Poor digital TV reception, how to improve it. Digital television in the country

It's hard to imagine life modern man no TV. At the same time, some take full advantage of the advanced smart functionality of receivers, while others choose to watch programs and movies using the old proven method - using digital or analogue broadcast signals. At the same time, the pleasure of watching programs is often spoiled poor quality receiving TV signals. In our article we will try to talk in as much detail as possible about the methods of strengthening them.

What determines the quality of TV broadcasting?

There are several factors that influence the quality of the transmitted image:

• The television receiver is located at a great distance from the signal repeater.
• The presence of external obstacles, both natural and artificial. These can be the walls of high-rise buildings, hills, lowlands and a large number of trees.
• Poor quality connecting cable.
• The antenna is installed in the wrong location or is poorly oriented in space.
• The presence of significant metal structures in the signal path or in the immediate vicinity of a television tower.

In almost each of the listed cases, the leading role is given to the TV antenna. If this attribute is correctly selected and configured accordingly, then there is a real chance of improving the quality of received signals and stabilizing the broadcast.

The industry produces both indoor and outdoor antennas. Where they are installed is clear from their name. Let's look at each type in more detail.

Antennas for indoor use

Portable antennas are quite affordable prices can perform their functions perfectly if the place of their use is close enough to the repeater. This means a distance not exceeding thirty kilometers. And the highest effect can be achieved when the TV tower, as they say, is visible from the window. In this case, the signals will not deteriorate due to multiple reflections from the walls of buildings.

For indoor antennas, it is customary to divide them into two categories, depending on the design features:

1. Frame. This type of antenna has an open metal frame. Their operating range is UHF (decimeter). It includes frequencies from 300 MHz to 3 GHz, but, as a rule, frequencies above 900 MHz are not used for television broadcasting.
2. Rod. “Horned” as they were popularly called. With their help, television signals are reliably received in the meter range (VHF), that is, at frequencies from 30 MHz to 300 MHz.

For effective use indoor antenna it is necessary to find a place where it will work most effectively. This means that it must encounter as many obstacles as possible on the path from the broadcaster to the receiver of television signals.

If all conditions are met, but a high-quality picture cannot be achieved, then you can try using an antenna that has active amplifier. In addition, there are also autonomous signal amplifiers, which we will discuss below.

If the user lives in close proximity to the translator, then he may have to purchase a device diametrically opposed to the amplifier, which is called an attenuator. But it serves to attenuate the signal, which helps prevent picture and sound distortion that appears as a result of a too strong TV signal.

Outdoor antennas

• Half-wave vibrators.
• Wave channels.
• Log-periodic antennas.
• Common-mode antenna arrays.

In order to cover the meter and decimeter ranges, it is recommended to use a combined solution, in which one design contains elements of several of the above types of antennas.

The quality of the received TV signal is directly dependent on the height at which the antenna is installed. A significant impact may be caused by nearby high-voltage power lines.

Depending on the type of signal amplification, there are several other types of outdoor antennas. Passive outdoor antennas belong to the class of the simplest passive devices, since their design does not contain components capable of amplifying the TV signal.

IN active antennas The signal is amplified due to the presence of a special microcircuit in them. Amplifiers can be either built into the antenna structure or independent of it.

Types of antenna amplifiers

When selecting an amplifier TV signal it is necessary to take into account its technical parameters:

• Frequency range. The majority of antennas sold on the domestic market are designed to work with local frequencies. However, there are exceptions.
• Gain. For the meter range this figure is 10 dB, and for the decimeter range - from 30 to 40 dB.
• Noise figure. The recommended size is no more than three decibels.

The secondary parameters in the selection process are supply current (from 30 to 60 mA) and voltage (from 5 to 12 V). There are also differences in the place where the amplifier is located (directly on the receiver or near it).

