The simplest antenna amplifier. The use of television antenna amplifiers mv and dmv, circuits

So, imagine this situation: in the evening you decided to watch your favorite TV program, and suddenly the TV stopped showing - cable TV was turned off. Or another case: you arrived at the dacha, already prepared for the rest and found that you forgot to buy an antenna for the TV - not a single channel works. How to proceed in such a case? The answer is simple - you need to make an antenna for the TV with your own hands from improvised materials, because most likely the cause of the breakdown is in this device. Next, we will look at the most simple options manufacturing, which require a minimum of improvised parts and time.

Idea #1 - Beer cans in action!

This version of homemade television antenna is the easiest and fastest to manufacture. The maximum number of channels that you can catch is 7, but this figure can vary significantly depending on the region, terrain features and distance to the TV tower.

To make a beer can TV antenna, you will need the following materials:

• 2 small self-tapping screws, also called "bugs" (not needed if you have a soldering iron);
• 2 prepared beer cans (empty, washed and dried)
• from 3 to 5 meters television cable(can be taken from a failed device);
• soldering iron and tin (for better fixing of contacts), availability is optional;
• screwdriver;
• wooden trempel (hanger);
• tape or tape.

Finding all the materials in the house will not be a problem, so having prepared them, we immediately get down to business.

In order to make a homemade antenna from cans, you need to perform the following steps:

1. We prepare the cable. First, at a distance of 10 cm from the edge, you need to make a shallow circular incision and remove the top layer of insulation. Having opened access to the screen, we turn it into one bundle. After that, we cut off the middle insulating layer, exposing the copper core of the cable by a few cm. At the second end of the wire, there should be a regular antenna plug.
2. Preparing banks. With containers that will act as a signal receiver, there will also be no difficulties. First you need to choose the optimal dimensions of beer cans. It is better to use liter ones, but if there are none, containers of 0.5 and 0.75 liters will do a good job.
3. Let's make contacts. At this stage, the twisted cable screen is fixed on one bank, and the copper core itself on the other. Fixation is carried out with bedbugs using a screwdriver or a conventional screwdriver. However, it is recommended to fasten the wire not with bedbugs, but with a soldering iron. The result should look like this:
   
4. We collect a homemade antenna for the TV. The signal receiver is ready, now we are making a supporting structure, which we have a trempel or an ordinary hanger. In no case should it be made of wire or metal. Using electrical tape, we fix the containers to the trempel (as shown in the photo). We draw your attention to the fact that the banks must be strictly on the same straight line, otherwise the homemade product will not work and stably catch the signal.
   
   
5. Setting up a TV antenna. Now you need to experiment with the optimal distance between the banks, as well as the place where the device is suspended and its position, so that the homemade product catches many channels. We turn on the TV and determine exactly how the receivers should be located and where is the most suitable place for their work. This completes the technology for creating the device.
   
   

As you can see, the whole process is quite simple and does not represent anything complicated. The optimal distance is 75 mm between the ends of the cans, and the best installation location is near a window or on an outrigger mast. In individual cases, the distance between banks can be made larger or smaller.

Visual video instruction on creating a simple antenna from cans

Idea number 2 - Use wire

Another no less good option that is advisable to use in the village is a homemade antenna from copper wire with amplifier.

All you need to make is:

• amplifier (suitable from an old device, for example, an inoperative or disassembled antenna);
• two pieces of wire 180 cm each, it is advisable to choose thick and stiff so that the wind does not damage the device;
• a piece of metal (or wooden) plate 15 * 15 cm;
• electric drill with a set of drills (preferably a welding machine);
• small bolts;
• a hammer;
• iron pipe;
• a television cable of a suitable length with a plug (sold in radio stores, it is not expensive, you can remove it from a non-working device).

So, in order to make a copper wire antenna for a TV yourself, you need to follow these steps:

Pay attention - in the photo examples, both the amplifier, and the reflector, and the wire are covered with paint. Painting protects the structure from corrosion and other adverse factors, significantly extending the service life homemade antenna for TV.

