Today we share life hacks on how to make a TV antenna with your own hands. An antenna is a device for emitting or receiving radio waves. There are transmitters, receivers, and transmitters. The editors learned that a simple design can be made from copper and brass wire, copper pipes, wires, and even tin cans.

Tin Can TV Antenna

You can make a TV antenna yourself, from improvised materials, even from empty beer cans. This method is the fastest and easiest. You can make a design of electrodes and disks. Maximum amount there will be seven channels.

You will need:

1. can;
2. plug;
3. antenna cable;
4. screwdriver;
5. adhesive tape or insulating;
6. wooden trempel;
7. self-tapping screws (2 pcs).

The room design guarantees reliable reception of an analog signal within the city and without coordination for a cable (with a length of up to 2 m).

Distance between banks:

where λ is the wavelength. Dipoles should be no more than 3-4 pieces. If there are fewer of them, the gain will be insignificant, more - there will be problems with cable matching.

The signal quality will noticeably improve if you place a metal mesh screen on the back.

Distance between screen and main structure:

How to make a design:

How to improve the antenna?

An amplifier is needed if the translator is far away. With an amplifier, the design receives the signal more reliably, but the DIY option may not work here.

You can use a magnet around which several turns of a television cable will be wound (it is assembled near the TV and on the antenna).

If the question is how to amplify the signal of a home structure so that instead of 7 20 channels are clearly broadcast, you must:

• buy special preamplifier TV signal;
• find the place of ideal signal reception;
• get rid of the interference that metal objects create.

How to make a fast antenna:

How to assemble an antenna for digital TV?

Homemade design should be:

1. carefully crafted with a high degree accuracy without loss of signal power;
2. strictly directed along the axis of the electromagnetic wave emanating from the transmitting center;
3. targeted by the type of polarization;
4. have protection against side interference signals of the same frequency coming from any sources: electric motors, radio transmitters, generators.

How to make your own antenna for digital TV (DVB T2):

Simple digital TV antenna: what are the options?

It will require a piece of coaxial cable with a characteristic impedance of 75 ohms and a plug to connect the structure.

The algorithm is this:

1. with an ordinary knife, the outer shell is cut off from the free end;
2. take the length with a small margin, since it is easier to bite off a small segment during adjustment than to run for a new cable;
3. the shielding layer is removed from this section of the cable, the inner core is exposed and the insulation is removed;
4. insert a plug socket into the connector on the TV signal prefix, direct the bare wire of the inner core across the incoming electromagnetic wave;
5. remember about horizontal polarization;
6. the terrestrial digital antenna must be fixed on the windowsill or with a piece of adhesive tape on the glass;
7. interference and reflected signals are shielded by a strip of foil located at a small distance from the central core;

Types of antennas and which ones can you make yourself?

There are "Polish", "eight" and "square". The digital antennas for the TV tuner and set-top box must be tuned to the same frequency.

IMPORTANT! Both the set-top box and the tuner must be able to decode the signal.

"Polish" antenna and digital TV

It provides high quality and reliable reception. analog television(+ UHF), but completely unsuitable for receiving modern digital TV.

"Eight": manufacturing algorithm

Simple design for DVB T2, which can be made from copper wire Ø 3 mm. The reflector is not used. The upper side of the segments is 14 cm, the side is 13 cm.

We measure the wire 112 cm long and begin to bend:

1. We bend the 1st segment with a length of 14 cm (for the antenna - 13 cm and 1 cm - for the strength of the loop);
2. 2nd and 3rd, like 6 and 7 - 14 cm;
3. 4th and 5th - 13 cm;
4. 8th - 14 cm - 13 cm and 1 cm - with a strength loop.

We clean the loops, twist and solder - they will become contacts for connecting the cable. For soldering, we strip the cable from the antenna side by 2 cm and 1 cm from the plug side, the joints are sealed with any elastic hot melt adhesive.

What is a "square" and is it worth it to take it yourself?

