DIY FM antenna: types, how to make, how to connect, reasons for signal attenuation

Features of radio wave propagation

Before turning to step-by-step instructions on how to make an antenna yourself, it is necessary to clarify the features of radio signal transmission in the VHF and FM bands.
This will help you better understand the principle and design of the antenna. Important to remember:

• reception of a high-quality signal is possible only within visibility (for example, when a television and radio tower is visible from the window of a house);
• capturing a signal at a great distance from the broadcasting object in the evening and at night is problematic;
• precipitation weakens or completely interrupts signal transmission.

Types of antennas

Any device that receives radio waves has a sensitivity threshold. If the received signal is lower than this, the sound volume and quality will be poor. The radio wave weakens when moving far away from the transmitting station or due to deteriorating weather. This is especially true for the FM and VHF bands due to the characteristics of wave transmission. To overcome these difficulties, strengthen and improve the signal quality, any radio needs an antenna. Their design features and dimensions are determined by the range of the receiver: there are multi-kilogram antennas with coverage of thousands of square meters. km and simple homemade crafts in the form of wire above the ground.

The whole variety of antennas for radio stations is divided into directional and non-directional, as well as mobile and stationary. Directional ones work on the principle of connecting point to point or point to many points within 50-100 meters. Non-directional ones have coverage over the entire area around them.

There are also such radio antennas as:

• Rod - in the form of a regular rod or a rounded shape;
• Wire – curved in various required positions;
• On once fashionable boomboxes and music centers you can find telescopic antennas - folding structures made of metal rods, reminiscent of telescopes;

Telescopic antenna

• A retractable antenna is available on almost every car; its advantage is that such a retractable structure can be installed anywhere in the car (roof, fender, etc.), the receiving element is a removable rod with anti-noise winding, which allows you to make the radio sound clear and loud even at high driving speeds. The rod goes into a plastic casing, where there is a stainless steel spring, which retracts the antenna into place when it is deflected in the direction of travel.

Regardless of the type or type of radio antenna, their operating principles are the same.

Note! Quite often, the quality of a radio signal does not depend on the type and condition of the antenna for a radio receiver or music center, but on the technical capabilities of these devices themselves with their receiving chips.

What types of antennas are there?

Radio antennas are divided by purpose:

• for home detector receivers and music centers;
• automobile;
• aviation;
• special (satellite communications, military).

Trapping devices vary in range - from ELF (extremely low frequencies) with a wavelength of 10,000 km or more) to HHF (hyperhigh frequencies) with an oscillation size of 0.1-1 mm.

Frequencies used for broadcasting are 148.5 kHz - 108 MHz.

FM radio stations cover 88-108 MHz (ultra-short 3-meter waves).

The following designs are used in everyday life:

• devices with a reversal - aperture antenna;
• products with traveling wave;
• linear devices.

Antennas are classified according to shape and material into:

• telescopic;
• frame;
• pin;
• wire;
• rod;
• foil;
• coaxial.

According to the directional pattern, structures can be narrowly directed and circular. Based on the bandwidth, narrow- and broadband devices are distinguished.

Antenna options

All types of radio antennas can be divided into mobile and stationary, they can also be directional and non-directional.

Directional ones are characterized by orientation to a specific point (signal source) in space; they operate over short distances (50-100 m). Omnidirectional are focused on the signal over the entire surrounding area.

The antenna can also be rod, wire or telescopic. The latter is a folding structure reminiscent of a multi-legged fishing rod. Such models are often found on tape recorders, stereo systems, and cars.

Whatever the type of antenna, the principle of operation of the devices is the same.

Peculiarities

Do not forget that the signal tends to deteriorate and sometimes disappear completely at night, and also depending on weather conditions. For example, in rain, snow or strong wind. However, it should be noted that if there is a signal, the whip antenna will ensure its high-quality transmission. In addition, not all music centers are capable of improving signal reception with hardware. This problem is especially observed in inexpensive models, where, regardless of which antenna is connected to the system, no changes in the signal reception level are observed.

In rare cases (as an experiment), users try to improve reception by plugging the plug of a regular household TV antenna into the FM socket. Under no circumstances should you do this; it does not always help; most often, problems with short circuits and power surges may arise.

Don't also forget that:

1. Reliable reception is possible only when directed towards the signal source.
2. In the evening and at night, the signal weakens significantly due to the absence or reduction of long-range reception.

An antenna for any music center can be made with your own hands, the main thing is to carefully follow the instructions and be patient.