Idea #3 - Home HDTV Device

If the first 2 options worked at a frequency of no more than 270 MHz, then the following manufacturing method will allow you to enjoy a better picture, because. The signal range can reach up to 490MHz. The only detail that is unlikely to be found among household trifles is a matching transformer from 300 to 75 ohms. It will need to be purchased in advance from a specialized store, however, some plugs already contain this part.

Although there is an instruction on the net for making a homemade transformer, you can find and use it, this will significantly increase your skills in assembling homemade antennas.

From the materials you will need:

1. Scotch
2. Cardboard
3. Stationery knife
4. Foil
5. stapler
6. Scissors
7. Marker
8. Roulette
9. Glue (pencil or PVA)

Having prepared all this school set, let's get down to business!

First you need to draw (or print on a computer) this diagram:

Now, according to the scheme, we cut out all the spare parts, including the necessary pieces of foil:

After that, you need to make a reflector with dimensions of 35 * 32.5 cm (height and width). Cover one side with foil.

In the middle we cut out two identical rectangles, which are necessary in order to fully assemble the signal catcher for a homemade antenna for the TV. The rectangle should be 3.5 cm long, its purpose is to maintain the distance between the reflector and auxiliary parts.

We glue the parts onto the rectangle, and when the glue sets, we drill holes for the TV cable.

We connect the transformer and cable using twists, adhesive tape or a soldering iron. A more powerful TV antenna is ready to use! It should also be noted here that this homemade version is only suitable for indoor use, because. paper will get wet quickly from outdoor use.

Assembly digital antenna from TV cable and cardboard box

Another option for a powerful device made at home:

HDTV antenna from improvised means

Idea number 4 - Apartment option

There is another way to do powerful antenna for a TV from improvised means, which is suitable for both street and apartment use.

To make the device, you will need the following materials and tools:

• 4-meter wire made of copper, with a cross section of 4 mm.kv;
• a board of arbitrary thickness, 55 cm long and 7 cm wide;
• wood screws;
• ruler or tape measure;
• simple pencil;
• screwdriver;
• soldering iron;
• antenna plug.

So, first, we transfer the drawing to the workpiece and drill holes in the board:

Then we transfer the drawing data to the board and drill in the appropriate attachment points.

Next, the copper wire must be straightened and cut into 8 equal pieces of 37.5 cm each.

In the middle of each of the 37.5 cm pieces, insulation must be removed (as shown in the picture). To do this, use a sharp knife, stationery is perfect.

We cut off 2 more pieces of wire 22 cm long and divide them into 3 equal parts, bend slightly and in these places, again, remove the insulation.

We bend the prepared wire in bare places. We draw your attention to the fact that for those segments that are bent in half, the distance between the ends must be made 7.5 cm (the optimal value for receiving the signal of a home-made television antenna).

Next, we attach a plug to the finished homemade product, and we already connect a television cable to it.

This completes the manufacturing process. We choose a suitable place and direction where the signal reception is best, and install the device.

We have tried to select the most simple instructions. We hope that now you know how to make a home TV antenna with your own hands! Please note that today on the Internet you can find many other options in which inventors come up with more and more new manufacturing options, using, for example, copper and aluminum tubes, disks, electrodes ... The choice of components for assembly is usually determined only by their availability, so do not be afraid to experiment and come up with your own, original manufacturing methods.

Related content:

Noise on your favorite radio station, poor TV reception in the country, or a friend's voice disappearing in the phone's speaker - all this is the result of a weak signal from the transmitter. An antenna amplifier is the solution to each of these problems.

The need to use a television amplifier usually arises when the length from the source to the receiver is too long. Its use can also be called large quantity antenna connectors in the apartment, because each separation of the antenna signal leads to its weakening. The purpose of installing an amplifier is simple - to improve the quality of the transmitted television signal. And if it's about digital signal? You probably already know that in order to receive digital TV in the most remote regions, as a rule, you need to use a good narrowly directed antenna. And to preserve the quality of the signal before it hits the digital receiver, it needs to be leveled and strengthened. A modern digital antenna amplifier will do just fine with this function. Such an amplifier, in addition to a high gain, is characterized by high resistance to external disturbances. A modern amplifier for DVB-T2 can serve both to amplify reception from a conventional antenna, and to branch it into several outputs, or to sum up signals from several antennas.