A modification of the three-square design with 6 elements and a transformer, confidently accepts digital and analog channels at a distance of up to 10 km line of sight.

• double square

Behind the main frame is a reflector, the side of the main frame is 0.254λ, the side of the reflector is 0.278λ, the distance between the frames is 0.089λ.

Another version of the double square is two rings.

butterfly antenna

Shortwave small-sized antenna, shaped like a butterfly. For its manufacture, a copper wire Ø about 2 mm is required, for external use 4 mm is also allowed, for home use - a conventional television coaxial cable 75 Ohm.

Rectangular wire frame (length and width):

1. for TV - 500x200 mm;
2. for Wi-fi (omnidirectional) and Bluetooth - 90x30 mm.

We twist the frame crosswise and cut it with wire cutters so that two triangles are formed. We solder the coaxial cable and fix it with brackets (adhesive tape) on the dielectric ebonite, wood or plastic.

Powerful TV antenna: what should I know about it?

In order for the device to function like a conventional antenna, its receiving circuit must be improved.

Algorithm:

1. we buy signal amplification equipment;
2. connect to the device to eliminate signal interference;
3. wrap the cable at both ends with insulating tape;
4. we make a screen for high-quality reception: a kind of metal mesh, which is isolated from the TV and fixed behind the receiver;
5. an ordinary metal mesh from an ordinary fence will do for the screen;
6. add iron bars and connect them symmetrically to the screen to amplify the signal (it is necessary that the entire structure is of the same type of metal to avoid oxidation)$
7. in the center of the installation we place another amplifier and solder the contacts to the receiver.

IMPORTANT! Such a television structure is installed on the roof with a reference to the nearest television tower.

Versatile design

Necessary tools and materials:

• copper wire (length 4 m, cross section 4 mm2);
• board of any thickness, but 7 cm wide, 55 cm long;
• soldering iron;
• wood screws;
• tape measure or ruler;
• screwdriver;
• simple pencil.

Algorithm:

1. cut the copper wire into 8 parts, the length of each is 37.5 cm;
2. remove the insulating layer in the middle part of each of the received parts of the wire;
3. cut off 2 more copper wires (22 cm each) and divide them conditionally into 3 equal parts;
4. at the inflection points, remove the insulating layer;
5. we bend the wire in prepared (bare) places;
6. the distance between the ends of the wire bent in half 7.5 cm;
7. fix the plug, connect the TV cable.

How to make an antenna for digital TV (DVB T2) yourself:

Log-periodic (all-wave) design

This is a collecting line with halves of dipoles installed alternately on it. The length of a piece of wire forming a half-dipole will be equal to λ/4.

IMPORTANT! Do-it-yourself outdoor structures can give amplification up to 25 dB, about 12 dB indoor.

LPA is an ideal device for receiving both analog signals, as well as digital ones. To calculate the parameters, it is necessary to know the value of the progression index (from 0.7 to 0.9) and the opening angle α (30-60°). We take as a basis the proportion and calculate the necessary parameters:

τ=B2/B1=B3/B2=Bn/(B(n-1)) = A2/A1=A3/A2=An/(A(n-1))

The gain is better, the larger τ. The directivity can be increased by decreasing the angle α.

Calculation of parameters:

1. determine the values ​​of B2 and A2;
2. calculate B1 and A1 and other parameters.

What are the types of antennas? Homemade simple homemade antenna

Home construction is mounted from copper or brass wire. Aluminum is not suitable because it oxidizes quickly.

The wire is cleaned from both ends of the insulating material, one end is attached to a pipe or battery, the opposite is inserted into the television connector. The amplifier of the necessary frequencies is a pipe that runs through the whole house and goes upstairs. Immediately there is a signal, the antenna catches 5 channels.

• For an apartment with a balcony

A longer wire is taken, since the TV and the balcony area will need to be connected. The wire is stripped on both sides, one end is connected to the TV in a cable socket, and the other is pulled out to the balcony and attached to ropes or strings. Such an antenna gives a sharper image, and there are more channels with it.

