Antenna amplifier for TV channels do it yourself. How to improve the reception of a TV antenna

  1. Antenna location
  2. Antenna design change
  3. Common mode effect

TV is in every home. But it is not always possible to receive your favorite TV show with a good image quality: either the telecentre is located far enough, or its transmitter emits a not very powerful signal on the air, or the conditions do not allow orienting the receiving TV antenna to the telecentre. To improve the reception of the TV signal will help antenna amplifier .

TV is in every home. But it is not always possible to receive your favorite TV show with a good image quality: either the telecentre is located far enough, or its transmitter emits a not very powerful signal on the air, or the conditions do not allow orienting the receiving TV antenna to the telecentre. To improve the reception of the TV signal will help antenna amplifier. It is usually located on the roof near the receiving antenna, but not everyone has the opportunity to place a useful device on the roof or attic, so the amplifier is usually located in the room, not far from the TV. The article provides descriptions of two proven antenna amplifier circuits. Both devices amplify the entire transmitted television signal spectrum: meter and decimeter waves. As a rule, additional amplification is required for new decimeter channels broadcasting on "moderate" power.
Broadband antenna amplifier is designed to amplify television signals, both in the meter and in the decimeter range. It does not need balancing and tuning. The amplifier has two identical amplification stages (10 dB), performed on low-noise transistors T1 and T2 (S790T) with their inclusion according to the circuit with a common emitter and amplitude-frequency response correction circuits in the received frequency band (R1, C3) and (R5, C5 ). Although the transistor is also imported, it is very easy to find it for sale on the radio markets and in the stores of radio components.

Specifications amplifier
Gain: 20 dB.
Power supply: 9 ... 12 V.
Input / output impedance: 75 ohms.
The dimensions of the printed circuit board: 55x55 mm.

The dimensions of the printed circuit board: 55x55 mm

Fig. one. General form antenna amplifier 30 ... 850 MHz

Table 1. List of radio components for amplifier assembly:

You will need

  • - Antenna amplifier and power supply for it;
  • - antenna splitter;
  • - antenna cable 75 Ohm;
  • - Ohmmeter;
  • - soldering iron and materials for soldering;
  • - materials for sealing the hole in the wall.
  • - antenna connectors;
  • - antennas of various designs.

Instruction

Do not use room antenna if your home is equipped with a collective. Install a special branching device (KRAB - subscriber cable household splitter) and with its help, give a signal with collective antenna to those of your existing TVs, which previously operated with indoor antennas.

If it is impossible to use a collective antenna, check whether the frequency range of the room antenna corresponds to the frequencies of the channels you are watching. For example, if you prefer decimeter channels, it makes no sense to try to receive them with good quality using a meter antenna, and vice versa. Telescopic antennas allow not only changing the position of the knees, but also adjusting their length, and one should not think that they should always be fully extended. The higher the channel frequency, the shorter they should be extended. Excessive length can worsen reception as well as insufficient, and it is best to select it by experience.

Connect the indoor antenna to the TV not directly, but through a special antenna extension cable. This will allow her to move around the room. Find the position that provides the best reception. Sometimes it is useful to place a video recorder with a tuner near the antenna, and connect it to the TV with a long low-frequency cable. This will allow to avoid interference if their source (for example, a computer) is located near the TV.

In case the movement of the room antenna failed to improve reception, use an outdoor one. Place it on a wall opposite the television station, protect it from atmospheric precipitation, seal the cable entry into the room. In a private house, the best place for an outdoor antenna is the roof. In no case do not use an outdoor antenna in the event that your home is not within the range of a lightning rod.

While in the zone of uncertain reception of a telecentre signal, use an antenna with an amplifier. Having bought a set of an amplifier and an antenna compatible with it, fasten the board with two screws designed for it, and connect a coaxial cable to the board itself. On the opposite side, connect to it instead of the usual plug a special one designed to supply the power supply voltage for the amplifier to the cable and at the same time prevent this voltage from entering the TV. Such a plug with the power supply is included in the scope of delivery of the amplifier.

