If the development of terrestrial digital television continues at this pace, then in the near future satellite television will die as a class. After all, the cost of equipment for its reception is disproportionately less, and anyone can make an antenna at home within 30 minutes, spending no more than 100 rubles on it.
After the article was published, I continued my experiments. And the reason for this was the very good performance of television signal reception. Which prompted me to think that the signal level in my case is strong enough to receive digital terrestrial television in DVB-T2 format, and most likely I can get by with a simpler antenna.
After visiting the official website of the Volgograd branch of the Russian Television and Radio Broadcasting Network, I found out that DVB-T2 broadcasting in Volgograd is carried out from two places. One is the well-known “Mamaev Kurgan”, where the TV and Radio Center is actually located, and the second is “Nagorny” (the village of Nagorny, in fact this is the Krasnoarmeysky district). The distance to the second transmitter in my case is only 5 km. This explains the good signal quality, so you can get by with a simpler antenna.
I began to “dig” the Internet for the simplest antennas of the “pin” type. Which in practice looks like an antenna connector with a piece of bent antenna cable stripped of braid.
Don’t be surprised, but this piece of antenna wire with a connector perfectly picks up a digital television signal of the DVB-T2 standard. With 100% quality. I wrote about my reception conditions and the distance to the television center transmitter in the previous one. The antenna is working!
Here is the data on the signal reception quality of the first multiplex, the result is 100%:
The picture is similar at the second multiplex, the result is again 100%:
I post the photo in such a way that the receiver and the antenna inserted into it can be seen. So that no one thinks this is a joke. And here is a rear view of the antenna inserted into the receiver:
The antenna for receiving digital terrestrial television DVB-T2 is a UHF antenna. Therefore, when calculating its size, you should know for which broadcast channel we are making it. Unfortunately, there is no simple antenna that would receive all television channels equally well.
In my case, the first and second multiplex are broadcast on UHF channel 37 (average frequency 602.5 MHz) and UHF frequency channel 39 (average frequency 618.5 MHz), respectively. And in order for our antenna to satisfactorily receive the signal from both multiplexes, we will tune it to the average frequency of 610.5 MHz.
Determine the average wavelength. Wavelength = speed of light / frequency of TV channel, where the speed of light is 300 thousand km/sec; channel frequency – 610.5 MHz. Thus, wavelength = 300/610.5 = 0.491 m. To make the antenna, we need ¼ of the wavelength, i.e. 0.491/4 = 0.123 m.
Next, take a piece of cable. We disconnect the antenna connector on one side. We retreat about 2 cm from it and cut off the insulation along with the screen. We make the central conductor, together with the insulation, equal to a quarter of the wavelength that we need. For clarity, we use the figure below:
Let me remind you that the distance from my house to the Nagorny transmitter is approximately 5 km, the windows of the room (kitchen) where the antenna is located face the side of the panel house opposite from the TV tower. The antenna works great under these conditions. The signal level and quality of image and sound are not affected by the weather or time of day. The quality is always 100%.
As a digital television signal receiver I used (clearly visible in the photo) a DVB-T2 Supra SDT-92 digital TV receiver and an old POLAR37 CTV4015 TV.
I remembered an institute joke that “antenna theory” (and I had such a subject) is a science that adapts to practice. That is, a craftsman assembled an antenna from beer cans or gaskets from the cylinder head of an internal combustion engine and the pundits sat down to come up with laws and formulas to explain from a scientific point of view why this antenna works.
Even if you connect the pieces with a standard coaxial connector, the signal quality is guaranteed to deteriorate.
This inexpensive antenna for the garden gives good results. If you plan to receive only with this antenna, then its two long side “whiskers” can be unscrewed.
They give good results, especially for remote signal reception when it is quite weak.
Many TV viewers use the “Polish” antenna - a grid and four rows of antennae. It doesn’t matter where it was made, they used to call it “Polish”, and sometimes “mesh”. Very often it does not demonstrate the best characteristics for receiving a digital signal.
Very few are represented in the retail network; they are familiar only to radio amateurs. They are poorly protected from radio interference, although they have a fairly uniform frequency response.
Only in very rare cases does it show good results for. Even if you paid dearly for it, the result may be zero.
If you only want an indoor antenna as an on-air antenna for your dacha, you may be “advised” to buy it more expensive and “better”. But if you hope that she will start giving you a wonderful signal in your room, then this hope is in vain. If there is a bad signal in the house, no antenna will help. External - this is the solution to the problem if there is no reception in the room.
