Antenna from profile. Making and setting up an indoor antenna with your own hands
Digital encoding of the television signal allows it to be delivered to the receiver while minimizing any losses. To support the technology, the TV needs an antenna for DVB-T2. Making such a device with your own hands is much cheaper than buying a ready-made one, paying about 3 thousand rubles for it. Terrestrial digital television displaces all similar types of signal transmission, while offering high-quality broadcasting and a variety of channels.
Changes on air
Making an antenna for an old-style tube TV was considered prestigious in its time and showed the level of skill, in modern world Interest in homemade devices does not fade, and many people make DVB-T2 over-the-air antennas with their own hands. Manufacturers of industrial equipment adapt to changing reception conditions by connecting modern electronics to standard well-known designs, completely ignoring the fact that the main condition for the operation of the antenna is its interaction with the terrestrial signal.
In recent years, almost all broadcasting takes place in the DVB-T2 range, which reduces the cost and simplifies, from an economic point of view, the antenna-feeder system of transmission stations. Periodic maintenance requires fewer highly qualified personnel, and their work becomes less harmful and dangerous.
Television broadcast transmitters cover all large cities and sparsely populated villages with signals, so catching waves from unattended low-power stations in remote areas becomes important if you install an antenna for DVB-T2 reception, made with your own hands from scrap materials.
Due to the expanded construction of reinforced concrete buildings within the city, the conditions for signal propagation in populated areas have changed significantly. Multi-storey buildings with a metal frame are like mirrors, reflecting waves several times until they are completely attenuated.
There are many TV channels broadcast on the air today. A digital signal differs from others in that it either exists or it doesn’t; there is no middle position. Other transmission systems differ in that the channels perceive interference differently, which reduces their broadcast quality, and sometimes the image may simply disappear. A self-made antenna for DVB-T2 will allow you to receive the same signal for all channels that show the same high-quality picture.
The digital broadcast signal is special in that it is not affected by interference; if it is one and a half decibels higher than the noise, then good reception is achieved. Signal dropout is affected by cable mismatch or phase distortion at any point in the transmission from the camera to the tuner, and the image can be scattered into small pieces even with a strong signal.
Basic features for making an antenna
Before making DVB-T2 with your own hands, you should study the principle of its operation.
For catching digital signal required, which can be very simply constructed even from a simple cable, having made the correct calculation.
The theory says that digital signals are easily transmitted in the UHF range and can be received by any type of antenna, but in reality this does not always work out.
Do TV antenna You can do it yourself at minimal cost and without the help of others, but you should remember that the resulting device is inferior in reception quality to professional devices.
Requirements for antennas
New conditions for broadcasting, distribution and on-air reception have changed the basic requirements that DIY TV antennas must meet. DVB-T2 has abolished the previously significant directional and protective coefficients. They do not matter in modern devices, since the air is polluted, and even small penetrating interference can only be dealt with by electronic means. At the same time, the antenna's own gain (GA) plays an important role.
An antenna that tracks the air well has a power reserve for the received signal, which allows the electronics to sift it from interference and noise. A modern antenna for DVB-T2, made with your own hands, preserves electrical parameters naturally, and does not adapt to acceptable parameters using engineering techniques. It is consistent over the entire operating frequency range without the use of balancing devices.
Antenna amplitude and frequency characteristics
The antenna is made as smooth as possible; phase distortions arise due to sharp emissions and dips. Single-frequency antennas are stretched to an acceptable noise-to-signal ratio, thus allowing them to receive up to 40 channels. But they are additionally equipped with matching amplifiers, which absorb waves or distort phase indicators.
The most effective digital DVB-T2 antenna is made by yourself:
- frequency-independent - with low performance, but cheap and easy to manufacture, constructed in a short period of time, intended for reception in relatively clean air on a short distance from the transmitting station;
- periodic band, catching all waves in space, ideally sorting them, which has a simple design, ideally works in tandem with a freeder throughout the entire reception range.
If we talk about the design, then the most simple antenna DVB-T2 is made with your own hands in the “eight”, “Polish” and “square” versions.
