DIY antenna options
A simple TV antenna can be made from materials that are usually found in any home.
For example, you can even make a satellite dish out of foil, a metal can, an umbrella and a wire.
With the help of foil, you can make such a receiver:
- Foil is leveled and glued at the bottom of the box.
- From 2 pieces of TV cable, you need to remove the insulation by 2.5 cm.
- Twist the braid of the cable into a separate contact.
- Make a “figure eight” from the pieces of cable, while the contacts should not be fastened in the middle and be located 1 cm.
- Place the cable outside the box (no foil).
- Another cable is taken that will connect the antenna to the receiver.
- Its end is stripped, the braid is also twisted separately.
- In one place, 3 central cores and 3 cable braids are connected.
- We place the TV antenna in the place of the best reception.
Consider the simple and popular options for TV antennas: from beer cans, coaxial cable and zigzag.
To make a TV antenna work properly, you need to adhere to some principles.
First, you need to decide where the structure will be used: in the garage, in the country, in the house, in the apartment, etc. Based on this, choose the type of receiving device and from which you can assemble the antenna.
The main elements that you may need are a TV cable, metal strips, wires, insulating materials, adhesive tape, a soldering iron, self-tapping screws.
The elements of the receiving device, especially through which the useful signal will pass, are best connected by soldering
The best signal reception will be if the distance from the TV tower to the receiver is not obstructed by buildings, trees and other interference. In this case, in order to catch the signal, a simple wire will be enough. And a room TV antenna in such a situation will be very easy to manufacture and does not require an amplifier.
Outdoor antennas can be similar in design to indoor antennas, but must be made of more durable materials that can withstand the weather. Placed directly next to windows or on the roof.
If the signal is too weak, an amplifier may be required.
So, how a TV antenna should be made with your own hands:
- The device should be made neatly and with the smallest possible connections to reduce signal loss;
- The television antenna must be positioned along the axis of the electromagnetic wave for the best capture of its constituent elements;
- Must be protected from interference;
- It is important to know the frequency of television broadcasting, on which the size of the receiving device will depend.
From coaxial cable
This is the most basic version of a cable TV antenna for receiving a digital or analog signal. Such a design can be done independently within half an hour.
A coaxial cable is an electrical wire for transmitting radio frequency signals. Comprises:
- Outer shell;
- An outer conductor, which is otherwise called a shield or braid;
- Insulation that separates the center core from the braid;
- Inner conductor (center conductor).
This cable can be 50 or 75 ohms. For the manufacture of homemade antennas, it is recommended to take 75 Ohm.
A piece of cable with a length of at least 0.5 meters is required. On the one hand, remove the upper insulation and the insulation of the central core by 5 cm. The core with the braid should be twisted. Now you need to step back from this end by 20-22 cm and remove everything until the central core is isolated. The length of this section will be about 2 cm. Then the same distance is measured as it was before this section, that is, 20-22 cm. Only the upper insulation is removed from a section of 1 cm. Now a loop is made: the bare end is screwed to the gap without external insulation.
It is better to wrap bare places with electrical tape, especially if the antenna will be used outdoors
The device must be directed towards the tower.
You can make an antenna out of copper wire.
For this, the ends are stripped of insulation. One end is attached to the TV, and the other to the heating pipe, which will act as an amplifier. Such a wire antenna can receive about 5 channels.
It is possible to make a loop receiving device from the wire for receiving a digital signal. To do this, you need to calculate the length of the loop. You need to know the average frequency of the signal. And 300 divided by this frequency. The resulting value will be the length of the loop. A piece of wire is closed in a ring, and a cable is soldered to the ends. Coax can be used instead of wire. Then the ring antenna will be similar to the one described above.
Despite the simplicity of the design, this method, with correct calculations, reduces interference and confidently receives the signal.
To improve the signal, you can try to perform antenna gain.
Consider the options for how to strengthen the TV antenna with your own hands:
- Position the receiving device as close to the window as possible, removing obstacles;
- Adjust the position;
- You can lengthen the antenna with a piece of wire;
- Add a signal amplifier to the design;
- External position as high as possible.
An antenna is a device that can receive or transmit radio waves. The types of terrestrial television antennas (that is, those that receive a signal from towers or repeaters) can be divided by location into:
It makes sense to use indoor antennas for a TV only with a good signal, and external ones are used in the country or far from TV broadcasters. In addition to the location, TV signal receivers are divided into:
- Passive. receive a signal only due to their shape;
- Active. the signal passes through the converters.
The signal quality from a passive TV antenna will directly depend on its size. the larger it is, the better.