However, even the use of components High Quality and reliably operating equipment does not always guarantee satisfactory quality of received television programs. This indicator may be negatively affected by low-quality coaxial cable, used for connection, and poor-quality elements for its connection. It is recommended to purchase a cable that has a thick central core and a standard characteristic impedance of 75 Ohms.

In addition, sources of interference in the picture may be Appliances And external sources. The latter are most often radio stations and cellular transmitters. There is only one protection against them - antennas with a narrow radiation pattern.

Antenna reception of signals digital television broadcasting or analog is not significantly different. Just need digital support UHF, provided that there is a DVB-T/T2 receiver in the TV itself. If it is not there, you will have to purchase an external TV tuner.

In conclusion, let's say a few words about satellite dishes. The diameter of their bowls can range from fifty centimeters to five meters. The sensitivity of the antenna is directly dependent on the size. Correctly installing and configuring a satellite dish is not at all easy, and therefore the involvement of highly specialized specialists is necessary to carry out this work.

Reception of digital TV signal (DVB-T2) in extremely harsh conditions.
Due to the greyhound nature of Tricolor, I decided to “finish off” digital terrestrial TV at my dacha.
The first (winter) attempt ended in failure: it worked in cold weather, but at zero and above there was not enough signal. Reasons: in summer the absolute humidity is much higher than in winter, lowland near the river and nearby forest. Let me remind you that my directional relief to the repeater gives a completely “closed interval”, i.e. the signal should not pass through... A relief with a refractive ellipse is attached. A
I bought a highly sensitive receiver (-82dBm) and moved the antenna from the house away from the forest (to the summer kitchen). Now it’s 100 meters to the forest, but it was probably 20 meters (an acute angle towards the repeater).
I bought and connected/stretched 23-25 ​​meters of RG-6U cable.
I installed an antenna lightning arrester at the receiver input. We should probably install it at the output of the amplifier, but we won’t get around to it yet. And at the entrance antenna amplifier It has short circuit By DC, so I think it’s protected well.
Result, in general, positive (compared to what it was before): at 650 MHz the signal strength is 80%, and at 722 MHz - 48%. On both, “quality” is 100%, which I don’t believe. Of course, 48% is not enough, but it works. On the verge. When the receiver warms up and as the play progresses, there are signal interruptions... Moreover, the antenna had to be very precisely aligned in the direction.
I didn’t like it and decided to “finish off” further.
I installed a second amplifier in the house in front of the receiver (an ancient one, from an old antenna).
At the same time, I had to overcome the excitation of the amplifier and the too strong signal.
A strong signal won out over splitters, which is right for me, because I want to distribute DVB-T2 around the house.
Now both multiplexes have a signal level above 90%. And the quality... - see Note-3.
Liked.
Lightning protection:
I attached a meter-long thick aluminum lightning rod to the top of the antenna mast, and organized it through an aluminum-to-copper adapter With his lower part(and not from the bottom of the mast!) a copper descent to the grounding, for which I bought and hammered a galvanized pipe 1.6 meters under the antenna. A steel cable was welded to the same grounding, to which it was tied antenna cable, going from the summer kitchen to the house. Copper to steel pipe - through stainless washers.
Note-1:
It is assumed that the TV (at least) and the rest are grounded, otherwise interference may form at the receiver input (up to 100-150 Volts), which, with the antenna grounded and temporarily open antenna input may (when connected) break through the mast antenna amplifier at the output. And this is not a theory, but a cruel truth of life.
Note-2:
It’s strange that my signal quality indicator is almost always 100%. I do not believe!

