DIY simple antenna for fm radio is a great way to enhance the quality of the received radio signal. First, let's figure out how to replace the standard antenna with a dipole one.

Most modern radios are equipped with sockets for connecting conventional antennas - both built-in and external telescopic. You can make a high-quality radio antenna without resorting to high costs, just a single visit to an ordinary hardware store is enough, and, of course, you need to know what you can use to make an antenna for a radio.

Materials for work

• Ceramic insulators and elements for their connection. They are necessary in order to prevent the antenna cable from closing to adjacent surfaces. These devices can be purchased at any radio market or found in some abandoned building.
• Thin steel wire for connecting insulators.
• Roller blocks required to secure the external radio antenna in a taut position.
• Antenna plug.
• Two-position switch, designed to protect against thunderstorms.
• A coil of copper wire with a diameter of 1.5 to 2 millimeters. You can, of course, use steel wire, but copper is much more pliable and more convenient.

Antenna type

Now let's decide on the type of radio antenna to be assembled. There are three main types of antennas for an FM receiver, suitable for DIY assembly, the diagrams of each of them are shown below:

• Linear antenna
• Traveling surface wave antenna
• An aperture antenna, that is, a swing antenna.

Instructions on how to make an antenna

Installation of any horizontal type antenna begins with the choice of a support, to which we will subsequently attach the insulators. The first support should be on the roof of the house, and for the second, you can choose a tree with the appropriate height. We attach the insulators to the posts using steel cables.

The outer part of the antenna should not be pulled too tight, as when the air temperature drops, the wire contracts and can break.

Roller blocks are used to reduce vibration. To use them, you need to fix a small weight on the opposite end of the wire by connecting it to the antenna.

The receiving element of the future antenna should be a single piece of a single material. If a whole piece of wire is not available, then you can combine several elements from a single material by stripping and soldering with tin solder.

The mount for the vertical antenna receiving element is a stand that excludes the change in the position of the wire during strong winds.

If there is very little space for placing the antenna, then the design can be modified: we cut the wire into several pieces and connect the end of each of them with molten tin to the cable. The soldering point must be reliably insulated. Below is a photo homemade antenna suitable for fm radio.

The best replacement for the trap would be a homemade indoor antenna. In this case, the insulators are mounted indoors, while as close to the ceiling as possible (this is recommended to improve signal reception), and the wire is pulled horizontally or rolled in a spiral.

Manufacturing of a resonant frame antenna

Such antennas are often used by mechanics to receive shortwave signals. For directional signal reception, the antenna is simply turned in the desired direction. Such designs allow receiving radio signals much clearer thanks to the magnetic elements.

So how do you make a similar fm radio antenna at home? First you need to find an aluminum hoop with a diameter of 77 centimeters and a cross section of 17 millimeters, which can be obtained from any sporting goods store.

If you still can't find the hoop, you can use plumbing pipes made of plastic and metal, or a copper tube with a diameter of 1.6 cm.

The assembly sequence for such a design is extremely simple:

• We solder the central core, the winding and a piece of coaxial cable to the contacts of the variable capacitor.
• The other end of the cable, the central core and the winding are soldered to the aluminum hoop. You can also use a car clamp, which must first be cleaned at the pairing point.
• The dimensions of the structural elements are calculated so that the length of the frame, in this case the hoop, is five times the length of the tie loop.
• Remove the insulation layer from one end of the cable and from the central core by about one centimeter.
• We remove the insulation in the middle of the cable, having previously canceled from it 5 millimeters in each direction. Then we remove the cable sheath, since the above actions will lead to its rupture.
• We adjust the range of our radio receiver so that the structure has a resonance of 5-22 MHz. With a different value of the capacitance of the capacitor, the parameters of the receiving-transmitting device can be changed.
• The frame parameters can be changed depending on the desired receive range. So, for the reception low frequencies the diameter of the hoop is chosen within one - one and a half meters, and for high-frequency reception - 70 centimeters.

These simple rules will allow you to build a device that can work in different bands.

conclusions

We have presented to your attention the simplest and most popular ideas and drawings of antennas for fm radio, suitable for hand-made assembly. Most of these structures are extremely simple in both installation and operation, and will allow you to easily solve many everyday tasks.