- Ease of manufacture;
- Low cost: it is possible to make from scrap materials;
- No need for separate meals.
Nevertheless, the disadvantages are quite significant:
- Immunity to interference: it is very important to choose a location for a good signal;
- A great height is required for installation, additional reinforcement must be used;
- Bulky, not suitable because of the dimensions for installation at home, mainly used for outdoor installation.
In active antennas, various decoders and amplifiers are additionally used to make the signal stronger. Therefore, their advantages are as follows:
- Can be used anywhere, even with a low signal level;
- They can be of various sizes and shapes;
- You can adjust the level of gain and noise suppression;
- Low impact on the signal quality of terrain, weather, various buildings.
- Complex device;
- Need a power source;
- Higher cost;
- Less reliable due to the presence of electronics.
Radio waves that are transmitted over the air (wave transmission medium) have a certain size and frequency. The television channel is in the range of meter and decimeter frequencies:
- Meter waves (MW) have a length of 1 to 10 m and a frequency of 30 to 300 MHz;
- Decimeter waves (UHF) have a length of 0.1 to 1 m and a frequency of 300 to 3000 MHz.
According to the frequencies of the received signals, TV antennas can be divided into the following types:
- All-wave. Able to receive both analog and digital signals, but the receiving distance is short.
- Log-periodic. Can receive VHF and UHF waves.
- Decimeter. Designed for short wave only.
All-wave, otherwise they are called frequency-independent, reception devices are extremely simple in design, so you can make them yourself. The most famous of them: “butterfly”, from beer cans, from two petals. Most often used at a short distance from the repeater and with little interference.
Log-periodic receiving devices consist of a main rod and transverse bars with increasing length. In manufacturing, it is much more difficult than the previous ones. Correct design requires knowledge of all frequencies used, as well as orientation to the repeater. But, if the design calculations are made correctly, the antenna will transmit the signal very efficiently.
Decimeter meters can have both very simple and very complex designs. The most famous: “eight”, ring, frame.
Most channels, including digital ones, are broadcast in the UHF range. The design of such repeaters is simpler. But bending around obstacles with waves of this length is worse, and reflections and distortions play a strong role in signal quality.
Based on these features, you need to figure out how TV antennas can be made on their own.
In addition to typing in terms of wave reception, location, and the presence of electronic elements, television antennas also differ in all kinds of constructive implementation: wave channel, traveling wave, zigzag, frame, etc.
From beer cans
The simplest way to replace a broken TV antenna is to create one from beer cans.
Let’s figure out a way to make a simple antenna for digital TV, made from improvised means, namely from metal cans.
- Beer cans with a smooth surface (pre-wash and dry), in the simplest version. 2 pcs;
- Self-tapping screws;
- A piece of TV cable;
- Electrical tape or tape;
- A stick made from a material that does not conduct electricity (you can use a tremple).
- The cable must be taken of such a size that it is enough for the height at which it is planned to hang the antenna. If there is no plug on a piece of cable, it is stripped from one side of the winding and the plug is pushed onto it.
- The other end is also stripped of the winding. Inside there is a central core and braid (screen).
- Holes are made in cans on the same sides. It doesn’t matter if it is the top or bottom of the can.
- A central core is attached to one bank with a self-tapping screw, and a braid to the other. In this case, you need to make a loop that will grip the self-tapping screw. And when screwing in, he must grip it well with his hat.
- Instead of self-tapping screws, you can solder contacts.
- The cans must be tied to the stick so that they are on the same axis. The distance between the banks is usually taken from 7 to 10 cm.
- When the optimal distance is selected, the cans are securely fixed with adhesive tape.
It is better to fix the cans with an elastic band first so that it is convenient to adjust the distance
When you made such an antenna with your own hands, when using it outdoors, it is advisable to build a protective cap, for example, from a plastic bottle. If moisture gets in, the contacts will oxidize and the signal will deteriorate. The street version can be improved by adding several sections with banks.
This TV antenna is also called “eight” or Kharchenko’s antenna. Shows one of the best signal receptions among devices that you can do yourself. Its scheme is as follows:
Dvb t2 is the newest digital TV broadcast format. The digital format has many advantages over the analog one: it is more resistant to interference, the signal will be more widely available, and its quality is better. Digital format requires smaller antennas and lower transmitting power.
Making an antenna for receiving dvb t2 is quite simple. It should be noted that digital TV is transmitted in UHF.
Now let’s look at how an antenna for digital TV can be made with our own hands:
Any material that conducts electrical current is needed. This can be a tube, wire, corner, etc. The easiest way is to use wire made of aluminum, brass or copper (these 2 options are better), with a thickness of 2 to 5 mm. You will need to make 2 rhombuses from the material, as in the figure. You can also use welding electrodes, each of which will be the side of a rhombus.