When should I use this device and what should I be guided by when buying it? You will learn this from this guide.

What factors affect the deterioration of the television signal

Symptoms of poor analog TV reception are not difficult to notice - the picture is distorted and disappears. As for the weakening of digital television, it is also easy to detect, but with the only difference that we are not dealing with ripples (snow) on the screen, but with video stream breaks. On a weak TV broadcast, the picture may freeze, pixelate, or change color (usually green).

Causes of signal degradation

Each reason for the deterioration of the air should be analyzed individually, since its reception depends on local conditions: on the direction in which the signal passes, what obstacles are in its path, on the presence of hills, tall buildings in your area.

Before you finally decide to use an amplifier for your TV, let's get acquainted with the most likely causes of TV signal degradation.

• Transmitter Maintenance

In almost all cases of problems with TV display, their cause is on the user's side - cases on the sender's side are usually a break in the maintenance of the transmitter, which sometimes takes several hours.

• Hardware failure

Outdoor antennas are exposed to external natural influences from day to day. Frost, heat, blizzards and rain - all this antenna is able to endure for years. If it is installed correctly. And if not, then one day moisture will penetrate the wires, splitters, amplifiers, and the problem will arise at the least expected moment.

• Wrong antenna

The most common cause of poor reception is too low a signal level that comes from the antenna. The only correct solution would be to use its best model - preferably directional, not necessarily with an amplifier. But the situation can be partially improved by installing the antenna higher.

• Too high signal strength

Too much intake can also be a common cause of problems. Living near a TV tower and using a high gain antenna, we can overload the signal at the tuner's input.

• Cables

Has a significant impact on the quality of reception. An old one with frayed insulation, bought at a flea market or worse - from pieces that you scraped together "through the barns and bottomholes" can cause such strong attenuation that it will absorb the signal from even a very good antenna before it reaches the TV.

• Separators and connectors

The properties and number of splitters used also affect the picture quality. Each such passive element (i.e. one that is not an amplifier) ​​reduces the reception level. Careless installation of connectors, especially outside the housing, can lead to rapid oxidation of the connections and, as a result, to a significant attenuation of the TV signal.

• Noises

We are surrounded by a mass of transmitting devices - relay stations, mobile phones, modems, routers, radio stations, alarms, etc. Radio waves from different frequency ranges can interfere with TV reception. Interference is caused even by devices without antennas: a microwave oven, fluorescent lamps, electric vehicles.

Between the devil and the deep sea

Problems with TV reception also overtake people living on the border of signals received from two transmitters. In this case, it is necessary to find out which transmitter is stronger and in which direction the antenna should be pointed. In such places, a directional antenna will work best.

TV Signal Amplifiers

To check whether the antenna amplifier will help to “squeeze” a more powerful signal out of the antenna, you can quite in a simple way. You can connect any TV as close as possible to the antenna, and if the signal does not improve, it may mean that something is wrong with the antenna. However, if the picture on the screen improves, then you should think about buying an amplifier. Just what is it?

Another feature is the way the amplifying circuit is powered. If your DVB-T2 digital television antenna amplifier requires 5 volts, then it is better to supply them via cable from the tuner itself. Worse, when the amplifier "asks" 12 volts. There are two options here, both with problems to come:

1. its power supply with a low-frequency transformer for a 50 Hz power supply. The block is not as light as impulse blocks for recharging mobile phone, this block does not give high-frequency interference, but produces low-frequency ripples, which over time can degrade the performance of the antenna amplifier;
2. a power supply with a pulse conversion, very light, practically does not heat up, does not give low-frequency ripples, but is guaranteed to produce high-frequency noise, which is not at all useful to the amplifier.