Photo antenna for fm radio

Cassette recorders today can only be found in rare cars, but modern cars are equipped with more serious systems that play the role of whole multimedia complexes capable of performing hundreds of different tasks. Nevertheless, drivers love to listen to the radio and watch TV on the road just as before. Unfortunately, most inexpensive radio tape recorders with good functionality stop "catching" radio stations as soon as the car enthusiast leaves the city limits. The sound becomes distorted and bouncing, image synchronization is disturbed, and noise appears. These signs indicate that the signal has become worse and soon you will have to drive on the highway in complete silence.

It should be said right away that even the most advertised brand will not guarantee you a high-quality radio signal. Therefore, if you like to listen to the radio on the road, then buying a more expensive radio will not help. It is better to purchase a tape recorder with an antenna and supplement it with a special amplifier.

Antenna amplifier

An antenna amplifier for a car radio can be bought ready-made or you can make it yourself. When choosing a model, you must focus on the following characteristics:

• the frequency response should be uniform;
• the device must operate in a wide range, regardless of temperature and power;
• minimum "noise";
• the gain factor should be about 15-25 decibels. A lower value will not improve the reception quality.

It is better to buy amplifiers that can be installed on the antenna itself. If the device is located in the area of ​​the antenna input, it can lead to an increased noise-to-signal ratio, which will undoubtedly affect the sound quality.

Most Popular Amp Models

And they are not. An example is the amplifier of "domestic" production "Triada 304". Such an amplifier costs about 650 rubles. The reviews about this amplifier, let's say right away, are not the best. Judge for yourself what good can be in it if it is empty inside.

Most likely this miracle, registered under a Russian name, was produced wherever you think ... And there are a lot of such amplifiers.

The antenna with a built-in amplifier "Bosch Autofun Pro" has earned positive reviews.

Only here is the catch. Here are the photos. One antenna is "left" (left) and the other is the original (right). One catches nothing, and the second one perfectly caught 100 km.

DIY antenna amplifier

Antenna amplifier for car radio is a device that you can make yourself. For this, a classic two-stage circuit with 8 main resistors is used. Elements R1, R2, R4 and R6 in this case will stabilize the changes in the transistor VT1 if at some point there is a voltage surge or the temperature rises sharply. All components must be selected so that the maximum amplitude and frequency characteristics of the device are provided.

In addition, transistors of the bipolar type 2SC2926 are often used in amplifiers, at a frequency of less than 1 GHz. This will reduce the noise level from the amplifier itself. All components of the two-stage circuit must be soldered on the board in the correct sequence. After assembly, you need to connect the amplifier input to the antenna input, and send the output to the radio receiver. To do this, use a cable with a resistance of at least 75 Ohm. It is important to observe the polarity.

It is better to organize power supply with a network with a voltage of 12 volts. After that, you can connect the made board to the radio (ANT output). So, the amplifier will start working as soon as you turn on the car radio.

Curious, you can try to make such an amplifier. As you feel, unsubscribe.

In custody

If we talk about what is better - a ready-made antenna amplifier for a car radio or a homemade one, then it is worth noting several advantages of each of the options. The finished device is inexpensive and you just need to connect it. In turn, homemade device does not require special skills and knowledge, but at the same time it allows you to get a clearer signal and reduce interference.

An antenna radio amplifier is necessary in order to ensure reliable and uninterrupted reception of radio waves without interference in all directions. Despite the fact that in recent years, car audio manufacturers have been producing car radios with high functionality, this is not enough for high-quality radio reception, especially outside the city limits.

1 What properties should a quality amplifier have?

Very often, motorists, succumbing to advertised brands, seek to acquire a "super-sophisticated" antenna, the manufacturer of which claims the high capabilities of the device for receiving radio signals. Usually, real work the device is far from the promises of commercials.

In order to catch radio in the entire frequency range, a high-quality antenna amplifier is enough. When choosing it, one should focus primarily on the maximum possible reception of a high-quality signal in a certain area. In addition, it is assumed that the power of the radio signal amplifier will completely cover the entire broadcasting frequency range.