The outer sides should be slightly longer. This is done so that the rhombuses in the middle do not connect.
But these parameters are more suitable for home use. often you can find a recommendation to take the side of a rhombus 45 cm.
You can make your own calculation of the antenna dimensions for digital TV. To do this, you need to know the wavelength of the signal transmission and divide by 4. These will be the sides of the rhombuses
There are also calculators for calculating the parameters of “bi-square” antennas, which can be found in Internet resources.
When the length of the wire is measured, you need to take a margin of 1-2 cm for the loop, which will close the circuit. You can simply twist or solder the remaining end.
After that, a coaxial cable is taken and stripped. The contacts will need to be soldered to the central corners of the rhombus, which do not close. The central core is soldered to one corner, and the braid to the other. The central part can be placed in a plastic case and filled with glue for reliability.
To reduce third-party interference, you can install a screen behind the receiver. It can be just foil stretched over plywood or a lattice made of metal tubes or wire. The screen should be located on the opposite side of the tower and not in contact with the antenna.
If the antenna will be used outside, you can assemble it with an amplifier. The amplifier can be a simple board that is attached to the antenna mustache or a larger device that requires mains power.
In the case of an amplifier, the “figure eight” is attached to the plate, while the wire can be flattened at the attachment point, and the amplifier can be immediately attached in the central part.
You can improve the design of the “figure eight” by adding more rhombuses symmetrically.
Consider a few more complex television antenna devices.
4 ways to make an antenna for your TV yourself
Despite the constant development of television broadcasting (transition to digital format, the possibility of installing satellite or cable television, Internet TV), the use of antennas is still relevant. This is especially true in the suburbs and rural areas. Sometimes the TV antenna breaks down, and there is no place nearby where you can buy it. Therefore, information on how exactly you can make an antenna for a TV with your own hands may be useful.
Antenna amplifiers should be installed as close to the antenna as possible. The amplifier is best powered via a coaxial feeder cable through an isolation.
The power supply decoupling diagram is shown in Fig.:
The decoupling device is installed at the bottom of the TV and is supplied with 12 V power from a separate low-power power supply unit (adapter). Two-stage antenna amplifiers consume no more than 50 mA current, so the adapter power should not exceed 5-10 W.
All switching of the antenna amplifier on the mast must be done using soldering, since the installation of mechanical contacting elements (connectors, etc.), operating in the most difficult climatic conditions, will ultimately lead to failure due to corrosion of the contacts.
When choosing an amplifier, it is necessary to ensure the attenuation in the feeder cable and the loss in the signal addition and branching circuits with the gain of the amplifier. Usually, with an average cable length of 20-30 m, the attenuation in it is 10 dB, hence. taking into account the losses in the addition devices. signal branching, you should choose an antenna amplifier with a gain of 20-30 dB.
Difficult are the cases when it is necessary to receive and amplify weak signals in the presence of strong signals from other transmitters. In this case, both weak and strong signals enter the amplifier input. A strong signal at the input of the antenna amplifier can block its operation or transfer the operation of the first stage to a nonlinear mode. mixer mode. In this case, one image is superimposed on the other on the TV screen. That is, the image of one channel shows semitransparent image frames of the other channel.
This means that the gain of the amplifier you have chosen is too high and can be reduced by decreasing the supply voltage of the amplifier. To do this, it is advisable to use a separate power supply unit with smooth voltage regulation in the range from 5 to 12.6 V.
It should be noted that UHF amplifiers are strongly influenced by VHF signals, since the power of the VHF transmitters is not commensurate with the UHF transmitters. To weaken the influence of VHF signals in front of the UHF antenna amplifier, you need to install a high-pass filter, which will remove the VHF range and allow only UHF signals to pass with low losses.