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FM antenna design for receiver

Such antennas are designed to convert radio waves in the FM range into electrical signals perceived by the receiver. The simplest designs are a vibrator, half the size of a wave. Such antennas do not have directional properties and perceive too much interference radiation from the surrounding space. If the FM receiver is mobile, you can, by making some movements, find the best direction of the signal. For stationary receiving radio devices, a wave channel tuned to the broadcast receiving beam is more suitable, while the best sound quality will be on a couple of channels (mostly radio stations of this type broadcast in a range of about 10 megahertz).

Additional Information . If it is necessary to expand the radio broadcast beam, you can connect 2-3 half-wave vibrators in parallel in a vertical position and solder them onto round cylinders.

The required 50 ohm resistance is not always achieved; such an FM antenna must be amplified with devices for matching. Thus, vibrators can be mounted on cone-shaped guides, representing a fan, “opened” from the center to the borders.

FM antenna fanning out

When using steel and sheet metal in construction, it is possible to obtain even 300 ohms. Thus, it turns out to receive a fairly large number of FM channels. To further expand reception in this range, it is sometimes necessary to assemble and connect an antenna array.

Antenna connection

The antenna for the radio receiver is connected in several ways:

• Direct: the antenna (usually telescopic antennas) is an integral part of the receiving radio device, while the “ground” phase is its body itself. The (active) resistance with such a connection reaches thirty ohms, and the reactive one is removed by altering the resonance circuit. Such antennas are not symmetrical. The grounding must be reliable (the length of the bare wire must exceed 1/10 wavelength), otherwise interference due to loop radiation is possible;
• With non-resonant power supply: a transmission line is used for directional transmission of radio waves, and its characteristic impedance must be equivalent to the antenna impedance. This connection allows you to get rid of losses and provide the best radio signal level;

Important! The excess cable between the FM antenna and the radio receiver should be cut, because each additional meter greatly reduces the receiver's sensitivity. After matching the resistance, bringing it closer to 50 Ohms, radio signal reception improves significantly.

• With the resonant type of power supply of communication lines, the ease of passage of radio waves directly depends on the length of the wave itself. For such antennas, feeders of half the wavelength (or multiples) are chosen, and the wave resistance is no longer so important, the antenna is matched. The frequency that an FM antenna perceives is the carrier frequency, quite often these are sine waves with a leading frequency of 50 hertz (harmonics).

Connection and configuration rules

The design of a radio for a car involves connecting 3 wires. The first is required for grounding and installation of the receiver. It is connected to a metal fastener and then tightened. The second is for food. It is connected to a wire extending from the receiver.

The third is necessary to establish contact. Connects to a special connector in the radio. Sometimes combined with a power cord. Wires are laid only when the installation is completed.

The antenna must not be mounted next to other metal elements.

If the device is installed outdoors, it must be protected from adverse environmental conditions. If this is not done, the metal may oxidize due to rain or snow, which will lead to malfunctions of the device.

How to make a radio antenna

If you have a technical mind and skillful hands, you can assemble a completely working radio antenna with your own hands. To do this you will need the following simple tools:

• a small coil of purified copper wire or metal foil;
• sharpened knife;
• pliers/cutters.

In the easiest case, you can take a ready-made television antenna and simply solder the connectors for the TV to those needed for the radio.

A homemade antenna for the VHF and FM bands can be constructed from the most ordinary foil or a piece of wire, only the sizes will vary.

The simplest indoor wire radio antenna

A homemade FM antenna is constructed on a dried board 15 by 15 centimeters using a sheet of foil 13 by 13 centimeters, thickness 15 mm (can be made up of several “shreds”). The algorithm of actions is as follows:

1. on the foil we cut a square with a side of 1 decimeter, we get a frame;
2. a 3 mm thin rectangle is separated from below;
3. glue the resulting square frame onto plywood or a board to give the future antenna strength;
4. to connect a shielded cable (its resistance is from 50 to 75 ohms), attach the central core of the antenna with a soldering iron to the bottom right;
5. the screen is attached in the central part, shifted to the left by 2.5 cm.

For antennas in the VHF range, a plate is taken with a side of at least 18 centimeters, a foil square with a side of 15 and a half centimeters, and a frame thickness of 1.8 centimeters.

Not all FM radio signals have full coverage, which can be picked up by the built-in antenna. Signal amplifiers for an existing or self-made radio antenna come to the rescue. Sometimes it is enough to simply wrap a standard antenna with copper wire and bring its end out into the window. This tactic helps make the radio signal a little stronger, but does not improve the sound quality. In this case, the end of the wire must be carefully cleaned with a knife. Some radio enthusiasts insert their additional wire antenna into the socket on the rear panel of the music center, but this can damage the receiver and even short circuit the home network.