Choosing an amplifier for a TV

Not every antenna amplifier works perfectly, some of them have a lot of their own noise, others are even worse, easily excited. Therefore, if you get a bad result with one antenna amplifier, you can try to choose a TV amplifier of a different model or with a different power supply. For example, experiment to see if the antenna will work better if you apply voltage not from the “native” power supply, but from a digital tuner.

An antenna amplifier will not be able to help or even harm if:

• the reception level goes off scale for the limiting parameters of the amplifier;
• the antenna, in addition to the main signal, catches strong interference, which the amplifier will multiply;
• The signal level is extremely weak.

Amplification of the analog signal

The golden rule of good TV reception: in order to get good, it is advisable not to worsen it. To prevent this from happening, lay it correctly, monitor the health of the antenna and diagnose any depressurization in your residential television network in time.

If the distance to the transmitting transmitter is large and the reception is very weak, then an additional signal amplifier must be installed.

If you receive analog air on a passive antenna, and distribute the signal to several receivers, then you first need to amplify it, and only then divide it into directions. An active antenna splitter can do this.

CATV amplification

Since its inception, cable networks have not changed much. The local provider company receives quite a lot of television channels from the satellite, forms a television package from them, and distributes them to our homes, charging for this from each subscriber. To reach our house, the signal passes several times through the intermediate main TV signal amplifier, enters the TV signal amplifier of the apartment building, is amplified again in it, and is distributed to the apartments. And yet, while this signal went from the premises of the provider company to our house, it weakened a little.

Methods for ensuring reliable TV signal reception

There is no ready recipe. Each case is specific and requires an individual approach. What to do in this situation? In many cases, the signal does not require maximum amplification, just as it is not necessary to amplify the entire “bouquet” of signals.

To make sure which case we are really dealing with, it is necessary to accurately measure the signal level from the receiver antenna. This is necessary in order to understand whether we are receiving a direct or reflected signal (or even several), and to determine the next steps.

One way to get good reception is to correct the direction of the antenna or its height position, and often both. Sometimes it is enough to move the antenna mast a meter or two to get much better quality air.

A level meter is also worth having on hand when you need to make sure that the broadcast quality is sufficient and only requires additional amplification, or maybe you are receiving a strong but excessive signal? In the case of a strong signal, you can choose the right antenna. It may also be enough to deliberately change the direction of reception or the location of the antenna to attenuate the signal, while at the same time eliminating its reflected beams.

When receiving digital TV, it should be remembered that when strong radio frequency vibrations are superimposed on each other, you need to make a choice in favor of a passive directional antenna without using any amplifying elements. The amplifier to the TV antenna in this case will contribute to intermodulation, which will lead to malfunctions and instability of the digital decoder.

Ways to amplify the power of a TV antenna

In fact, ways to increase the power of a TV antenna can be correlated with medical approaches: apply "therapy" or go straight to the "surgical" path. As for drastic measures, the very first step here is to change the antenna itself to a stronger and more expensive one. This also includes the purchase of an active antenna instead of a passive one.

But you can act more gently, especially if your antenna has served you honor by honor for more than one year:

• experiment with the direction of reception;
• raise the antenna higher;
• if possible, clear the path of the signal;
• eliminate all "non-contacts", replace the cable;
• equip the antenna with a signal amplifier. Many external antennas have the technological ability to install a reinforcing board, if it turns out that it is needed.

Using the Antenna Amplifier

The antenna signal amplifiers of the TV are the very first, after the antenna, to perform the initial correction of its level.

The type of device that is right for you depends on the reception conditions in your area and on the specific needs of the entire television installation. If you need to amplify the entire RF band, you can use a fixed-gain broadband amplifier. If, on the contrary, in your area the correct reception of frequencies from the upper UHF band is significantly affected by high-frequency transmitters and interference occurs, caused, for example, by passing cars or a neighbor's lawn mower, then you will need a different amplifier model - with a fixed gain, but with a limited operating range frequencies.
Modern amplifiers from various manufacturers have a fairly ergonomic shape, which, in fact, allows them to be mounted anywhere. This means that you can use the amplifier in an existing antenna installation without having to dismantle the antenna. However, it should be remembered that due to the violation of the signal-to-noise ratio with increasing distance from the antenna, it is recommended to install it as close to the antenna as possible.