A high-quality antenna amplifier for a modern car radio should:

• maintain the operating mode even under conditions of a wide range of powers and temperatures;
• have a high dynamic range to prevent overloading due to high input signal levels;
• be characterized by a minimum noise figure;
• have a coefficient of reinforcing properties of the order of 15-25 decibels;
• cover the entire range of existing frequencies with the operating band of the amplifier.

Thus, when purchasing a device or making an antenna amplifier with your own hands, it is necessary, first of all, to pay attention to the possibility of installing it on the antenna itself or in the immediate vicinity of it.

If you install a part near the antenna input, this can provoke an increase in the "noise-to-signal" ratio, while high-quality reception of frequencies may even be difficult in some areas.

2 How to choose the right antenna amplifier?

Amplifiers offered on the market from various manufacturers are usually assembled in a two-stage scheme, however, their operation in different ranges may differ from each other. Such devices are designed to increase the signal, and almost all car owners who have installed this part on their car note a significant improvement in reception.

All antenna amplifiers found on store shelves must comply with communication system standards and be certified in accordance with GOST.

Regardless of the quality and cost of the device, there are a number of side factors that, under certain circumstances, can affect the reception of the radio signal. Among them, the following should be highlighted:

• Signal overload in urban areas. To avoid radio interference, it is recommended to turn off the amplifier or set the minimum gain.
• Using an amplifier with an active antenna. This combination leads to the opposite effect and degrades the reception level.

3 Overview of popular models of antenna amplifier

Perhaps the most popular amplifier for a car radio among domestic manufacturers is the "Triad 304" model. Among the advantages of the device, one can single out a relatively low price, decent quality and optimal functionality, the ability to turn off amplification in the zone of a confident signal.

As for amplifiers of foreign origin, the most popular are devices manufactured by Prology. For example, a model such as the TFB-100 is capable of operating simultaneously with several antennas and qualitatively amplifying signals from the digital and analog ranges with equal accuracy.

In addition to the models presented, there are also a huge number of manufacturers of similar devices, each of which seeks to surprise car owners with their "chips". However, many motorists prefer to make a radio antenna amplifier with their own hands, using the classic two-stage circuit and special kits for self-assembly. Such sets are produced by Master-Kit and others.

4 Making an amplifier in a two-stage circuit with your own hands

A DIY amplifier for a car radio is performed according to the classical scheme with eight main resistors. Thus, resistors R1, R2, R4 and R6 are designed to stabilize changes in VT1 transistors in the event of voltage or temperature changes. The elements in the circuit are chosen to provide the maximum characteristic of the amplitudes and frequencies of the amplifier.

In addition, the circuit uses special biopolar transistors of the 2SC29 type with a frequency of less than 1 GHz. This minimizes the amount of noise generated by the amplifier itself. All elements of the two-stage circuit are mounted on a special board using soldering. You can solder the elements with your own hands or contact an electronics specialist who will conduct the connection in the correct sequence according to the diagram. The board can be purchased from a set of parts from the same Master-Kit company. You can find the part in specialized stores.

After assembling a homemade radio amplifier, it is necessary to connect the contacts: the amplifier input with the antenna input, the output using a special cable with a resistance of at least 75 Ohm goes to the radio receiver. The cable can be additionally insulated and fixed directly on the board with clamps, passing them through specially provided holes. It is very important to strictly observe the polarity when connecting the amplifier to the power supply of the vehicle itself.

For power supply with the network, it is better to use a voltage of 12 volts and connect the board to the output of the ANT radio tape recorder. In this case, the voltage will be supplied when the car radio is turned on. If you are installing the device from the outside of the car, you should take care of additional insulation and airtightness of the case, but it is better to install the RF amplifier close to the antenna.

The advantage of self-manufacturing of the part is that, if necessary, you can change the circuit and get a clearer signal at the output and minimize the amount of interference that occurs.

Sometimes, due to a poor-quality radio receiver on the car radio, you have to buy separate HF amplifiers for normal radio reception. At the same time, it is quite difficult to choose such amplifiers, given that there are now a lot of cheap Chinese products on the market that do not really work.

Once I was given such an amplifier for repair, or rather, so that I assemble a normal amplifier in the same case.