Figure-of-eight antenna
Refers to easily constructed devices, made like a standard figure eight, from which the reflector is removed. The ideal material is an aluminum strip, corner, tube, tire, or other profile. The top dimension is 140 mm, the side length is 130 mm, but these dimensions are given as a guide; during manufacturing they should not be kept exactly to the millimeter.
To begin with, cut a wire 112 cm long, begin to bend the first part 140 mm long, of which 130 mm goes to the antenna, and 10 mm remains for the loop. The next two sections are bent equally to a length of 140 mm, the next two - 130 mm, the next pair - 140 mm, then another 140 mm, then - 130 mm and make a second loop. The connections are pre-cleaned, connected and soldered; they are also contacts for fastening the cable core.
Stripping the cable and plug is done using a scalpel and a file. After soldering, the joints are sealed and secured with glue from a hot gun. If we talk about the plug, then the glue is poured into the solder joint, then into the cavity of the cap, the excess is then removed. The joint is assembled so quickly that the adhesive mass does not harden. The result is an eternal, strong and elastic connection. To make contact, we strip the ends of the cable from the plug side by 1 cm, from the antenna side by 2 cm.
When connecting by soldering, a do-it-yourself indoor digital DVB-T2 antenna is also sealed with glue, where it is recommended to install a rigid frame at the point of contact according to the size of the joint. If the device is made for yourself and will be rigidly fixed during operation, and transfer is not needed, then the frame is not made. A device made of this type easily picks up digital signals in the direct line of sight of a television tower at a distance of up to 10 km when installed outdoors.
Using a “Polish” antenna
The “Polish” antenna received its name during the times of the former Soviet Union as a reliable device for receiving signals from Soviet television, as well as channels in the UHF range. Digital broadcasting is practically not received on it due to its low efficiency. Some amateurs are trying to bring the design to ideal by shortening the long decimeter mustache and removing the reflector. In some cases, such a change allows you to adjust the image in digital format, but it is impossible to guarantee a reliable result. Speaking about Polish devices, we can note the high-quality operation of the amplifier, which works effectively with a digital signal.
Antenna type "square"
This DIY indoor DVB-T2 antenna is a modified copy of the standard design, known as “three squares,” which has six components and a matching transformer. Homemade antenna This type confidently copes with the reception of digital TV channels at a distance of up to 10 km in a straight line; for longer distances a signal amplifier is required.
The antenna design is simple to implement. The main structural element consists of round aluminum wire and single-core wires. The wire is bent to obtain six squares and a matching tap is made, which is a transformer high frequencies so that the signal matches the cable and the DVB-T2 antenna with the amplifier. With their own hands they solder the wires to the points, wrap them with copper wire and tin them with a soldering iron.
The cable is attached to the antenna with special clamps or using ordinary insulating tape. The cable is connected by placing a support, using a wooden plank or other material. When installing indoors or outside a building, the main condition is fine tuning to the television tower. This is done using a navigator; if there is no line of sight, the direction is clarified until the effect of receiving a powerful signal.
Antenna made from beer cans
The technology for manufacturing such an effective antenna is very simple and does not require special skills.
Using a thick awl or screwdriver, make neat holes in the neck of each of the two cans, then screw screws into them. The cable ends are freed from the braid, the copper wires are cleaned of varnish with a knife, and they are attached under the screw heads. It is very good to solder the resulting connection, but not necessary.
The DVB-T2 digital antenna is almost made with your own hands; it remains on the prepared rail or pipe to secure the cans so that there is a distance of 7.5 cm between them. The second cable end is equipped with a standard plug that is connected to the receiver; the device is installed in the place where the signal is best recorded. Placing this type of device outdoors requires reliable protection from bad weather. This is done with any waterproof material, often plastic bottles are used. large size. The antenna receives up to 15 channels satellite television and digital broadcasting.
Using Instruments and Amplification
At a certain distance from the television tower, the antenna is capable of receiving signals without installing additional amplifying devices. To receive a signal from a greater distance, use a wave amplifier with separate power supply. The device is installed near the tuner, and the matching device is made additionally; for its manufacture you need:
- potentiometer for gain adjustment;
- standard decoupled throttles L4 and L3;
- coils L2 and L1 are wound according to dimensions from the directory;
- a metal screen to separate the output circuits from the device circuit.