Criteria for the right choice

The procedure for choosing an amplifying device is not particularly complicated. This equipment is designed to improve the quality of on-air reception, so its choice will be determined, first of all, by the quality of the incoming signal, which will guide you to connect a device with a suitable gain.

But do not forget that with a weak signal in your area, it is important to consider the antenna's own gain, as well as the height of its placement. And the amplifier will be useful when the distance from the antenna to the decoder is significant, and you have to amplify the signal to reduce its losses in the cable.

When choosing a signal amplifier for an antenna, it is also important to be guided not only by its amplifying capabilities. Equally, the parameters of the device's own noise are involved here. Both signal strength and signal quality at the very beginning of your residential TV network will have a decisive influence on the correct functioning of the entire installation, ensuring a clear and flawless TV broadcast.

A good TV antenna amplifier can be powered by the voltage that the tuner itself generates - this gives a good chance for the final video quality. Therefore, it is better to purchase devices in which the microcircuit is powered by 5 volts.

There are unpleasant situations when TV broadcasting spoils bad signal coming from the equipment. In this case, you need to buy quality amplifier television signal.

The deterioration of the cable TV signal in the apartment occurs for various reasons:

1. Poor choice of TV antenna.
2. The house is located far from the repeater.
3. Lots of natural noise.
4. The antenna cable is out of order.
5. The transmitter is incorrectly configured.
6. Used old technology.

To increase the connection, you need to use one of the proven methods.

How to amplify the TV antenna signal:

1. The first step is to change the location of the antenna. It must be directed exactly towards the TV tower.
2. Buy good amplifier TV antenna signal. This is an electrical apparatus that is connected directly to the device.
3. Increase the number of antennas on the roof to achieve a clear image. Each of the devices must be placed in the highest place in the house.
4. Replace the antenna with a more powerful analogue.
5. Reception may interfere with various metal parts that are encountered on the way. Therefore, it is advisable to remove all these items so as not to disrupt communication.
6. If a antenna cable fails, then there can be no question of any signal quality. If there are problems, you need to check it. In the event of a short circuit or break, you will need to buy a new sample.
7. Use the effect of an in-phase antenna array. Several receivers are used to create a complex system so that the total load on the phases is uniform.

These are the main ways to improve antenna reception. One of the most effective is to use an amplifier.

How to choose an antenna amplifier

The choice of a digital TV amplifier must be approached responsibly.

To buy a quality option, you need to be guided by several parameters:

1. Distance of the TV device from the repeater. The indicator should be within 10-150 km.
2. Select the correct frequency range.
3. TV signal level in the device. A stable option for a summer residence or at home is 100 dB per microvolt.
4. The gain must be 40 dB or higher.
5. You should find out the type of device for which you need amplification.
6. The noise level should be 3 dB or less.
7. The current consumption indicator is 30-60 mA.
8. The device must be placed near the receiver, or directly in the antenna housing.

If the house uses digital television, then you should purchase equipment with a voltage indicator of 5 V. When using digital set-top box DVD-T2 with this number, you do not have to additionally purchase a power supply for the amplifier.

Popular models for TV signal:

1. Televes 5523. This is a product of an Italian company that has a good gain of 16 dB. It also automatically lowers the level extraneous noise. Qualitatively increases the power of the TV antenna.
2. Terra HA 123. It is used to improve the signal even when installed in a country house. The gain is 20 dB or higher, and therefore the instrument can be used for different frequencies. The model is very well suited for cottages.

Suitable models for satellite and on-air television:

1. Gecen A05-02. The signal level increases up to 21 dB. To improve the quality of television terrestrial TV, you will have to purchase an additional power source.
2. Polish SWA models. Usually they are installed on lattice antennas. The gain range can be from 49 to 790 megahertz. For installation work, studs or a threaded connection are used.