I would like to present the design of a cheap FM amplifier for a radio receiver.
It turns out that this is not an amplifier at all, but God knows what. The circuit consists of only pairs of transistors, moreover, one of them is just for flashing the LED.

Power is supplied from on-board network car 12 Volts and…. nothing happens, only the LED indicator is on and that's it - no other reactions from the car radio are observed, with or without an amplifier - the reception is the same.

The photo shows the board of such an antenna amplifier, mind you - I did not repair anything, and I did not touch the board at all, but bloopers are visible on the board - a large piece of solder, it is not clear why, an extremely dirty board, oxides everywhere, and generally a non-working useless thing.

The price of such an amplifier is around 200 rubles, in exchange for a penny you can assemble an antenna amplifier at home. A couple of working circuits of such amplifiers are presented below.

These schemes are very similar to each other, there are very few differences. Both have been tested and are quite workable options, they are clearly more useful than Chinese trinkets, and they also do not contain scarce components.

The entire element base can be found in an old radio or radio tape recorder. Just one low-power transistor KT368, which can be replaced with any other RF transistor, the SS9018 / C9018 is perfect from imported analogs - in theory, the same thing.

And I also want to note one point, if you decide to buy a bike, for yourself or for your children, then I would like to recommend Pegasus. An excellent ratio of price and quality is offered by the Ultrasport company.

You will need

• - a piece of wire several meters long;
• - plug;
• - metal clip for curtains;
• - soldering iron, solder and neutral flux;
• - OIRT-CCIR converter;
• - antenna amplifier or active antenna.

Instructions

In some cases, unstable reception in the VHF range is due to the low sensitivity of the receiver or radio. It should be noted that there is no dependence of this parameter of the device on its price. Try to receive the same station in the same room with several receivers - the one that will provide the most reliable reception is the most sensitive one.

It is possible to indirectly determine the mediocre quality of the radio path of a receiver by the presence of an antenna socket, despite the fact that it has an antenna. If there is a socket, the manufacturer could have added it precisely in order to compensate for the low sensitivity.

An external antenna is a piece of wire several meters long. Unwind it completely. To one of the ends of the wire, solder either a plug, the type of which corresponds to the type of socket on the receiver, or a metal clip for curtains, put on the telescopic antenna. So that such an antenna does not need to be supplied with lightning protection, in no case make it external.

Sometimes the following tool can help improve FM reception. Wind about 20 turns of insulated wire directly over the sheath of the coaxial cable going to yours. Connect one of its ends to the receiver in the manner indicated above.

Pocket players, mobile phones are used as FM radio stations or headsets. Change this accessory to another one with a longer wire, or grow it yourself if you know how to do it. The quality of reception and the number of received radio stations will increase significantly.

Often, even in the center, the receiver receives very few radio stations just because it is designed for the VHF-1 range (65 - 74 MHz), while most stations today operate in the VHF-2 range (88 - 108 MHz). Rebuilding the device from one range to another is a very painstaking operation, so you should only take on it if you have the necessary experience. In the absence of such experience, a special attachment will help - the CCIR-OIRT converter. This device is commercially available on radio markets.

You can improve the quality of reception in the FM range of a car radio using an antenna amplifier or an active antenna. When choosing this device, it should be remembered that often under the guise of such amplifiers "dummies" are sold, in the cases of which there is nothing but a resistor and an LED. Therefore, they should be purchased only in company stores.

Some people like to use the car radio at home by connecting it to the power supply and speakers. There is a misconception that in this case it will work well even without an antenna. But, having connected even a very short antenna to the radio tape recorder, everyone can be convinced of the opposite.

Walkie-talkies are very popular among people who constantly need to keep in touch with each other. These are security guards, taxi drivers, truckers. Use mobile phone unprofitable through high tariffs. But in such cases, it is necessary that the radio be quite powerful so that you can talk without restrictions.

Instructions

If you need to increase the range of the radio, replace its helical antenna with a four-wave special pin, which can be bought in any market. You can also use and coaxial cable which will significantly increase the signal. Replacing the antenna is necessary because manufacturers often set the maximum range within a kilometer radius.

The next step is to adjust the frequency of the walkie-talkie in the most optimal way so that it sends the signal to the greatest possible distance.