If the wire turns out to be powerless, you can design a rod-type antenna, which, being highly directional, better resists urban radio noise. The antenna-pin is made up of an arrow that acts as a power element, a pair of passive receiving devices (directors), a loop-type vibrator and a reflector-reflector. The dimensions of such a directional antenna are determined by the range to which the radio receiver will be tuned.

The whip antenna is assembled according to the following plan:

1. a power structure is mounted on the façade of the building;
2. into a pre-prepared socket on the radio/music receiver. a wire is inserted in the center;
3. The found radio transmitting stations are configured.

More complex amplifiers of FM radio signals require solid knowledge and skills. Despite such efforts, waves can sometimes disappear at night (due to the lack of long-range perception of radio waves) and under unfavorable environmental conditions (rain, strong wind, heavy snow).

Homemade antenna

Anyone can do it; for this we need a few simple tools that are available in every home:

• A piece of copper wire.
• An ordinary kitchen knife.
• Pliers.

Note that not in all regions of our country the FM signal stably covers the entire territory. In some remote locations, the conventional built-in antenna of a music center is not enough. In this case, device owners begin to try to strengthen the signal on their own. Most often you can see a standard FM antenna wrapped in wire. In other cases, this wire is placed outside the window (for example, through an open window), in the hope that it will somehow strengthen the signal. Indeed, such practice often helps, and the radio still manages to be picked up.

So, let's take a closer look at how to make such a standard antenna amplifier with your own hands. This is done in stages:

1. Take a piece of copper wire.
2. Measure the length you need and cut using pliers or wire cutters.
3. Now strip the cut piece of wire using a regular knife.
4. Next, you should securely tape the cleaned wire to the existing antenna and try to catch the signal.

If significant improvements have not occurred, then you should pay attention to the back of the music center. In the area where the plug sockets are located there is often a so-called input for additional antennas

Some manage to amplify the signal by inserting a wire into this socket, but it is worth noting that such a practice can lead to unstable operation of the device as a whole, and sometimes to breakdowns. Moreover, the effectiveness of this method seems very doubtful.

If amplification with a wire-type device does not help, you can try to assemble a rod antenna. It is highly directional and more resistant to urban interference. Most often, it is made from an existing old television antenna, taking into account the fact that some television broadcasting frequencies have shifted or even switched to online or satellite broadcasting.

In order to make it yourself, you need:

1. Secure the load-bearing structure to the outside of the building.
2. Plug the wire into the corresponding socket of the music center (to make it you will need a plug for the corresponding socket and the ability to work with a soldering iron).
3. Search for radio stations.

Of course, there are options for homemade antennas with a more complex manufacturing algorithm, but their assembly will require much more skills and time. Wire and whip antennas are the simplest options available to any user when it is necessary to improve the signal using improvised means.

DIY pipe antenna

The main supporting element of this radio antenna is heating or water pipes. Required materials for creation:

• used transformer core (from an old TV);
• electrical tape, tape, office glue;
• foil made of thin copper or brass;
• one and a half meters of copper wire (diameter ¼ sq. mm);
• connecting pins.

For winding, the first layer is a ferrite core, a couple of layers of electrical tape on top, followed by a single foil layer. Exactly 25 turns of wire are wound onto such a screen blank with an overlap of 1 centimeter for better contact insulation. You should remember about the mandatory taps on turns No. 7, 12 and 25. The circuit is connected to other parts, and the ends of the wire are inserted into the pins. The tap from the 7th turn is inserted into the grounding socket, and the remaining two are connected to the antenna terminals.

The final stage is setting up the radio signal reception; this is done by simply selecting the connection of the winding to the connected circuit. Such homemade radio antennas reliably receive a signal even in a severe thunderstorm, thanks to reliable grounding.

If the radio receiver is located in an area where the reception is very weak and of poor quality, you can assemble an omnidirectional antenna yourself using a coaxial cable. For this you need:

• wooden slats;
• one and a half meters of cable (television cable is best);
• one and a half meters of PVC pipe (section diameter 2 cm).

Homemade antenna from coaxial cable

Constructing such an antenna is quite simple. A cut is made on the wire to remove the insulating layer (but the braid must remain intact, this is important!). Having loosened and slightly stretched the braid, the screen is turned out to the place of the cut. The final stage is to install and securely fasten the antenna inside the plastic tube and mount it on a wooden rail. The adjustment to search for a radio station signal is made in the vertical direction, and not by rotating the homemade antenna 360 degrees.