The amplifiers are placed no further than 3 meters from the place where the DVB-T2 cable antenna is installed, which receives power from its own unit with its contacts. When installing an antenna near a broadcasting tower, it is not recommended to use an additional amplifier, since a strong signal degrades the image and has an additional effect on the entire structure. The recommended cable length is three meters; a larger wire will lead to imbalance of the balun.
Application of a symmetrizer
This device is needed for any type of antenna, and it does not matter whether it was made at a factory or in a craftsman’s workshop. Antenna for DVB-T2, made by yourself, gives good quality images when connected to a tuner. If the cable length is more than 10 m, then when installed outside the building, inconsistencies in the resistance of the external space and the cable arise. In this case, it is necessary to use a symmetrizer in a comprehensive antenna solution, which greatly improves the quality of the image on the screen.
Cable laying and antenna installation
The main rule is to install the antenna at a height. If this cannot be done in the room, you need to move the device to an external wall. To install an antenna in a private building, digital broadcasting operators rely on a device height of 10 m. If the antenna is located on the ground floor of a house, then nearby metal structures and industrial facilities cause poor reception.
When placing the antenna under a canopy or the roof of a house, pay attention to the roofing material - it should not contain a metallized coating or spraying. Metal tiles, corrugated sheets, iron or foil insulation create significant interference with signal reception digital television.
For high-mounted receiving antennas on a metal mast or pin, a steel rod of at least one meter in size is provided, to which a grounding wire is connected. The device located on the roof is included in common system grounding of the house.
The cable is not routed through smoke and ventilation ducts, and is not hung on existing electrical wires, even if they look more than reliable. The holes in the walls are placed at an angle so that moisture from the street does not flow into the room; special plugs are used that are commercially available. If the antenna is made well and correctly, take the cable and wall sockets high quality, since after the final finishing of the walls it is difficult to redo the cable in the wall and replace it with a more reliable one.
Compliance with safety precautions when installing the antenna
Before installing or adjusting an already mounted antenna at a height, make sure that this action is safe:
- do not climb onto weakly secured and shaky structures; if working at height is associated with danger, be sure to wear a mounting belt and attach it to a fixed part of the building structure;
- The assistant is not allowed to hold the end without first securing it; if he falls, the assistant will not be able to hold his body weight in his hands;
- It is forbidden to climb to a height alone, when structures are icing, to walk on an old roof, or to step on connecting seams;
- Do not install the antenna in rain or fog.
In conclusion, it should be said that it is quite simple to make your own receiving device in order to watch digital television. DVB-T2, a home-made antenna, is almost as good in quality (if you follow the right technology) as store-bought counterparts. The cost of materials will allow you to save a decent amount of money, which is important for some people.
A super simple and super quick to make antenna from a coaxial cable for receiving digital television channels can be made with your own hands in about 5 minutes. For this you will need absolutely nothing except the cable itself. And this is the main advantage of this antenna.
You can't live without a TV now.
This design will definitely help you out, for example, when you have just moved into your home and have yet to install a cable or install a stationary antenna. Of course, this is not the only example where this truly simple loop antenna will help.
Now in the comments someone will definitely write that there are even simpler antennas, like a whip one. To make it, it will be enough to simply remove two insulations from the cable and everything will work. Of course, I agree with this, but the loop antenna that I will make from coaxial cable will have much greater gain, due to its directivity and resonant closed circuit.
Making an antenna from coaxial cable
This is what the version made from black cable looks like.
Now let's start making the antenna in order. All we need is less than half a meter of coaxial cable of any color. I took the white one.
We retreat 5 cm from the edge of the cable and remove the top insulation.
Next, remove the insulation from the central core.
Now we twist everything together neatly and tightly.
Then, from the edge with the insulation removed, we retreat 22 cm and cut out a 2 cm piece of the top insulation and the shielded wire from the hose, without touching the insulation of the central core.
Now we measure another 22 cm from the end of the cut and make a cut 1 cm wide only by removing the top insulation. We do not touch the cable shield.
Next, take the end of the cable from which we started. And we wrap it very tightly at the last cut, forming a circle of the antenna.