Antenna for giving

Stable signal reception at a distance of up to 30 km is established by passive structures both in winter and in summer. For long distances, more powerful structures are needed, preferably with an amplifier. For hilly terrain and ultra-long-range reception, the antenna must be raised higher using a mast for this.

For a classic design for a summer residence, you will need:

1. wire (Ø 1.5 mm) - based on - 1.5-2 m per antenna and 5-6 m at a distance from the structure to the TV;
   2. the outer part of the prepared wire (twist 1-1.5 m into a ring, Ø from 356 mm to 450 mm);
2. the inside of the antenna (make a second ring out of wire, dimensions - 180 mm;
3. finished rings - the basis of the future antenna - are fixed on a piece of plywood (a piece of wood is also possible), but so that the tree does not overlap the rings and does not hang out;
4. orient the finished structure with rings in the direction of the signal source, rotate the antenna to search for the best signal.

Antenna Kharchenko (biquadrat)

This is an external zigzag design with a reflector.

Z-antenna system with reflector provides the same parameters as
LP antenna. The difference lies in the main lobe - it is twice as long horizontally, which allows you to catch a signal from all directions.

The UHF antenna is made of a copper tube and a 6 mm thick aluminum sheet.

Car antenna: internal and external

• Internal

You will need a frame device, which is laid at the back under the glass seal. In the upper part, it is narrower, but the dimensions are not those required at a frequency of 27 MHz. For this reason, a capacitor is installed in the center, with the help of which the TV antenna for the car is tuned to resonance on the desired channel.

IMPORTANT! There are several receiving frequencies - 27 and 65 MHz, 28.2 and 68 MHz.

Manufacturing algorithm:

1. we take the MGTF 0.5 wire, which is laid along the edges of the rear window in the form of a trapezoid;
2. the same is done with the upper part;
3. the poles are arranged so that it is easy to add wires for a matching capacitor;
4. to remove the signal, use the RK-50 cable;
5. in the center of the rear window, 5-25 PF are fixed, to which both cables are directed strictly vertically.

Universal compact TV antenna in the car:

• External

For a good signal, you need to fix a pair telescopic antennas from the radio. The case can be taken from the Polish device.

Figure 11 - Polish design - the basis for an internal auto antenna

Supplying power to the amplifier:

1. we take the connector for the active TV antenna and solder the wire to it;
2. we pass the cable from the TV antenna so as not to pinch it;
3. it is screwed to the connector;
4. the wire soldered to the connector is connected to the +12 output on the radio to turn on the amplifier or active antenna.

There are active in-salon combined TV antennas with external elements for receiving MV / UHF.

In addition to the above, there are meter (crossed aluminum tubes) and fractal antennas.

Do-it-yourself fractal Wi-fi antenna:

IMPORTANT! All stories about the efficient operation of a mercury antenna are a big misconception. Science does not know a single principle by which a mercury antenna could work. The editors warn that making a mercury antenna on your own is a so-so idea and a dangerous undertaking.

What is a digital TV multiplex?

A digital multiplex is a set of channels of the same frequency. There are two multiplexes: the first is available in all cities with digital TV, but not all towers are ready for the second. For installation, you will need a receiver and an antenna with DVB T2 support.

equipping country cottage area We try to make it as comfortable as possible for your stay. And this means that over time it acquires the amenities to which we are so accustomed in Everyday life– water supply, heating and, of course, electricity. And where there is the latter, sooner or later television will definitely appear. But how, you ask, to spend it in the country, if the purchase of an antenna, which, by the way, is quite expensive, is not provided for in the personal budget? Yes, very easy! A few basics of radio electronics, a couple of pieces of iron and a minimal soldering kit, and now, well tired in the garden, you are located on the country terrace to watch the evening news block.

Radio electronics and television: simply about the complex

The most important thing for any antenna is its ability to interact with a signal distributed over the air.

Currently, TV broadcasting is carried out in one single range - decimeter, and television transmitters cover almost the entire more or less populated area. This makes it possible to "catch" a TV signal anywhere.