Update dated July 11, 2015:
Note to those who insist that reception does not deteriorate when it rains.
The other day we had a wild downpour. So during it, the signal at 722 MHz completely disintegrated, and was added to 650...
It’s clear, because My signal-to-noise ratio is borderline. And the antenna is not the longest-range...
I scratched my turnips and tore up the ones that were lying around old antenna, made 6 directors about 14.5 cm long (this is the length of the directors of the purchased part of the antenna), screwed them to the main antenna. After this, the signal level, deliberately roughened to 50%, rose to 65% (compared to a purchased antenna). How many in decibels, of course, is unknown...
We're waiting, out of the rain!
Update dated July 21, 2015:
Result of antenna modification:
Today we had a very heavy downpour again, both of my Tricolors (I temporarily have two antennas pointing at 36E) went off for 5-10 minutes, and my CETV didn’t turn off for a second...
Here, by amplifying the antenna itself, I raised the signal-to-noise ratio and therefore the signal was no longer “on the edge” and the effect was no longer noticeable. However, the signal level during rainfall decreased from 91% to 72% (at the minimum point).

Now the antenna looks like this:

Addition to the antenna modification results:
There were heavy rains and thunderstorms. I noticed that at the moment of a distant lightning discharge the image is disrupted for 2-3 seconds...
Note-3:
I bought a slightly different receiver from the same company for a friend and was additionally convinced that the almost constant 100% signal quality on my receiver was a fiction. This new receiver"measures" more or less normally. The quality on it (from the same antenna-feeder system) is 60-70%. By the way, its software menu and controls are different.
Apparently, I will shake the manufacturer/representative to provide a software update, which is much better in terms of convenience.
Note-4:
Forum member about static electricity during snowfall from an antenna on the 27 MHz band ( copper wire vertical):
Note-5:

Many of us have heard of active home antennas for TV, but not everyone knows how they differ from passive ones? The difference is that it has an amplifier inside, which requires electrical power from an adapter, power from 9 to 12 Volts. This device can be used to improve the quality of TV channel reception on the antenna. Most often, amplifiers are used in the UHF or meter ranges, but they can also be installed far from the receiver, which is located at a considerable distance.

To improve the quality of signal reception by an antenna, an amplifier is sometimes connected to it. This device is useful when the distance from the TV broadcaster to the receiver is large, or you have chosen the wrong model of satellite or cable antenna. Using the device, it is possible to significantly improve the quality of the picture reproduced by the TV. The location of this device next to the receiver is usually considered correct, because the signal coming from it along the cable is reduced.

An antenna amplifier is a device that can add power to the received signal. Its presence helps you view active broadcast channels in higher quality.

Antenna amplifiers for TV have the most various parameters, and may differ in appearance. In addition, some types of devices are designed for very distant reception, while others are designed for close reception. They are installed next to street or indoor receivers.

Types of amplifiers:

1. Broadband. This type An analog amplifier is designed to improve picture quality on several devices simultaneously (such devices are often installed in apartment buildings and entrances). Such a model can work not only in UHF, but also in the HF range.
2. Multi-band. They provide improved received images from receivers that are installed on high masts. They are used small systems collective reception.
3. Range. Thanks to this species devices can receive a passive signal from particularly distant stations. These range models correct reception, eliminating strong noise.

All types of amplifiers are designed to improve the signal. Your task is to correctly determine which type of device is suitable for your antenna.

Smart device: TV antenna amplifier

Host TV antenna designed to receive from a television center electromagnetic radiation, pointing it at the conductive elements entering the coaxial cable. According to design outdoor antenna manages to obtain and enhance weak signal different power. Based on this, the concept of the direction coefficient of a television antenna is introduced, which shows how many times the output signal level exceeds the signal received from a half-wave vibrator.

An amplifier for a TV antenna helps to obtain a signal of the required strength, which helps proper operation television device. The quality of the image that the board displays on the screen depends on it.

The modern market for television devices presents us with many different models. Because of this, many people sometimes find it difficult to decide which device is best for them.

