The TV shows poorly from the antenna - ways to solve the problem. TV antenna repair: weak or no signal

In most apartments and even private houses within any even small city, there are now almost no problems with the quality of television signal reception, since cable television is installed almost everywhere. Most apartment buildings in cities with a population of over a million may have several cable TV operators, which gives residents a pretty good choice.

But as you move away from city centers, the availability of cable TV high quality gradually “reduces to nothing.” And outside the city, as a rule, cable television completely absent.

Therefore, most summer residents are content with watching at most a few channels terrestrial television, which manages to be caught on . Moreover image quality often leaves much to be desired. Especially if the summer cottage is located far from the emitting terrestrial television station, then on the TV screen you can see a lot of interference from "snow" to "streaks" and black and white image instead of a color picture.

In most of Russia, terrestrial television is still transmitted to analog format. This method of signal transmission has one significant drawback: the signal-to-noise ratio drops significantly with distance from the emitter.

With distance from the television center, noise (interference) begins to dominate more and more over the main signal. This is precisely what manifests itself in the appearance of “snow” on the screen. If the cottage or village is very far from the transmitting station, then the noise will eventually interrupt the signal completely, and It becomes impossible to watch a TV channel at all.

Now the country is introducing the transmission of TV signals in digital format, and over time it is planned to completely abandon the transmission television programs in analog format.

What is the advantage of digital TV over analogue?

Transmission of a signal “digitally encoded” compared to direct transmission in analog format gives a number of advantages:

• Increasing the noise immunity of transmission and recording paths of television signals.
• Reducing transmitter power.
• Significant increase in the number of TV programs transmitted in the same frequency range.
• Improving image and sound quality in TV receivers.
• Creation of TV systems with new standards of image decomposition (high-definition television).
• Creation of interactive TV systems, when using which the viewer has the opportunity to influence the transmitted program (for example, video on demand).
• Function "To the beginning of transmission".
• Archive of TV programs and recording of TV programs.
• Transmission of various additional information in a TV signal.
• Select a language (more than the usual two) and subtitles.
• Extension functionality studio equipment.
• Possibility of adding radio to multiplexes

But there are also some flaws:

• Fading and scattering of the picture into “squares” when the level of the received signal is insufficient, the data is either received with 100% quality or restored, or is received poorly with the impossibility of restoration.
• Almost complete signal fading during thunderstorms.
• Even a transmitter with a power of 10 kW and a transmitting antenna height of 350 m provides confident reception over a distance of 50 km, and as a result, the need for a larger number of transmitting centers than with analog TV (more frequent placement of transmitting antennas).

Since we are discussing from the point of view of an ordinary user mainly only image quality, then we can highlight only one main feature of digital terrestrial TV over outdated analogue:

Digital TV is very resistant to interference. To do this, the signal is encoded with some redundancy. Digital tuner will produce a perfect picture even if there is large quantity interference And it will do this until the signal-to-noise ratio drops to a minimum, when the signal arrives at the very edge of the equipment’s capabilities.

That is, in analog broadcasting, as the signal level drops, you will see the picture worse and worse. IN digital broadcasting you will not notice the signal drop until the tuner is no longer able to restore the lost pieces of the image, and it “disintegrates into squares” and then disappears completely.

Types of digital television

Based on the transmission channel, digital TV can be divided into four types:

• Cable (DVB-C)
• Terrestrial (DVB-T2)
• Satellite (DVB-S)
• Internet TV (IP TV)

We will not consider cable TV and IP television in the country due to their great rarity. But satellite and terrestrial digital television broadcasting in the countryside is relevant.

Moreover, satellite DTV has been used by consumers for quite some time, and in particularly remote areas there are no alternatives to it at all. We will look at it in our separate article.

But on-air DTV began to enter the lives of gardeners and summer residents relatively recently. Let's talk about him in more detail today.

Terrestrial digital television in the country

The terrestrial digital television network in the Russian Federation is still in the process of construction and currently available mainly near large cities. But it already covers a significant part of the dacha areas. Therefore, the issue of connection has become very relevant lately.