But for this you have to take into account a few simple nuances.:

Based on this, among the whole variety of television antennas, the most accessible for self-manufacturing will be such types as:

1. All-wave (frequency independent)

It does not have high parameters, but it is the simplest and cheapest to manufacture - it is based on a metal frame, and ordinary beer cans or other tin containers act as receivers.

1. log-periodic range

Such an antenna can be compared to a fishing net that sorts prey when it is caught. This type antenna systems also has a simple design, but provides higher parameters than the all-wave.

1. Decimeter zigzag

For the decimeter range, the dimensions and complexity of the design of such an antenna are greatly simplified, and it can work in almost any reception conditions.

The subtleties of manufacturing television antennas

The elements of the antenna, through which the useful signal currents pass, are always connected by soldering or welding. But if the device is placed outdoors, for example, on the roof of a country house, such contacts will soon be corroded by corrosion.

If we are talking about a home-made antenna for giving, you should not strive for the ideal quality of contacts - if they rust or burst, then at least not soon. But it is desirable that the connections in the antenna design be as small as possible, which will provide stable and fairly clean reception.

The braid and the center core of the coaxial cable are currently made of inexpensive alloys that are resistant to corrosion. Unlike classical copper, they are difficult to solder. Therefore, care must be taken not to burn the cable.

For the manufacture of the antenna and its cable connection, it is desirable to use:

Aluminum wire for the manufacture of antenna elements should not be used - it will oxidize very quickly and lose the ability to conduct an electrical signal. Copper or cheaper brass is best suited for this.

The antenna receiving area should be as large as possible. To do this, several metal rods of the same metal should be symmetrically attached to the screen - a frame that screens out ethereal and electrical noise.

Buying a simple signal amplifier that connects directly to the antenna will solve the problem with a weak and dirty signal.

As a result, the system will provide normal receiving power. All that is needed for this is to take the antenna to the roof of the country house and point it towards the nearest television tower.

Do-it-yourself frequency-independent antenna

The simplest all-wave is a pair of metal plates mounted on a wooden rail and connected by several turns of copper wire of any diameter. The width of such an antenna should be equal to its height, and the opening angle of the canvases should be 90 °. It is not necessary to solder the wire to the point of zero potential of the all-wave - it is enough to ensure its reliable fastening.

The frequency-independent antenna is capable of receiving both meter and decimeter signals from almost any direction. The disadvantage of this option is a unity gain and zero CPD - an indicator of the ratio of the signal power received to the main lobe of the antenna to the sum of the interference power at the frequency received by the other elements. That is why the all-wave is not suitable for receiving a TV signal in an area with strong interference or where the terrestrial signal is too weak.

To make your own frequency-independent antenna, you will need:

• antenna cable;
• several tin cans;
• self-tapping screws;
• plug;
• insulating tape;
• screwdriver;
• wooden rail;
• copper wire.

Banks are fixed on a rail (mast) with electrical tape at a distance of about 7 cm from each other.

Self-tapping screws are screwed into them, to the protruding ends of which the stripped ends of the antenna cable are screwed. The latter is fixed on the rail and laid along the external building structures of the country house to the place where you plan to put the TV.

You can improve the design of the all-wave oven by adding a few more sections from tin containers. After that, it remains to securely fix its mast in a vertical position, connect it to the TV and set up the tuner.

Another option for an all-wave antenna designed to receive a meter signal is a fan vibrator, which is popularly called a slingshot antenna.

Production of a log-periodic television antenna

The “speech therapist” antenna is a receiving line (a pair of metal tubes) with halves of linear dipoles perpendicularly connected to it - pieces of a conductor with a diameter of a quarter wave of the working signal. The length and distance between the latter changes exponentially.

For the manufacture of a log-periodic antenna, it is necessary to perform a number of calculations:

1. The beginning of the calculation of the length of the dipoles is performed from the second in length.
2. Taking the reciprocal of the progression index, the length of the longest dipole is calculated.
3. Then it remains to calculate the shortest - the first - dipole, and then, based on the selected frequency range, the length of the "zero" dipole is taken.