Equipment advantages:

1. Even if the TV signal is very weak, the device will increase it. So you can enjoy watching anywhere, even far from the TV tower. This question is especially relevant for owners of cottages.
2. The device will generate a minimum noise figure during operation.
3. The device improves the quality of broadcasting in several wavelength ranges.

Each electrical device has not only pluses, but also minuses:

1. If the device receives too strong signals of different frequencies, then it may periodically reboot.
2. Under bad weather conditions and during a thunderstorm, picture quality may deteriorate as the amplifier reacts to electrical discharges in the decimeter range. An outdoor street TV signal amplifier in the country is effective only in the absence of a thunderstorm.
3. There will be passive losses at the output.

How to make an amplifier with your own hands

If for various reasons there is no possibility or desire to buy an amplifier in a store, you can make it yourself at home. The equipment will have low power consumption and will not cause interference. frequency range its equal to 900 MHz or slightly less.

To make an amplifier with your own hands, antennas for a TV use the following scheme:

The principle of operation of an antenna for a TV or how to improve the signal with a homemade product:

1. Voltage is applied to input 1.
2. Resistor R1 produces a bias in the desired zone. It is connected to the second input.
3. Output 6 receives the input signal. And at this moment, the amplified television signal is removed from the 3rd node, and goes to the receiver.

If you assemble the microcircuit correctly, then there is no need to configure it.

Many factors affect the reception of a television signal, and for this it is necessary to use amplifying devices. They have many advantages: high gain, mobility and a wide selection of models in stores.

Using the equipment, you can easily enjoy watching TV without interference.

AT modern world one of the most popular entertainment is watching your favorite TV shows. Sometimes the received signal does not meet the requirements of users, which significantly reduces interest in television. Due to various factors, the quality of the picture or sound may deteriorate. A cable TV signal amplifier for an apartment or a private house will help solve this problem.

General information

Before installing any additional device, it is necessary to understand the causes of malfunctions, as well as to study in detail all the ways out of this situation. All this information will help you choose the most efficient cable TV signal amplifier and avoid any problems.

Causes of signal degradation

There are a large number of factors that can have a negative impact on the quality of a TV picture. Their number may vary due to the characteristics of the landscape, the quality of the equipment and the conscientiousness of the services that control the repeaters.

The main reasons for the deterioration of the quality of the TV picture:

Advantages and disadvantages of amplifiers

A TV signal amplifier for an apartment, like any other similar device, has its advantages and disadvantages. They influence the choice of a particular model of equipment and allow you to accurately determine the most effective option.

Among the positive qualities antenna amplifiers worth highlighting the following:

Despite these advantages, amplifiers have several disadvantages. They must be taken into account before buying equipment and starting to use it. AT otherwise you may encounter various problems that will create additional difficulties and increase financial costs.

Among the shortcomings are the following:

• High degree of susceptibility to strong electrical discharges. This negative side is especially pronounced during a thunderstorm and leads to additional interference in reception.
• Self-excitation of the amplifier (the occurrence of electrical oscillations in the absence of any external influences).
• Frequent overload. It can be the result of exposure to powerful signals in the meter frequency range (from 49 to 230 MHz).
• Passive output loss.

Purchase and installation of the device

In order for the television amplifier to perform its functions efficiently, it is necessary to choose it correctly. It is important to take into account the many factors that can degrade the signal and cause equipment to malfunction. Only in this case it is possible to achieve the desired result and avoid any negative consequences.

Criterias of choice

Buying a TV signal amplifier is considered a rather complicated undertaking. The owner of the TV needs to take into account various options to help you choose the best device model. This work can be done independently or with the help of a qualified specialist. The first option is much cheaper, but requires some experience and knowledge in this area.

You need to choose a television amplifier according to the following parameters:

Varieties of devices

The purchase of one of the amplifier models depends on the type of television used. According to this criterion, all devices are divided into 3 groups and are used only in certain cases.

Types of amplifiers:

Mounting order

After all the necessary equipment has been selected, the installation process should begin. This work can be done with your own hands or with the help of a highly skilled craftsman. Self installation more accessible, cheaper, but always associated with certain risks.