Remember? We're talking about ethereal, so forget about satellites. You will not receive terrestrial television in the DVB-T2 standard through a satellite tuner. You will not connect the T2 tuner to the . We receive the T2 signal from the nearest broadcast tower in the UHF range. To a regular over-the-air antenna for a summer residence, not a “dish”.
The time has come to install the TV cable. I plan to have a lot of TVs. The city is 40 km away. The broadcaster is even further away. The task is to provide televisions with stable reception of the DVB-T2 signal. I will use signal dividers, which will further weaken the signal received by the antenna. There is a need to use DVB-T2 antenna amplifier. Since the frequencies of both DVB-T2 packages are in the UHF range, I looked at a directional, passive UHF antenna with a gain of 14 dB.
A large distance to the translator and dividing the signal into several TVs will greatly weaken the signal, so you can’t do without a UHF antenna amplifier, also known as a DVB-T2 amplifier. Decided make an antenna amplifier for DVB-T2 with your own hands and see what comes of it.
Since standard signal dividers, including those that I purchased, do not pass electric current, powering the amplifier via a cable will not work (or the power must be routed via cable to the divider).
Gain from 30dB depending on the selected transistors. Amplifier power supply 12 volts.
I used transistors BFR193. They are very cheap and have good performance. High gain 50-200. High limit operating frequency up to 8000 MHz. SMD version. They have a low self-noise level.
Can order BFR193 transistors in China, but ours were a little cheaper.
Ceramic capacitors. We make the conclusions of capacitors and resistors as short as possible. You can use SMD, I just made it from what was at hand.
Coil L1 is made from a piece of copper wire 3.5 cm long with a diameter of 0.8 mm. Its diameter is 4 mm and contains two and a half turns. I wound it on the smooth part of a 3.3mm drill (the coil itself will be about 4mm).
The board can be made without etching by simply cutting out the pads. Let's look at the drawing.
We make the board from double-sided fiberglass. We connect the top and bottom layers with four pins and solder them.
I used a transformer power supply to reduce noise, with voltage stabilization at 12 volts. The amplifier consumes about 12mA.
Everything worked fine for me right away without any setup. The setting involves selecting resistors R1 and R3 so that the currents on the collectors of transistors VT1 and VT2 are 3.5 mA and 8 mA, respectively.
Conducted tests at work. In the depths of the room. Yard well. As an antenna, a piece of SHVVP wire. The result without an amplifier shows nothing at all. I connect the amplifier and, as they like to say in advertising, the result exceeded all my expectations, a stable picture without a hint of failure.
List of parts for a homemade DVB-T2 antenna amplifier (UHF).
Digital signals have been known to everyone for a long time. All television organizations have switched to the new format. Analogue television devices have moved aside. But despite this, quite a few are in working condition and can last for more than one year. In order for outdated equipment to complete its allotted operational life, while still being able to view digital broadcasting, you will need to connect DVB-T to the TV receiver and catch wave signals with a zigzag antenna.
For those who want to save their family budget and at the same time receive high-quality television broadcasting, you need to pay attention to the Kharchenko antenna for digital TV with your own hands.
This unique design has been known for a long time, but found itself relatively recently.
After radio communications appeared, the relevance of using an antenna device increased. Since the 60s of the twentieth century, the then recognizable engineer Kharchenko flaunted a design of 2 rhombuses. This device allowed him to catch US airwaves.
This is a double square made of thick copper wire. The squares are connected through open corners; this is where the cable from the TV is connected. To increase directivity, a grid made of material capable of conducting current is mounted at the rear.
The perimeter of the squares is equal to the wavelength to which the reception is tuned. The diameter of the wire should be about 12 mm for broadcasting from 1 to 5 TV channels. The design turns out to be far from compact, in the case of assembly for radio communications and meter-wave TV with up to 12 channels.
To make the device lighter, 3 wires of a smaller cross-section were used. Despite this, the size and weight remained impressive.
The antenna in question received its second wind when broadcasting appeared in the UHF range. Most people know rhombuses, triangles and other homemade figures in the form of antenna devices for receiving a signal of decimeter waves. Antennas of this type can be found on balconies and windows of both private houses and multi-storey buildings.
At the beginning of the 2000s, American professor Trevor Marshall came up with a proposal to use this design in Bluetooth and Wi-Fi networks.
