We make a TV antenna. Diy terrestrial antenna for tv. Cable routing and antenna installation

Antenna is a device for receiving or transmitting radio waves. For a TV, an antenna is required to receive analog TV signals and digital data streams. There are situations in life when it is urgently necessary to find out information from television outside urban conditions. For example, in the village or in the country. Or you just want to save some money on buying an antenna so you can save it for more important things.

For such cases, we suggest that you assemble the antenna at home with your own hands. It will take only an hour and a half of your personal time and will require simple, practically handy materials.

Required components

You may ask: what is needed to make an antenna with your own hands? First, it is worth listing the main materials:

• Wire, preferably aluminum or copper, is the basis of our antenna. Any other conductive material can be used;
• Coaxial cable - for connection to a TV set;
• Connector for connecting to a TV;
• Nails or self-tapping screws - antenna mount;
• Soldering iron with flux for brazing copper / aluminum (depends on the wire material).

Now let's talk about additional, optional components:

• You can use a junction box for wires or a jar lid as a body;
• Additional insulation for wires - recommended if you hang the antenna outdoors.

Create an antenna

First, look at the photo of a homemade antenna - it consists of two squares touching each other at the corners. To calculate the dimensions of your antenna, you need a Kharchenko antenna calculator.

In the “Frequency” box, enter the center frequency in the range of receiving channels (it depends on the type of signal and on your region, usually 690 MHz for digital and 470 MHz for analog TV). The results will appear: you need the number L1 - this is the length of the outside of the square.

Cut off a piece of wire approximately 1 meter long, measure 4 pieces in succession on it, corresponding to the L1 value. Bend a double square along the marks, cut off the extra piece of wire.

Strip the ends of the wire and solder them together with solder and flux. Strip and solder the wire to the antenna. For reliability, you can solder the wire to the plug. Additionally, wrap the soldering points with electrical tape or fill with sealant.

Additionally, install the housing, making grooves for the antenna in it, fill it with glue or sealant. You can hang the antenna on a self-tapping screw or a nail. Connect the cable on the other side to the plug.

Ready! Now you know how to make an antenna for digital or analog TV with your own hands. You can enjoy watching your favorite TV shows!

Tin can antenna

For those who found the above method difficult, we offer a simpler solution.

You will need simpler materials and much less time (about half an hour). This antenna, which is much easier to make with your own hands, is well suited as a room antenna.

You will need:

• At least two cans (from beer or carbonated drinks);
• Wooden slats - for the antenna holder, you can take another one for the vertical mast;
• Coaxial cable;
• TV plug;
• Tools and fasteners: screwdriver, self-tapping screws and electrical tape / tape;
• If you have the above materials, you can safely get to work:
• Rinse and dry the jars;
• Screw the jars to the rail using tape or electrical tape, the distance between them should be about 7.5 cm;
• Clean the coaxial cable: you should have two conductors;
• Attach the conductors to the bank: screw the conductors to the self-tapping screws, screw the self-tapping screws to the bank, after cleaning the surface of the can from paint. With the skill, you can solder the conductors to the tin;
• Attach the cable to the rail with electrical tape;
• You can use several rails with banks at the same time, installing them on a common mast at a short distance from each other;
• Install the resulting antenna at your discretion;
• Connect the cable from the other end to the plug;
• You can search for channels!

Now that you know how to make an antenna with your own hands, you can access your TV signal in any situation and anywhere.

Diy antenna photo

Once a good TV antenna was in short supply, purchased quality and durability, to put it mildly, did not differ. Making an antenna for a "box" or "coffin" (old tube TV) with your own hands was considered an indicator of skill. Interest in homemade antennas continues today. There is nothing strange here: the conditions for receiving TV have changed dramatically, and manufacturers, believing that there is nothing essentially new in the theory of antennas and will not be, most often adapt electronics to well-known designs, without thinking about the fact that the main thing for any antenna is its interaction with the signal on the air.

What has changed on the air?

Firstly, almost the entire volume of TV broadcasting is currently carried out in the UHF range... First of all, for economic reasons, it greatly simplifies and reduces the cost of the antenna-feeder system of transmitting stations, and, more importantly, the need for its regular maintenance by highly qualified specialists engaged in hard, harmful and dangerous work.

Second - TV transmitters now cover almost all more or less populated places with their signal, and a developed communication network ensures the delivery of programs to the most remote corners. There, broadcasting in the habitable zone is provided by low-power unattended transmitters.

Third, the conditions for the propagation of radio waves in cities have changed... Industrial noise leaks into the UHF weakly, but reinforced concrete high-rise buildings for them are good mirrors that repeatedly re-reflect the signal until it is completely attenuated in the zone of seemingly reliable reception.

Fourth - There are a lot of TV programs on the air now, tens and hundreds... How diverse and meaningful this is is another question, but now it makes no sense to count on the reception of 1-2-3 channels.

Finally, digital broadcasting has been developed... The DVB T2 signal is a special thing. Where it even slightly, by 1.5-2 dB, exceeds the noise, the reception is excellent, as if nothing had happened. And a little further or to the side - no, how it was cut off. The “digital” is almost not sensitive to interference, but if there is a mismatch with the cable or phase distortions anywhere in the path, from the camera to the tuner, the picture can crumble into squares even with a strong clear signal.

Antenna requirements

In accordance with the new reception conditions, the basic requirements for TV antennas have also changed:

• Its parameters, such as the directional action coefficient (directivity factor) and the protective action coefficient (COP), do not currently have a decisive significance: modern broadcast is very dirty, and according to the tiny side lobe of the directional diagram (DI), at least some kind of interference can get through, and you need to deal with it already by means of electronics.
• Instead, the antenna's own gain (KU) is of particular importance. An antenna that “catches” the ether well, and does not look at it through a small hole, will provide a power reserve for the received signal, allowing electronics to clear it of noise and interference.
• A modern television antenna, with rare exceptions, must be band-based, i.e. its electrical parameters should be preserved in a natural way, at the level of theory, and not squeezed into an acceptable framework by engineering tricks.
• The TV antenna must be matched to the cable in its entire operating frequency range without additional matching and balancing devices (USS).
• The frequency response of the antenna (AFC) should be as smooth as possible. Phase distortions are inevitably accompanied by abrupt surges and dips.

The last 3 points are due to the requirements for receiving digital signals. Customized, i.e. operating theoretically at the same frequency, antennas can be "stretched" in frequency, for example. UHF wave-channel antennas with an acceptable signal-to-noise ratio capture 21-40 channels. But their coordination with the feeder requires the use of USS, which either strongly absorb the signal (ferrite), or spoil the phase response at the edges of the range (tuned). And such an antenna, which works well on the “analog”, will receive bad reception of a “digital” antenna.

In this regard, from all the great antenna diversity, this article will consider antennas for a TV, available for self-production, of the following types:

1. Frequency independent (all-wave)- does not differ in high parameters, but it is very simple and cheap, it can be done in literally an hour. Outside the city, where the air is cleaner, it may well be able to receive a digit or a sufficiently powerful analogue not a short distance from the television center.
2. Range log-periodic. Figuratively speaking, it can be likened to a fishing trawl, which sorts prey when fishing. It is also quite simple, ideally matches the feeder in its entire range, absolutely does not change the parameters in it. The technical parameters are average, therefore it is more suitable for a summer residence, and in the city as a room.
3. Several modifications of the zigzag antenna, or Z-antennas. In the MV range, this is a very solid construction that requires a lot of skill and time. But on the UHF, due to the principle of geometric similarity (see below), it is so simplified and shrunk that it can well be used as a highly efficient indoor antenna under almost any reception conditions.

Note: The Z-antenna, if we use the previous analogy, is a frequent nonsense, raking everything in the water. As the air was littered, it was out of use, but with the development of digital TV, it again found itself on a horse - in its entire range, it is just as perfectly coordinated and holds the parameters, like a "speech therapist".

Accurate matching and balancing of almost all antennas described below is achieved by laying the cable through the so-called. point of zero potential. It has special requirements, which will be discussed in more detail later.

About vibrator antennas

In the frequency band of one analog channel, up to several tens of digital channels can be transmitted. And, as already mentioned, the digital works with a negligible signal-to-noise ratio. Therefore, in places very far from the television center, where the signal of one or two channels barely finishes, places, for receiving digital TV, the good old wave channel (AVK, wave channel antenna), from the class of vibrator antennas, can also find application, so at the end we will devote a few lines and her.