If there is no absolute certainty in the success of the event, then it is best to contact a specialist. In this case, the costs will increase, but the quality of work will increase.

For installation you will need the following items:

• MAX2633 chip;
• resistor with a resistance of at least 1 kOhm;
• a set of capacitors with a capacity of 1 nF.

It is important to prepare everything necessary for work in advance so that during the process you do not get distracted and do not waste precious time. The assembly of the structure must be carried out in the correct sequence. Only in this case, the device will perform its functions qualitatively and amplify the signal.

Full procedure:

During the assembly and installation of the signal amplifier, it is necessary to take into account not only the recommendations of manufacturers, but also follow the advice of professionals. They will help you avoid most of the simple mistakes and achieve the desired result in the minimum amount of time.

A TV signal booster is a useful and inexpensive device. With it, you can eliminate various interference and significantly improve the quality of the television picture. With the right approach to choosing a device and following all the recommendations of professionals, you can achieve the desired result and reduce the likelihood of malfunctions.

The receiving television antenna receives electromagnetic radiation from the television center, which induces currents on its conductive elements that enter the coaxial cable. Depending on the design of the antenna with directional properties, it is possible to obtain a signal of different power. In this regard, the concept of the directivity coefficient of a TV antenna is introduced, which shows how many times the signal at its output exceeds the signal from a half-wave vibrator if it is placed in the same place in space.

TV antenna with amplifier

The actual power gain, taking into account losses, will be:

K p \u003d KND ∙η,

where η is the coefficient useful action, taking into account losses.

Application

The level of the electrical signal coming through the TV antenna input does not always suit the user. To improve the performance of the receiver, you need a signal amplifier located nearby. Especially it is required outside the city, where there is no cable network.

At the dacha, signal reception conditions are worse than in the city. It is influenced by interference and remoteness from the television center. Despite the fact that the TV amplifier slightly distorts the input signal, experts recommend using it.

At high altitudes, the signal comes from top to bottom and weakens significantly at the end. If it has low power, it attenuates to a large extent to the connection socket. In the cable, the signal is lost by 0.2-0.7 dB / m.

Amplifier selection

The antenna amplifier is connected as close as possible to the TV antenna. Placement near the receiver will increase the noise along with the transmitted signal, the picture will be worse. The power supply can be placed near the amplifier, as well as separately.

Home antenna made together with an amplifier

The parameters that determine the correct choice of amplifier are as follows:

• distance from the television center;
• required frequency range;
• the type of antenna for which the signal is being amplified.

The maximum distance to the signal transmission source should not exceed 150 km. At a distance of less than 10 km, an amplifier is usually not installed, since the signal level is quite high. To obtain a normal signal, it is advisable to choose an antenna well. How to make a do-it-yourself TV antenna from wire.

The gain should not be too high, otherwise significant noise may appear from self-excitation. Many of the manufactured models have different characteristics. Here you should contact the master, who knows how to improve reception, and will help you choose the right device. Installing a broadband amplifier on the antenna makes it possible to cover the entire range of television broadcasting.

In Russia, antennas with Polish-made amplifiers (ANPREL company) are common. Their own gain is small, and the parameters are mainly determined by an additional amplifier. It has the following disadvantages: self-excitation, high level generated noise, overload from powerful MV band signals, damaged by lightning, passive output losses.

For the most part, TV amplifiers operate according to a standard two-stage circuit based on high-frequency bipolar transistors with a common emitter.

Amplifiers on two stages: SWA-36 (a) and SWA-49 (b)

The amplifying stage captures the broadband band. The input signal is applied to the base of the transistor (T1) through a capacitor (C1). Required linear characteristic it is created by applying a bias voltage through a resistor (R1). But at the same time, the gain decreases. The next stage was created in a similar way with the stabilization of the transistor (T2) in the emitter feedback circuit through a resistor (R4).