To achieve maximum receiving power, there should be a distance of 0.03-0.05 wavelength between the dipoles, but not less than twice the diameter of any of them.

The length of the finished LP antenna is about 400 mm. The diameter of the base of the LP antenna should be 8-15 mm, and the gap between their axes of the receiving line is taken no more than 3-4 dipole diameters.

For normal operation of the LP antenna, you need to select a high-quality and fairly thick (about 6-8 mm in sheath) coaxial cable. Otherwise, you will not be able to compensate for the attenuation of the decimeter waves, as a result of which the TV tuner will not be able to pick up the signal.

The cable to the receiving line cannot be fixed from the outside, as this sharply reduces the quality of signal reception.

When installing such an antenna, it is necessary to ensure its wind resistance, and if you use a metal pipe as a mast, you need to install a dielectric insert - a wooden block - at least 1.5 cm long between it and the receiving line.

It is possible to improve the design of the LP antenna by installing linear or fan-shaped hangers of a meter field on it. This system is called delta.

Antenna scheme "Delta"

Zigzag antenna for giving

The Z-antenna system with a reflector provides almost the same TV signal reception parameters as the LP antenna. However, its main lobe is horizontally twice as long. This makes it possible to catch a signal from different directions, which is especially true for rural areas.

The decimeter zigzag antenna has small dimensions, but its operating range is practically unlimited. The material for the manufacture of such a system is copper tube or a sheet of aluminum about 6 mm thick. If you chose the latter, soldering it with ordinary solder or flux will not work - in this case, the fastenings are made with bolts. For outdoor installation, such an antenna will be ready only after sealing the connection points with silicone.

The design of the zigzag antenna consists of the following elements:

• barbell;
• wire cloth;
• metal plates for attaching the canvas;
• cross rails;
• dielectric plates and gaskets;
• mounting plate;
• feeder line;
• power plate.

Any of them can be made with your own hands from improvised materials or purchased at the nearest radio electronics store.

The sidewalls of the Z-antenna are made of all-metal or in the form of a mesh covered with a sheet of tin. When laying a coaxial cable along the body of the antenna, its sharp bends should be avoided. To do this, it is enough to reach the side capacitive insert and not let it go beyond it. At the point of zero potential, the cable sheath is carefully soldered to the web.

This class also includes such types of antennas as ring and reflex, which are also not particularly difficult to manufacture.

Options for self-manufacturing television antennas in the photo

There are other types of antennas suitable for self-production - wave, "Polish", simple frame and even primitive satellite ones. But whichever option you choose, a competent calculation of the parameters is required. The technique can be found in the technical literature on radio electronics. However, it is much easier and easier to ask advice from those who already have experience in the manufacture of this kind of antenna.

Self-made antenna for giving on video

Separately, it is necessary to dwell on the materials that are used in the manufacture of the antenna. Antenna elements can be made of tubes, rods, strips or corners of any metal. In accordance with the surface effect, high-frequency currents flow exclusively along the surface of the metal, so a thin-walled tube or a solid rod of the same diameter is exactly the same in its properties.

Usually television antennas made of aluminum or its alloys. This is due to the fact that the antenna from such tubes is quite strong and light. However, the electrical properties of aluminum antennas are not high enough due to the fact that poor contacts are often formed at the junctions of antenna elements, caused by an oxide film covering the surface of aluminum alloys. This can lead to antenna failure over time.
It gets even worse when, when assembling the antenna, elements or coupling bolts from different metals are used. In this case, due to the contact potential difference, a galvanic couple arises, destroying the metal at the junction. Therefore, aluminum antennas are best connected using gas welding or, in extreme cases, using aluminum tie bolts, nuts and washers. Before assembling, it is useful to clean the elements at the joints well with a file and generously lubricate with technical petroleum jelly to prevent the formation of an oxide film.