If the amplifier is chosen incorrectly (with a high gain) or if the antenna is poorly matched to the cable, then the amplifier may be excited and then there will be continuous ripples on the TV screen, but most often in rural areas where there are no powerful transmitting telecentres nearby, it is possible to use amplifiers with a gain 40-50 dB:
In fig. the diagram of the antenna amplifier is shown. designed to amplify the signals of all 12 channels of the meter range. Its amplification factor is 25 dB at a voltage of 12.6 V. The consumed current is not more than 20 mA. The counter-parallel connection at the input of diodes D1, D2 protects the amplifier transistors from damage by lightning discharges. Both stages are assembled according to a common emitter scheme. Capacitor C6 provides correction of the constant characteristics of the amplifier in the high frequency region. To stabilize the mode of the transistors, the amplifier is covered with negative feedback from the emitter of the second transistor to the base of the first. To avoid self-excitation of the amplifier due to parasitic feedback between the stages through the power supply, a decoupling filter R4 C1 is used.
the diagram of the amplifier for the decimeter range 470-790 MHz (channels 21-60) is shown. This amplifier has a 30 dB bandwidth gain at 12 V supply and a current consumption of 12 mA. Both stages are assembled according to the scheme with a common emitter on microwave transistors with a low level of intrinsic noise. The lower limit of the amplifier bandwidth is limited by the input high-pass filter, and the upper one. parasitic capacitances of transistors and installation. Thanks to resistors R1 and R3, temperature compensation of the transistor mode is provided. The L1 high-pass filter coil is wound with a PEV-2 wire with a diameter of 0.8 mm and contains 2.5 turns. Winding is carried out on a mandrel with a diameter of 4 mm. The amplifier is powered via a coaxial cable.
A simple broadband antenna amplifier provides about 10 dB of gain over the entire television broadcast range. The amplifier is a cascade with a common emitter and deep negative feedback through Rl C2, as well as emitter correction R5 R6 C5 Sb. The amplifier is powered by a cable. The antiparasitic circuit R4 SZ ensures the stability of the antenna amplifier, with high SWR in the cable, which is possible when the input impedance of the TV is significantly different from the wave impedance of the cable.
Choosing an antenna amplifier for a TV or creating it yourself
Currently, there are such types of television broadcasting:
- Broadcast. the signal is sent from the TV tower to the receiver;
- Satellite. the signal is sent from the satellite to the user’s individual dish-antenna;
- Cable. the TV signal is transmitted through the cable;
- Internet TV. transmission is carried out via an Internet cable.
Terrestrial TV stands at the origins of television, but despite its long history, it does not lose its relevance. A huge part of the viewer audience continues to use this particular type of television broadcasting. The main disadvantage of over-the-air transmission is the presence of a coverage area. That is, the further the receiving antenna is from the repeater, the worse the signal is obtained. To some extent, you can solve this problem with an amplifier for the TV antenna.
Consider the types of such devices, the characteristics for their selection, the pros and cons, as well as the methods of making such devices with your own hands in order to amplify the signal yourself.
What is an antenna amplifier
You may have heard the concepts of passive and active antenna. Passive antennas receive signals only due to their shape. But active ones include some converters in order to increase the useful signal.
A passive antenna can be made active by adding an amplifier. This option is much more convenient than purchasing an antenna with a built-in amplifying device. If it fails, the device is easy to replace. Yes, and it can be placed not necessarily on the antenna, but, for example, in the attic, which will allow the device to remain operational longer.
So, an amplifier for a TV is a device that amplifies the TV signal and reduces the level of interference, which allows you to get a better image on the screen.
The terrestrial waves of television channels are in the range of meter (MV) and decimeter (UHF) frequencies. The former have a frequency from 30 to 300 MHz, and the latter from 300 to 3000 MHz.
According to the range of received frequencies, amplifying devices can be:
- Broadband. covers a wide range of waves;
- Band (operate in the decimeter or meter range);
- Multi-band (can work in both bands).
As a rule, if the signal is good, then a wideband amplifier is sufficient. In the case of poor reception, it is preferable to choose a narrow-beam device, which in its range will do its job much better than a broadband one.
DVB-T2 is a standard used for digital broadcasting. Digital channels are capable of working only in the UHF range, respectively, amplifying devices of this range are suitable for digital television.
Amplifying devices also differ in the required supply voltage. The most common ones are 12 volts. They require an additional power supply. Sometimes the blocks are adjustable.
5-volts can be connected directly to a TV tuner or TV set via coaxial cable. Most often they are attached directly to the antenna.
They are also classified by the type of television, which are called so:
Cable and satellite amplifying devices are used extremely rarely, since the quality of the signal they transmit is already quite high. In rare cases, an amplifier is used for cable TV if multiple television devices are connected to the cable.
But antennae are used quite often. Further we will focus specifically on antenna amplifying devices.
Signal degradation reasons
Before deciding to install an antenna amplifying device, first you need to figure out what is the reason for a poor-quality signal:
- The distance to the repeater is too far;
- Incorrect selection or orientation of the TV antenna;
- The presence of obstacles in the signal path: high-rise structures, buildings, trees, etc.;
- Distribution of a signal to several receiving devices;
- Deteriorated cable or obsolete television equipment.
