Super simple and super quick to make antenna from coaxial cable for receiving channels digital television you can do it yourself 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
Despite the rapid development of satellite and cable television, reception of terrestrial television broadcasting is still relevant, for example, for places of seasonal residence. It is not at all necessary to buy for this purpose ready product, a home UHF antenna can be assembled with your own hands. Before moving on to the consideration of designs, we will briefly explain why this particular range was chosen TV signal.
Why DMV?
There are two good reasons to choose designs of this type:
- 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 larger number unattended low-power transmitters and thereby expand the coverage area.
- This range is selected for digital broadcasting.
Indoor TV antenna “Rhombus”
This simple, but at the same time, reliable design was one of the most common in the heyday of on-air television broadcasting.
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 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 quite acceptable, this is not necessary.
The material you can use is aluminum, copper, and brass tubes or strips 10-15 mm wide. If you plan to install the structure outdoors, 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 circuit.
The cable is laid as shown in the figure, namely: it did not have sharp bends and did not leave the side insert.
UHF 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. Antenna amplifier circuit for the UHF range List of elements:
- 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 copper wireØ 0.8 mm (2.5 turns need to be made); L2 and L3 are high-frequency chokes 25 µH and 100 µH, 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 factors – 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 method of power supply; 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 perfectly suitable for the arms of a decimeter range 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 and not aluminum, you can solder the cable instead of using self-tapping screws).
- B – places where the cable shielding is attached.
- C – central vein.
- D – 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 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 picture quality, provided there is sufficient signal power.
Making an antenna from copper wire
There is a design that is much simpler previous version, which only requires a piece of copper wire. It's about about the narrow band loop antenna. This solution has undoubted advantages, since in addition to its main purpose, the device plays a role selective filter, reducing interference, which allows you to confidently receive the signal.
Fig.4. Simple frame UHF antenna loop type for digital TV reception For this design, you need to calculate the length of the loop; to do this, you need to find out the frequency of the “digit” for your region. For example, in St. Petersburg it is broadcast on 586 and 666 MHz. The calculation formula will be as follows: 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 the length of the loop should be 48 centimeters.
If you take a thick RG-6 cable with braided foil, it can be used instead of copper wire to make a loop.
Now let's tell you how the structure is assembled:
- A piece of copper wire (or RG6 cable) with a length equal to L R is measured and cut.
- A loop of suitable diameter is folded, after which a cable leading to the receiver is soldered to its ends. If RG6 is used instead of copper wire, then the insulation from its ends is first removed, approximately 1-1.5 cm (the central core does not need to be cleaned, it is not involved in the process).
- The loop is installed on the stand.
- The 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 “digits”, provided that the calculations are carried out correctly.
Do-it-yourself MV and UHF indoor antenna
If, in addition to UHF, there is a desire to receive MF, 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 unit is used; if you have problems purchasing it, you can use homemade device, the diagram of which was given above (see Fig. 2).
It is important to maintain 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 wave channel, however, it shows good results if the signal is of sufficient strength.
DIY figure eight antenna for digital TV
Let's consider another common design option for receiving “digits”. It is based on the classic scheme for the UHF range, which, because of its shape, is called “Figure Eight” or “Zigzag”.
Rice. 6. Sketch and implementation of the digital eight Design dimensions:
- outer sides of the diamond (A) – 140 mm;
- internal sides (B) – 130 mm;
- distance to the reflector (C) – from 110 to 130 mm;
- width (D) – 300 mm;
- the pitch between the rods (E) is from 8 to 25 mm.
The cable connection location is at points 1 and 2. The material requirements are the same as for the “Rhombus” design, which was described at the beginning of the article.
Homemade antenna for DBT T2
Actually, all of the examples listed above are capable of receiving DBT T2, but for variety we will present a sketch of another design, popularly called “Butterfly”.
The material can be used as plates made of copper, brass, aluminum or duralumin. If the structure is planned to be installed outdoors, then the last two options are not suitable.
Bottom line: which option to choose?
Oddly enough, the simplest option is the most effective, so the “loop” is best suited for receiving a “digit” (Fig. 4). But, if you need to receive other channels in the UHF range, then it is better to stop at “Zigzag” (Fig. 6).
The antenna for the TV should be directed towards the nearest active repeater, in order to select the desired position, you should rotate the structure until the signal strength is satisfactory.
If, despite the presence of an amplifier and reflector, the quality of the “picture” leaves much to be desired, you can try installing the structure on a mast.
In this case, it is necessary to install lightning protection, but this is a topic for another article.
The popularity of the Internet among the population is constantly growing. However, many people live in places where the signal is very weak or non-existent. In this regard, the problem of increasing the power and quality of Internet reception becomes very acute. Slow speed takes a lot of time and does not give the desired result. Therefore, an external Kharchenko antenna, designed in the form of a thick copper wire, often comes to the rescue. The connection between squares occurs in places where the corners are not closed, where the connection is made TV cable.