The biquad antenna is also an antenna device of a Soviet engineer. This option is created according to the same principles as a regular biquadrat. A distinctive feature is that at the tops of the squares, instead of the corners, there are additional squares.
As for the sizes of these squares, they are identical to the usual ones. This avoids additional calculations. It is enough to use the standard biquadrat calculation.
Let us remind you that the wires in the place where they intersect require insulation from each other.
Kharchenko's DIY television antenna for DVB T2 is quite economical. In order to assemble the structure, you will need the following parts:
As for tools: pliers, hammer, sharp knife. If you plan to attach the antenna device to a wall or other surface, you will most likely need a drill for mounting.
Before you start creating the design, you will need to calculate the Kharchenko antenna. This will allow you to assemble an effective device with maximum accuracy. The dimensions of the DVB T2 zigzag antenna play a significant role in increasing signal reception.
Since technology has stepped forward, there is now no need to leaf through reference books or look for formulas for calculating dimensions. And even more so, carry out complex mathematical calculations in order to correctly develop a sketch or future drawing.
After this, you receive information: about the required length of the copper wire, its sides, and diameter.
Step-by-step instructions that will allow you to quickly assemble a Kharchenko antenna for digital television with your own hands:
As for the reflector, previously it was made of textolite boards that were coated with copper. Today, this component is made from metal plates. It is on this principle that the design for receiving digital television is made. Nothing complicated. Everything you need is at hand.
The device has been created, it’s time to check the effectiveness of the work done. To test the reception quality of the wave channel, you need to connect the antenna to the receiver. Turn on the TV and receiver.
Open the main menu of the set-top box, select automatic channel search. On average, this process will only take a few minutes. You can find channels manually, but to do this you will have to enter their frequency. To test Kharchenko’s design for a TV, it’s enough to simply evaluate the quality of the broadcast. If the channels show well, then the job was done correctly.
What to do if interference is visible? Rotate the TV antenna and see if the picture quality improves. Once the optimal location is determined, simply secure the device. Naturally, it should be directed towards the TV tower.
Note.
Since 2009, television broadcasting has stepped up to new, previously unattainable heights. Namely, the transition to a qualitatively new level of broadcasting in digital format. Four years later, the second generation of this method saw the light, which received the name dvb t2. This technology had the advantage of single-frequency transmission. That is, many channels were transmitted in one band, where each individual program had its own slot. Therefore, the antenna for digital TV has gained new milestones in popularity.
The fundamental difference of the new method allowed companies to significantly reduce costs. This also applies to the factor of direct organization of operation, as well as scheduled technical maintenance. Unfortunately, at the moment there are also disadvantages, yet progress is not at its final point.
The main problem is that to receive a digital signal, you need to avoid interference. And the transmission itself must be of high quality, that is, geolocation plays a role. As a result, residents of rural areas who are quite far from the source are often unable to properly receive a digital television signal. At the same time, the megalopolis has its own problems. Huge masses of modern buildings, constructed of reinforced concrete, serve as a kind of screens, blocking the entry of decimeter waves. As a result, in some cases, catching the transmission becomes problematic.
A simple device - an antenna for digital television - can significantly help with this problem. Just a couple of decades ago, almost every home was equipped with a TV with this kind of device. Moreover, they usually did it on their own, it did not cause any difficulties. In our time, the need has decreased somewhat, but has not disappeared. Not many people know how to make an antenna for digital television with their own hands. After all, analogues and finished goods appeared.
Unfortunately, their prices can be quite steep. Good products start at a price of three thousand rubles and above. Considering the fact that you can make dvb t2 with your own hands in a short period of time, the savings become very, very decent.
But you must be very interested in one question: will the simplest self-assembled structure be as effective as a purchased one? To answer the question, it is necessary to understand the operating principle of decimeter waves and the modern digital television system in the dvb t2 range. The meaning is simple, the signal is either caught or not. There is no middle level.
It is impossible to catch a transmission with interference, poor quality, or disappearing. Either "yes" or "no". Thus, in most cases, a homemade product is not at all inferior to a paid plate. Of course, its acceptance rate is worse; after all, it is performed by non-professionals in makeshift conditions. However, this does not matter if you were able to catch the signal in principle. If it exists, it will be one hundred percent high quality.
Often, when looking through the answers to the question - how to make an antenna for digital TV dvb t2, you will notice that on the network it is sometimes called satellite. This is a key mistake. Because she has nothing to do with this. After all, this TV broadcasting technique uses a satellite that is located high up, and accordingly produces a different type of channel. Whereas in our case we are talking about a horizontal channel.