There is a possibility that you can improve the signal without an amplifier.
To do this, you can perform the following actions:
- Try to change the position of the antenna;
- Remove metal objects from the antenna and other objects that are in the signal path;
- Install a more powerful antenna;
- Check cable for continuity.
If the antenna picks up strong interference, or the reception level is higher than the amplifier can withstand, it is better to refuse to use it.
It should be understood that the amplifier will increase not only the useful signal, but also the interference, since it is not a filter. Therefore, if there is a problem with a too noisy signal, you must first think about another antenna. And if the TV signal is too weak, then it will not be possible to amplify it.
In addition, if there are twists in the connected cable, this also increases the amount of noise. It is better to use soldering to connect structural elements.
Digital television is gaining momentum every year. This is due to greater resistance to interference, better quality of the transmitted picture. But, if the signal is insufficient, the broadcast will be interrupted. This problem is similarly solved by an amplifying device.
A digital TV signal amplifier is no different from any other. It is only important that he works in the UHF. Sometimes it is recommended to install such devices with a voltage of 5V, so that you can connect them directly to the tuner. In this case, there is no need for a separate power supply unit.
Advantages and disadvantages of antenna amplifiers
When planning a home television network, one must take into account the fact that when using several amplifying circuits, the video stream can be significantly distorted. Therefore, the number of such devices should be the smallest.
The advantages of these devices include the following:
- Even a weak TV signal can be received;
- Small noise factors;
- You can improve the signal in several frequency ranges at once.
- Using a wideband amplifier can overload the acceptable signal level, so it must have controls on different bands to avoid this problem;
- Self-excitation of the device;
- Susceptibility to lightning discharges;
- Signal loss at the output.
Amplifying devices correct the signal after the antenna for the TV. Therefore, which one to choose depends on the terrain and on the needs of television equipment.
So, installing an amplifier for a TV antenna in the country or in the countryside solves the problem of a weak signal very well.
Another important point is the power supply. Each amplifier has a power supply unit that can be built-in or external. The built-in will work well with the stability of the electrical network and consumes up to 10V. If it burns out, you will have to replace the entire device. Therefore, if the network has power surges, it is better to use external units. They have larger sizes and different input voltages depending on the amplifier (5, 12, 18, 24 V).
Do it yourself
An amplifier is a board or a separate stationary device that is attached to a cable or antenna. The market offers a wide range of such devices, but if you wish, you can make a homemade amplifier. The most common components are needed for this. And they can be found anywhere that radio parts are sold.
To assemble them, however, you need to have some knowledge of electronics and experience in soldering elements. But if you are still going to make an antenna amplifier with your own hands, here are some diagrams with a description.
- Amplifier circuit based on the max2633 microcircuit:
- VT. max2633;
- R = 1 kΩ;
- All 1nF capacitors.
A constant current source with a voltage of 2.8-5.2 V is required. The circuit does not require adjustment, it gives a noise level of about 2 dB and a gain of about 13 dB, which can be lowered by increasing the resistance. Suitable for indoor antennas, designed for VHF, provides frequencies up to 900 MHz.
Next, let’s look at how to make broadband amplifier circuits.
- Circuit on a transistor connected according to the principle of a common emitter:
- VT1. KT368;
- C1 = 1000pF, C2 = 33pF, C3 = C4 = 15pF;
- R1 = R4 = 10 Ohm, R2 = 470 Ohm, R3 = 51 kOhm.
This circuit requires a 9V voltage source and has a high gain. Gain and frequency response may vary depending on the transistor used.
- A circuit based on a transistor connected according to the principle of a common base:
- VT1. KT315;
- C1 = 1000 pF, C2 = 33 pF, C3 = C4 = 15 pF;
- R1 = 51 ohms, R2 = 10 k ohms, R3 = 15 k ohms, R4 = 1 k ohms.
The inductor L or the choke is wound on a ferrite ring with a permeability of 600 N. For the meter range, 300 turns of PEV wire with a cross section of 0.1 mm are needed.
This scheme differs from the previous one in a smaller KU, but in a larger frequency band.
- DIY two-stage UHF circuit. This is another option for how to strengthen the TV antenna signal:
- VT1 = VT2. GT311D;
- C1 = 1000pF, C2 = 33pF, C3 = C4 = 15pF;
- R1 = 680 ohms, R2 = 75 kΩ, R3 = 1 kΩ, R4 = 150 kΩ;
- L1 = 100 μH, L2 = 25 μH, L3. a coil on a frameless basis with a diameter of 4 mm made of PEV wire (0.8 mm), consisting of 2.5 turns.