It is not recommended to significantly increase the K p of the antenna amplifier, since it creates its own noise, which is amplified along with the input signal. The scheme is easy to do with your own hands.

You can improve the circuit using the SWA-49 model. This is achieved by using filters L1C6, R5C4 and increasing K p by adding capacitors (C5) and (C7).

Other ANPREL models differ slightly from the above circuits in the presence of frequency correction circuits at the output and the organization feedback, on which the magnitude of the gain depends. If it is close to the stability threshold, there is a high probability of self-excitation of the amplifier.

Televisions themselves have significant signal amplification. The larger it is, the higher the intrinsic noise becomes. Therefore, it must be understood that reception capabilities may be affected to a greater extent by their own noise interference than weak signal at the entrance. The signal must be at least 20 times higher than the noise floor voltage. Closer to this value, the image becomes bad, and small details are no longer distinguishable.

The transistor of the first stage has the maximum influence on the noise level of the antenna amplifier. You should choose the right amplifiers for the noise level, which should not exceed 2 dB. It may not be indicated in the instructions, but it can be found on the Internet or company directories.

The gain is needed mainly to compensate for losses in the cable. They are especially large on channels 21-60 and amount to 0.25-0.37 dB / m. An industrial splitter adds losses that are listed on the case. In this case, it should be taken into account that the indicated value of signal attenuation (usually - 3.5 dB) may differ in different wavelength ranges. This can be the maximum or average value. In any case, you need to take a factory product, and not a home-made one. Then 12-14 dB should be added to the total attenuation in order to capture weak signals.

What does an antenna splitter look like?

Antenna signal strength

The reasons for the weakening of the signal from satellite dish there may be several:

1. Failed to adjust the position of the antenna. It is enough to turn it quite a bit. If the fastening screws are loose, they should be tightened.
2. The appearance of an unexpected obstacle that should be removed or the location of the antenna should be changed.
3. Cable failure. The best option is its replacement. It is important to make a quality mount so that it does not dangle from the wind.
4. Excessive cable length. A better one is selected or an amplifier is installed.
5. If everything is in order, but the signal is not enough, you should purchase an antenna with a larger diameter.

The signal amplifier for the satellite TV antenna is installed between it and the receiver. With a cable length of 40 m, the signal attenuation will be 40x0.37 = 14.8 dB, and together with a splitter - 18.3 dB. The input level of the receiver is 48-75 dB. If it is close to the lower limit, you will need an amplifier. If we take a 20dB IF model, it will have a factor of 20 dB, which is sufficient to compensate for attenuation.

Frequency range satellite dishes is 950-2400 MHz, for which this amplifier is suitable (Fig. below a). You can also purchase the Gecen A05-20 model with similar parameters (Fig. b).

Satellite dishes (a) and an amplifier for them (b)

You should purchase amplifiers designed for the frequency range of the television antenna. The upper limit for terrestrial television is 950 MHz and for satellite it is 2400 MHz.

Do-it-yourself amplifier

A simple device on a microcircuit with your own hands can be assembled even by a beginner. It does not create much interference, practically does not consume energy and operates at frequencies up to 900 MHz.

Amplifier chip, which you can assemble with your own hands

The basis of the circuit is a low-noise low-voltage amplifier microcircuit (power supply 2.7-5.5 V). The circuit draws only 3mA of current. Voltage is applied to the input (1). Offset to the working area creates a resistor (R1) connected to the input (2). The input signal from the antenna is fed to output (6), and the amplified signal is taken from output (3) and fed to the receiver. Capacitors (C1-C3) are added to the microcircuit, separating the alternating signals from the constant component of the power supply voltage. When properly assembled, the circuit does not need to be configured.

With your own hands, you can also make devices according to the previously given schemes, for example, such as SWA amplifiers.

How to improve the signal. Video

The video below will tell you how to improve the signal of a television antenna.

It is better to purchase factory-made antennas and TV amplifiers, since they are made according to calculations. If you make the devices yourself, they will be an order of magnitude lower in quality. For TV reception in the country, you must have devices High Quality due to the distance from the television center and the presence a large number interference.