About satellite reception

There is no point in making a satellite dish yourself. The head and the tuner still need to be bought, and behind the external simplicity of the mirror lies a parabolic surface of oblique incidence, which not every industrial enterprise can perform with the required accuracy. The only thing that homemade people can do is set up a satellite dish, about this.

About antenna parameters

An accurate determination of the above parameters of antennas requires knowledge of higher mathematics and electrodynamics, but you need to understand their meaning when starting to manufacture an antenna. Therefore, we will give a somewhat rough, but still clarifying meaning of the definition (see the figure on the right):

• KU - the ratio of the received antenna to the main (main) lobe of its DN of the signal power, to its own power, received in the same place and at the same frequency, non-directional, with a circular, BP, antenna.
• KND - the ratio of the solid angle of the entire sphere to the solid angle of the opening of the main lobe of the DN, on the assumption that its cross section is a circle. If the main lobe has different sizes in different planes, you need to compare the area of ​​the sphere and the cross-sectional area of ​​the main lobe.
• CPV is the ratio of the signal power received to the main lobe to the sum of the interference powers at the same frequency, received by all side (back and side) lobes.

Notes:

1. If the antenna is band, the powers are calculated at the frequency of the wanted signal.
2. Since there are no completely omnidirectional antennas, a half-wave linear dipole oriented in the direction of the electric field vector (according to its polarization) is taken as such. Its KU is considered equal to 1. TV programs are transmitted with horizontal polarization.

It should be remembered that CG and CPV are not necessarily interrelated. There are antennas (for example, "spy" - single-wire traveling wave antenna, ABC) with high directivity, but unity or less gain. Such people look into the distance as if through a diopter sight. On the other hand, there are antennas, eg. Z-antennas, in which low directivity is combined with significant gain.

About the intricacies of manufacturing

All elements of antennas through which currents of a useful signal flow (specifically, in the descriptions of individual antennas) must be connected to each other by soldering or welding. In any outdoor assembly, the electrical contact will soon be broken, and the parameters of the antenna will deteriorate sharply, up to its complete disrepair.

This is especially true for points of zero potential. In them, as experts say, a voltage node and a current antinode are observed, i.e. its greatest value. Zero Voltage Current? No wonder. Electrodynamics has gone from Ohm's law on direct current as far as the T-50 is from a kite.

Places with zero potential points for digital antennas are best made bent from solid metal. A small "creeping" current on welding when receiving an analogue in the picture, most likely, will not affect. But, if a digit is received at the border of noise, then the tuner may not see the signal due to "creeping". Which, with a pure current in the antinode, would give a stable reception.

About cable soldering

The braid (and often the central core) of modern coaxial cables is made not of copper, but of corrosion-resistant and inexpensive alloys. They are not soldered well and, if you heat it for a long time, you can burn the cable. Therefore, you need to solder the cables with a 40-W soldering iron, low-melting solder and flux paste instead of rosin or alcohol canin. There is no need to regret the paste, the solder immediately spreads along the veins of the braid only under a layer of boiling flux.

Antenna types

All-wave

An all-wave (more precisely, frequency independent, PNA) antenna is shown in Fig. She - two triangular metal plates, two wooden slats, and a lot of copper enameled wires. The diameter of the wire does not matter, and the distance between the ends of the wires on the rails is 20-30 mm. The gap between the plates, to which the other ends of the wires are soldered, is 10 mm.

Note: instead of two metal plates, it is better to take a square of one-sided foil-clad fiberglass in triangles cut out on copper.

The antenna width is equal to its height, the opening angle of the canvases is 90 degrees. The cable laying diagram is shown in the same place in Fig. The point marked in yellow is the quasi-zero potential point. It is not necessary to solder the cable braid to the web in it, it is enough to tie it tightly, for coordination there is enough capacity between the braid and the web.

ChNA, stretched in a window 1.5 m wide, accepts all meter and DCM channels from almost all directions, except for a dip of about 15 degrees in the plane of the canvas. This is its advantage in places where it is possible to receive signals from different telecentres, it does not need to be rotated. Disadvantages - a single CU and zero CPA, therefore, in the interference zone and outside the zone of reliable reception, the PNA is not suitable.

Note : there are other types of PNA, for example. in the form of a two-turn logarithmic spiral. It is more compact than the RNA of triangular canvases in the same frequency range, therefore it is sometimes used in technology. But in everyday life this does not give any advantages, it is more difficult to make a spiral PNA, it is more difficult to coordinate with a coaxial cable, therefore we do not consider it.

On the basis of CHNA, a very popular once fan vibrator (horns, flyer, slingshot) was created, see Fig. Its KND and KZD are something about 1.4 with a fairly smooth frequency response and linear phase response, so it would be suitable for a figure even now. But - it works only on MV (1-12 channels), and digital broadcasting goes to UHF. However, in the countryside, with a rise of 10-12 m, it may be suitable for receiving an analogue. Mast 2 can be made of any material, but the fastening strips 1 are made of a good non-wetting dielectric: fiberglass or fluoroplastic with a thickness of at least 10 mm.

Beer all-wave

The all-wave antenna from beer cans is clearly not the fruit of the hangover hallucinations of a drunken radio amateur. This is really a very good antenna for all reception situations, you just need to get it right. Moreover, it is extremely simple.

Its design is based on the following phenomenon: if the diameter of the arms of a conventional linear vibrator is increased, then the working band of its frequencies expands, while other parameters remain unchanged. Since the 1920s, the so-called. the Nadenenko dipole based on this principle. And beer cans in size are just suitable as the arms of a vibrator on a UHF. In essence, CHNA is a dipole, whose shoulders expand indefinitely to infinity.

The simplest beer vibrator of two cans is suitable for room reception of an analogue in the city, even without coordination with the cable, if its length is not more than 2 m, on the left in Fig. And if you assemble a vertical in-phase lattice from beer dipoles with a half-wave step (on the right in the figure), match it and balance it with an amplifier from the Polish antenna (we will talk about it later), then, thanks to the vertical compression of the main lobe of the DN, such an antenna will give good ku.

The gain of the "beer" can be further increased by adding at the same time the KZD, if a screen from the grid is placed behind it at a distance equal to half the lattice spacing. The beer grate is mounted on a dielectric mast; the mechanical connections of the screen with the mast are also dielectric. The rest is clear from the trace. rice.

Note: the optimal number of lattice floors is 3-4. At 2, the gain in gain will be small, and more is difficult to match with the cable.

Video: making the simplest antenna from beer cans

"Speech therapist"

A log-periodic antenna (LPA) is a collecting line, to which halves of linear dipoles are alternately connected (i.e., pieces of a conductor with a length of a quarter of the working wave), the length and distance between which change exponentially with an exponent less than 1, in the center in Fig. The line can be either configured (with a short circuit at the end opposite to the cable connection) or free. An LPA on a free (unconfigured) line for receiving a digit is preferable: it comes out longer, but its frequency response and phase response are smooth, and the coordination with the cable does not depend on the frequency, so we will stop at it.

LPA can be manufactured for any, up to 1-2 GHz, pre-specified frequency range. When the operating frequency changes, its active area of ​​1-5 dipoles shifts back and forth along the canvas. Therefore, the closer the progression index is to 1, and, accordingly, the smaller the aperture angle of the antenna, the more gain it will give, but at the same time its length increases. On the UHF, 26 dB can be achieved from an outdoor LPA, and 12 dB from a room one.

LPA, we can say, in terms of the combination of qualities, an ideal digital antenna, therefore, let's dwell on its calculation in more detail. The main thing to know is that an increase in the progression rate (tau in the figure) gives an increase in gain, and a decrease in the LAA aperture angle (alpha) increases directivity. The screen for the LPA is not needed, it has almost no effect on its parameters.

The calculation of a digital LPA has the following features:

1. They start it, for the sake of a reserve in frequency, from the second longest vibrator.
2. Then, taking the reciprocal of the progression rate, calculate the longest dipole.
3. After the shortest, based on the specified frequency range, dipole, add another one.

Let us explain with an example. Let's say our digital programs are in the range of 21-31 TCEs, i.e. at 470-558 MHz in frequency; wavelengths respectively - 638-537 mm. Let's also assume that we need to receive a weak noisy signal far from the station, so we take the maximum (0.9) progression rate and the minimum (30 degrees) aperture angle. To calculate, you need half the opening angle, i.e. 15 degrees in our case. The opening can be further reduced, but the length of the antenna will increase prohibitively, according to the cotangent.

We consider B2 in Fig: 638/2 = 319 mm, and the arms of the dipole will be 160 mm each, up to 1 mm can be rounded. The calculation will need to be carried out until you get Bn = 537/2 = 269 mm, and then calculate another dipole.