The gain can be increased by adding stages, but the noise figure will also increase. Therefore, you need to deal with them using various filters and low-noise transistors.
To assemble a device that amplifies the antenna signal for a TV with your own hands, you need for all circuits:
- Prepare items and consumables;
- Make a printed circuit board;
- Solder all components;
- Check the circuit for operability;
- Connect to antenna and TV receiver.
When manufacturing a board, it is not advisable to use mounting panels and a hinged assembly, as this can lead to an increase in noise.
What to look for when choosing an amplifier
Consider how to choose antenna amplifiers for your TV. To choose a signal amplifier, you need to pay attention to the following parameters:
- Location of the device. There are amplifiers mast or external, which are installed on the mast, and internal. indoors. The use of internal antenna amplifiers is much more convenient, but there is also more signal loss. In UHF, it is better to use the mast type;
- Distance to the TV tower. The maximum distance should not exceed 150 km, and for less than 10 km there is no need to install an amplifier, it is enough to choose and install the antenna correctly;
- The range of frequencies used. If the signal source is weak, then it is better to use a range amplifying device for specific frequencies;
- The gain (KU) and noise of the device. There are special tables for device models, where these values are presented. KU is usually sufficient 15-25 dB. And the noise figure for the UHF should not be more than 3 dB, in other ranges it can reach 6-8 dB;
- Output signal level. This is the maximum signal level above which distortion or interference will appear. The higher this characteristic, the better, but the cost of the device also increases with an increase in this parameter;
- Number of entrances. If we take an amplifier with several inputs (for each frequency range), then the probability of overload also increases. It is better to use a separate device for each band.
The gain should not be chosen on a “more is better” basis. Overloading the device may occur if the value is too high.
Which amplification device is suitable for digital TV? For digital broadcasting, you need an antenna for UHF with a frequency of 470 MHz. Accordingly, the amplifier must also be designed for this range.
Of course, it is impossible to say with certainty which device will be the best for your case.
How to connect an amplifier to a TV
Connect this device as close to the antenna as possible to minimize quality loss. An exception may be indoor television antennas, which have a too short cable, and in such cases an amplifying device is usually not required. The close position of the device to the TV increases the noisy signal.
If the antenna is already installed, then the device is simply screwed with bolts and nuts directly to it. In this case, it is better to ensure its protection from natural influences. Some amplifiers are already manufactured with a protective housing. It can also be placed in the path between the antenna and the TV. And with the help of an adapter, the power supply is connected. Either the amplifier is powered through the antenna cable.
The connection must be carried out on de-energized equipment and it is imperative to put grounding to the antenna. But if lightning hits the antenna, the amplifier will still burn out. You can put a device called lightning protection. It will work on the principle of a fuse: when a high voltage passes through it, the fusible element will break the circuit.
How to connect an amplifier for digital TV? The recommendations remain the same. The only thing is that the TV must have a DVB-T2 tuner or set-top box. However, if you have already used digital TV, then you already had the opportunity to watch it. For the amplifier, no additional elements and settings are needed.
So, in order to improve the signal of a television antenna, you need to install an amplifying device. Despite its small size and low power consumption, it is able to provide powerful amplification of transmission quality.
If you have a little knowledge in radio engineering, you can assemble the amplifier board yourself. But the consumer is offered a wide selection of both separate devices for amplifying the TV signal, and active antennas with already built-in devices. If you have a good antenna, there is no point in changing it to an active one. It’s enough just to strengthen it.
The important parameters of the device are the gain and noise factors, as well as where it will be located: outside or inside the room.
General manufacturing principles
Before you figure out what and how the antenna for the radio is made with your own hands, it should be said a little about what the principles of its manufacture and design should be in order for its effectiveness to be maximized. First, you need to understand that if the radio does not work well on the antenna, which it has, which is the case quite often, then a homemade FM antenna that amplifies the signal is the only way out. In addition, it must be positioned as correctly as possible and at the correct height so that there are a minimum amount of interference for high-quality work. An important point that must be taken into account before starting the creation of such a device is polarization.
A good antenna for long-range reception should be positioned exclusively vertically, like the wave itself.
In addition, it should be understood that any device that receives radio waves has a certain sensitivity threshold. If the signal is below it, the reception quality will be poor. Radio waves are usually weakened when there is a great distance between the receiver and the station transmitting radio waves. Poor weather conditions can also be a factor. These points also need to be taken into account when choosing the design and type of antenna. Usually they are in the following direction:
And in terms of mobility, they can be as follows:
Important! Non-directional models work on the principle of connecting point to point or point to many others within a radius of 50-100 meters. But non-directional ones can work in the entire area around them.