To make the right choice when purchasing, you need to consider several points:

1. Gain. It is calculated based on the approximate distance between television device and the signal source (broadcasting tower). It cannot be more than 150 km. But at a distance of 10 km or less, there is no need to amplify the signal; you just need to determine a suitable antenna.
2. Antenna type. SWA models are suitable for array receivers. They operate in frequencies from 49 to 791 MHz.
3. Frequency range. An excellent solution for an ordinary outdoor receiver would be to install a broadband variety, only more good result will show the device operating only in certain range frequency

You need to know that the lower the noise figure of the device, the better the picture on the TV screen will be.

How to choose a TV signal amplifier: digital and conventional types

In order for the television antenna to better catch the signal, you can connect an amplifier to it. This device helps improve the quality of reception if the distance to the television center is particularly large, or if you have a weak, bad antenna. Especially often, devices that amplify television signals are installed by residents of the lower floors of high-rise buildings, for summer cottages, and in rural areas.

How to choose a digital TV signal amplifier so that it brings maximum benefit and does not have to be changed? To do this, you need to know the reception level of your antenna and the distance to the transmitting television center.

An amplifier for the TV antenna is installed so that the image stops snowing and the picture becomes clear. Depending on the distance to the transmitting center, it is necessary to select a device for the TV with appropriate gain factors. The longest distance cannot go beyond 150 km. If the distance to the transmitting installation is less than 10 km, then the antenna amplifier is not installed. All you need to do is choose the right antenna.

For correct selection devices you need to know:

• Distance to the nearest transmitting station;
• The frequency range you need;
• The type of antenna you already have.

There is no need to chase maximum gain. Such devices may not operate properly and produce loud noise.

We create a television signal amplifier from improvised means

An indoor antenna equipped with an amplifier makes it possible to provide a high-quality and clear picture on the TV screen, remove noise and find more channels. To do this, you do not have to purchase the device in the store.

It is not at all difficult to make a television signal amplifier yourself. To do this, you can use a variety of available means.

Let's look at an example of manufacturing simple amplifier using beer cans. An amplifier for an antenna of this type can be made in 10-15 minutes. and it will function perfectly. In order to make it, you need to get: a power cable, a plug, two tin cans, a screwdriver, self-tapping screws, adhesive tape/duct tape, a stick like an old wooden trample.

Stages of creating a device for signal amplification:

• We connect the beer cans and the stick using electrical tape. You need to ensure a distance between the cans of somewhere around 7-7.5 cm. If the cans have rings, it is easiest to attach the cable to them.
• We screw self-tapping screws into the cans. To do this, we strip the ends of the cable and attach it with screws.
• Using adhesive tape, we connect the stick and the wire to give the device stability.
• Cover the jars with a large plastic flask with the bottom and neck cut off.
• We make a hole in the middle of the container. It will be possible to pull the cable through it.
• When you assemble the device, pour a little boiling water onto the nylon bottle. It will help change the shape of the plastic bottle and ensure a good seal of the hole.
• We connect the device and configure it. This block you need to configure it so that it works flawlessly.

If desired, you can improve the design by adding several sections to it.

What is a TV signal amplifier (video)

Often, even in the city, when used regular TV there are problems with the signal Polish antenna. To avoid this problem, you can connect cable or satellite television. For those. Those who do not have the opportunity to install expensive equipment must connect an antenna amplifier. This device will be useful when the TV tower is too far away, or you have chosen the wrong antenna. This device can be purchased ready-made in a store, or made independently. The main thing is to correctly determine the power of the existing television antenna and the distance to the nearest populated area.

You will need

• - alcohol-containing cleaner;
• - soldering iron;
• - new tv cable;
• - programs to improve signal quality

Instructions

Research TV cable. His protective layer must not be violated. Very often during repair work the cable is accidentally touched. Its integrity is violated. Because of this quality transmitted signal noticeably . If your cable is very old, it should be replaced. The fact is that over time, wires begin to lose their chemical and physical characteristics. The level of current conductivity decreases. And this entails deterioration signal. Additional unnecessary connections should also be avoided. If the cable is too short, then you should not extend it or insert it, as the connected wires may have different cross-sections and characteristics. If you decide to extend the cable, then the connection point is necessary. Then the loss of transmitted current will be minimal. Also, do not forget to carefully insulate the joint.