Now we count A2 as B2 / tg15 = 319 / 0.26795 = 1190 mm. Then, through the index of progression, A1 and B1: A1 = A2 / 0.9 = 1322 mm; B1 = 319 / 0.9 = 354.5 = 355 mm. Then, sequentially, starting with B2 and A2, we multiply by the indicator until we reach 269 mm:

• B3 = B2 * 0.9 = 287 mm; A3 = A2 * 0.9 = 1071 mm.
• B4 = 258 mm; A4 = 964 mm.

Stop, we already have less than 269 mm. We check whether we will keep within the gain, although it is already so clear that it is not: to get 12 dB or more, the distance between the dipoles should not exceed 0.1-0.12 wavelengths. In this case, we have for B1 A1-A2 = 1322 - 1190 = 132 mm, which is 132/638 = 0.21 of the B1 wavelength. It is necessary to "tighten" the indicator to 1, to 0.93-0.97, so we try different ones until the first difference A1-A2 is halved or more. For a maximum of 26 dB, a distance between the dipoles of 0.03-0.05 wavelengths is needed, but not less than 2 dipole diameters, 3-10 mm on the UHF.

Note: the remainder of the line behind the shortest dipole, cut off, it is needed only for the calculation. Therefore, the actual length of the finished antenna is only about 400 mm. If our LPA is outdoor, this is very good: you can reduce the aperture, getting more directivity and protection from interference.

Video: antenna for digital TV DVB T2

About the line and the mast

The diameter of the tubes of the LPA line on the UHF - 8-15 mm; the distance between their axes is 3-4 diameters. Let's also take into account that thin "laces" cables give such an attenuation per meter to the UHF that all antenna-amplifying tricks will come to naught. You need to take a good coaxial for an outdoor antenna, with a sheath diameter of 6-8 mm. That is, the tubes for the line must be thin-walled, seamless. It is impossible to tie the cable to the line from the outside, the quality of the LPA will drop sharply.

It is necessary, of course, to fasten the outer LPA to the mast for the center of gravity, otherwise the small windage of the LPA will turn into a huge and shaking one. But it is also impossible to connect a metal mast directly to the line: you need to provide a dielectric insert at least 1.5 m long. The quality of the dielectric does not play a big role here, a painted and painted wood will go.

About the Delta antenna

If the UHF LPA is consistent with the amplifier cable (see below, about Polish antennas), then you can attach the shoulders of a meter dipole, linear or fanlike, to the line, like a "slingshot". Then we get a universal MV-UHF antenna of excellent quality. This solution is used in the popular Delta antenna, see fig.

Antenna "Delta"

Zigzag on air

The Z-antenna with a reflector gives the gain and SPL the same as the LPA, but the main lobe of its BP is more than twice as wide horizontally. This can be important in the countryside when there is TV reception from different directions. A decimeter Z-antenna is small in terms of dimensions, which is essential for indoor reception. But its operating range is theoretically not unlimited, the frequency overlap while maintaining the parameters acceptable for the figure is up to 2.7.

The design of the MV Z-antenna is shown in Fig. the path of the cable is highlighted in red. In the same place at the bottom left - a more compact ring version, in common parlance - "spider". It clearly shows that the Z-antenna was born as a combination of a PNA with a range vibrator; there is in it something of a rhombic antenna, which does not fit into the topic. Yes, the "spider" ring does not have to be wooden, it can be a metal hoop. Spider accepts 1-12 MV channels; The DN without a reflector is almost circular.

The classic zigzag works either on 1-5 or 6-12 channels, but only wooden slats, enameled copper wire cd = 0.6-1.2 mm and a few scraps of foil-clad fiberglass, so we give the dimensions through fraction for 1-5 / 6-12 channels: A = 3400/950 mm, B, C = 1700/450 mm, b = 100/28 mm, B = 300/100 mm. At point E - zero potential, here you need to solder the braid to the metallized base plate. The dimensions of the reflector are also 1-5 / 6-12: A = 620/175 mm, B = 300/130 mm, D = 3200/900 mm.

The band Z-antenna with reflector gives a gain of 12 dB, tuned to one channel - 26 dB. To build a single-channel zigzag on the basis of a band zigzag, you need to take the side of the square of the canvas in the middle of its width at a quarter of the wavelength and recalculate all other dimensions proportionally.

Folk zigzag

As you can see, the MV Z-antenna is a rather complex structure. But its principle shows itself in all its splendor on the UHF. The UHF Z-antenna with capacitive inserts, which combines the advantages of "classics" and "spider", is so simple to make that it earned the title of national one in the USSR, see fig.

Material - copper tube or aluminum sheet with a thickness of 6 mm. The side squares are solid metal or covered with a mesh, or covered with a tin. In the last two cases, they need to be soldered along the contour. The coaxial cannot be sharply bent, so we drive it so that it reaches the side corner, and then does not go beyond the capacitive insert (side square). At point A (point of zero potential), the cable sheath is electrically connected to the canvas.

Note: aluminum is not soldered with ordinary solders and fluxes, therefore, aluminum "folk" is suitable for outdoor installation only after sealing the electrical connections with silicone, because everything in it is on screws.

Video: example of a double triangular antenna

Wave channel

Antenna wave channel (AVK), or Udo-Yagi antenna available for self-production, is capable of giving the highest KU, KND and KZD. But it can receive a digit on the UHF only on 1 or 2-3 adjacent channels, because belongs to the class of sharply tuned antennas. Its parameters outside the tuning frequency deteriorate sharply. AVK is recommended to be used with very poor reception conditions, and for each TCE to make a separate one. Fortunately, it's not very difficult - AVK is simple and cheap.

The work of AVK is based on “raking” the electromagnetic field (EMF) of the signal to the active vibrator. Outwardly small, light, with minimal windage, the AVK can have an effective aperture of tens of wavelengths of the operating frequency. Shortened and therefore having a capacitive impedance (impedance) directors (directors) direct the EMF to the active vibrator, and the reflector (reflector), elongated, with inductive impedance, rejects to it what has slipped past. A reflector in AVK is needed only 1, but directors can be from 1 to 20 or more. The more there are, the higher the AVK gain, but narrower its frequency band.

From interaction with the reflector and directors, the wave impedance of the active (from which the signal is removed) vibrator drops the more, the closer the antenna is tuned to the maximum gain, and the coordination with the cable is lost. Therefore, the active dipole AVK is made looped, its initial characteristic impedance is not 73 Ohm, as in the linear one, but 300 Ohm. At the cost of reducing it to 75 Ohm, an AVK with three directors (five-element, see the figure on the right) can be tuned almost to a maximum gain of 26 dB. A typical AVK DN in the horizontal plane is shown in Fig. at the beginning of the article.

The AVK elements are connected to the boom at the points of zero potential, so the mast and boom can be of any kind. Propylene pipes are very suitable.

The calculation and adjustment of AVK for analog and digital are somewhat different. Under the analogue wave channel, you need to count on the carrier frequency of the image Fi, and under the number - in the middle of the TVK spectrum Fc. Why so - here, unfortunately, there is no place to explain. For the 21st TVC, Fi = 471.25 MHz; Fc = 474 MHz. UHF TVKs are located close to each other at 8 MHz, so their tuning frequencies for AVK are calculated simply: Fn = Fi / Fc (21 TVK) + 8 (N - 21), where N is the number of the desired channel. Ex. for 39 TVKs Fi = 615.25 MHz, and Fc = 610 MHz.

In order not to write down a lot of numbers, it is convenient to express the size of the AVK in fractions of the working wavelength (it is considered as A = 300 / F, MHz). The wavelength is usually denoted by the small Greek letter lambda, but since there is no default Greek alphabet on the Internet, we will conventionally designate it as the large Russian L.

The dimensions of the AVK optimized for the figure, according to the figure, are as follows:

• P = 0.52L.
• B = 0.49L.
• D1 = 0.46L.
• D2 = 0.44L.
• D3 = 0.43l.
• a = 0.18L.
• b = 0.12L.
• c = d = 0.1L.

If you do not need a lot of gain, but it is more important to reduce the size of the AVK, then D2 and D3 can be removed. All vibrators are made from a tube or rod with a diameter of 30-40 mm for 1-5 TVK, 16-20 mm for 6-12 TVK and 10-12 mm for UHF.