How to connect to terrestrial DTV?

Most reliable way to find out, ask your neighbors in your dacha area, perhaps some of them are already watching TV channels in digital form. Then you can be completely sure that “the signal is reaching you.”

If no one in the area has yet heard of digital TV, then you need to try to find out whether your site falls within the boundaries broadcast radius of a local emitting DTV station.

Coverage area

The broadcast radius of a DTV station usually lies within 20-50 km, depending on the terrain and building density. On average about 30 km is reliable reception zone.

Each region has its own local organization - DTV operator, which is responsible for building and maintaining the network. On their website you can usually see the locations of broadcast stations and even coverage maps. Or you can get information from them by phone or written request.

The DTV network in the Russian Federation is being built by the Federal State Unitary Enterprise Russian Television and Radio Broadcasting Network.

Each region has a division of this organization.

You can call and find out everything by phone numbers in your region from the page.

If you are lucky and you find out that your dacha is located in the digital broadcast zone, then it’s time to decide necessary equipment for DTV reception.

Equipment

So, you already have a TV in your dacha, a plot in the DTV broadcast zone. Let's start installing digital television at the dacha. What else is needed to receive a signal? At a minimum you need an antenna.

Antenna for digital television reception

Universal HF/UHF antenna for digital TV reception

If a digital TV tower is nearby, then it is enough indoor antenna. I will say even more, I personally confidently caught a DTV signal in the city of Ufa on a meter-long piece of wire.

If the signal level is not so ideal, then you will need to install an antenna at your dacha to receive digital channels. Nowadays, most antennas on sale are well suited for this, since they support reception of signals in the decimeter range (UHF/UHF).

For example, you can install the antenna “GAL”, “Locus”, “Zenith”, “Meridian”, “Ether”, etc. I bought my antenna in Auchan for 1000 rubles.

If you know the exact location of the DTV tower, then everything is simple: point the antenna on her and that's it. Usually this is enough to catch a signal and watch digital TV without problems.

If the exact direction is not known, then you need to gradually rotate the antenna until you find the best position. Majority digital set-top boxes have signal level and quality indicator, which is displayed on the TV screen and from which you can find the best antenna position. This is usually done by two people: one person rotates the antenna, the second monitors the signal level.

When you have found the maximum possible signal level and the antenna is installed in the desired direction, you need to search for channels on the set-top box.

Setting up digital television at the dacha

The easiest way is to find the “Auto search for channels” item in the set-top box menu, and then the set-top box will do everything itself: it will find all available digital channels and number them in order.

List of digital terrestrial television channels

Now the interesting part: what channels does digital television show for free??

Since my dacha is in the suburbs of Ufa, and I am writing from my own experience, it means that I am considering digital terrestrial television in Ufa. But as far as I understand, list of channels throughout Russia will be the same with rare exceptions, so the information will be useful to everyone, not just residents of Bashkortostan.

At our dacha the DTV shows 20 channels: 10 at each multiplex.

List of digital television channels

Here full list channels in Ufa:

I hope I helped you understand all the nuances of digital TV. If you have any questions, write, I will definitely try to help you.

If, after turning on the TV, you see only the inscription NO SIGNAL on its screen, it becomes clear that there are problems with the antenna.

Also, a poor-quality signal will indicate a malfunction of the antenna (although it may not be the cause).

In many cases, owners of television receivers manage to solve problems with the antenna themselves. Another question is the competence of the actions taken and their safety.

How to properly repair an antenna and when you can’t do without the help of a TV technician?

Checking the serviceability of the antenna

Depending on the type of antenna connected to the television receiver, TV It happens:

• analog,
• satellite,
• digital (terrestrial, cable digital, satellite, IP television).

Whatever the type of antenna, if there are any problems with it or poor signal reception, you need to check:

1. Is the plug inserted tightly and into the correct connector?
2. Is the antenna mechanically damaged?
3. How well is the cable connected to the antenna, and is it in the proper position and condition? Defects, cable breaks, damaged contacts, corrosion at the antenna connection - all these are malfunctions that need to be eliminated.
4. Are the channels configured correctly? Are all or some of them configurable? Pay attention! There may be a separate search for broadcast and cable TV.