In dachas, in cars, even in urban built-up areas, those who like to listen to the radio are well aware of the problem of a weak signal and quiet sound of radio transmissions, especially in the FM range. Antennas for radios of various types and types of signal reception help correct the situation. They can be purchased in special stores, or you can make them yourself; fortunately, the technology is simple, and the parts can be bought at any radio market.

Assembly instructions

You can make both inactive and active (with an amplifier) ​​devices with your own hands. The production technology consists of several stages:

• preparing the necessary tools;
• direct assembly;
• fastenings to the machine body;
• connections.

Assembling different types of antennas for a radio with your own hands differs significantly even in the selection of necessary tools.

Production of an inactive installation

Passive antennas without an amplifier are considered quite simple in design. To create such a device, you will need:

• copper wire (diameter from 1.5-2 mm);
• high quality nut;
• good file;
• screwdriver;
• thermal glue (can be replaced with heat shrink tube);
• screw (diameter M5);
• lock-nut.

Assembly is carried out in stages. For this:

1. Take copper wire and twist it to a length suitable for a particular car.
2. The resulting spiral is placed on an M5 screw, secured with a nut and a lock nut of the same size (soldered on top). The structure is treated with thermal glue, or wrapped using heat shrink tubing.
3. The surface is sanded with a file. This procedure is done provided that the spiral has been treated with glue (only after the substance has completely dried).
4. Install a homemade antenna. The spiral blank is inserted into the hole made (at the base), and the wires are connected.

To give the installation an aesthetic appearance, a film is glued onto it, treated with a primer, and painted. The passive device is ready.

Creating an active fixture view

A special feature of this technique is the presence of equipment that enhances signal reception. When creating internal active installations, frame structures are used. This requires the following tools:

• copper wire, always with insulation (diameter - 2 mm);
• home amplifier (a television device will do);
• high-quality soldering iron;
• a connector that is suitable for a radio;
• good nippers;
• glue.

An amplifier housing designed for a regular home antenna is often used as the basic basis for the device. Solder a wire to it, which, in turn, will connect to the radio. This is necessary for the amplifier to receive and transmit signals.

The antenna plug is connected to the socket, and a connector is mounted at the other end of the wire. The power cable for the amplifier in car radios is considered the control cable; it is painted blue.

An active type receiver is mounted on the roof of the car so that signals are well received. To do this, two holes are drilled in the housing - mounting and auxiliary. The antenna wire is laid around the perimeter of the driver's door, fixed with glue. After installation on the roof of the car, attach the (side) cable to the rack and carefully connect it to the car radio.

Installation and connection features

Traditionally, active types of antennas for radios are installed on windshields in the upper right corners or behind rear-view mirrors. Passive installations for receiving signals are placed on car bodies, usually mounted on roofs.

Any antenna should be mounted only on a clean surface. For installation, use glue or masking tape, bolts, nuts, lock nuts for grounding, and a drill suitable for the diameter of the antenna wire. The mounting area must be degreased with a special cleaner.

Fix the devices with glue or masking tape. After installation, wires are laid from the antenna to the radio. This is done either around the perimeter of car doors or windows, or directly around the interior through special openings.

The design of an ordinary car antenna has three wires:

1. The first is used to ground the device. It attaches to a metal mount on the body. Secure the wire with a bolt, a strong nut and a lock nut.
2. The second is used to power the device. It is connected to the wire coming from the radio.
3. The third is a contact one; it is connected to a specially designed connector.

Most often, the second wire is combined with the third; by connecting the power, the contact function is activated, and the antenna begins to receive the signal.

Antennas for a radio station: general manufacturing principles and instructions

If the receiver does not work fully with the existing built-in antenna, then a homemade indoor radio antenna that amplifies the signal can be the solution. The device is placed at the maximum height to avoid possible interference with operation.

Before you make your own antenna for a car radio or other equipment, you need to take into account an important fact: to receive a radio wave, its polarization is important. Devices for FM signals should be positioned vertically, following the type of wave itself.

A do-it-yourself FM radio antenna is quick and easy to make if you prepare all the necessary tools and parts in advance. The simplest option is a pin one. To do this, take any material that conducts current and install it vertically. The lower part is connected to the receiver.