AVK requires precise coordination with the cable. It is the careless implementation of the matching and balancing device (OSS) that explains most of the failures of amateurs. The simplest USS for AVK is a U-loop from the same coaxial cable. Its construction is clear from fig. on right. The distance between signal terminals 1-1 is 140 mm for 1-5 TVK, 90 mm for 6-12 TVK and 60 mm for UHF.

Theoretically, the knee length l should be half the working wavelength, and this is what most publications on the Internet say. But the EMI in the U-loop is concentrated inside the cable filled with insulation, so it is imperative (especially for a digit) to take into account its shortening factor. For 75-ohm coaxials, it ranges from 1.41 to 1.51, i.e. l you need to take from 0.355 to 0.330 wavelengths, and take it exactly so that the AVK is an AVK, and not a set of glands. The exact value of the shortening factor is always included in the cable certificate.

Recently, the domestic industry began to produce reconfigurable AVK for numbers, see fig. The idea, I must say, is excellent: by moving the elements along the arrow, you can fine-tune the antenna to the local reception conditions. It is better, of course, for a specialist to do this - the element-by-element adjustment of the AVK is interdependent, and the amateur will certainly get confused.

About "Poles" and amplifiers

For many users, Polish antennas, which previously received an analogue decently, refuse to take the figure - it breaks, or even disappears altogether. The reason, I beg your pardon, is a bawdy commercial approach to electrodynamics. Sometimes it is a shame for colleagues who have slapped such a "miracle": the frequency response and frequency response are similar either to a psoriasis hedgehog, or a horse comb with broken teeth.

The only good thing about the "Poles" is their antenna amplifiers. Actually, they do not let these products die ingloriously. Amplifiers "poles", firstly, low-noise broadband. And, more importantly, with a high impedance input. This allows, at the same intensity of the EMF signal in the air, to supply the tuner with several times its power at the input of the tuner, which makes it possible for the electronics to "rip" the figure out of the very ugly noise. In addition, due to the high input impedance, the Polish amplifier is an ideal OSS for any antennas: whatever you hook to the input, the output is exactly 75 ohms without reflection and creep.

However, with a very bad signal, outside the range of reliable reception, the Polish amplifier no longer pulls. Power is supplied to it via a cable, and the power supply decoupling takes 2-3 dB of the signal-to-noise ratio, which may just not be enough for the figure to go in the very outback. Here you need a good TV signal amplifier with separate power supply. It will be located, most likely, near the tuner, and the OSS for the antenna, if required, will have to be done separately.

The diagram of such an amplifier, which showed almost 100% repeatability even when performed by novice radio amateurs, is shown in Fig. Gain control - potentiometer P1. Isolation chokes L3 and L4 are standard purchased. Coils L1 and L2 are dimensioned in the wiring diagram on the right. They are part of the signal bandpass filters, so small deviations in their inductance are not critical.

However, the installation topology (configuration) must be followed exactly! And in the same way, a metal shield is required, which separates the output circuits from other circuits.

Where to begin?

We hope that experienced craftsmen will also find some useful information in this article. And for beginners who do not yet feel the air, it is best to start with the beer antenna. The author of the article, by no means an amateur in this area, was at one time quite surprised: the simplest "pub" with ferrite matching, as it turned out, and MV takes no worse than the tested "slingshot". And what is worth doing both - see the text.

(2 estimates, average: 4,00 out of 5)

said):

And on the roof there was a satisfactory reception for a Pole. I have 70 - 80 kilometers to the TV center. These are my problems. From the balcony it is possible to catch from 30 channels pieces 3 - 4, and then with "cubes". Sometimes I watch TV channels from the Internet on the computer in my room, and my wife cannot watch her favorite channels normally on her TV. Neighbors advise to install cable, but you have to pay for it every month, and I already pay for the Internet, and the pension is not rubber. We pull it all, pull it, and it’s not enough for everything.

Pyotr Kopitonenko said:

It is not possible to put an antenna on the roof of the house, the neighbors swear that I go and break the roofing felt roofing and then their ceiling is leaking. Actually, I am very “grateful” to that economist who received a prize for economy. I came up with the idea of ​​removing the expensive gable roof from the houses and replacing it with a flat roof covered with bad roofing material. The economist received money for saving, and people on the top floors now suffer all their lives. Water flows over their heads and onto the bed. They change the roofing material every year, and it falls into disrepair during the season. In frosty weather, it cracks and rainwater and snow flows into the apartment, even if no one walks on the roof !!!

Sergey said:

Greetings!
Thanks for the article, but who is the author (I don't see the signature)?
LPA according to the above method works fine, UHF 30 and 58 channels. Tested in the city (reflected signal) and outside the city, the distance to the transmitter (1 kW), respectively: 2 and 12 km approximately. Practice has shown that there is no urgent need for the “B1” dipole, but one more dipole before the shortest one has a significant effect, judging by the signal intensity in%. Especially in a city, where you need to catch (in my case) the reflected signal. only I made an antenna with a "short circuit", it happened, just there was no suitable insulator.
In general, I recommend it.

Vasily said:

IMHO: people looking for an antenna for receiving ETsTV, forget about LPA. These broadband antennas were created in the second half of the 50s (!!) of the last century in order to catch foreign TV centers on the shores of the Soviet Baltic. In magazines of that time, it was bashfully called "ultra-long-range reception." Well, they loved watching Swedish porn at night on the Riga seaside ...

In terms of appointment, I can say the same about “double, triple, etc. squares ", as well as any" zigzags ".

Compared with a "wave channel" similar in range and amplification, LPA are more cumbersome and material-intensive. The calculation of the LPA is complicated, intricate and looks more like fortune-telling and fitting the results.

If in your region, ETsTV is broadcasting on neighboring UHF channels (I have 37-38), then the best solution is to find a book on the network: Kapchinsky L.M. Television antennas (2nd edition, 1979) and make a "wave channel" for a group of UHF channels (if you broadcast more than 21-41 channels, you will have to recount) described on page 67 and further (Fig. 39, Table 11).
If up to the transmitter 15 - 30 km, the antenna can be simplified by making it four - five elements, simply without installing directors D, E and Zh.

For very close transmitters, I recommend indoor antennas, by the way, in the same book on pages 106 - 109, drawings of wide-range indoor "wave channel" and LPA are shown. The “wave channel” is visually smaller, simpler and more graceful with higher gain!

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When resting outside the city, sometimes, in addition to enjoying nature and fresh air, sometimes you want to watch your favorite TV series or an important football match. In contrast to the city, the coverage of villages with high-quality TV signals leaves much to be desired. In this situation, even the purchase of an antenna operating in a wide range of decimeter and meter waves does not guarantee a high-quality picture.

You can also try to assemble the antenna with your own hands, because a country house is the best place for experiments.

The simplest antenna option

As you can see in the photograph, the antenna is the simplest wave receiver. For manufacturing, you will need two tubes and a television cable, as well as knowledge of the signal transmission range of the nearest television tower.

Typically, reception is carried out at frequencies from 50 to 230 MHz, forming twelve channels. For each of them, tubes of certain sizes are used. To receive a signal at a frequency of 50 MHz, the distance between the outer edges of the tubes should be within 271-276 cm.On channel 12, the same distance is 66 cm.

Information about the dependence of the length of the blanks on the receiving frequency, as well as the schemes of homemade antennas, can be easily found on similar thematic Internet resources.

For making an antenna in artisanal conditions, we present you a list of what you can make an antenna from:

• Two tubes of steel, aluminum or any other metal alloy with a diameter of 8 to 24 mm. They must be the same in diameter, material and wall thickness.
• Availability of TV broadcast cable, rated for 75 Ohm resistance. The length of the wire is cut at the point of connection, taking into account the slack margin of 50 cm.
• Textolite blank or material from getinax (at least 5 mm thick).
• Fasteners for installing pipes on the holder.
• Bracket for the future antenna in the form of a metal pipe or corner. When installing the receiver at a low height, you can use a wooden stand.
• Soldering kit, anti-oxidation silicone fluid and electrical tape.

Assembly principle

The length-matched workpiece is divided into two equal tubes, which are crimped on one side. The tubes are fixed at a distance of 6-7 cm from each other, and their ends are fastened to the textolite blank with clamps. The resulting structure is fixed with a bar in an upright position.

To connect the cable, you must lay a loop designed for a resistance of 75 ohms. The middle conductors of the cable are stripped and twisted with flattened tube ends, and the braid is connected using a copper wire. The connection of the rest of the loop and the cable going to the output to the television device follows the same principle.

The resulting loop and the rest of the cable length, in order to avoid interference, should be securely fixed to the vertical stand. The required antenna height is adjusted locally, observing the signal change.