Often a new, newly installed TV does not receive a signal. Most often the problem is in the settings, but the likelihood is poor quality technology itself is not excluded.

If you have been using TV for a long time, first of all, double-check that you have not forgotten to pay for TV! You can always call the operator to double-check the payment and at the same time clarify whether there are any problems with his work.

If you are convinced that everything is in order externally with the antenna and its connection and you paid for the TV, likely:

1. The socket into which the antenna plug is inserted is damaged.
2. The antenna itself is faulty.
3. The TV tuner is damaged.
4. Some element inside the TV is faulty.
5. Software problems.

To repair your antenna, tuner and TV, invite an experienced TV technician from VseRemont24 to your home!

Factors affecting signal quality

If channels are shown, but signal reception leaves much to be desired, it is highly not recommended to continue watching. This is dangerous for your eyesight and psyche.

Characteristic poor signal quality faulty TV antenna:

• interference, ripples, noise,
• glitches, displacement, jumps, temporary disappearance of the image,
• inability to configure channels.

These same problems, provided that the antenna is working properly, indicate a breakdown inside the TV. Probably faulty:

• receiver,
• controller.

Do not forget about the need to take into account weather conditions when receiving a TV signal.

Negative How the antenna operates is affected by:

• snow,
• hail,
• rain,
• heavy clouds,
• strong wind,
• storm.

Everyone knows that during a thunderstorm, antennas attract lightning. But a lightning discharge damages the amplifier only of those antennas that were originally incorrectly installed.

Please note that the TV itself will only break due to a direct hit by powerful lightning on the antenna.

Attention! If your antenna is not on the ground, it needs to be ground. Check grounding. If it is not there, invite a TV technician to reinstall the antenna.

During a thunderstorm, many people pull out the antenna plug from the TV, hoping to protect the equipment. While it is much more correct to close the braid with the central wire.

If you simply pull out the plug during a thunderstorm, then the next time you connect it to the TV receiver, a powerful discharge may occur. It's deadly danger!

The television signal also deteriorates for a television that is too close or, on the contrary, far from its source of distribution. This factor also needs to be taken into account when searching for the causes of antenna malfunction.

Antenna with an amplifier of the “Grid” type and digital television - are they compatible?

The grille does not accept DVB T2, what should I do? Why is the antenna not working? How to use the “Pole” without an amplifier? All this and other questions are in this article.

Hello, dear visitors!!

It is no secret that the “Polish Grid” antenna has gained wide popularity among users. She's already for a long time serves the people and often tortures its users. Now, analog television is being replaced by digital television, DVB-T2, and many people have various questions about the use of this antenna.

I have previously written about the use of a Polish antenna for DVB-T2, answering in the comments and not much in the articles themselves. Therefore, in this note, in one place, I will try to collect more full information about the use of this type of antennas for both analogue and digital television.

Quick navigation through the article

Polish antenna for receiving digital television

Is the “Grid” antenna suitable for receiving DVB-T2?

The Polish antenna is broadband, i.e. capable of receiving signals in both the meter and decimeter ranges. This means it is suitable for receiving DVB-T2 digital television signals.

However, she is not the best option for this purpose, and often in order to receive a digital television signal, some modifications are required. But all this is not difficult to do.

These alterations and more will be discussed in this article.

How does the “Grid” antenna perform with digital TV?

If you live not very far from a digital television signal translator, then this type of antenna can behave rather strangely.

By default, the Polish antenna is used with an amplifier and power supply. And if, when using such an antenna, provided that all connections are made efficiently, something incomprehensible happens to the signal, for example:

• The signal is completely absent, the antenna does not pick up anything.
• During setup, the signal level scale jumps from zero to one hundred.
• There is reception, but at times the signal weakens or disappears completely. The image often “freezes” - freezes for a while, crumbles into cubes, and the sound stutters.
• Out of 20 possible channels, only 10 are shown.
• The signal disappears or weakens when cars pass nearby (if the antenna is installed low and next to the road)

All these are precisely those cases when some alterations will be required.