The amplifier allows you to receive even the weakest signal When creating an antenna, you should strive to ensure silent operation

Required funds

The set of tools and parts will be like this:

1. Ceramic insulators, as well as connecting elements for them. Avoid shorting the antenna wire to nearby structures. Such products can be purchased on the radio market or found in old buildings.

2. A thin steel cable for connecting insulators.
3. Roller blocks. We use them for the purpose of installing an external T-shaped antenna for a radio under tension.

4. Plug to connect the antenna.

5. Lightning protection device. A two-position switch should serve precisely this purpose. A good outdoor antenna can be quickly disconnected from the equipment and grounded during a thunderstorm.

6. A piece of copper wire. Diameter – 1.5-2 mm. You can also use steel wire coated with zinc. Copper will be more convenient to do the installation work.

Antenna for the receiver: what materials are required for work

To make a good FM receiver, you need to think in advance about what it will be made of.

A do-it-yourself car radio antenna is assembled from the following components:

• tube with heat shrink function;
• high voltage wire;
• PVA glue;
• ruler;
• compass;
• wire for unwinding - PEV.

The antenna must be assembled strictly according to the instructions in order for it to catch the signal well.

Simple, affordable materials are used to manufacture the antenna. It is recommended to choose an aluminum bracket

FM antenna amplifier

An FM antenna for a music center can be made with your own hands in a few hours if suitable parts are selected in advance. In addition, you should definitely understand the principles of operation of the equipment, only then the design will be working.

Outside the city, communication is much worse than within a populated area, but you can improve its quality by installing an antenna for a VHF radio receiver with your own hands.

To compensate for losses when receiving a signal, you need to raise the device as high as possible. The antenna amplifier most often works even in the most hopeless cases. Signals below 60 Hz are filtered out and only high signals are received.

To make such an amplifier, you need to use two coils. They are wound using a PEL wire to the antenna. To ensure operation of the device, it is necessary to connect a current of at least 12 A. All connections are secured using a shielded cable.

If after installing the antenna the signal on the device is very weak, you can raise the amplifier higher

It is necessary to provide amplification on the VHF band

FM indoor antenna: linear

To get a good signal you need an FM radio antenna, which is not always easy to buy. If the model you need is not on sale or you don’t want to spend extra money from the family budget, you can make a device for receiving the signal yourself from scrap materials.

TV cable can be purchased at any radio store. If you need a telescopic antenna for a radio receiver, it is also not always possible to buy it, so it is better to use the instructions for making the device yourself.

Antenna for radio in car

A simple VHF antenna amplifier for a car can be made in ten minutes. The telescopic flexible antenna is made from special materials and radio components. Homemade devices can break down just as quickly as store-bought ones, so before you install an antenna in your car for the radio, you need to choose a suitable location for it.

It is also possible to manufacture a solid antenna, which will require: copper wire, cable, metal pin for mounting the structure, tools for working with metal, soldering iron and insulators.

When choosing a metal pin, you need to pay attention to the thread - it must fit the size of the bracket. It is best to use ready-made anchor bolts, which can easily secure any structure.

The next step is to prepare the space inside the car. The casing is removed where the antenna will be installed, then the cable is laid and secured. You must act carefully so as not to break the holders and clips.

If the dimensions of the head unit and antenna do not match, it is recommended to resolder the connector, but you can use an adapter. The operation of the receiver is checked, after which the structure can be assembled and the panel closed. If a homemade antenna is assembled correctly, it will work well, regardless of external circumstances.

Antenna with copper wire

To connect TV or radio, you need to ensure that the wave frequency is sufficient. For this, both purchased and homemade antennas are used. One option is a device assembled from copper wire. To do it, you need to follow the instructions.

Making a digital TV antenna from copper wire is very simple, but you need to make sure that all the given steps are followed correctly. If the device does not work, then it may not be assembled correctly, or it may simply need to be raised higher.

Receiving antenna type

In fact, on the HF band the type of receiving antenna is not so critical. Usually a 10-30 meter long wire is sufficient, and a coaxial cable can be connected at any convenient location on the antenna, although to ensure greater broadband (multi-band), it is better to connect the cable closer to the middle of the wire (you will get a T-antenna with shielded reduction). In this case, the braid of the coaxial cable is not connected to the antenna.

Wire antennas

Although longer antennas can receive more signals, they will also receive more interference. This somewhat equalizes them with short antennas. In addition, long antennas overload ("phantom" signals appear throughout the entire range, the so-called intermodulation) household and portable radios with strong signals from radio stations, because they have a small dynamic range compared to amateur or professional radios. In this case, you need to turn on the attenuator in the radio receiver (set the switch to the LOCAL position).