Such an antenna requires precise calculation for digital terrestrial television. To improve directionality, some designs may include a grating or continuous screen made of conductive material. Such a biquad antenna allows you to solve many problems with signal reception and Internet speed. Homemade designs, including Various types Kharchenko antennas are made relatively easily and include metal and plastic parts, as well as elements from other materials, connected different ways. Similar designs can be easily made independently, including the Kharchenko antenna for TV with your own hands.
Kharchenko antenna for modem
Currently, many users are looking to increase the speed of their mobile internet. This problem is especially acute for those who live at a considerable distance from base station using the Internet at very low speed. In such situations, most the best way out from the situation becomes a Kharchenko antenna for a 3g modem with your own hands, which is quite easy to make at home.
This frame structure has been known as a UHF antenna since the 60s of the last century. It has a zigzag frame configuration which makes the device very efficient.
The system consists of two square elements. In order to calculate the antenna for a 3g modem at a frequency of 2100 MHz, the size of each side of the square must be 53 mm. The entire design is made in the form of an interlocking structure, including two diamond-shaped figures with internal angles of 1200. This is done in order to reduce internal resistance devices. The diamonds are connected to each other by soldering. The high-frequency cable is also soldered here.
More accurate data can be obtained using online calculator to calculate the Kharchenko antenna, into which you just need to enter the necessary initial data.
To increase efficiency, the device can be used in conjunction with a reflector. Usually this part is metal plate, and the most suitable material for its manufacture is foil-coated PCB. IN in this case antenna includes determining the distance between the receiving device and the reflector. After calculations and procurement of materials, a Kharchenko antenna for the modem can be made with your own hands.
The parts are connected to each other using hot-melt adhesive. Commit required distance between the elements you can use any object with the most suitable sizes. Then the antenna is connected to the device. Since modems do not have connectors for connecting external antennas, they are simply wrapped with wire, which is then connected through a cable to the receiving device. If necessary, a Kharchenko antenna for a 4g modem can be made using the same scheme.
Upon completion of assembly, at the opposite end of the cable that will connect to the modem, you need to assemble a so-called matching device, designed specifically for such devices. For this purpose, copper foil is used, the same as in printed circuit boards. The calculation of the antenna for the 4g modem is the same as in the previous version.
If there is a connector for external antenna, the cable is connected using a special adapter. After all connections, the antenna for the modem is considered ready for use. Setting up signal reception for 4g is done experimentally by slowly rotating the structure around its axis until the clearest signal is obtained. The quality of the signal is determined by the number of lines on the icon displayed on the computer or mobile phone.
Kharchenko antenna for digital TV
Digital television uses the UHF wavelength range. Therefore, before designing, Kharchenko antennas for DVB t2 should be made in order to maximize signal reception.
The design itself looks quite compact, is made in the classic version from two rhombuses, the result is a zigzag antenna without a reflector. Any conductive material can be used as a base, for example, a copper or aluminum conductor with a diameter of 1-5 mm. Tubes, strips, corners, profiles, etc. are also suitable. Copper wire 3 mm thick is best suited for these purposes. It bends, aligns and solders very easily. Next, it must be manufactured in a certain sequence. The resistance of the television cable should be approximately 50-75 Ohms.
Quality digital signal does not depend on distance, as happens in analogue television. In this case, when the TV antenna is working normally, the signal enters the TV receiver normally, but if there are malfunctions, then there will be no signal at all. Accordingly, there will be no image. If there is a signal and it is received normally, then the image will be of the same quality on all channels. This factor must be taken into account when performing for digital TV, although individual settings may be different for a particular region.
Directly TV antenna Kharchenko is made in a certain sequence:
- First you need to measure a piece of wire with a total length of 112 cm and bend it, keeping the dimensions of the sections alternately 13 and 14 cm.
- After all the bends, two ends are formed, which must be stripped to a distance of 1.5-2 cm. Loops are made at the ends and fixed to each other. The joints are completely sealed. Then, the central core is soldered to one of the joints, and the braid to the other. The result is a finished antenna or double square.
- Biquad antenna for a TV requires a television cable of approximately 3 meters. From the antenna side it is stripped by 2 cm, and from the plug side by 1 cm. The plug can be chosen at your discretion. Just like the wire, it needs to be cleaned using a needle file or some sharp object. Thus, zigzag antenna Kharchenko for digital TV is almost ready for use.
- After soldering is completed, all joints should be filled with hot glue from a gun. While the glue has not cooled, its excess must be collected. The result is a connection that is both reliable and elastic. On the antenna itself, the soldering points are also filled with glue.
Kharchenko antenna for phone
A remote directional antenna can significantly increase the capabilities of a mobile phone and improve the quality of communication when the subscriber is in a remote area. It is not always possible to find the most suitable option, so the best way out is the Kharchenko antenna for cellular communication, made from scrap materials with your own hands.
Most affordable option is the standard design discussed above. Such an antenna should be sized based on specific operating conditions. All necessary materials sold at a hardware store. The simplest designs can connect directly to the cable and do not require any special settings.
First of all, you need to stock up copper wire, with a diameter of 2-3 mm. You can take an insulated wire and strip the insulation from it. If connections are to be made without soldering, special F-type antenna connectors and connectors will be required. When you plan to connect two Kharchenko antennas in parallel, you may need a reflector, which can be tin or aluminum. Insulation of joints is carried out using heat shrink tube or electrical tape. For soldering connections you will need a soldering iron.