Instruction

Take into account when installing the antenna terrain characteristics. The zone of guaranteed reception of a television signal depends on the terrain. If possible, install the antenna at the highest point adjacent to your home. To ensure the required height of the antenna device, if necessary, use an additional mast, having securely fastened it with wire braces.

Choose the optimal design of the receiving antenna . The requirements for it are: simplicity and reliability, sufficient spatial selectivity, the ability to pass a wide frequency band, a small input impedance and a high signal gain a. For the area of ​​uncertain reception, the ratio of signal a to noise level is also of particular importance.

With a small distance from the telecentre (several tens of kilometers), use an antenna with a simple or loop vibrator, consisting of three elements, to improve the received signal . Antennas of this type are produced by industry, but with the minimum amateur radio skills, it can be produced on its own.

Check the antenna installation and configure it. To do this, select the optimum ratio of the dimensions of the antenna elements required for receiving the signal from the selected stations. Correctly orient the design in space, aiming the antenna at the broadcasting center or repeater.

Use a special antenna to enhance the signal . The size, design and method of connecting such a device can be very different. When choosing an amplifier, pay attention to the frequency characteristics and noise level indicated in the technical documentation. Configure the amplifier used for a particular model of television receiver, entrust the professional. Otherwise, the effectiveness of the device will be low.

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

Antenna location

Quality television signal depends on the location of the antenna. Concrete wall , metal fences and structures greatly hinder the passage of the signal, so most often it is located outside the house, on a wall or roof. If it is known where the nearest transmitting tower is located, the antenna should be turned in its direction.

Antenna design change

Almost any antenna can be connected to a special amplifier of a television signal. It works on 220 V, you can buy an amplifier in most electronics stores. To make the right choice, it is important to know some parameters: noise ratio (it should be as low as possible, preferably not more than 2 dB), Ku gain (calculated based on the presence of cable branches and its length).

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

Some antennas require special setup before use. It should check whether the frequency range is set to accept a particular signal.

Common mode effect

If we take several identical antennas and spread them horizontally and vertically in such a way that the phases of the signal are the same in them, then we can achieve a significant gain. For example, if a single antenna gives a factor of 7 dB, then a double one - up to 10 dB, consisting of four parts - up to 12 dB, etc.

The basic rules of the common-mode grille: parts can be purchased or manufactured independently, but necessarily the same. It is important that the “floors” and “rows” be completely symmetrical, with the same length of lines, cable jumpers. For fixing, frames of insulating materials, such as wood or plastic, are used.

You will need

  • - alcohol-containing cleaner;
  • - soldering iron;
  • - New TV cable;
  • - programs to improve the quality of the signal

Instruction

Explore the TV cable. Its protective layer must not be broken. Very often during repair work the cable is inadvertently touched. His integrity is broken. Because of this, the quality of the transmitted signal drops noticeably. If your cable is very old, then it should be replaced. The fact is that over time, the wires begin to lose their chemical and physical characteristics. The level of conductance is reduced. And this entails a signal degradation. Additional unnecessary connections should also be avoided. If the cable is too short, then you should not build it up or insert it, so the connecting wires can have different cross-sections and characteristics. If you still decide to ramp up the cable, the junction must be soldered. Then the loss of the transmitted current will be minimal. Also do not forget to insulate the junction carefully.

Get a powerful receiver. When connected to a satellite dish, this device will significantly improve the quality of the received signal . An alternative could be an antenna amplifier. This amplifier is best bought with separate power to get a cleaner signal. It is recommended to connect amplifiers and a satellite dish through a surge protector. The fact is that the constant minor fluctuations in the current have a detrimental effect on such devices, and an unforeseen sudden jump can not only interfere with the TV screen, but also damage the amplifier and the dish.