If you are using a long wire and connecting to the end of the antenna, it would be better to use a 9:1 matching transformer (balun) to connect the coaxial cable, because The “long wire” antenna has a high active resistance (about 500 Ohms) and such matching reduces losses on the reflected signal.

Transformer for antenna long wire 9:1

Matching transformer WR LWA-0130, ratio 9:1

Active antenna

If you do not have the opportunity to hang an external antenna, then you can use an active antenna. An active antenna is, as a rule, a device that combines a loop antenna (either ferrite or telescopic), a broadband low-noise high-frequency amplifier and a preselector (a good active HF antenna costs over 5,000 rubles, although for household radios there is no point in purchasing an expensive one, it will do just fine something like Degen DE31MS). To reduce interference from the network, it is better to choose an active antenna that runs on batteries.

The point of an active antenna is to suppress interference as much as possible and amplify the desired signal at the RF (radio frequency) level without resorting to conversion.

In addition to the active antenna, you can use any indoor antenna that you can make (wire, frame or ferrite). In reinforced concrete houses, the indoor antenna should be located away from the electrical wiring, closer to the window (preferably on the balcony).

Magnetic antenna

Magnetic antennas (loop or ferrite), to one degree or another, under favorable circumstances, can reduce the level of “urban noise” (or rather, increase the “signal-to-noise” ratio) due to their directional properties. Moreover, the magnetic antenna does not receive the electrical component of the electromagnetic field, which also reduces the level of interference.

Magnetic loop antenna

By the way, EXPERIMENT is the basis of amateur radio. External conditions play a significant role in the propagation of radio waves. What works well for one radio amateur may not work at all for another. The most visual experiment of radio wave propagation can be carried out with a decimeter television antenna. By rotating it around the vertical axis, you can see that the highest quality image does not always correspond to the direction towards the television center. This is due to the fact that radio waves, when propagating, are reflected and “mixed with others” (interference occurs) and the highest quality signal comes from the reflected wave, and not from the direct one.

Tools and materials

It should be said that there are a huge number of options for creating antennas. They are made from copper wire, and from a tube of capacitors, and from wire, and even from a television cable. And this is not a complete list of materials from which an antenna can generally be made. If we talk about materials, then to create an antenna you will need to have the following elements on hand:

• heat-shrink tubing;
• winding cable type PEV-2 0.2–0.5 mm;
• high-voltage wire or coaxial cable;
• ruler;
• nest;
• calipers;
• glue for plastic.

This is a rough list of materials and may vary depending on the materials you have on hand. In addition, it will not be superfluous if before this you develop a diagram of the device that you will make. Device drawings allow you not only to determine what dimensions are needed to receive a particular wave range, but also make it possible to correctly calculate the necessary parameters of the device itself - type, length, width, some design features. In addition, you can immediately roughly determine the place where to solder the socket, if necessary.

How to choose an amplification module

The first criterion by which an FM signal amplifier for a car radio is selected is its power supply type. There are two types of devices on the market today.

1. With external power supply. Such an amplifier has a tap, one wire for connecting to the vehicle’s on-board network.
2. Powered by antenna cable. Such devices connect only to a certain class of radio tape recorders. The latter must have the option of power supply via an antenna cable.

Regardless of the technical solution, connecting the antenna amplifier to the car radio is not difficult. However, the main thing is to buy a device with the right characteristics. The criteria for choosing the optimal model are as follows.

1. The frequency band is selected depending on the type of radio and the radio tuner installed in it. If this is an old cassette model that receives short, medium and fm waves, a wideband amplifier will be required. For modern radio tape recorders, a narrowband model operating only in the FM range is sufficient.
2. Type of antenna to be connected. For conventional pin models, a conventional amplifier is used. When using directional (also called dipole) antennas on a car, a more complex device will be required. The circuit solution includes a matching module.
3. The gain should be between 10 and 30 dB. Today you can buy models with a higher indicator. However, it is not recommended to do this in a large number of cases.

It is worth talking in more detail about choosing the optimal gain. It is determined not only by the desired reception range. The fact is that the maximum power of the car radio amplifier determines the final signal level at the device input. However, there is a technical limit to its increase.

If the installed antenna amplification module is very powerful, and the car is located in an area of ​​reliable reception, in a large city, the radio will simply stop receiving the radio. The protection system will work. The amplification device, generating an excessively strong signal, will take its value beyond the technical limit. As a result, in order to protect the primary reception circuits, roughly speaking, the antenna input will be blocked.