In my area, which is the Belgorod region, at a distance of 25 km from the broadcast tower, “Poles” often behave exactly like this! What is the reason? Let's figure it out and fix it!

By the way! If in setup mode, the signal level indicator scale on the TV screen jumps from zero to one hundred percent. Back and forth without stopping. This does not mean that the signal is lost! This indicates that the signal is unsuitable for decoding. Without taking action, watching DTV is not possible!

So! If you observe anything from the list, then the likely reason is that the antenna amplifier is too powerful to receive a DTV signal; in this situation, it does not help, but interferes! The signal is too strong.

Because common cause is the signal is over-amplified, then the conclusion suggests itself - the gain needs to be reduced!

Yes! Often, simply reducing the power of the amplifier helps, and for this, you don’t need to change it at all, you don’t even have to remove the antenna.

It would be nice to display a signal level scale on the screen when “experimenting” with the antenna. This can be done by pressing the “Info” button (usually you need two clicks, sometimes three) Or you can enter the manual search mode, enter the number of the TVC on which broadcasting is carried out in your region. Typically, in this mode, the equipment displays a signal strength indicator. Using this scale it is convenient to see the results of work.
By the way, you can find out which channels are broadcasting in your area

How to reduce the power of the amplifier without removing the antenna? Four ways!

In order to reduce the power of the amplifier, you need to lower the voltage that powers it.

There are several methods on how this can be done. Choose depending on your situation.

Method one, the easiest

If you have used adjustable block power supply, then there are no problems, just turn the regulator counterclockwise to reduce the voltage supply to the amplifier. The regulator can change the voltage within the range of approximately two to twelve volts. At the same time, monitor the signal level and choose the best position of the regulator. Please note that changes on the signal level scale will not occur instantly, but with a slight delay.

Attention! One condition for all the methods below!

To apply all the methods described below, you must do the following! Disconnect the standard antenna power supply and install a regular cable on the TV TV plug. Do not use the plug from the power supply! It has a separating capacitor inside the separator, it will be superfluous. That's why,

Method two

If you use a set-top box, you can supply power to the antenna amplifier directly from it. So instead of 12 Volts, to the amplifier, by TV cable, only 5 volts will come from the console. This reduction in nutrition often helps.

To do this:

1. We install a regular TV plug on the cable.
2. We go to the set-top box menu and find the item where the antenna power is turned on. For example: “Antenna Power On/Off”

This feature may be called differently in different set-top boxes, but all models have it.

Method three

If you have a TV with a built-in DVB-T2 tuner and you do not use a set-top box, then you can supply 5 volts directly from USB port TV.

To do this:

1. Again, you need to install a regular plug.
2. Will need to apply special TV. (approximately 150 - 300 rubles)

Method four

You can try removing the power supply to the amplifier altogether.

1. Installing a regular TV plug
2. Without any power we connect it to the set-top box/TV.

Sometimes this helps, but not always. It happens that without power, the signal amplifier does not pass through at all.

These were ways to remake the “Polish Antenna” for digital television, which did not require removing the antenna itself. But it also happens that even five volts is already too much, over-amplification occurs, and removing the power from the amplifier completely did not help either.

In such a case, there is a method described below, but it involves the need to remove the antenna or get to the installation site of the amplifier. This complicates things somewhat, but for that reason it is the most the right way adapt the Polish girl to the digital figure.

Using a Polish antenna without an amplifier

This method gives excellent results in the area good signal DVB-T2, for example from a TV tower in Belgorod at a distance of 25-30 km. It catches perfectly in line of sight.

In addition, the most problematic areas of the array antenna are immediately removed - the amplifier and power supply. They are simply not needed. It is better, of course, to purchase a matching board. But it is not always possible to find it. Therefore, let’s connect directly – I’ve done this many times! Checked! Works!