In principle, the antenna can be made of any metal; copper, brass, bronze, steel or stainless steel. Compared to aluminum antennas, such antennas will of course be significantly heavier. In all cases, it is desirable to connect the antenna elements in such a way as to exclude the possibility of poor contacts due to corrosion or destruction from electrolysis. To do this, all connections are best welded or soldered. In this case, the antenna elements can also be made of different metals. If steel elements were used and soldered using an acid flux, the soldering points must be thoroughly washed with hot water to remove its residues, otherwise the flux residues will lead to severe corrosion of the metal for a short time.

It should be remembered that soldering serves only to ensure good electrical contact. Soldering with tin solders does not withstand mechanical loads. Therefore, it is necessary to ensure the strength of the connections by other methods (rivets, bolts, etc.), and after assembly, these connections should be soldered. The exception is brazing, which has sufficient strength. To avoid corrosion, the antenna after complete assembly and soldering of the feeder with the matching device to it is thoroughly cleaned of oxides and well painted over in several layers with oil or nitro paint. Synthetic car enamels can also be used. These dyes are good dielectrics and do not affect the operation of the antenna at all. It is undesirable to use aluminum paints, since they have a finite resistance value.

The cable connection points to the antenna elements must be sealed to prevent moisture ingress. The best sealing is achieved by using plasticized epoxy resin. Such a resin in the form of an epoxy adhesive of the EDP brand is commercially available in stores. household goods. The place to be sealed is superimposed on a piece of plasticine, a recess of the appropriate shape is made in it and filled with resin. After it hardens, the plasticine is removed, and the surface of the resin is processed with a file to give it an even shape. For a good fit of the resin to the metal, it must first be degreased with acetone.

Based on the book by V.A. Nikitin "How to achieve good TV performance."

The length of the tubes, and hence the total length of the vibrator, depends on the frequency of the received television station. And it can lie in the range from about 50 to 230 MHz. This entire operating range is divided into 12 channels - they are marked on the TV's program selector knob. the second - 229-234 and then, respectively - 177-179, 162-163, 147-150, 85, 80, 77, 75, 71, 69, 66 cm. Therefore, before you start building the antenna, find out on which channel it leads broadcasts local TV center or repeater.

So, the length of the tubes was determined. Their diameter can be 8-24 mm (most often used, tubes with a diameter of 16 mm). Flatten one of the ends of each tube and attach the tubes with metal clamps to the Holder and? insulating material (textolite or getinaks with a thickness of at least 5 mm) so that the required distance is obtained between the remote ends, and the flattened ends are 60-70 mm apart from each other. Attach the mounting petals to the flattened ends with screws - they will serve as a kind of tube outlets. It is better, of course, to weld the petals to the ends of the tubes so that the contact is more reliable.

Install the tube holder. on the mast, which will later be installed on the roof. Now you need to connect a reduction to the antenna from a coaxial cable RK-1, RK-3, RK-4 or another with a wave impedance of 75 ohms. But it is impossible to solder the cable conductors directly to the tube leads. A matching device is installed between the drop cable and the antenna, which is a loop of two segments of the same coaxial cable. The length of the segments depends on the received television channel.

For the first channel, the size should be 286 cm, and 12 - 95 cm, for subsequent channels - 242 and 80, 187 and 62, 170 and 57, 166 and 52, 84 and 28, 80 and 27, 77 and 26, 74 and 25, 71 and 24, 68 and 23, 66 and 22 cm.

The connection of the matching device is shown in Figure 2. The central cores of the cable and the segments are soldered directly to the terminals of the tubes and to each other, and the metal braids are connected by segments of copper wire without insulation. Soldering must be strong and reliable, and soldering points are protected with insulating tape.

The matching loop and drop cable are attached to the mast. The length of the drop cable must be long enough to connect to the TV after installing the roof antenna. At the end of the cable, a connector is installed that plugs into the TV jack.