When the actual use of the car involves both its movement in the city and travel far beyond its borders, it is recommended to install an amplifier blocker. This is a circuit that turns it off if necessary, making a bypass to the main cable channel of the antenna. You can buy an amplifier that turns itself off when a certain limit signal is reached at the output.

Step-by-step instruction

Here are a few instructions for creating antennas, each of which will help you make a really high-quality FM module for receiving radio waves. So, to make such a device, you must adhere to a certain algorithm of actions.

1. Take any high frequency coaxial cable. We dismantle its braid and remove the outer insulation. You can also use high-voltage wires from transformers of the same name, which are used in monitors and televisions equipped with a cathode ray tube. They have greater rigidity and will be an excellent option for receiver antennas.
2. Now you need to cut a piece measuring 72 or 74 millimeters from the prepared wire. Moreover, accuracy must be maintained down to the millimeter. Using a soldering iron, we solder a small piece of wire to the cable, from which a coil will later be wound from a suitable piece of plastic. The wires will need to be wound about 45 turns. In this case, a piece of internal insulation with a length of 1.8 centimeters will be used. If desired, you can recalculate the coil for a different diameter. But you need to observe 2 points:
   the length of the coil will be 18 millimeters;
3. the inductance should be 1.3–1.4 μH.
4. Now we carefully wind 45 turns. Once this is done, you can see the gaps on its end sides. You will need to pour a little glue into them to make the structure stronger.
5. At the next stage of antenna assembly, you need to put a heat-shrink tube on the resulting structure. It should be heated by some convenient method. But it is best to do this using a closed fire, or you can use a hair dryer.
6. If you need a loop antenna, then its special feature is the presence of an aluminum hoop. Its diameter is 77 centimeters, and the internal diameter should measure 17 millimeters. You can easily find such an element in any sports store. You should also have a copper tube on hand. If such an antenna is required, then the central core, braid, and also a small piece of coaxial type wire should be soldered to the contacts of the variable capacitor. We solder the second end of the wire, the central core and the braid to the above-mentioned aluminum hoop. You can also use car clamps, which should be thoroughly cleaned first. Their diameter should be from 1.6 to 2.6 centimeters. You should also do a good cleaning of the contact area.
7. The ratio of the circumference of the frame to the circumference of the communication loop should be 1: 5. In addition, 1 centimeter of insulation should be removed from the tip of the cable and from the central core. And also from the middle of the cable for the FM antenna, you should mark 5 millimeters in both directions and remove the external insulation. After this, we remove the cable braid to break it.
8. Now you should check the range of the antenna and make sure that the frame has resonance in the range of 5–22 MHz. If the capacitance of the capacitor is different, then these parameters can be changed. If you need low-frequency ranges, then it is better to take a frame with a larger diameter - one or one and a half meters. If we are talking about high frequencies, then a frame of 0.7 meters will be enough. This completes the creation of the loop antenna.

2

A rather interesting option would be a pipe or magnetic antenna. By the way, it can be not only internal, but also external.

The main load-bearing part of such a device will be a heating pipe or water pipe. To make an antenna of this type, you will need to have on hand the following elements:

• a used transformer core that can be removed from some old TV;
• insulating tape;
• glue;
• scotch;
• foil made of thin brass or copper;
• about 150 centimeters of copper wire with a diameter of a quarter square millimeter;
• pins for connection.

First, to wrap the first layer, a core made of ferrite is laid, and on top there are 2 layers of electrical tape, followed by a single layer of foil. Now 25 turns of cable with a 1-centimeter overlap should be wound onto this screen blank so that the contact insulation is the best. And also we should not forget that it is necessary to make mandatory taps on the 7th, 12th and 25th turns. The circuit should be connected to other parts, and the ends of the wire should be inserted into the pins. The tap from the seventh turn should be inserted into the grounding socket, and the other 2 should be connected to the antenna terminals.

The final stage of work will be to set up radio signal reception. In this case, it will be carried out by the usual selection of a winding connection to a connected circuit.

Another fairly common and simple option for creating an antenna of this type is a device made of foil. To create it you will need the following materials:

• wire cutters or pliers;
• knife;
• a roll of foil or copper wire;
• dry board in the form of a square that has a side measuring 15 centimeters.

There is nothing difficult in creating such a device. To make it, you will need to follow several steps.