Beer can antenna

Is one of the most popular ideas for homemade TV signal receivers. Instead of pipes, in the absence of material, simple beer cans can be used.

For the manufacture of such a television receiver, the following parts are required:

• two beer cans of 0.5 l each;
• wooden or plastic piece 50 cm long;
• TV cable RG-58;
• soldering iron, flux for soldering on aluminum and solder;

To make a receiver from beer cans, follow the instructions below:

• Through the bottom of the can, in its center, a hole 5-6 mm in diameter is drilled.
• We lay the cable through the hole in the bank and bring it out through the neck.
• The can is fixed evenly on the left side of the workpiece in a horizontal position.
• We bring the cable through the neck to a distance of 5 cm, cut the insulation by 3 cm, remove the wire braid by 1.5 cm and solder it to the surface of the can.
• Solder the outgoing cable to the bottom of the second can.
• Attach the second can to the first at a minimum distance using tape or other sticky material.

The other end of the cable is fitted with a TV-in connector. This antenna option is also suitable for digital broadcasting. If the TV supports the popular format (DVB T2), or there is a set-top box suitable for an old TV, then the signal can be received from the nearest relay tower. In this case, it is necessary to know the location of the repeater, in the direction of which the antenna should be directed to search for the signal.

This circuit is suitable for making an antenna designed to receive meter wave channels. Just use a liter container instead of half-liter cans.

In case you do not own soldering, there is another connection method. Two beer cans are attached at a minimum distance from the workpiece holding the entire structure. At the end of the cable, carefully remove the insulation 3-5 cm. Twist the braid of the wire into a bundle and, giving the shape of an eyelet, put it on the self-tapping screw.

In the same way, put the eyelet on the self-tapping screw at the second conductor. Then you connect the wires, using self-tapping screws, to each bank. In terms of long-term contact retention, soldering is much better than mechanical fasteners. It is advisable to tin the surface before soldering.

The fastening with self-tapping screws, although it is reliable, but when moisture gets on the antenna, the contacts of the home-made device oxidize, which will lead to a loss of signal.

Photo instructions on how to make an antenna

The improvement of a suburban area involves an increase in the comfort of living for summer residents. One of the invariable attributes of passive entertainment is the television.

Away from the city, there are often problems with the signal and broadcast quality. An antenna made for a summer residence with your own hands allows you to solve this issue, spending a minimum of money and time. There are a lot of home-made devices, their choice is determined by the distance from the TV tower and the type of signal.

In this material, we will consider the assembly of the simplest homemade models - the article provides detailed instructions for manufacturing with diagrams and drawings. There is also a list of materials and tools required for work.

When starting to make a homemade device, you need to have an idea of ​​the possible design options and the rules for their assembly.

The whole variety of television antennas is usually divided into several types:

1. All-wave... Frequency independent antenna is the cheapest, easiest to manufacture. The base is a metal frame, and tin containers or beer cans are used as receivers. The design does not have high performance parameters, but it is quite suitable for a summer residence if the broadcast tower is located nearby.
2. Log-periodic... The principle of operation is comparable to a fishing net that sorts prey when caught. The device is easy to manufacture, and its parameters exceed the characteristics of all-wave models. Antennas differ in coordination with the feeder for any range.
3. Decimeter... Designs that function well regardless of the reception conditions. Various forms of execution are possible: zigzag, rhombus, circle, etc.

The parts of the antenna, along which the currents of the useful signal run, are joined or soldered. However, when the device is placed on the roof of the house, such contacts will corrode over time.

In addition to this rule, when creating an antenna for a summer residence with your own hand, it is advisable to adhere to the following rules:

1. The central core, the braid is made of inexpensive alloys that are resistant to corrosive processes. However, they do not lend themselves well to soldering - work is carried out with extreme caution so as not to burn the wire.
2. To connect the elements, you must use a 40 W soldering iron, flux paste, low-melting solder.
3. It is undesirable to use aluminum wire to create structural details. The material quickly oxidizes, losing its ability to conduct a signal. The best option is copper, the available alternative is brass.

The receiving area of ​​the trap must be large. In order to increase it, metal rods can be symmetrically attached to the frame that filters out ethereal noise.

Connecting the simplest signal amplifier to the antenna will significantly improve the quality of the broadcast transmission. Factory products are already equipped with this element

The tandem of a homemade antenna will provide the necessary receive power. It is enough to take out the structure to the roof and install it in the direction of a nearby television tower.

Building Instructions for the Best Antennas

You can assemble many interesting and effective antennas with your own hands. Consider detailed instructions for making the best and easiest models to make.

DIY # 1 - Simple TV Antenna

If the repeater is located within 30 km from the dacha, then the most common design, assembled from two tubes and a cable, will do. The wire connects to the corresponding input jack on the TV.

Scheme and choice of materials

A typical device for a primitive dacha antenna is shown in the figure below. It can be seen that two tubes of the same length are joined on a plate, which in turn is fixed to the mast.

The first step is to find out the broadcasting frequency of the local TV tower - the length of the pipes depends on the parameter.

The broadcasting band range is 50-230 MHz. Each channel needs its own antenna whisker length.

For the manufacture of an antenna, pipes made of duralumin, steel, brass are suitable. Their diameter can range from 8-24 mm, most often they take 16 mm. The main condition is that the segments must be equivalent, prepared from pipes with the same properties.

Necessary materials:

• metal pipe- the cut is 6 cm shorter than the length determined from the table values;
• 75 Ohm wire, the required length is the distance from the TV set to the antenna plus 2 m for the sag and the matching loop;
• thick electrical insulating getinax- thickness from 4 mm;
• metal stripes, on the plate;
• antenna mast- it can be a corner, with a low height, it is permissible to use a wooden block.

For work, it is advisable to stock up on a soldering iron, solder, flux. It is recommended to solder the connections of the central conductors - this will extend the service life of the device and improve the image quality.

To protect against oxidation, the joints must be filled with silicone, epoxy resin. An affordable, but not reliable way is to wind it with electrical tape.

Assembling and setting up an invention

First, cut the pipe to the desired size and saw it into two equal parts. You can use metal cutting pliers.

The distance between the inner ends of the tubes is 6 cm, between the far ends - the distance indicated in the table.

Subsequent progress of work:

1. Fasten the antenna mustache to the holder with clamps, and fix the getinax plate itself on the mast.
2. Connect the pipes through a matching device - cable loop, type RK-1,3,4. The element parameters are displayed in the right column of the table, the manufacturing principle is shown on the antenna device diagram.
3. Solder the central cores to the ends of the tubes, connect the braid with a piece of a similar conductor.
4. Dock the center conductors of the ends of the matching loop with the TV cable. Connect the braid with a copper wire.
5. Fix the loop and the wire going down on the rod.
6. Raise the mast to the roof of the country house, adjust the antenna.

It takes two people to determine the optimal position of the device. The first turns the antenna on the street, and the second monitors the change in the image on the TV.

Having caught a good signal quality, the structure is fixed in the selected position.

Homemade # 2 - loop antenna from the pipe

The module is a little more difficult to create, but expands the reception range to 40 km. The main difficulty lies in the need to bend the pipe.

The braid and foil must be twisted into a bundle. You should end up with two conductors: a central strand and a twist. Both elements must be tinned. The wire should stick out 2 cm, cut off the excess

Solder the plug on the other side of the cable. The wire must be cleaned by 1 cm, the conductors must be formed and tinned.

In areas where soldering is performed, clean the plug with emery, wipe it with alcohol. Solder a mono-core to the central outlet, twist to the side one. Squeeze the grip around the insulation, screw on the plastic tip, alternatively fill it with non-conductive sealant. Before the composition dries, assemble the plug.

The order of connecting the elements

The final stage of the assembly is the docking of the frame and cable. If there is no binding to a specific channel, then it is better to spike at the midpoint to expand the signal capture.

The split end of the cable is connected to the two sides of the square in the center. Before the final fixation, you can check the performance of the antenna. If everything is normal, then the soldering point is sealed.

In a mini-container, holes are made for the elements of the squares, a frame with a wire is laid and filled with a sealing compound.

DIY # 4 - double square antenna

Narrowband design will solve the problem of a weak signal or blocking the broadcast with stronger air. The antenna is also suitable for receiving digital television. The main condition for work is a clear orientation towards the signal distributor.

Device diagram and dimensions

Structurally, the TV antenna is presented in the form of two frames connected at the top and bottom by arrows. The large square is the reflector, the smaller one is the vibrator.