At this point, our antenna is ready for use. Of course, this is not necessary, but if you hang the antenna outside, it is better to insulate all exposed areas of the cable with electrical tape. You can also add a rigid frame, but this is optional.
Antenna location
We direct the antenna to a repeater or television tower. The direction can also be selected experimentally by rotating the antenna.The best option would be to place it outside the window, since the walls of the house greatly dampen the high-frequency signal.
The test showed excellent results
This is a very simple and effective antenna for receiving digital and analogue television. Suitable for use both at home and outdoors. The antenna is a "bi-square" (double square) - this is the simplest and most popular design to replicate.
To build an antenna you will need very little:
- - Coaxial cable.
- - TV connector.
- - Copper wire is about a meter long, with a diameter of 2 - 4 mm. Any one will do, even steel.
- - Flux with solder.
- - Plastic round junction box for the housing. Or any other.
Making an antenna for receiving digital television (DVB-T)
I will make an antenna to receive digital television channels. To begin manufacturing, you first need to calculate the dimensions of the future antenna. And to calculate the dimensions you need to know the middle of the reception range digital channels. The average frequency is approximately 690 MHz. If you want to make an antenna for analog channels, then take, say, 470 MHz for UHF, etc. (TV channel ranges can be viewed)Next we go here -
Enter the frequency and press “CALCULATE” and see what L1 is equal to. L1 is the square arm for the antenna. In my case, for a frequency of 690 MHz it is approximately 105 mm. The required number has been found, nothing else is needed.
Now we proceed directly to the construction of the bi-square antenna. We measure out approximately 90 cm of thick copper wire and bite it off either with wire cutters or pliers.
Next, we straighten the wire with our hands, making it smooth without the waves that formed after winding it from the reel.
We measure four 10.5 cm segments in a row on this wire.
Then we bend the double square. The wire is thick and bends with difficulty, which is good - it will not bend from accidental influences.
We bite off the excess wire, leaving an allowance of about a centimeter in order to solder the closed circuit.
We clean the connection points and future soldering.
We solder the circuit with solder and flux. Here it is better to use a more powerful soldering iron, since thick copper wire is difficult to heat up.
We strip the television cable and solder it to the antenna as in the photo.
In principle, the antenna is ready for operation. I won't stop there and will make a body for the central part.
Here's what I need.
Since the round box is too deep, I cut off exactly half with a hacksaw.
Then I will melt the grooves for the antenna with a soldering iron. This can be done with the same hacksaw.
I fill the connections of the wires with the body and the soldering points with glue.
Everything is ready. I'll hang the antenna outside the window on a nail.
Watch the video on how to make an antenna for a TV
Digital television these days continues to spread every day. Providers offer their services in this area by selling expensive devices. However, you can “catch” terrestrial digital television using a homemade antenna.
We invite you to watch a video on making an antenna:
So, we will need:
- decimeter antenna;
- calculator;
- antenna cable;
- cable connector;
- ruler
First of all, it should be noted that to receive digital TV channels you need a TV that supports the DVB-T2 format, in otherwise the antenna will not perform its intended purpose. It should also be clarified that providers often advertise so-called digital antennas, which are allegedly created specifically for receiving digital TV channels. This is not true, since you can catch such channels even with a wire. Now that you've sorted out the materials and the introductory part, you can get to work.
Next, we find our district or city on the website to find out the advisory support center or, more simply put, the broadcasting center. The next thing is to call the support center and find out on which channel the digital television is broadcast. The author, for example, broadcasts on channel 27. At the end of this stage, we find out the channel frequency.
Now, using a calculator and a special formula, we have to find out the required length of our antenna. The formula is extremely simple: 7500 must be divided by the number of channel frequencies. The author’s channel frequency is exactly 522000 kHz, that is, you need to divide 7500 by 522. It turns out to be approximately 14.3. We round the result obtained after division and get the length of the antenna in centimeters.
Next, take a regular antenna cable, strip it on one side and insert the connector.
The next thing is to take a ruler and measure the result obtained by dividing, leaving 2 centimeters at the base. That is, if the author needs a cable 14 centimeters long, he measures 2+14 cm.
Cut off the end. After this, we make a cut on the base line and clean it to the edge. We remove the cable protection because we don’t need it. We also cut off the foil.