The only thing is that you will have to get to the antenna itself to connect the cable as in the photo below.

As you can see, the cable is attached directly to the antenna elements. The amplifier board can be removed, but it can also be left in place; it makes it easier to secure the cable. The plug must be installed as usual.

The long whiskers of the antenna can be cut/broken off to the size of the short whiskers, so they will work in the desired UHF range.

How to properly mount an amplifier on an array antenna

The above described methods that can be used to receive digital terrestrial television and only in an area of ​​strong signal when the amplifier interferes. But if you are not so lucky with the signal, then the amplifier will be just right and the methods described above will no longer suit you!

However, here too many are faced with the problem of reception quality and often these are problems of improper installation, nothing more.

It happens that when using an amplifier, the antenna does not work, or sometimes it works, sometimes it doesn’t work, and this applies not only to reception, but also primarily to analogue television. The reasons may be different, but one of them is very common - the amplifier is not installed correctly. It would seem nothing complicated, but let's figure it out.

The problem is that the contact pads on the amplifier plate are only on one side, and in in this case on top, while the antenna elements are on the bottom, under the amplifier.

This means that the amplifier contacts can only connect to the loop-shaped elements of the antenna through bolts. In this situation, there is a high probability that the bolt will pass inside the hinge and not touch it, or barely touch it. And this means that it has oxidized a little and that’s it. End of the film.

This method is also correct, but at the same time the cable connection to the amplifier becomes inaccessible, which makes inspection difficult, since if something happens you will have to unscrew the board.

Other malfunctions and problems with installing this antenna

One of the malfunctions of this antenna, which few people know about, manifests itself as follows. On the TV screen, horizontal stripes float over the image, each about 5 cm wide. The reason is in the antenna power supply, or rather in the capacitor that is there, it needs to be replaced. (block or capacitor) whoever can.

If the indicator in the antenna power supply goes out, this does not mean that it is faulty; there may be a short circuit somewhere in the cable connections.

For example: at the junction, one wire from the cable braid protruded and touched the terminal where the central core should be connected. This can also happen on the amplifier side. Another reason for the indicator to go out is a failed amplifier. It’s easy to check the short circuit, just disconnect the power supply from the cable and turn it on; if the indicator lights up, fix the short circuit.

The soldering inside the separator is often broken, look at this picture, it shows the weak points.

Often the problem arises due to poor-quality cable connection to the separator and amplifier. For example, like this, with a bunch of protruding wires and a central core which, if you pull the cable a little, will close with a clamp.

So, it is important to connect everything correctly and efficiently! How to achieve this? Let's look at the example of a separator. See the photo below. We cut the cable.

P.S. If the braid is thick and fits tightly on the cable, then you can not separate it or roll it into a bundle, but leave it on the cable and carefully cut it off, leaving only enough to clamp the fastening clamp, but so that it does not stick out too much beyond its limits and therefore not shorted to the center wire.

And we do the same with the tourniquet.

Antenna amplifier, how to choose the right one

A big mistake is made by users trying to buy the most powerful amplifier, and this is exactly what often happens: “Give me the most powerful amplifier” they say to the seller who wants to achieve, good quality TV signal and... are disappointed.

Why is this approach not correct? The fact is that an excessively strong signal is bad; this is exactly the case when the oil in the porridge may be unnecessary. An excessively strong signal may cause reverse effect, strong interference for analog TV, for digital TV - cubes, stuttering and even complete absence of image.

The point is that along with the useful signal, various interferences also increase, and often strong amplifiers have a large percentage of their own noise, which also affects the quality.

Therefore, the power of the amplifier needs to be selected; if you do not know which amplifier number is best in your area, ask your neighbors who managed to achieve good signal reception. Often local sellers who sell antenna equipment are also aware of this, ask them.

Amplifier parameters for TV antenna

A table of parameters can help in the choice, which also indicates the approximate distances from the television center at which the use of a specific amplifier is recommended.