The upper arrow is made of metal, and the lower one is made of getinax, textolite or other insulating material.

Requirements for the TV antenna device:

• the centers of the squares should be on the same line, this line looks towards the transmitter;
• the smaller frame has an open contour, the ends are fixed to the textolite plate;
• the upper part of the antenna mast is made of wood.

The parameters for the manufacture of two-element frame teleantennas are taken from the table. The dimensions of the working elements depend on the type of waves: decimeter or meter.

Explanations to the table: B - the length of the side of the smaller square, P - the value of the larger frame, A - the distance between two elements, W - the loop in a short-circuited bridge

In a three-frame design, the distance between the ends of the middle frame is increased to 5 cm.

Assembly and connection

To connect the frame to the antenna cable, a balun short-circuited loop is required. The device is constructed from sections of the antenna wire.

The right element is a loop, the shortened left element is a feeder. A television cable is attached to the place of their docking. The length of the segments is determined according to the table, taking into account the wavelength of the signal.

Do the same with the feeder, leaving the core of the cable.

Further sequence of works:

1. Solder the central core of the feeder, the braid of the loop to the left end of the vibrator.
2. Attach the twist of the feeder to the right end of the active frame.
3. Dock the bottom of the loop with the braid of the feeder with a metal jumper. Solder the harnesses with low-melting solder.
4. The cable cuts must run parallel, the distance is 5 cm. To fix the distance, a dielectric material is used. The matching device is mounted on a textolite plate.
5. Solder the TV cable to the bottom of the feeder by joining the corresponding elements - a braid with a braid, a rod with a rod.

The use of a matching device reduces the likelihood of interference, eliminates the effect of a double image. You cannot do without it at a considerable distance from the transmitter.

Homemade # 5 - Tin Can TV Antenna

The original design of the antenna from available tools noticeably improves the signal quality. This option is suitable for a summer residence in the suburbs, not far from the TV tower.

To create a primitive device, you will need: 2 beer cans of 0.5 or 0.75 liters each, self-tapping screws, a television cable 3-5 m, a screwdriver, a soldering iron, tin, a wooden pin or hangers, electrical tape.

The subsequent actions can be broken down into several stages.

Cable preparation and connection of contacts

When preparing the cable, stepping back 10 cm. Cut the cable into two conductors - a central core and a braid twist. At the other end of the cable, you need to install a regular plug.

Carrying out the supply of contacts, the twisted screen of the cable is fastened to one can, the copper core to the other. Self-tapping screws are suitable for fixing.

Assembling a homemade structure

When assembling, it is necessary to make a supporting structure under the signal receiver. In the simplest version, you can use ordinary clothes hangers. A wooden stick will do as well.

.

Subject to a number of standards, assembly and connection technology, it will be possible to make an effective device for replacing a standard TV antenna.

Do you have a homemade antenna at your dacha? Please share with other users a unique photo of your homemade product, tell us what materials you needed and how long it took you to assemble.

Or maybe you assembled a TV antenna according to one of the schemes discussed in this material? Tell us about your experience of using this model, add a photo in the comment block.

High-quality antennas have always been difficult to get - the Soviet industry practically did not produce them, so people themselves made them from improvised means. Today, the situation has practically not changed - in stores you can find only light aluminum Chinese handicrafts that do not show good results and rarely live for more than a year. What if you like to watch TV, but there is no good reception? The answer is simple - make a TV antenna with your own hands. With free time and a couple of skillful hands, everyone can handle it.

Introduction

Most recently, analogue television was operating in Russia, but now almost the entire country has switched to digital broadcasting. Its main difference is that it operates in the decimeter range.

You can create a homemade antenna for the digital range at home

This was done for reasons of economy and safety - maintenance of the transmitting antenna-feeder stations is actually not required, their maintenance is minimized, the harm from contact with powerful transmitters for masters is minimal. But such stations have one serious drawback - low power. And if in a big city the signal can often be caught even on a piece of copper wire, then it can be difficult to receive it far from the transmitter. If you live outside the city, in remote areas or villages, you will have to assemble your own antenna and put it outside in order to pick up the desired signal.

Attention: signal problem can occur even in the city center. Decimeter waves are practically not damped by other sources, but are reflected from thick reinforced concrete walls. In modern high-rise buildings there are many places where they completely fade out before reaching the TV receiver.

It's also worth noting that DVB-T2 (the new TV standard) offers a fairly consistent but weak signal. With a noise level one and a half to two units above the norm, the TV reproduces the air quite clearly, but as soon as the noise exceeds 2 dB, the signal completely disappears. Digital television is not sensitive to electromagnetic interference - it is not knocked down by a working refrigerator or microwave. But if there is a mismatch in the system anywhere, then the picture stops or crumbles. A quality homemade TV antenna will solve this problem, but in some cases, it will have to be taken outside or on the roof.

Basic requirements for antennas

The standards for television operating in the USSR do not fit modern realities - the coefficients of protective and directional action today practically do not affect the signals. The air in cities is clogged and contains a lot of dirt, so you shouldn't pay attention to these coefficients. You are guaranteed to receive interference on any antennas, so there is no need to seek to reduce the CPV and CPI. It is better to improve the antenna gain so that it receives a wide range of air and selects the desired stream, rather than focusing on a specific signal. The processor of the set-top box or TV itself will isolate the necessary signals and create a normal picture.

Classic Polish antenna with amplifier

So, how to make an antenna for your TV with your own hands? Experienced engineers recommend building band antennas. They must be correctly calculated, receiving signals in the classical way, and not due to engineering "optimizations" and traps. Ideal - the device fully complies with theoretical calculations and geometry. Also, the constructed antenna must be matched to the cable at operating ranges without the use of matching devices. In this case, the frequency response is best created smooth and even, since phase distortions appear during a dip or jump in the amplitude-frequency response.

Attention: analog antennas with ferrite USS, which provide full reception of the old signal, practically do not work with DVB. It is necessary to build a “digital” antenna.

In this article, we will analyze modern types of antennas that work with new digital broadcasting.

Antenna types

What do-it-yourself digital TV antennas can be assembled at home? There are three most common options:

1. All-wave, or as radio amateurs call it - frequency independent. It is assembled very quickly, does not require high knowledge or specialized tools. Well suited for the private sector, villages, dacha cooperatives - where the air is not clogged with garbage, but not far from the transmitter.
2. Do-it-yourself log-periodic band TV antenna. It has a simple design, it receives a signal well at close and medium distance from the transmitter. It can be used as a remote if the transmitter is located far away, or as a home wall antenna.
3. Z-antenna and its variations. Many radio amateurs are familiar with meter-long "zeshki" - they are quite large and require a lot of effort to assemble. But in the decimeter range, they are quite compact and do their job well.

Nuances of construction

If you want to build a quality antenna, you must master the art of soldering. Do not twist the contacts and guides - during operation they oxidize, the signal is lost, the picture quality deteriorates. Therefore, all connections are soldered.

Such connections are unacceptable - be sure to solder them.

You also need to deal with the zero potential points at which currents occur even in the absence of voltage. Experts recommend making them from a single piece of metal, without using welding at all. Even well-cooked pieces can make noise at the edge values, while a solid strip will “pull” the signal.

Also, when creating a homemade antenna for digital TV, you need to deal with the soldering of cables. Today, copper is practically not used for braiding, since it is expensive and quickly oxidizes. Modern braiding is made of steel, which is not afraid of corrosion, but it is very poorly soldered. It must not be overheated or pinched. Use 36-40 watt soldering irons, flux and lightweight solders for the connection. Dip the winding well in the flux and apply the solder - it works great with this method of application.

All-wave antenna

The all-wave antenna has a fairly simple design. It consists of triangles, copper wire, and wooden battens. You can study the design in more detail in the picture - it does not represent something supernatural.

The thickness of the wire can be any, the distance between adjacent wires is 25-30 mm, the distance between the plates is no more than 10 mm. It is possible to improve the design by eliminating the plates and using PCB. He needs to be given the appropriate shape or simply remove the copper foil in the shape of a triangle.

The rest of the proportions are standard - the height of the device must match the width, the plates diverge at right angles. Zero potential is located on the extreme line of the home TV antenna, just at the intersection of the cable with the vertical guide. To avoid quality loss, the cable must be pulled to it with a tie - this is enough for matching. Such an antenna, hung out on the street or directed at a window, receives virtually the entire frequency range, but has a small dip, so you need to set the correct angle when fixing the antenna.

