DIY car antenna. Why are strange antennas needed on government cars (19 photos) Car antenna diagram and operating principle

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The external car antenna of most popular cars often breaks down and gets damaged. There are frequent cases of theft or vandalism when parking a car in a yard. Finding a factory antenna is problematic; car manufacturers rarely produce simple devices as spare parts. If the receiving device on your car of an outdated design is broken or stolen, there is often no other choice but to make an antenna for the car radio with your own hands. Most drivers prefer to listen to FM radio broadcasts, for which stable reception does not require long flexible or telescopic antennas.

General principles of operation of a car antenna

Making an antenna for a car radio with your own hands at home is quite simple. But before manufacturing, you need to decide on the main parameters - the length of the antenna, its location, and the complexity of the design.

According to the postulates of radio engineering, a car antenna is defined as a quarter-wave vibrator grounded to the car body. Antennas for automobile transmitting radio stations reach a length of two and a half meters and must operate in a vertical position. For standard car radio receivers, such parameters are redundant.

For stable reception of radio signals in the most popular VHF FM band, where most stations for motorists operate, a whip antenna 10–20 centimeters long is sufficient. A do-it-yourself external antenna for a car radio will be the simplest solution when replacing outdated head units designed only for receiving long and medium waves.

Without considering antennas for receiving television signals, radio waves Wi-Fi Internet, let's focus on simple car antennas, which are divided into external and internal. Internal antennas, shielded by the car body, have weaker radio wave reception. For their stable operation, additional reinforcement or a complex frame structure is required. Only a trained radio amateur can independently calculate and manufacture a high-quality internal antenna; there is no point in starting such a design for novice tuning enthusiasts.

The process of making a homemade antenna

Flexible and telescopic antennas for manufacturing require the selection of special antenna materials and additional radio components. Plus, they break just as easily as your car's previous antennas.

A stationary solid antenna that imitates the fashionable “shark fin” receiving device is easy to manufacture. To make such a homemade antenna for a car radio with your own hands, you will need simple materials and tools:

metal pin with thread;
fixing nuts;
copper wire;
metal tools;
soldering iron and soldering supplies (flux, solder, rosin);
insulators;
antenna cable.

The main element of the antenna is a metal pin, the thread of which is selected according to the size of the standard location of the antenna or the mounting bracket you have chosen. Standard pre-threaded anchor bolts work well for the antenna base. At the opposite ends of the pin, you need to drill two holes for attaching the copper wire of the antenna vibrator. Unshielded wire is wound in two layers along the entire length of the pin.

The wound wire is clamped with fixing bolts and sealed in the upper hole of the antenna. For the outer layer of insulation, amateurs use various materials: Cold Welding glue, epoxy resin, polymorphus, thermoplastics. Molten vinyl and carbon fiber have proven themselves to be bad, causing interference with radio wave reception.

After manually molding thermoplastic or epoxy, the antenna will look inconspicuous.

After trying on the antenna at the installation site and checking its performance, the outer surface is processed on a lathe and finished by hand.

Depending on the color of the material used, the finished antenna can be left black or painted with waterproof acrylic paint to match the body color.

You can watch the video on how to make an antenna for a car radio with your own hands for outdoor trips:

Connecting an outdoor antenna

The easiest way to install an antenna is for owners of cars that have a regular place on the body for installing a receiving device. In such models, it is enough to carefully screw the antenna into the existing connector (usually a screw one), without having to worry about laying the internal cable.

A well-processed homemade antenna on the roof looks no worse than the fashionable “shark fin” antennas that are equipped with expensive Mercedes, Audi and BMW.

If there is no regular place on the car body, a homemade antenna for a car radio can be installed on magnetic brackets or vacuum suction cups. It is preferable to use magnetic holders, which are more firmly held on the roof of the car while in motion.

It is undesirable to make unnecessary cuts in the car body, so you can use existing technological holes or minimally expand the grooves of the rear light seals. All cable outlets on the body must be sealed with sealant. Remote magnetic brackets for taxi drivers’ radios are well suited for conversion. In this design, you only need to remove the extension coil (located at the base of the antenna) and connect the cable directly to the pin. Theoretically, the best place to install the antenna is considered to be the center of the roof, but usually car enthusiasts install a homemade device on the left wing or in the rear of the roof.

