lack subscription fee. For reception you only need a set-top box (receiver) and an antenna for digital television, and an excellent image is guaranteed with any TV. An impeccable image is achieved through a qualitatively different method of signal transmission than in the case of analog television. The digital signal is not subject to interference and interference and is much less dependent on the distance to the transmitter.

What channels can I receive with a digital TV antenna?

IN first and second already available today in Moscow and in many regions for free admission multiplexes (packages) of channels, including 20 federal ones (Channel One (1TV), "Russia-1", "TVC", "NTV", "Channel 5" (St. Petersburg), "Russia-2", "Russia-24" ", "Russia-Culture", "Carousel", "OTR" (1st multiplex); "REN-TV", "STS", "Domashny", "TV-3", "SPORT-PLUS", "SPAS ", "STAR", "MIR", "TNT", "MUZ-TV" (2nd multiplex). The expansion of the broadcasting area of ​​the third federal multiplex of 10 channels continues. During 2015, the third multiplex was launched, with a total number of at least 10 channels, including HD. Digital television is already broadcast in more than 80 regions of Russia.

Antenna for digital television - how to choose?

Depending on the location of installation, antennas can be indoor or outdoor, respectively for home and garden. They are also divided into active and passive, depending on the presence of a built-in signal amplifier operating from the network. If you live near a TV tower, passive (without an amplifier) ​​reception is recommended. indoor antenna: Amplifying the signal may cause distortion. When moving away from the TV tower, for example at a dacha or in country house and the presence of obstacles (trees, buildings) is necessary outdoor antenna with built-in or external signal amplifier. The main condition when choosing an antenna for digital television should be reliable reception in the UHF range. Attention, you can find outdoor antennas in the section Outdoor antennas for digital television

Is it possible to make the antenna work for two TVs?

You can connect two or more TVs to one antenna for digital television. However, if you use one receiver for reception, then each TV will show the same channel. To watch different channels at the same time, you need to purchase receivers for other TVs.

The delivery department will deliver the goods you have chosen to any point in Moscow and the Moscow region.

Seal

The plots are located from the city to different distances 10 km, 50 km and more, and from the TV tower the distance can be even greater and be 100 - 150 km. This is a significant distance and for stable reception of digital television in the country you need an active antenna.

Let me start with the fact that stable reception at distances of up to 30 km can be provided by passive antennas, and in order to ensure stable reception both in summer and winter over long distances, you need to use a more powerful one with an amplifier, and for hilly areas, as well as beyond long-distance reception, you also need to raise it higher using a mast.

To transmit a signal in digital TV, the decimeter range (UHF) is used with frequencies of 470 - 862 MHz (channels 21-69), so when choosing an antenna for your dacha, you need to focus on them. However, you shouldn’t rely only on this type to receive DVB standard T2 are also applicable to all-wave (broadband), capable of receiving both the decimeter range and the meter range 48 - 230 MHz.

Modern antennas are made of steel or aluminum and have an operating temperature range from -50 to +50 degrees with protection from external influences (snow, rain). Metal is heavier, but unlike aluminum, it is more reliable against deformation. Their forms are different, but the most effective, time-tested, so to speak. broadband antenna MV/UHF - wave channel. Such an antenna for the dacha for receiving digital TV is the best option.

The most common antennas today are “Delta” and “Locus”. They have different odds gain (measured in decibels, dB) or adjustable, so you need to look at their characteristics. You need to understand that an-na itself has its own amplification, just like an amplifier.

Offered by sellers digital antennas and the amplifiers are nothing more than a publicity stunt. Amplifiers, if they are not something special, by their purpose simply amplify the signal, in in this case television, in the entire frequency range of TV broadcasting. In the case of antennas, designating them as digital means that they are capable of receiving decimeter waves.

When installing an antenna on a mast, be sure to use grounding, even if the metal mast is on the ground. This will help drain static electricity into the ground during a thunderstorm (and of course when struck by lightning), which will prevent the amplifier from failing. Grounding the grid (reflector) of a Polish antenna improves its performance, as it reflects the signal back to the vibrators, which amplifies it.

If you intend to do active antenna yourself, then you can find a lot of various solutions, even from beer cans, the only question is whether they will work effectively and I advise you not to waste time, they are not that expensive. For example, an inexpensive so-called “Polish” one for receiving digital television in the country, with a range of up to 100 - 120 km, will be just the thing.

Antenna amplifiers

“Polish” all-wave antennas use SWA amplifiers with different gains; you need to purchase them separately, depending on the distance from the tower. You can navigate using the following table:

So let's summarize. If you need an antenna for a TV at your dacha, then if the distance from the TV tower is from 10 to 30 km, choose from indoor active ones, with greater distance— choose among street (outdoor) ones. The greater the distance, the greater the gain should be. Nothing bad will happen if the antenna for the dacha has a slightly higher gain than necessary, so to speak, the margin will not hurt and then 10 or 20 channels (depending on the region) will be shown without problems.