By the way, this design can be upgraded with ordinary aluminum cans for beer and cola. The principle of its operation is as follows: with an increase in the span of the shoulders, the working band expands, although the other indicators remain within the original limits. The Nadenenko dipole, which is often used in military developments, works on the same principle. Aluminum cans are ideal in shape and size, creating vibrator arms in the decimeter range.

Dual-bank TV antenna

You can create a simple can antenna simply by soldering two cans to the cable. This do-it-yourself indoor TV antenna is suitable for watching channels at a short to medium distance from the transmitters. There is no need to coordinate anything in this circuit, especially if the cable length is less than 2 meters.

You can complicate the design by collecting a full-fledged lattice from eight cans and using an amplifier from a conventional Polish antenna. This design is perfect for outdoor hanging in areas remote from the transmitter. To amplify the signal, a metal mesh can be placed at the back of the structure.

Z-antenna

There are complex designs of Z antennas with multiple loops, but in most cases they are not needed. The structure can be easily assembled from ordinary copper wire 3 mm thick. If you do not have one, then just buy a 3 mm single core copper wire with a length of 120 mm - this will be enough for you to work. This construction consists of two segments. We bend the wire according to the following scheme:

1. The starting section is 14 centimeters long. Its edge is folded into a loop to connect with the latter (loop 1 cm, the total length of the first piece is 13 cm).
2. The second piece is bent at 90 degrees (it is better to bend it with pliers to keep the angles). Its length is 14 cm.
3. The third piece is bent 90 degrees parallel to the first, length 14 cm.
4. The fourth and fifth pieces are 13 cm each, the bend does not reach the loop by 2 cm.
5. The sixth and seventh pieces are 14 cm each, bend at 90 degrees.
6. Eighth - returns to the loop, length 14.1 cm goes to a new loop.

Next, you need to well clean the two loops and solder them. The opposite corner is also cleared. The contacts of the cable are soldered to them - to one the central one, to the second - the braid. There is no difference to which contact to solder... It is advisable to insulate the welded places, for this you can use sealants or hot-melt glue. The ends of the cable are soldered to the plug and are also insulated with a cambric.

You can assemble such an antenna in half an hour.

To avoid misalignment of the segments, the edges can be reinforced. To do this, take a regular plastic cap from a five-liter bottle, cut 4 slots in it so that the wire sinks to the base. Cut the fifth hole for the cable. Then put the antenna in the cover (after checking the quality and reliability of the soldering), and fill it with hot glue. The resulting structure will be practically eternal - it is able to receive a stable signal at a distance of up to 10 km from the source.

So, you already know what you can use instead of an antenna for a TV. In fact, the designs are much larger than those that we have described, but even these will be quite enough for you. If you live far from the signal source, you will need amplifying antennas - you can get by with the classic amplified polka. Well, if everything is bad with the air, then use satellites.

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Simple antenna for receiving digital TV - do it yourself

Digital TV T2 is gaining momentum in popularity. And this is natural, digital television is replacing analog television and this is an irreversible process. Moreover, in the near future, analogue broadcasting will be discontinued altogether. What should users who have TVs without a T2 receiver and no cable TV do?

The answer is simple - buy a T2 prefix. To date, the price of T2 consoles has dropped a lot and does not look sky-high. The advantages are quite big: you get a lot of channels in digital quality, without a monthly fee, at minimal cost and without buying a new TV.

Only by comparing the quality of digital and analog TV will you never regret your choice.

Quite a lot has been written about the choice of T2 receivers. Moreover, new models are constantly being released. I would advise you to take an inexpensive, but new model, after reading reviews on the websites of online stores. As a rule, any receiver works, but the antenna is of great importance. Even if you are not far from the TV tower, but block high-rise buildings, etc.

- and this is almost always, then a good antenna is a guarantee of trouble-free (and most importantly - nerve-racking) high-quality reception of the maximum number of digital TV channels.

But an expensive antenna is not always a good antenna. Especially if you have a distance of 50 km or more from the TV tower. The shops offer "special" antennas for T2. In fact, there is nothing "special", you need a good antenna for the DCM range.

If you still have an old DCM antenna, first of all try to connect it. The widespread "Polish" antennas are not suitable for receiving digital T2 channels.

I propose a proven version of a simple, at the same time well-proven, homemade antenna for T2.

The shape of the antenna is not new, it has been used for a long time also when receiving the DCM of analog television, but the dimensions are optimized for receiving digital T2 channels.
It is worth noting that the Internet offers a large number of options for homemade antennas for T2: from beer cans, from the antenna cable itself, a converted Polish one, etc.

This is for the completely lazy, well, you should not expect quality from such antennas.

So. The long-known "eight" is taken as the antenna shape. The antenna body is made of any conductive material of a suitable cross-section. It can be copper or aluminum wire with a thickness of 1 to 5 mm, tube, strip, bus, corner, profile.

Copper is of course preferred. I used 6mm copper tube. Copper wire is also a good option. I just had such a pipe.

Dimensions (edit)

The outer side of the square is 14 cm, the inner side is slightly smaller - 13 cm. Due to this, the middle of the two squares does not converge, we leave a gap of about 2 cm.
All you need is a tube, wire or other material, 115 cm long (this is with a small margin).

The first section is 13 cm + 1 cm for the loop (for strength) if made of wire, or riveted for overlapping soldering for the tube.

The second and third - 14 cm each, the fourth and fifth - 13 cm each, the sixth and seventh - 14 cm each, and the last eighth - 13 cm + 1 cm, again for connection.

We clean the ends by 1.5 - 2 cm, twist two loops behind each other, and then seal the joint. This will be one pin of the cable connection. After 2 cm, another.

From a copper tube it looks like this

The tube is a little more difficult to bend, but great accuracy is not required from us.

Small flaws in the shape do not affect the performance of the antenna. But the fact that the area of ​​the conductor is increasing is a plus.

Well, the conductivity of copper is higher than that of aluminum and, moreover, steel. The higher the conductivity, the better the antenna's reception.

The joint prepared for soldering is pre-riveted and cleaned.

For soldering, you must use a powerful soldering iron (from 150 W). Simple radio amateur for 30 watts. do not solder. Soldering acid can be used.

Check the geometry again and solder the connection

Everything simple DIY antenna for T2 ready.

If you are not particularly bothered by the aesthetic appearance, you can simply fix the antenna on a glazing bead or any other handy holder. This antenna was located in the attic, so the simplest mounting method was used - electrical tape. If the antenna will be placed outdoors, take care of more aesthetic and reliable fasteners.

This is a variant of the T2 antenna made of aluminum wire with a diameter of 3 mm.

Fixed with one screw on the window. The distance to the TV tower is about 25 km. True, the 6th floor, I did not check it below, but under these conditions the signal level is 100% and the quality is 100%. The cable is old, 12 meters to the TV. Receives all 32 channels. At first I was worried that it was not copper, but as it turned out, in vain. Everything worked out great on ordinary aluminum wire (which was available). That is, if you have a zone of confident reception, then you can not bother and feel free to use aluminum (I don’t know, maybe steel will do).

This antenna does not use any amplifiers. It is set up very simply - you turn it according to the maximum signal level and quality on the channels of your tuner.

DIY digital antenna

Check the rest of the channels and fix the antenna. If the reception is poor, you can experiment with not only turning, but also changing the location and height. Very often, the signal can be many times stronger, when the antenna is displaced by only 0.5-1m to the side or in height.

Good luck - the antenna has been tested - it is 100% efficient and better than at least half, or even more purchased antennas, where they save on everything and sell bullshit for good money.

Types of television receiving antennas

Split vibrator (dipole)

There are dipoles: wave, half-wave, quarter-wave.
Wave vibrators have a length equal to the wavelength of the received signal, half-wave - half, quarter-wave - quarter. The characteristic impedance of the dipole is 300 Ohm, therefore, for matching with a TV cable and TV in an amateur environment, a half-wave matching loop made from a piece of a TV cable is used.

The drop cable (for all TV antennas) must have a characteristic impedance of 75 ohms. The dipole is analogous to the indoor antenna supplied with televisions.
Well-known antennas: Locus, Delta and the like, in the meter range, are a split dipole, which is matched to the cable using a special transformer.
Antenna properties - broadband.

The gain is 1 dB. The radiation pattern has the same size front and back lobes, so it with equal success "catches" radio waves in the working band from all directions, a useful signal and interference.

The tilt of the vibrators has little effect on the gain and radiation pattern of the antenna.

Combined antenna: meter - split dipole, decimeter - log-periodic

The loop vibrator is a single channel antenna.