After this, we bend the cable at the base line at a right angle. The antenna is ready. All that remains is to install it outside so that it faces the transmitting antenna. It is worth noting here that if the distance from the transmitting antenna is more than 15 km, then you will have to use an antenna amplifier.
Digital television is broadcast in the UHF range. Therefore, you can use almost any UHF antenna. But I needed simple, easily repeatable and strong UHF antenna range.
Such that you could carry it with you, and on occasion you wouldn’t mind giving it to people for a small amount.
The basis was taken from the famous “ eight“, with the difference that I used it without a reflector.
The material for the antenna sheet can be any conductive material of suitable cross-section. It can be copper or aluminum wire with a thickness of 1 to 5 mm, a tube, strip, busbar, corner, profile... I took copper wire with a diameter of 3 mm. Easy to solder, easy to bend during assembly, easy to straighten if bent.
The outer side of the square is 14 cm, the inner side is slightly smaller - 13 cm due to the fact that the middle of the two squares does not converge, about 2 cm from corner to corner.
So, if you are not making an antenna from wire, then measure it this way - the top sides are 14 cm, the sides are 13.
All sizes are approximate. Don't be afraid to get shortchanged or make mistakes. Our plans do not include making an antenna that meets all standards. We need a simple but workhorse. A surrogate, but reliable. Surrogate because:
1
. Personally, I definitely couldn’t keep the sizes.
2
. There is no reflector.
3
. I took a 50 ohm cable instead of 75 ohm, but with a thick braid. Friends usually used this cable for car antennas for 27 MHz radio stations.
Nevertheless, the antenna works quite well.
A digital signal has a peculiarity; it either exists or it doesn’t. When receiving analogue television, different channels were shown with different levels of interference, and when removed, the level of snow on the screen simply increased until the signal completely disappeared. In digital, the signal is almost the same on all channels, and if there is reception, then there is all channels.
I have tested this antenna on more than a dozen TVs in our region.
So. We measure a piece with a total length of 112 cm and bend the wire. The first section is 13 cm + 1 cm for the loop (for strength). The second and third are 14 cm each, the fourth and heels are 13 cm each, the sixth and seventh are 14 cm each, and the last eighth is 13 cm + 1 cm stiffening loop.
We strip 1.5 - 2 cm at both ends, twist the two loops behind each other, and then solder the joint. This will be one cable connection pin. After 2 cm another. It doesn’t matter where to solder the central core or the braid.
Solder spacing 2 cm
I took about three meters of cable. In most cases, it’s enough if you don’t do it for yourself personally. For yourself, measure out as much as you need.
I stripped the cable from the antenna side by two centimeters, to the plug - 1 cm. If the plug is like in the photo. You can take any, stronger.
Stripping the cable
The plug was cleaned with a file and a scalpel.
After sealing, both soldering points are filled with glue from a gun. On the plug, first hot glue is poured into the soldering area and into the plastic cap, with a reserve; the excess can then be removed. Then, before the glue cools down, everything quickly comes together. You can’t gnaw such a joint with your teeth. Reliable and at the same time flexible.
The soldering on the antenna itself is also filled with glue, but for the rigidity of the structure, a frame is taken - any lid, box, .... I took the cap from a 20-liter water bottle, of which I had accumulated a sufficient amount. If you are making an antenna like me for mass production, then it is better to immediately use common materials that are literally lying under your feet for better repeatability of the antenna. If the antenna is made in a single copy for quick riveting, then you don’t have to fill anything at all.
The result is such a design that can be stuck anywhere - on a cornice, on a curtain, on a window frame. To do this, you can carry with you a piece of wire, a couple of screws, a couple of pins...
Antenna assembly
If the antenna is dented during transfer, it can be straightened easily and without damage. This is perhaps its main advantage.
I don’t always carry this design with me, but only when I receive a specific order to connect a DVB-T2 digital television tuner. It fits easily with the tool in my backpack.
It is more convenient to make several antennas at once. Takes less time.
This is how my friend fixed the antenna, using it as an outdoor one. The tower is about 9 km away. Reception is reliable despite the simplicity of the antenna.