Good afternoon, V.Yu.
The visitor in the latest posts with experience on FM radio antennas is me. The antenna turned out to be easy to manufacture and I decided to repeat it for FM reception and compare it with previously made ones, by ear, instrumentation, and ease of use. The goal was to obtain a signal with a minimum of interference for high-quality sound radio in stereo mode. I made two antennas. The first one is made of wire 3 mm thick. The second is made of metal-plastic. Made from metal plastic it turned out to be a little better in terms of the level of received signals. By ear - less low frequencies, more highs and clarity of each instrument in the orchestra.
Measurement method - there is a receiver with a signal level indicator in decibels. We number the FM stations and look at the level of the received signal from the station in dB, then we sum up all the values. We obtain the numerical value of the antenna based on the received signal level parameter. All antennas were placed under the same directional conditions. Wire on a window 303 cm long in the form of a rectangle with a gap along larger side 2 cm (51 cm x 102 cm) - has a value of 491 dB, a directional loop phased loop antenna made of wire - 459 dB, the same one made of metal - 485 dB. As can be seen from the presented values, the metal-plastic antenna is comparable to a full-size frame equal to length mid-FM waves.
Now on to the manufacturing technology. It is somewhat different from yours and is made without soldering. The base is a rail (30 x 6 x 3 cm). Remained from renovation (2 pieces). Wire antenna - circumference 75 cm (quarter wave mid FM range). Two circles of the same length. We take a light self-tapping screw (not dark - it has a cone head) with a flat head for a Phillips screwdriver. We make a hole in the rail with a drill or other method so that the wire enters the hole with little resistance. You can slightly bend the ends of the wire for this purpose. We insert the two ends of the loop into the hole in the rail and do not connect them to each other (leave 5 mm between the ends of the loop). We do the same with the second loop at the other end of the rail. The distance from the end of the rail is 1 cm. We screw the screws on top of the rail so that the end of the screw fits into the loop wire at the end. This ensures contact of the coax with the frame. Under the self-tapping screws we screw the central core of the coaxial and the braid with different sides framework. For example, the central core is on the left, and the braid is on the right in the direction from the beginning of the rail to its end. We lay the coaxial between the frames and attach it to the screws (screw it under the screw head). The second loop is also attached and the ends of the coaxial are secured under the screws securing the second loop. The descent is in the form of a coaxial - I got a length of 7.5 meters, we fasten it under the screws of one of the frames (the central core is on the left, and the braid is on the right. We tighten everything - the screws ensure contact of the wires with each other with the head, and contact with the loop with the end. The distance between with self-tapping screws - 2 cm We connect the other end of the coaxial cable to the receiver through the connector you need. That's it - the antenna is ready.
Metal-plastic differs in manufacturability. 20 mm pipe, also after repair. Bent into a ring without any problems. Loop length 75 - 1.5 cm (as recommended in the article) = 73.5 cm. Attaching the loop to the rail is also a self-tapping screw, but of a larger size so that it goes through the metal-plastic and is well secured to the wood, by 10-15 mm. There is a distance of 1 cm between the ends of one loop. The screws from the end of the loop are still at a distance of 0.5 cm. We get a distance of 2 cm between the screws of one loop. We lay a piece of plastic between the loops and fasten it with screws to the rail, so that the coax can be inserted inside. We connect the coax in the same way as in the first case to the ends of the loop, the central core and the braid. We ground the tube between the antenna loops (connect it to the braid). We insert a piece of coax into the pipe between the loops, connect the c.z. and braid. We also connect the reduction coaxial to the self-tapping screws of one of the loops (central ring and braid). We first clean the ends of the loops from vinyl to aluminum so that the head of the screw presses the wires to the aluminum and at the same time secures the loop to the wooden batten.
Best regards, Andrey

In the days of huge tube TVs, a good antenna for high-quality analogue television reception was in short supply. Those that could be bought in stores were not of high quality. That's why people made TV antennas Do-it-yourself UHF. Today many are interested homemade devices. And even when digital technologies are everywhere, this interest does not fade.

Digital era

This era also affected television. Today T2 broadcasting is developing especially widely. It has its own characteristics. In those places where the signal level slightly exceeds the interference, sufficient quality reception. There is simply no further signal. A digital signal does not care about interference, however, in a situation where there is a cable mismatch or various phase distortions almost anywhere in the transmitting or receiving path, the picture can appear in squares even with a strong signal level.

There have been other changes in modern television. Thus, all broadcasting is carried out in the UHF range, the transmitters have good coverage. The conditions under which radio waves travel through cities have changed greatly.