It is good to use an adjustable power supply; it allows you to reduce the supply voltage of the amplifier, and thereby “strangle” excess gain.

How to protect your antenna, TV or receiver from thunderstorms

Have you ever seen a TV damaged by a thunderstorm? Me many times!

Of course, damage varies, but in one case there was simply a burnt hole in the TV chassis with a diameter of about 15 cm. But this is rather an isolated case. Nevertheless, thunderstorms cause quite a lot of trouble. They knock out equipment and amplifiers on antennas. Is there any way to minimize the damage or avoid it?

Can! If you follow some rules.

1. It’s good if the antenna is grounded; in general, this is an installation requirement. Some antennas even have a welded grounding bolt near the mounting clamp. The antenna mast (metal) must be in the ground.
2. It is not always possible to organize grounding, and in such cases, amplifiers are changed quite often, almost after every thunderstorm. For an amplifier to fail, a direct lightning strike is not necessary; static voltage is sufficient. If possible, ground the antenna!

Use amplifiers with lightning protection.

There are a number of amplifiers with built-in lightning protection; of course, it will not save you from a direct hit, but such amplifiers practically do not fail from static. They can be identified by obvious signs. Let's look at the photo.

Such an amplifier has two glass diodes, those circled in yellow.

This is not necessarily an amplifier with the number SWA-1, it can be any number, but if it contains these two elements, then this is a version with lightning protection. Unfortunately, these don't come across often.

Use lightning protection for equipment.

It is also possible to protect your equipment from discharges; to do this, you need to insert a special unit into the break in the cable coming from the antenna or dish, which is called “Lightning Protection”

He may be from different manufacturers, vary in appearance, but its purpose is the same: To protect the equipment from discharges coming through the antenna cable.

It could be a barrel like this, which, using F connectors, is inserted into the cable circuit, between the antenna and the TV or set-top box receiver. If something happens, it will fail, but not the equipment, which is much cheaper.

Of course, it will not provide one hundred percent protection, if only because the discharge can arrive through network wire. But it does provide some protection along the antenna circuit.

If you really want to protect yourself completely, then in the event of a thunderstorm nearby, unplug all equipment from the outlet; simply turning it off with a button or using the remote control will not help. And remove the antenna cable from the socket.

You can do the same with a computer, disconnect it from the network and disconnect the wire through which the all-knowing Internet comes.

Well, on this romantic note, I’ll probably end my epic about the Polish antenna.

This is not at all difficult for you, and it will be useful for the development of the site. Thank you!

Instructions

Pay attention to the location of the antenna. Important role The height at which the antenna is located plays a role in signal reception. It doesn’t matter at all whether we are talking about radio or television. To amplify an indoor antenna, place it as high as possible. If the antenna is telescopic type, for best regards signal, it must be fully open.

Look where the antenna is pointing. If there are obstacles between it and the signal source, naturally the reception will be poor. Try to position the antenna so that there is no large tree, tall building, power line or any other structure in its path that could seriously interfere with signal reception. This way you can strengthen the antenna.

Use antenna amplifier in order to make the indoor antenna more powerful. This is a special device that facilitates signal reception. Also try using additional grounding. This will practically not change the antenna power, but the signal will be clearer. Any antenna is an open oscillating circuit. The larger the area oscillatory circuit, the greater the ability to receive a signal it has. Any long wire can serve as an antenna. Attach it to yours indoor antenna. This will increase its area, and therefore its power.

Use the last resort if none of the above methods help. Replace the indoor antenna with an external one. An external antenna is much better suited to quality reception signal, especially since there are much more options for customizing it. Point the external antenna in the direction that is optimal for signal reception. This will save you from the need to constantly adjust it, as is often the case when using an indoor antenna.

The quality of television and radio signals does not always satisfy viewers and listeners. Moreover, there can be interference even when there is a seemingly powerful antenna. In order to improve quality reception, the antenna must be configured correctly.

You will need

• coaxial cable, portable radios or cell phones.