1. First, cut a square out of foil. It should measure 13 centimeters on the outside, and the width of the foil strip should be 1.5 centimeters. A 3mm rectangle should be cut out at the bottom center to allow the frame to open.
2. The cut piece of foil should be glued to the board. Now you need to solder the inner rod of the shielded wire on the right and the braid on the left to the square of foil. This must be done with a slight shift to the right from the central slot - about 2.5 millimeters. By the way, the distance between the shielded wire and the braid should be the same. Here it must be said that if the antenna is used to operate in the VHF range, then the size of the square should be increased to 15 centimeters, and the width of the foil strip in this case will be about 18 millimeters.

Important! If you need to amplify the signal for this type of antenna, you can wrap it with a piece of copper wire. Its free end should be led out into the window.

In addition, there is a very simple option for creating a simple radio antenna. We will need to have the following materials and tools on hand:

• soldering iron;
• a plug to connect the antenna to the radio;
• roller blocks that allow you to fix the antenna in the desired position;
• steel wire;
• copper wire;
• switch;
• ceramic insulators.

Everything here will be extremely simple - just connect the wires, plug and rollers with a soldering iron. And the joints will need to be wrapped with electrical tape to strengthen the structure and maintain its integrity. In addition, to make such an antenna look as aesthetically pleasing as possible, it can be installed on a special stand, previously made of wood. As you can see, there are a considerable number of antenna models, each of which can provide a high-quality radio signal in different conditions.

Voice radio in the country: ways to strengthen the signal

In a suburban area, receiving radio broadcasts and music is good entertainment, including during gardening work. Unfortunately, in practice, many are faced with the fact that the receiver produces a large amount of interference. Sometimes the signal is completely lost, and it is simply impossible to find your favorite radio station by setting the slider to the desired wavelength range. All this indicates poor reception, which can be improved in simple ways.

Build up your antenna

No matter how you receive a radio signal, it requires an antenna. If we are talking about a receiver with a folding pin that is hidden in the case, then its size is often not enough, especially if we are talking about a place far from the city, where the reliable reception zone disappears. In this case, you need to make the antenna longer and raise it higher. In a private house, this is done very simply - a pole is fixed on the roof with a piece of wire, stripped of insulation, tied to it. The material for receiving the signal is not important - it can be either copper or steel.

Make a reverb

The simplest device that amplifies a radio signal is nothing complicated. It should be made in the form of a frame, usually triangular or square, made of three meters of copper wire stripped of insulation. In some cases, it can provide stable reception at a distance of 150 km from the city. One end is connected to ground, the other to the central output of the antenna socket.

Connect amplifier

This device is usually a box that is connected to the antenna frame. Inside the case there is an amplifier chip with active power supply. In order for the circuit to work, you need to plug in an adapter that produces 12 V DC. A cable comes from the amplifier, which connects to the FV receiver. This method is most widely used for receiving television signals, but where television broadcasts are received, the radio will be heard just fine.

The listed methods do not exhaust the possible recipes for amplifying a radio signal under various conditions. Radio amateurs on forums willingly share their inventions, and not all of them are difficult to manufacture.

Recommendations

If we talk about recommendations for the creation and use of such antennas, then first of all we should note several.

• There should not be any metallic foreign objects near such a device. Otherwise, they may interfere with the reception of the signal or reflect it, which will also negatively affect the quality of its reception.
• Care should be taken to protect the antenna from exposure to natural factors. Otherwise, its parts may rust and sooner or later the device will simply fail.
• In most cases, it is necessary to make drawings before starting work, where you need to describe in detail the dimensions and dimensions of the device, its type, as well as the algorithm of actions for its creation. This will make it possible to quickly and accurately implement one or another idea and obtain a high-quality antenna for receiving a stable FM signal.

How to make a radio antenna with your own hands in 15 minutes, see below.

Sources

• https://electrikexpert.ru/kak-sdelat-antennu-dlya-radio-fm-svoimi-rukami/
• https://amperof.ru/elektropribory/antenna-dlya-radio.html
• https://homius.ru/antenna-dlja-radio-svoimi-rukami.html
• https://stroy-podskazka.ru/radiopriemniki/antenna-svoimi-rukami/

Useful tips

It is important to choose the right location for installing the antenna. A car body can be both a kind of indicator of improved signal reception quality and an interference

The best place for mounting is the center of the roof. There should be no foreign metal objects near the catcher. It is better to purchase combined antennas for receiving various communication signals ready-made.

The installation must be protected as much as possible from the influence of the external environment so that contacts do not oxidize and parts of the entire structure do not rust.

An antenna made by yourself is an effective way to save money, improve the quality of signal reception, and allow you to technically modify the radio in your own car.