The antenna is strengthened with braces so that it stands firmly, and the vibrator is at a distance of at least 2 m from the roof.

To get the most powerful signal from the antenna, it must be oriented as accurately as possible to the television center (or to the repeater antenna). This work is best done with two or even three people. One slowly rotates the antenna around its axis, and the other, watching the TV screen, tells him about the change in contrast and image quality. The antenna is installed and fixed in such a position that the contrast is greatest and there is no multi-contourism in the image (the result of receiving a signal reflected from nearby buildings).

Despite the rapid development of satellite and cable television, the reception of on-air broadcasting is still relevant, for example, for places of seasonal residence. It is not at all necessary to buy a finished product for this purpose; a home decimeter (UHF) antenna can be assembled by hand. Before proceeding to the consideration of designs, we will briefly describe why this particular range of the television signal was chosen.

Why DMV?

There are two good reasons to opt for this type of structure:

1. The thing is that most channels are broadcast in this range, since the design of repeaters is simplified, and this makes it possible to install a larger number of unattended low-power transmitters and thereby expand the coverage area.
2. This range is selected for broadcasting "numbers".

Indoor antenna for TV "Rhombus"

This simple, but at the same time, reliable design was one of the most common in the heyday of on-air television.

Rice. 1. The simplest homemade Z-antenna, known under the names: "Rhombus", "Square" and "People's Zigzag"

As can be seen from the sketch (B Fig. 1), the device is a simplified version of the classic zigzag (Z-design). To increase the sensitivity, it is recommended to equip it with capacitive inserts ("1" and "2"), as well as a reflector ("A" in Fig. 1). If the signal level is acceptable, this is not necessary.

As a material, you can use aluminum, copper, as well as brass tubes or strips with a width of 10-15 mm. If you plan to install the structure on the street, then it is better to abandon aluminum, since it is susceptible to corrosion. Capacitive inserts are made of foil, tin or metal mesh. After installation, they are soldered along the contour.

The cable is laid as shown in the figure, namely: it did not have sharp bends and did not leave the limits of the side insert.

Decimeter antenna with amplifier

In places where a powerful relay tower is not located in relative proximity, you can raise the signal level to an acceptable value using an amplifier. Below is circuit diagram device that can be used with almost any antenna.

Rice. 2. Scheme antenna amplifier for UHF range

Item List:

• Resistors: R1 - 150 kOhm; R2 - 1 kOhm; R3 - 680 Ohm; R4 - 75 kOhm.
• Capacitors: C1 - 3.3 pF; C2 - 15 pF; C3 - 6800 pF; C4, C5, C6 - 100 pF.
• Transistors: VT1, VT2 - GT311D (can be replaced with: KT3101, KT3115 and KT3132).

Inductance: L1 - is a frameless coil with a diameter of 4 mm, wound with copper wire Ø 0.8 mm (2.5 turns must be made); L2 and L3 are 25 µH and 100 µH high frequency chokes, respectively.

If the circuit is assembled correctly, we will get an amplifier with the following characteristics:

• bandwidth from 470 to 790 MHz;
• gain and noise coefficients - 30 and 3 dB, respectively;
• the value of the output and input resistance of the device corresponds to the RG6 cable - 75 Ohm;
• the device consumes about 12-14 mA.

Let's pay attention to the way the power is supplied, it is carried out directly through the cable.

This amplifier can work with the simplest designs made from improvised means.

Indoor antenna made from beer cans

Despite the unusual design, it is quite functional, since it is a classic dipole, especially since the dimensions of a standard can are perfect for the arms of a UHF vibrator. If the device is installed in a room, then in this case it is not even necessary to coordinate with the cable, provided that it is not longer than two meters.

Designations:

• A - two cans with a volume of 500 mg (if you take tin, not aluminum, you can solder the cable, and not use self-tapping screws).
• B - places for fastening the shielding braid of the cable.
• C - central vein.
• D - the place of attachment of the central core
• E - cable coming from the TV.