In addition, before making any model, you should know that they are as follows:
- rod or pin. this type of such devices is presented in the form of a simple rod or a rounded shape; whip is the simplest type of design, any indoor antenna is usually whip;
- wire. such models are made of the material of the same name and are bent in various positions;
- telescopic are structures that fold up; they are usually made of metal rods that look like telescopes;
- retractable models are found in almost every car; the advantage of this design is that it can be installed anywhere.
Important! Regardless of the antenna design, the principles of operation will be the same everywhere.
Tools and materials
It should be said that there are a huge number of options for creating antennas. They are made from copper wire, and from a tube of capacitors, and from wire and even from a television cable. And this is not a complete list of materials from which an antenna can be made at all. If we talk about materials, then to create an antenna you will need to have the following elements on hand:
- heat-shrink tubing;
- winding cable type PEV-2 0.2–0.5 mm;
- high-voltage wire or coaxial cable;
- glue for plastic.
This is a rough list of materials and may vary depending on the materials on hand. In addition, it will not be superfluous if a diagram of the device that you will be making is developed before this. The drawings of the device make it possible not only to determine what dimensions are needed to receive a particular wavelength range, but also make it possible to correctly calculate the necessary parameters of the device itself. type, length, width, some structural features. In addition, you can immediately roughly determine the place where to solder the socket, if necessary.
Here are some instructions for creating antennas, each of which will help you make a really high-quality FM module for receiving radio waves. So, in order to make such a device, you should adhere to a certain algorithm of actions.
A rather interesting option would be a pipe or magnetic antenna. By the way, it can be not only internal, but also external.
The main bearing part of such a device will be a heating pipe or water pipe. To make an antenna of this type, you will need to have on hand such elements as:
- a used transformer core that can be removed from some old TV;
- insulating tape;
- foil made from thin brass or copper;
- about 150 centimeters of copper wire with a diameter of a quarter of a square millimeter;
- pins for connection.
First, for wrapping with the first layer, a core made of ferrite is laid, and on top there are 2 layers of electrical tape, after which a single layer of foil. Now, 25 turns of cable with 1 cm overlap should be wound around this shield blank for the best insulation of the contacts. And also do not forget that you need to make mandatory taps on the 7th, 12th and 25th turns. The loop should be connected to other parts and the ends of the wire should be inserted into the pins. The tap from the seventh turn should be inserted into the grounding socket, and the other 2 should be connected to the antenna terminals.
The final stage of work will be to configure the radio signal reception. In this case, it will be performed by the usual selection of the winding connection to the connected circuit.
Another fairly common and simple option for creating an antenna of this type is a foil device. To create it, you will need to have the following materials:
- nippers or pliers;
- a roll of foil or copper wire;
- dry plank in the form of a square, which has a side measuring 15 centimeters.
There is nothing difficult in creating such a device. To make it, you will need to adhere to several stages.
- First, a square should be cut out of foil. It should measure 13 centimeters on the outside, and the width of the foil strip should be 1.5 centimeters. At the bottom in the center, cut a 3 mm rectangle to open the frame.
- The cut piece of foil should be glued to the board. Now you need to solder the inner core of the shielded wire on the right and the braid on the left to the foil square. This should be done slightly with a shift to the right of the central notch. somewhere by 2.5 millimeters. By the way, the distance between the shielded wire and the braid should be the same. Here it must be said that if the antenna is used to operate in the VHF range, then the size of the square should be increased to 15 centimeters, and the width of the foil strip in this case will be about 18 millimeters.
Important! If you need to amplify the signal for this type of antenna, then you can wrap it with a piece of copper wire. Its free end should be brought out through the window.
In addition, there is a very simple option for creating a simple radio antenna. We will need to have at hand such materials and tools:
- soldering iron;
- plug to connect the antenna to the radio;
- roller blocks that allow you to fix the antenna in the desired position;
- steel wire;
- copper wire;
- ceramic insulators.
Everything will be extremely simple here. just connect the wires, plug and rollers with a soldering iron. And the joints will need to be wrapped with electrical tape to strengthen the structure and preserve its integrity. In addition, to make such an antenna look as aesthetically pleasing as possible, it can be installed on a special stand, previously made of wood. As you can see, there are many antenna models, each of which can provide a high-quality radio signal in various conditions.
If we talk about recommendations for the creation and use of such antennas, then first of all it should be noted several.
- There should be no metal foreign objects near such a device. Otherwise, they can interfere with signal pickup or reflect it, which will also negatively affect the quality of its reception.