Instructions

If the antenna is directional, try repositioning it so that there are no obstacles between it and the signal source. Such obstacles can be high-rise buildings or other structures, power lines, and so on. You can try the exact direction to the signal source. To do this, you can use the help of an observer monitoring the signal at the receiver. To communicate with it, you can use portable radios or.

If you have a directional antenna with flat polarization (type “Wave channel” and similar), check the polarization of the received signal. Adjust it according to the received data. To do this, you need to rotate the antenna relative to the axis directed towards the signal source. Most often, just trying to rotate the antenna 90° is enough.

Efficiency antennas can be increased using an antenna amplifier. But in this case, the gain limit is set based on the noise level. To reduce their level, use shielded reduction, that is, the antenna is best using coaxial cable.

Efficiency antennas, especially when receiving on long, medium and short waves, can be increased by installing additional grounding. It should also be borne in mind that the antenna must be impedance matched with input circuit radio receiver That is, it must be connected with the type and cable recommended in the instructions for the receiver or.

Please note

Long, medium and short wave antennas can be long lengths of wire. It is also recommended to install the mounting points of such antennas based on the highest reception volume of the desired stations. That is, it is necessary to change the position of the antenna.

Useful advice

If we are talking about an indoor antenna, then the best solution There will be installation of a stationary external antenna. This will dramatically improve the quality of reception. Also to external antenna It is recommended to connect portable mobile receivers and televisions when operating them in stationary conditions.

Receivers operating on ultrashort waves have long been commonplace. We use the radio at home, in the country and even in the car. But as you move away from the broadcasting station, the signal quality deteriorates noticeably. It is not always possible to install an effective receiving antenna, so using an antenna amplifier may be a solution to the problem. If you know how to use a soldering iron and understand the fundamental electronic circuits, then you can make one like this amplifier with your own hands.

Instructions

Check out circuit diagram antenna amplifier. It is made using a low-noise transistor, providing a gain of approximately 20 dB. At the input, low-pass filters with a cutoff frequency of 115 ... 120 MHz and a filter are connected in series treble with a cutoff frequency of 60... 65 MHz. This allows you to amplify signals from broadcast stations operating in the VHF range.

Make a list of the required parts. In addition to the transistor, you will need several resistors and capacitors, as well as inductors. The parameters of the elements are shown in the figure for step 1.

Take the transistor type KT3120A or KT368A (the second option is less preferable). It is advisable to use imported capacitors in the device, similar in parameters to domestic K10-17. Resistors of the MLT and S2-33 types will be quite suitable for the amplifier. Wind the coils from PEV wire using a mandrel with a diameter of 4 mm. Coil L1 contains 3.5 turns, and L2 - 4.5 turns of wire.

If you plan to use amplifier in a car receiver, add two relays and an additional power filter to the circuit. When power is applied, both relays turn on amplifier between the antenna and the receiver. When the power is turned off, the receiver input is connected to the antenna. Be sure to equip the car version of the amplifier with a metal case.

Prepare for installation of device elements printed circuit board made of fiberglass, foil-coated on both sides. The pattern of the printed tracks may vary (depending on the part layout you choose). Leave the second side of the board metallized and connect it with foil along the contour to the common conductor of the upper side. Make the board for the automotive version of the amplifier more elongated so that you can easily place a power filter and relay on it.

Assembled amplifier connect between the receiver input and the antenna socket, and make the connection with a short shielded cable if possible. When installing the device in a vehicle, place it close to the receiver in a shielded housing.

Check how effectively the device amplifies the signal. If necessary, reduce the capacitance of the capacitors and increase the inductance of the coils (but not more than one and a half times). Please note that in city conditions where the signal level of radio stations is high, the antenna amplifier should be turned off to avoid signal distortion.

Sources:

• make antenna amplifier

To improve the quality of the received image and “catch” previously inaccessible channels, it is not necessary to buy a new powerful antenna. The receiving ability of the antenna depends on various external factors, from the shape and design, changing which you can adjust the image quality.