Try changing the direction of the antenna 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 your neighbors on top for permission to install your antenna. Try to install the antenna on the side that is closest to the television tower. When connecting, carefully check all wires and connections. Cable plugs must not be oxidized or dirty.

Install special programs to improve image quality if you are watching TV channels using a computer. Currently, there is a considerable number of programs on the Internet that allow you to stabilize and improve the signal. Also much depends on the TV tuner. Before buying this device, consult with a specialist. It is better to overpay a little, but to get a good model that will give an excellent signal.

The level of the television signal depends on many parameters. If the connection is through wired technology, the quality problem is most often solved by troubleshooting wires. If you have a satellite dish, here, quite possibly, you may need additional equipment.

You will need

  • - adapter or receiver.

Instruction

If you are using cable television and when viewing problems were found related to the deterioration of the quality of the transmitted signal, check the condition of the cable. If its integrity has been violated, purchase a special adapter at radio outlets.

Cut the damaged part of the cable and connect both sides to the purchased adapter. You can also observe a deterioration of the signal associated with improper repair of the cable, this happens if instead of using the adapter, you simply taped the damaged area with tape and you cannot do it. The most correct solution to this problem is to call the master on the house. Also in the future, monitor the condition of the cables, and best of all hide them under the plinth.

I saw a couple of publications on the Internet today that offer simple actions to improve reception quality. To be honest, doubts immediately arose as to the suitability of such actions for television, nevertheless, I propose to look at it, since, at a minimum, this is interesting.


I propose, on my own, for 10 minutes, for free, to assemble a non-weighing foldable travel antenna for any USB receiving device (signal gain up to 60%).

  1. We take the box from any CD.
  2. We tear out and throw out the inner insert under the disk.
  3. We open as shown in the photo and try on the usb port of the laptop.
  4. We cut a hole in the lid of the box under the usb with the help of an awl or a nail heated above the stove (a knife and a handsaw will not help — plastic crumbles).
  5. We make two small holes on the side in order to fix the cover in the open position with a clip.
  6. We take aluminum foil and wrap the top and bottom of the box. If there is no foil at hand, then cut two cans of beer and turn them upside down with a mirror layer (glue or hot-melt adhesive).

Insert when needed.

For an ordinary PC, you can use a usb extension cable, placing it in the same hole with hot melt glue.

Although the author mentioned TV tuners, in fact - this is unlikely. If only because the antennas of TV tuners are usually external. But for Wi-Fi and 3G / GPRS-modems, the idea, in principle, can be workable. But it all depends on a bunch of factors. The signal is uneven and such a device can both improve and worsen the situation.

The principle of operation is probably - signal amplification due to a smaller reception angle - direction to the near station. The standard receiver has a circular direction for versatility, this device can be limited and sent to the source. The back diagram will be cut off and, thus, omnidirectionality will decrease and the signal will increase. The narrower the angle, the higher the gain.

Additionally, this device can work as a reflector, increasing the reception area. This in theory also enhances the signal. The larger the antenna, the better the gain.


Remove TV interference, increase the signal level by 20% and the brightness of the colors will help filter barrel. It costs only 30-50 rubles, depending on the thickness of the TV cable. You can buy it at any radio market or in stores of radio components. The installation is even primitive for a child - put a barrel on the cable 2 cm from the plug and snap it. It will not interfere even with those who have cable TV in the house, since there are no many colors. After installing this chip in a private house on a conventional antenna, noise went off and 3 additional TV channels were caught.

After installing this chip in a private house on a conventional antenna, noise went off and 3 additional TV channels were caught

There are two options here. Firstly, it may not be effective at all. If the TV cable is of high quality with a good shielding sheath, then what's the difference about it hanging on top Secondly, the advice can be harmful. Such a "filter barrel", on the contrary, can cause losses, because the carrier frequency of the signal is just comparable to the frequencies of electrical noise. Such filters, like, are used in low-frequency circuits and power supplies.

On the other hand, it is not difficult to try. The author reports that the effect was. Will try, please write in the comments.