The arms of this exotic dipole must be mounted on a holder made of any insulating material. As such, you can use improvised things, for example, a plastic clothes hanger, a mop bar, or a piece of wooden beam of the appropriate size. The distance between the shoulders is from 1 to 8 cm (selected empirically).

The main advantages of the design are fast production (10 - 20 minutes) and quite acceptable quality of the "picture", provided that the signal strength is sufficient.

Making a copper wire antenna

There is a design, much simpler previous version, which requires only a piece of copper wire. This is a narrow band loop antenna. This solution has undeniable advantages, since in addition to its main purpose, the device plays the role of a selective filter that reduces interference, which allows you to confidently receive a signal.

Fig.4. simple frame UHF antenna loop type for digital TV reception

For this design, it is necessary to calculate the length of the loop, to do this, you need to find out the frequency of the “numbers” for your region. For example, in St. Petersburg it is broadcast on 586 and 666 MHz. The calculation formula will be: L R = 300/f, where L R is the length of the loop (the result is presented in meters), and f is the average frequency range, for Peter this value will be 626 (the sum of 586 and 666 divided by 2). Now we calculate L R, 300/626 = 0.48, which means that the length of the loop should be 48 centimeters.

If you take a thick RG-6 cable, where there is a braided foil, then it can be used instead of copper wire to make a loop.

Now we will tell you how the structure is assembled:

• A piece of copper wire (or RG6 cable) is measured and cut off with a length equal to L R .
• A loop of a suitable diameter is folded, after which a cable is soldered to its ends, which goes to the receiver. If RG6 is used instead of copper wire, then the insulation is first removed from its ends, by about 1-1.5 cm (the central core does not need to be cleaned, it does not participate in the process).
• The loop is installed on the stand.
• An F connector (plug) is screwed onto the cable to the receiver.

Note that despite the simplicity of the design, it is most effective for receiving "numbers", provided that the calculations are carried out correctly.

Do-it-yourself indoor antenna MV and UHF

If, in addition to UHF, there is a desire to receive MV, you can assemble a simple multiwave oven, its drawing with dimensions is presented below.

To amplify the signal in this design, a ready-made SWA 9 block is used, if there are problems with its acquisition, you can use homemade device, the scheme of which was given above (see Fig. 2).

It is important to observe the angle between the petals, going beyond the specified range significantly affects the quality of the "picture".

Despite the fact that such a device is much simpler than a log-periodic design with a wave channel, nevertheless, it shows good results if the signal is of sufficient power.

Do-it-yourself figure-eight antenna for digital TV

Consider another common design option for receiving "numbers". It is based on the classic scheme for the UHF range, which, due to its shape, was called the "Eight" or "Zigzag".

Rice. 6. Sketch and implementation of the digital eight

Construction dimensions:

• the outer sides of the rhombus (A) - 140 mm;
• inner sides (B) - 130 mm;
• distance to the reflector (C) - from 110 to 130 mm;
• width (D) - 300 mm;
• step between the bars (E) - from 8 to 25 mm.

The cable connection point is at points 1 and 2. The requirements for the material are the same as for the Rhombus design, which was described at the beginning of the article.

Homemade antenna for DBT T2

Actually, all the examples listed above are capable of receiving DBT T2, but for a change, we will give a sketch of another design, popularly called the “Butterfly”.

As a material, you can use plates made of copper, brass, aluminum or duralumin. If the structure is planned to be installed on the street, then the last two options are not suitable.

Outcome: which option to stop?

Oddly enough, but the simplest option is the most effective, so the "loop" is best suited for receiving the "digit" (Fig. 4). But, if you need to receive other channels in the decimeter range, then it is better to stop at the "Zigzag" (Fig. 6).

The antenna for the TV should be directed towards the nearest active repeater, to select the desired position, rotate the structure until the signal strength is satisfactory.

If, despite the presence of an amplifier and a reflector, the quality of the "picture" leaves much to be desired, you can try to install the structure on the mast.

In this case, it is necessary to install lightning protection, but this is a topic for another article.