Antenna location

The quality of the television signal directly depends on the location of the antenna. Concrete walls, metal fences and structures greatly interfere with the passage of the signal, so most often it is located outside the house, on a wall or. If you know where the nearest transmitting tower is, the antenna should be pointed in its direction.

Changing the antenna design

Most often, the antenna design is thought out taking into account the standard search for an on-air signal. It can be changed using any metal object that conducts current: wire, cable, balcony dryer, central heating radiators, etc. Aluminum and copper items with a large surface area are best. Metal objects that are not in contact with the antenna, on the contrary, interrupt the signal.

Some antennas require special adjustments before use. You should check if the frequency range set to receive one or another signal.

Common-mode grating effect

If you take several identical antennas and space them horizontally so that the signal phases in them are the same, you can achieve significant amplification. For example, if a single antenna gives a coefficient of 7 dB, then a double antenna - up to 10 dB, consisting of four parts - up to 12 dB, etc.

Basic rules of the common-mode array: the parts can be purchased or made independently, but must be the same. It is important that the “floors” and “rows” are completely symmetrical, with the same length of lines and cable jumpers. For fixation, frames made of insulating materials, such as wood or plastic, are used.

Determining the reasons why the TV cannot pick up channels

Reasons why the TV cannot receive reception television channels, most often lies in incorrect settings antenna, failure of its amplifier. The reasons for the lack of signal in digital television are also most often problems with antennas.

There are always many reasons why TVs don't pick up channels. They can be the most banal - birds damaged the antenna, to problems with satellite or cable television. But in most cases, when suddenly the TV cannot pick up a single channel, the first thing you need to look for is the antenna. To know for sure why channels are not picked up, you should make sure that the TV video and its matrix are working properly. To do this, you need to connect the TV to some video playback device. If the TV has a good image, it means the video processor is working. Therefore, you should look for the reason in the antenna.

Sometimes this happens. An excellent, correctly oriented and mounted dish antenna, for example, Tricolor, there are many channels. But TV does not work well in bad weather (rain, snow) because... the signal disappears. This happens when a house or cottage is in an area of ​​​​uncertain reception, then there are three options to get a more confident signal. This means raising the antenna higher or purchasing an antenna amplifier.
The second reason when the TV does not pick up signals, it happens, lies in a malfunction in the TV, or rather in the TV antenna socket, which can simply break due to burnout of microcircuit parts. But, most people this problem You won’t be able to solve it on your own.
There are situations when an antenna is installed on a multi-meter rod, and when connected to a TV, the signal disappears after a few minutes of operation. Almost all channels found by auto-tuning disappear. The reason here may be the power supply, because... if it is not adjustable, it may output 15V instead of 12V and the antenna amplifier will burn out. Therefore, when you buy an antenna amplifier, always ask the seller for its part number and check whether it is suitable for your area. Sellers, as a rule, have a coverage map, which allows them to navigate the amplifier numbers and select them according to required power. Also, the reason for the disappearance of the signal may be oxidation of the television cable.

If the TV does not pick up channels when setting up and there is no digital television, then there are a number of ways to eliminate this problem or identify mistakes made. The most common reasons for setting up channels modern TVs, having a great variety of functions built into them, these are the problems associated with the antennas connected to them, such as:
1. Incorrect selection of antenna type.
2. Incorrectly installed structure,
3. No direction vector adjustment to the broadcast station

When TVs do not receive TV channels, you should use alternative methods for connecting digital frequencies, such as satellite set-top boxes or cables. In order to search using a cable, you need to connect wires from cable TV to the connector for connecting TV antennas. In the settings, when you select auto search in the menu, another window appears. When connecting digital TV, we choose not “cable” TV, but “another operator”. Then click on the “Full” item and select the search “digital channels”. We sort the channels using the remote control and put them in convenient positions.
There are still many problems associated with the loss of signals, both television antennas and cable antennas. But many breakdowns or defects can only be fixed by professionals, so you shouldn’t take risks; it’s better to entrust their correction to specialists who have experience, the necessary knowledge and tools.

TV malfunctions