Buy a powerful receiver. When connected to a satellite dish, this device will significantly increase quality received signal. An alternative is an antenna amplifier. It is best to buy such an amplifier with separate power supply to get a cleaner signal. It is recommended to connect amplifiers and satellite dish via network filter. The fact is that constant slight fluctuations in current have a detrimental effect on such devices, and an unexpected sharp jump can not only create interference on the screen, but also damage the amplifier and dish.

Try changing direction or satellite dish. If you receive a signal using external antenna, then find out the location of the nearest television tower relative to your home. The higher you live, the easier it is for the signal to reach you. If you live on the lower floors, ask permission to install your own antenna. Try to install the antenna on the side closest to the television tower. When connecting, carefully check all wires and connections. The plugs on the cables must not be oxidized or dirty.

Install special programs to improve picture quality if you are watching TV channels using a computer. Currently, there are a considerable number of programs freely available on the Internet that allow you to stabilize and improve the signal. Much also depends on TV tuner. Please consult a professional before purchasing this appliance. It’s better to overpay a little, but buy good model, which will give an excellent signal.

The level of a television signal depends on many parameters. If the connection occurs via wired technologies, then the quality problem is most often solved by troubleshooting the wires. If you have satellite antenna, here it is quite possible that you may need optional equipment.

You will need

• - adapter or receiver.

Instructions

If you use cable television and when viewing problems were discovered related to the deterioration of the quality of the transmitted signal, check the condition of the cable. If its integrity has been compromised, purchase a special adapter at radio equipment sales points.

Cut off the damaged section of the cable and connect both sides to the purchased adapter. You can also observe signal deterioration associated with improper cable repair; this happens if, instead of using an adapter, you simply covered the damaged area with electrical tape, but this should not be done. The most correct solution to this problem would be to call a specialist to your home. Also, in the future, monitor the condition of the cables, and it is best to hide them under the baseboard.

Instructions

Please note during installation antennas terrain characteristics. Guaranteed television reception area signal but it depends on the terrain. If possible, install the antenna on the most high point adjacent to your home. To ensure the required height antenna device if necessary, use an additional mast, securely strengthening it with guy wires.

Choose the optimal reception design antennas. The requirements for it are as follows: simplicity and reliability, sufficient spatial selectivity, the ability to pass a wide frequency band, low input impedance and high gain signal A. For an area of ​​uncertain reception, the level ratio is also of particular importance signal and to the level of interference.

If you are at a short distance from the telecentre (several tens of kilometers), use it to improve the received signal and an antenna of the “wave channel” type with a simple or loop vibrator, consisting of three elements. Antennas of this type are produced by industry, but if you have minimal amateur radio skills, you can make it yourself.

Check for correct installation antennas and configure it. To do this, select the optimal ratio of element sizes antennas required for admission signal and the selected stations. Correctly orient the structure in space by aiming the antenna at the broadcast center or repeater.

Use for improvement signal a special antennas th amplifier. The dimensions, design and connection method of such a device can be very different. When choosing an amplifier, pay attention to the information indicated in technical documentation frequency characteristics and noise level. Setting up the amplifier used for specific model TV receiver, have it done by a professional. Otherwise, the efficiency of the device will be low.

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

Almost any antenna can be equipped with a special television signal amplifier. It operates on a 220 V network; you can buy the amplifier at most electronics stores. For the right choice it is important to know some parameters: noise figure (it should be as low as possible, preferably no more than 2 dB), gain Ku (calculated based on the presence of branches and its length).

Most often, the antenna design is thought out taking into account standard search 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 work best. Metal objects that are not in contact with the antenna, on the contrary, interrupt the signal.

Some antennas require special settings before use. You should check whether the correct frequency range is set to receive a particular 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.