- Care should be taken to protect the antenna from environmental influences. Otherwise, its parts may rust and sooner or later the device will simply fail.
- In most cases, it is imperative to make drawings before starting work, where it is necessary to prescribe in detail the dimensions and dimensions of the device, its type, as well as an algorithm of actions for its creation. This will make it possible to quickly and accurately implement a particular idea and get a high-quality antenna for receiving a stable FM signal.
How to make a radio antenna with your own hands in 15 minutes, see below.
Where to point the antenna to receive a digital signal
To correctly determine the location of the TV towers, use the official website. karta.rtrs.rf. By going to the page, you will see a map with all the repeaters in the country, including coverage areas. In the search box at the top, enter your city of residence. Images with all towers in the area will appear on the map.
Click on the settlement and check the distance of the repeaters. Also, data on the broadcasting frequency, numbering of TV channels, the presence of multiplexes will be demonstrated.
How to amplify a digital TV signal with your own hands for 20 channels
How to amplify a digital TV signal on your own for standard digital 20 channels:
- Reposition the antenna. It is important that it is directed in the direction where the tower is located.
- Using the amplifier.
- Adding additional TV antennas.
- Pay attention to interference. remove metal objects.
- Check the cable, it may need to be replaced.
Pros and cons of antenna amplifiers
A digital TV signal amplifier has the following advantages:
- Eliminates bad quality.
- Receiving weak signals.
- Little noise.
- Signal enhancement over a wide frequency range
- Equipment can be overloaded by strong signals in the 49-230 MHz range.
- May be damaged during thunderstorms.
- Passive losses may occur at the output.
The peculiarity of such equipment is hidden in the power supply separate from the antenna. Today amplifiers can be divided into two types depending on the power supply:
- At 12 volts. Often used for summer cottages or indoor antennas.
- At 5 volts. Suitable for continuous digital TV broadcasts. Often used in sports bars.
How to choose an antenna amplifier for digital signal for TV DVB T2
When choosing an antenna amplifier, it is important to consider many conditions:
- Distance from the TV tower. It should not exceed 150 km.
- Frequency range.
- Output signal indicator. The ideal ratio is 100 dB per microvolt.
- Gain. not less than 40 dB.
- Coef. noise. no more than 3 dB.
- Power consumption. 30 to 60 mA.
Why is a bad digital TV signal
Initially, you should familiarize yourself with the reasons due to which the signal quality may be impaired. Probably, having corrected several provoking factors, you will not have to install an amplifier:
- A repeater is located far away.
- Incorrect TV antenna.
- The presence of natural noise.
- Obstacles such as trees or large structures.
- Damaged cable.
- Incorrectly set transmitter orientation.
- Old equipment.
- Bad weather.
- External interference at the antenna. This includes metal. For example, near the antenna there are metal objects through which electricity can pass.
- The TV signal is distributed to several receivers at once.
DIY digital TV signal amplifier. diagram
Before we look at the instructions for assembling your own amplifier, we will study the types of antennas currently in use:
- Telescopic. Another name is pivotal. Differs in simple manufacture and is used at a distance of up to 5 km from the tower. Circularly polarized to detect various radio waves.
- Patch antennas. Basically, in the manufacture of rectangular elements are used, protected by plastic. Has vertical and horizontal polarization. The main advantage is the increased KU indicator and the ability to accept re-reflection.
- Wave channel. It is the most used option. It is a structure of directors, reflectors and vibrators located on the traverse. The wave channel is often located outdoors, models with reflectors can be found. They are also often equipped with amplifiers and filters.
- Zigzag. The main advantage is the ease of assembly and the ability to accept the reflection. That is, zigzag antennas can be easily assembled at home.
You can amplify the digital signal of the TV antenna at home using the latter option, that is, using a zigzag antenna. In this case, the gain will depend on the number of squares. Thus, you can independently assemble the structure, spending a minimum of funds.
If you have any questions or complaints. let us know
Antenna amplifier can be easily assembled at home, focusing on the diagram. It will not require a lot of power, will not cause interference, and the frequency range will not exceed 900 MHz. Low voltage equipment powered from 3 to 5V will consume no more than 3mA.
What is the principle of operation of such equipment? Pay attention to the diagram showing input 1. voltage is supplied through it. The presence of a resistor marked as R1 and connected to input 2 will bias the voltage into the operating area. Output 6 receives the input signal, and the amplified signal will be removed from the third node and sent directly to the receiver.
Also with a video, which describes in detail the procedure for creating a zigzag Kharchenko antenna with an amplifier. www.YouTube.com/watch?v=3o0ZBUcL2f0.