Antenna parameters

Before starting manufacturing, you need to determine some parameters of these structures. They, of course, require in-depth knowledge in various fields of mathematics, as well as the laws of electrodynamics.

So, the gain is the ratio of the input power reference system to the input strength of the antenna used. All this will work if each of the antennas creates values ​​of intensity and flux density with the same parameters. The value of this coefficient is dimensionless.

Directional coefficient is the ratio of the field strength created by the antenna to the field strength in any direction.

It is necessary to remember that parameters such as KU and LPC are not interrelated. There is a UHF antenna for digital TV, which has a very high directivity. However, its gain is small. These structures are directed into the distance. Highly directional designs also exist. Here it comes in combination with a very powerful gain level.

Today you don’t have to look for formulas, but use special programs. They already take into account all the necessary parameters. All you have to do is enter some conditions - and you will receive a complete calculation of the UHF antenna, so that you can then assemble it.

Manufacturing nuances

Any structural element in which signal currents flow must be connected using a soldering iron or welding machine. Such a node, if it is located in the open air, suffers from contact failure. As a result, various antenna parameters and reception levels can become significantly worse.

This is especially true for points with zero potentials. According to experts, voltage can be observed in them, as well as current antinodes. To be more precise, this is maximum value current. Is it available at zero voltages? This is not surprising.

Such places are best made of solid metal. Creeping currents are unlikely to affect the picture if the connections are made by welding. However, due to their presence, the signal may disappear.

How and what to solder with?

It is not very easy to make a UHF antenna with your own hands. This involves working with a soldering iron. Modern manufacturers TV cable They don't make it copper anymore. Now there is an inexpensive alloy that is resistant to corrosion. These materials are difficult to solder. And if you heat them long enough, there is a risk of burning out the cable.

Experts recommend using low-power soldering irons, low-melting solders, and fluxes. Don't skimp on paste when soldering. Solder will lie correctly only if it is under a layer of boiling flux.

Catching T2

In order to enjoy digital television, it is enough to purchase a special tuner. But it does not have a built-in antenna. And those that are offered as digital specials are too expensive and pointless.

Now we will learn how to catch T2 on a completely homemade design. Homemade antenna DMV is simple, cheap, high quality. Try it yourself.

The simplest antenna

To assemble this structure, you don’t even need to go to the store. To make it, the usual antenna cable. You need 530 mm of wire for the ring and 175 mm from which the loop will be made.

The TV antenna itself is a ring of cable. The ends need to be stripped and then connected to the loop. And to the latter you need to solder a cable that connects to the T2 tuner. So, on the ring, the screen and the central core are connected to the loop screens. At the latter, the central cores are also connected. And the cable to the tuner is soldered as standard to the screen and the central core.

So we got a UHF antenna, made with our own hands. Its design turned out to be very cheap and practical. And it works no worse than expensive store-bought options. It needs to be fixed to plywood or plexiglass. Construction clamps are perfect for this.

"People's" antenna

This design is a disk made of aluminum. The outer diameter of the element should be 365 mm, and the inner diameter should be 170 mm. The disk should have a thickness of 1 mm. First you need to make a cut in the disk (10 mm wide). In the place where the cut was made, a printed circuit board made of PCB should be installed. It should be 1 mm thick.

The board must have holes for M3 screws. The board must be glued to the disk. Then you need to solder the cable leads to it. The central core should be soldered to one side of the disk, the screen to the other. As for quality, such a TV antenna will receive better with two discs, especially if it is located far from the television repeater.

Universal antenna

Nothing supernatural will be used to make this design. We will make it from various available materials. However, even though it is homemade, it will work perfectly in the entire decimeter range. So, this UHF antenna, quickly made with your own hands, is in no way inferior to store-bought, more expensive designs. It will be completely enough to take T2.

So, to assemble this structure, you will need empty cans of canned food or beer. You need 2 jars with a diameter of 7.5 cm. The length of each is 9.5 cm. You also need to stock up on strips of textolite or getinax, always with foil.

Our cans need to be connected to PCB strips using a soldering iron. The plate of this material that will connect the containers at the top should have a continuous coating of copper foil. The foil on the bottom plate should be cut. This is done for convenient cable connection.

It is necessary to assemble the structure in such a way that the total length is not less than 25 cm. This antenna (UHF range) is a broadband symmetrical vibrator. Due to its surface area, it has large gain factors.

If suddenly you cannot find suitable jars, then you can use containers with a smaller diameter. However, then the foil will have to be cut on the upper connecting plate as well.

"Beer" antenna

Do you like to drink beer? Don't throw away cans. You can make them out of them good antenna. To do this, you need to attach two beer cans to any dielectric material.

First you need to choose a suitable cable, and then bring it to mind. To do this, the cable must be stripped. You will see shielding foil. There will be a protective layer underneath. But under it you can directly observe the cable.