The gain is 1 dB. Directional pattern with the same front and back lobes.

Used as a reference antenna.

Antenna type "wave channel"

The loop vibrator is not used individually and is an active part for wave-channel antennas. An antenna "wave channel" is a set of an active element - a vibrator (usually a loop vibrator) and passive - a reflector and several directors mounted on one common boom.

Passive vibrators located in front of the active vibrator (towards the TV center) are called directors. Vibrators located behind an active vibrator are called reflectors.

The reflector serves to weaken the reception of signals from the rear of the antenna, which improves the noise immunity of the terrestrial antenna. With an increase in the number of directors, the width of the antenna pattern narrows and its gain increases. For long (more than 15 elements) antennas, it can be assumed that the gain increases by about 2.2 dB for each doubling of the antenna length.

It should be noted one nuisance associated with the use of multi-element antennas of the "wave channel" type: when passive elements are added to the loop vibrator, the input impedance of the antenna decreases. For consumers, this does not matter at all, since all antennas are equipped with a matching transformer. The uniformity of the frequency response of the antenna strongly depends on the quality of its matching with the cable and TV, with a slight mismatch, the unevenness increases and individual television channels will be "caught" with weakening.

In some cases, the best result is given by a log-periodic antenna, which has a lower gain (with an equal number of elements), but a more uniform frequency response.

Antenna type "wave channel"
Dual element antennas	Three-element antennas	Five-element antennas
rarely used, since their characteristics are not much better than those of a single vibrator.	The gain is 5.1-5.6 dB. The front lobe of the radiation pattern is larger than the back one, the opening angle is 70 degrees.	The gain is 8.6-8.9 dB. The front lobe of the radiation pattern is larger than the back one, the opening angle is 50 degrees.
Seven-element type antennas	Eleven-element antennas	Sixteen-element antennas
The gain is approximately 10 dB. The front lobe of the radiation pattern is larger than the back one.	The gain is approximately 12 dB. The front lobe of the radiation pattern is larger than the back one.	The gain is approximately 13.5 dB. The front lobe of the radiation pattern is larger than the back

Antenna Lumax "Wave channel", 6-12 TV channel

Antennas of the "Wave channel" type are widely used in various professional radio communication and radar devices.

Most of the television collective and individual antennas of industrial manufacture are also antennas of the "Wave channel" type. This is due to the fact that such antennas are quite compact and provide a large gain in a relatively small size.

Log-periodic antennas

Log-periodic antennas- broadband antennas providing reception of TV channels in a wide frequency range: meter and decimeter waves.

The operating frequency band of a log-periodic antenna at low frequencies is limited by the size of the largest and smallest antenna vibrators. In the operating range, a good match between the antenna and the feeder is ensured, and the gain remains practically constant. A log-periodic antenna with a number of vibrators equal to 10-11 is equivalent in gain to a three - four-element "Wave channel" antenna. At the same time, a log-periodic antenna operates in a much wider frequency band than an antenna of the "Wave channel" type, which allows one antenna to receive television channels of meter and decimeter waves.

The connection of the feeder to the LPA is made without a special balun and matching device. A cable with a characteristic impedance of 75 Ohm is inserted into the lower pipe from the end and exits at the end, which is directed to the telecenter, here the cable sheath is connected to the end of the lower pipe, and the central core is connected to the end of the upper pipe.
Principle of operation: depending on the wavelength of the received signal, several vibrators are excited in the antenna structure, the dimensions of which are closest to half the wavelength of the signal, which, according to the principle of operation, resembles several "Wave channel" antennas connected together, each of which contains a vibrator, a reflector and director.

At a given signal wavelength, only one triple of vibrators is excited, and the rest are so out of tune that they do not affect the operation of the antenna. This leads to the fact that the gain of the LPA turns out to be less than the gain of the "Wave channel" antenna with the same number of elements, but the bandwidth is much wider.

By analogy with amplifiers, the "antenna gain area": ​​the product (KU) by the width (BP) is a constant value, therefore, the wider the bandwidth, the lower the gain for the given antenna dimensions.

Log-periodic antenna REMO, 6-69 TV channel

A log-periodic antenna is used in the zone of reliable reception of TV channels to receive a large number of TV channels in favorable reception conditions (no interference and reflected TV signals).

Loop antennas

Loop antennas are intended for the conditions of receiving TV channels, when the simplest antennas or antennas of the "wave channel" type cannot provide satisfactory picture quality on the TV screen.

Two- or three-element loop antennas are used, which are otherwise referred to as "double square" or "triple square", respectively. Loop antennas combine high gain with simplicity of design with a relatively narrow bandwidth and do not require tuning.

Practical applications as television receiving antennas are rarely found. They were widespread (self-made versions) in the "Soviet era", when there was a shortage of television antennas on sale.
"Double square" Single channel. The gain is 9-11 dB.

Characteristic impedance of about 70 ohms. The front lobe of the radiation pattern is much larger than the back one.
"Triple square" Single channel... The gain is 14-15 dB. Characteristic impedance of about 70 ohms. The front lobe of the radiation pattern is much larger than the back one.

Common Mode Antenna Arrays

Common-mode antenna array is a complex directional antenna system consisting of separate weakly directional antennas, spaced apart and located in such a way that the phases of the signals induced in them are the same.

As a rule, an in-phase array is assembled from identical antennas located in several rows and several floors. The use of several antennas connected in an in-phase array instead of one antenna leads to a narrowing of the radiation pattern and an increase in the gain compared to the gain of a single antenna included in the array.
Single channel.

Gain - increases in the range from 4 to 5 dB when the number of antennas in the array is doubled. The characteristic impedance is approximately 70 ohms. The front lobe of the radiation pattern is several times larger than the back one.

Common-mode array of Channel Master, USA

"Polish" antennas

They are a four-level common-mode lattice equipped with a built-in amplifier.

How to make an antenna for digital TV with your own hands

They have a grid-shaped reflector located at the back of the antenna. Polish antennas became widespread in the early 90s, when the antenna market was not very diverse. Actually, it was not a Polish idea, Philips and other well-known companies had developments, the Poles made a cheap, affordable option.

The grille is equipped with a built-in antenna amplifier and shows good results in receiving remote TV signals from TV channels 6 to 69. Due to its low cost, the antenna design is very fragile and short-lived, and the long mustache of the meter range instantly bends under the weight of birds or the influence of the wind and loses its receiving properties.

Amplifiers are not immune to electrostatic electricity and often crash during lightning storms. The antenna is poorly shielded from interference, and often an "energized" amplifier is itself a source of interference.

The antenna is not suitable for urban use.
All-wave. The gain is its own on the UHF 13-14 dB, with an amplifier up to 40 dB. Characteristic impedance - 75 Ohm with matching transformer.

Traveling wave antennas

Traveling wave antennas it is customary to call directional antennas, along the geometric axis of which a traveling wave of the received signal propagates, these are aperiodic antennas.

Typically, a traveling wave antenna consists of a collecting line, to which several vibrators are connected, located at the same distance from one another. The EMF induced by the electromagnetic field in the vibrators is added in the collecting line in phase and enters the feeder.

The gain of a traveling wave antenna is determined by the length of the collecting line and is proportional to the ratio of this length to the wavelength of the received signal. In addition, the antenna gain depends on the directional properties of the vibrators connected to the collecting line. All vibrators of the traveling wave antenna are active, the signal energy received by them is transmitted to the collecting line. If the "Wave channel" antennas are narrowband and are able to effectively receive a signal only through one specific frequency channel, to which their sizes correspond, then the traveling wave antennas are broadband and do not need to be tuned at all.

Combined antenna: meter, traveling wave, decimeter, "wave" channel from Channel Master, USA. Reception radius up to 60 miles

Combined antenna: meter, traveling wave, decimeter, "wave" channel from Channel Master, USA.

Reception radius up to 100 miles

As you can see in the pictures: in the first case, the working band of the antenna is formed by inclined vibrators of various lengths, in the second case, the working band is formed using vibrators of two types and different sizes.

These antennas are not widely used on the territory of Russia, however, these antennas, without exaggeration, are an installer's dream. The working conditions of the installers on the roof are not a gift: snow and wind, frost and ice, rain and scorching sun. Assembling antennas in such conditions is not easy, but you take the Channel Master out of the box, straighten the vibrators until they are fixed in special clamps and the antenna is ready for installation.

For the price, these antennas are comparable to tri-band antennas, are mechanically strong and have good reception characteristics. There are two types of antennas with different numbers of vibrators.