An indoor antenna is a heterogeneous concept. There are many types that differ both in design and functionality. The most common option is the figure eight. At the same time, this is the simplest antenna for digital TV dvb t2, which you can make yourself. The name is based on visual similarities. That is, the external structure is a figure eight. It is made from twisted cable, respectively. This kind of product, or rather the principle itself, the methodology, is used everywhere in various industries.
So, we need the material itself. It is no secret that the most active substance when it comes to signal reception is copper. Therefore, it is logical to choose copper wire as a production material. True, in some cases it is permissible to use aluminum.
Sizes are not strictly limited. It is still impossible to calculate ideal dimensions at home, even knowing the broadcast frequency. Therefore, you just need to adhere to some frameworks, norms, nothing more. The height of our figure eight will be equal to 140 mm, while the width tends to 130 mm. Accordingly, even if you decide to increase or decrease the dimensions for some reason, you should not forget about these proportions and maintain them in any case. This is an important design aspect.
When calculating the total length of copper wire required to create a dvb t2 antenna, do not forget about the loop factor. That is, do not just calculate the length of the sides of the figure eight, otherwise the segment may turn out to be shorter. It’s better not to waste time on trifles and take it with a reserve. After you “roll” the figure eight itself, you need to solder the connections to improve performance properties. The cable must be stripped of its outer sheath, of course.
How to remove the cable sheath? This is a fairly simple procedure that does not require any skills. All you need is a sharp tool. A knife or paper cutter will do. The main thing in the stripping process is not to damage the copper wire itself, which is theoretically possible with excessive zeal.
After we have soldered the figure eight, the fastening points must be sealed using ordinary rubber glue.
The resulting design is reliable and easy to use. It can be installed in literally an hour, provided you have ready-made material and tools. And, as you remember, it saves from three thousand rubles and more. Not bad?
But the figure eight is not the only antenna for digital TV that you can make with your own hands. There are several other very interesting options.
An antenna for a long-range signal, in most cases, is used on the basis of squares. This is a double square, triple or simply “square” antenna. All these are various modifications and improvements of the same prototype. It is difficult to understand which one works better. Most likely it depends on the type of terrain. However, it has been proven that for UHF signals such a design is an almost ideal solution. Especially when it comes to remote areas. Transmission interception occurs at a distance of up to ten kilometers without additional means. But if there is a need for longer distances, then the device can simply be equipped with an amplifier, increasing the reception level by a colossal percentage.
For the construction you will need aluminum wire of round cross-section. It is not difficult to find; it is unlikely that someone at home does not have the remains of such material lying around. It is necessary to build two, four or six squares from it, depending on what specific type of antenna for digital television dvb t2 we want to make with our own hands. Next, you need to create a transformer to stabilize the signals. It is performed as a tap. The last step will be final soldering and application of copper wire to the surface of the structure.
It is worth noting that by creating an antenna for T2 with our own hands, we do not solve the problem with a poor signal in one fell swoop. Still, a simple product can only work if there is a broadcasting tower nearby. It will improve the flow of waves and receive images, but, alas, it will not be able to work miracles. If there is no tower as such within the area, it is located very far away, then any self-mounted structure will still have to be additionally equipped with an amplifier.
What is this device? Why is it needed? It is logical to assume that it amplifies the signal, redirecting it to our antenna. You can also make it yourself, but we’ll talk about that another time. It can be bought in specialized stores. It's not as expensive as some satellite dish, so it's quite possible to fork out the extra cash without seriously damaging your budget.
There are also some nuances in installing an amplifier, safety precautions, so to speak. Firstly, the installation is carried out at a distance of up to three meters from the main source of reception. That is, from our homemade product. It will only amplify the signal at this distance, place it somewhere behind the house, it won’t work in a barn, keep in mind. Secondly, it is important to understand the rationale for using an amplifier. If the signal itself is very stable, then you can get by with just a television antenna. Additional installation of an amplifier will result in an excess of signal power. This will cause deterioration in transmission quality, floating images, and unpleasant interference. So, you need to calculate in advance how much you need to improve the signal, how far away the broadcasting tower is.
As you can see, there is nothing supernatural in the design and installation of such products. You can get a high-quality image on your TV screen without additional financial investments, spending a little of your personal time.