For our antenna, you need to strip the top layer of this wire by about 10 cm. The foil needs to be carefully twisted so that you end up with a branch. The protective layer for the central core needs to be stripped to 1 cm.

On the other side, you need to solder a plug for the TV onto the cable. If you were a cable network subscriber, then you don’t even have to purchase this part and cable separately.

Now about the cans. It is advisable to use 1 liter beer containers. However, good German beer in such cans is expensive, and domestic beer is not sold.

Banks must be uncorked very carefully. Then you need to empty the container of its contents, and then dry it well. Next, use a self-tapping screw to connect our screen on the cable and the can. You need to screw the central core to the second one.

For more high quality image, it is better to connect the containers and cable using a jumper.

The cans must be secured to some kind of dielectric material. It is necessary to take into account that they should be located on the same straight line. The distance between them depends on the capacity. All this can only be determined empirically.

Zigzag

The UHF zigzag antenna has the simplest possible design. The part itself is broadband. Its design allows for various deviations from the original design parameters. At the same time electrical parameters it will hardly be violated.

Its input impedance in a certain range depends on the size of the conductors that will form the basis of the fabric. There is a dependency here. How larger width or the thickness of the conductors, the better the antenna will be matched to the feeder. In general, any conductors can be used to make the fabric. Plates, tubes, corners, and much more are suitable for this.

In order to increase the directivity of such an antenna, it is permissible to use flat screen, which will play the role of a reflector. The latter will reflect high-frequency energy towards the antenna. Such screens often have serious size, and the phase depends mainly on the distance.

On the practical side, only in rare cases is a reflector made from a single sheet of metal. More often it is made in the form of conductors that are connected in the same plane. For design reasons, you should not make the screen too dense. The conductors from which the screen itself will be made are connected by welding or soldering to a metal frame.

This design is very simple to make. It works well in the UHF range. In the USSR it was a real folk and irreplaceable model. It is small in size, so it can be used as an indoor UHF antenna.

The material will be copper tubes or aluminum sheet. The side parts can be made of solid metal. They are often covered with a net or covered with a tin. If one of the above methods is used, then the structure must be soldered along the contour.

The cable must not be bent sharply. You can see how to carry out this element in the presented pictures.

It must be guided in such a way that it reaches the side corner, but does not go beyond the antenna or side square.

UHF indoor antenna

This design is designed to be lightweight and confident reception digital television signals. It can be made easily and very quickly. To do this you will need an aluminum or copper rod. Its length should be up to 1800 mm. This antenna can also be used as an outdoor antenna.

The design is a diamond-shaped frame. There should be two of them. One acts as a vibrator, the second works as a reflector. To receive T2, we need the side of our rhombus to be approximately 140 mm, and the distance between them to be 100 mm.

After the frame is made and the structure becomes rigid, a dielectric is mounted between the two ends of our rod. It could be anything. The shape and size are completely unimportant. The distance between two points of the bars should be approximately 20 mm. The upper parts of our diamonds need to be connected.

The feeder can be made from cable. It must be connected to brass or copper petals, which should already be attached to the antenna terminal.

If the resulting design does not meet your expectations, for example, the reception quality is poor or the repeater is located far away, you can equip the antenna with an amplifier, and the result will be an active UHF antenna. It is used both in the city and in the country.

The simplest UHF loop antenna

This design resembles the number "zero". By the way, this is its gain factor. It is ideal for taking T2. This part can work better than the products offered in stores.

It is also called digital because it can be used to perfectly catch digital broadcasts. It is narrowband, which is a significant advantage. It works on the principle of a selective valve, which allows us to talk about reliable protection from interference.

For assembly you will need an ordinary coaxial cable with a resistance of 75 Ohms, as well as an ordinary TV plug. Of all the options, it is better to choose a cable with a larger diameter. You can use a cardboard box or anything else as a stand.

We determine how long the frame will be using programs for calculating antenna parameters. The material for making the frame can be used the same as for the cable. By the way, for calculations you need to know the frequencies digital broadcasting in your city.

The central cable core is not needed in the frame design. The stripped wire is twisted together with the core and braid of the frame. Then this connection needs to be soldered.

The structure must be placed on a dielectric base. It's best to keep it away from your tuner. It is important that there is no voltage at the antenna input.

So, we found out how to make a UHF antenna with your own hands. As you can see, this is not such a difficult task. But now you can watch your favorite TV shows in digital quality. And this design is installed in the same way as a regular store one - on the roof. You can use screws or a bolted connection. It should be installed in a safe place so that during gusts of wind it does not fly off along with a piece of slate. It is advisable that the antenna be mounted at the highest possible height. This way you will avoid interference when showing cable or digital television.