Copper wire, prepared in advance, is bent and turned into a zigzag frame, representing two diamonds. The sides of each of them are 80 cm long, and the total distance between opposite corners will be 226 cm. Next, the antenna calculator determines the point of connection of these diamonds as the point of connection with the cable. A piece of cable measuring 50 cm is soldered to this point, and an F-type connector is screwed to its opposite end. Next, the main cable of the required length is connected to the connector.
In some cases, calculating the Kharchenko antenna online involves installing a reflector that significantly enhances signal reception in a certain area. The design is the same as the antenna for T2, when the lower end of the frame and the reflector are connected to each other through the cable braid. For this purpose, a 50 mm long bolt is additionally screwed into the reflector, to which the F-type connector is attached using a tie. A cable and a frame located at a distance of over 40 mm are first soldered to this connector. Thus, Kharchenko’s antenna for a mobile phone, made independently in the most simple version, ready to use.
To directly connect the receiving device to mobile phone a pigtail is used, which is a special wire. One end of it is connected to the antenna cable, and the other - using a connector to the antenna socket of the phone. In this case, there is no problem calculating the antenna and there are no individual settings are not required, it is enough just to position the antenna in the most optimal way, focusing on the quality of the received signal. It is recommended to install the mast with the receiving device as close to the house as possible, preferably near a window, in order to minimize the cable length.
Digital television is sweeping the country; many people are buying TVs that already support this format. And who has previous generation equipment, you can buy digital set-top box() and connect it to your old TV, which does not support . In general, the format is worthwhile allowing you to watch television in digital format. BUT many sellers, along with set-top boxes and TVs, “sell” so-called digital antennas, sometimes the price of an antenna reaches 3,000 rubles. Although guys, you can make an antenna for digital television yourself, and very cheaply...
ADVICE! Guys, by the way, you can watch television without an antenna at all via the Internet, but for this you need another set-top box - read this really cool topic.
We continue the article...
To receive a digital signal, a so-called decimeter antenna. You can literally make it from an antenna cable. However, it needs to be calculated correctly. If you don't want to read the entire article, you can find desired item in the table of contents
What you need to make an antenna
1) We need a piece of antenna cable, about 30 cm long.
2) Antenna connectors, the so-called F - connector and male - female connector.
F - connector and male-female
3) Tools: a knife, wire cutters, a calculator and, of course, a tape measure (or a ruler).
Calculation
On home page We look for the tab - “CETV coverage map” and go to it.
“CETV coverage map” tab
A map of digital television coverage opened before us. We are looking for the nearest station for our city (I have Ulyanovsk, you are forgetting your city).
As you can see in my city, this is channel 56 - 754 MHz and channel 59 - 778 MHz.
Now we calculate the length of the antenna. I won’t go into complex technical formulas and terms; we don’t really need them. But to calculate the antenna, you need to divide 7500 by our frequencies.
THAT is: 7500/754=9.94 cm, this is for channel 56.
7500/778=9.64 cm, this is for channel 59.
Our antenna should be approximately 10 cm, and exactly - ((9.94 + 9.64)/2 = 9.79 cm)
For your city, you also need to display the average length for your stations, if you have several of them in the city. In the video below the article I calculated the antenna for Ulyanovsk and for Kazan.
Manufacturing
1) Take a piece of antenna wire and first attach an F-connector to the end. We simply strip the cable and screw on the connector so that the central wire is in the middle, and the screen (the wires and foil are in the mount), detailed (useful).
2) Set aside a couple of centimeters from our connector (this will be a kind of indent), then measure 10 cm and cut off the unnecessary cable.
3) Now from this 10 cm, we need to remove the plastic insulator and remove the “screen” (foil and small wires). There is no need to touch it further; we leave the cable in the insulator.
4) Our antenna is ready. You can try to connect.
Connection
You need to catch good point reception in the apartment, and it is not always enough to simply insert it into a TV or set-top box. I have such a place near the window, so I inserted an extension cord into the console and inserted the antenna into the extension cord. So far, I have not removed all this improvisedly, for an example of work (that’s why the cable weighs), and the antenna itself is inserted into it.
Well, as you can see, all channels are working normally, “first”, and “Russia”, and NTV, etc.
"First"
Thus, if you have 80 - 100 rubles, you can make an antenna for digital television (DVB-T2 standard) with your own hands, easily and simply.
Now video version
For those who do not show it - - MANDATORY! There's a solution to the problem!
That's all, I think my article is very useful and relevant. Read our construction site.
If the development of terrestrial digital television continues at this rate, 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. What prompted me to think that the signal level in my case is powerful enough to receive digital terrestrial television in DVB-T2 format, and most likely you 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 good quality signal, so you can get by with a simpler antenna.
I began to “dig” the Internet for the most simple antennas"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:
How to make an antenna for DVB-T2 reception
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 37 decimeter channel(average frequency 602.5 MHz) and 39 frequency channel decimeter range (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 old TV POLAR37 CTV4015.
Conclusions and reviews about the DVB-T2 antenna
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.