To connect an outdoor antenna, you must use a shielded coaxial cable. To lay the cable inside the cabin you will need:

Remove the interior trim from the cable entry point to the center panel. All operations must be carried out carefully, without using brute force, while maintaining the plastic clips of the fasteners.
Lay and secure the cable. It is advisable to avoid intersections with standard electrical wiring, which cause additional interference to radio reception.
Compare the antenna and head unit connectors. If necessary, resolder the antenna connector or use an adapter.
Check the operation of the car radio receiver.
Assemble the removed interior elements.

At correct assembly antennas, cable laying, the new receiving device will work no worse than the standard antenna.

Conclusion

By working on the appearance of the receiving device, you will avoid claims from traffic police inspectors who may find fault with a sloppily made homemade antenna. By sending us your feedback on your own experience in making antennas yourself, you will help fellow motorists avoid common mistakes.

Car antennas have long been considered an ordinary accessory, but such equipment often breaks down and is often simply stolen. Factory models are quite expensive, and it is often difficult to find a suitable one. However, you can make auto antennas for your radio with your own hands. The process is simple, but requires some professional skills.

The range of devices in stores is very large. Based on their intended purpose, this technique is divided into the following types:

Active antennas for car radios, when signal reception comes with a built-in amplifier. They are considered very powerful. Great for picking up signals over long distances.
Passive models. They work without amplifiers. They are considered simpler, they are much easier to do yourself. It is recommended to install such devices if car radios are used only in the outskirts of the city.

Antennas are also classified according to installation method. There are internal and external antennas:

Internal. They are installed in car interiors. This installation method is suitable for active models.
External. They are located outside car bodies. This installation is more suitable for passive devices. At the same time, the low power of the equipment is somehow compensated for.

To make an antenna for a car radio with your own hands, you need to take into account the operating principles of the signal catcher, determine the length of the device, its location, and the degree of complexity of the entire structure.

Conventional antennas for cars are quarter-wave vibrators that are grounded to the car body. Such devices can only be mounted vertically, and reach a length of 2.5 m. For antennas of standard car radios, these parameters are considered redundant.

That is why self-made external antennas for car radios are used to replace outdated oversized devices. To hear stable radio signals in the popular range, it is enough to use pin devices with a length of 10 to 20 cm.

In addition to significant cost savings, there are a number of advantages in using such technology. The following advantages are highlighted:

A self-made design can be adjusted to fit perfectly different models cars.
There will be no problem with the installation height for receiving radio signals.
Installing a homemade device is much easier than factory-made analogues.
You can improve the quality of signal reception with proper installation, as opposed to using purchased antennas.

It is worth noting that you can start designing yourself if you have skills in working with electrical engineering; otherwise, it is better to use the services of professionals or use store-bought analogues.

Do with my own hands You can use both inactive and active (with amplifier) devices. 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.

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. To do this:

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:

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.

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.

Homemade antenna - effective way saving money, improving the quality of signal reception, the possibility of technical modification of the radio in your own car.

The first radio for a car appeared in 1930, and to this day the radio in the car remains relevant. The small size of the car does not allow the installation of large antennas, so motorists widely use active antennas. Read about these devices, their purpose and types in the article.

Purpose of the active antenna

For any radio to operate, an antenna is required - a device that receives electromagnetic waves and converts their energy into an electrical signal. This signal can then be amplified and converted, which is what the radio receiver does. Reliable reception is only possible if the antenna is tuned to a specific frequency or frequency range - this setting is carried out by selecting the length of the antenna. In the simplest case, the antenna can be a half or quarter wavelength rod. For example, for the FM broadcast band the wavelength is approximately 3 meters, respectively, the antenna length should be from 0.75 to 1.5 meters.

It would seem that 75 cm is not much, but even for a car this is a significant amount; an antenna of such length is difficult to place on a car, and it can even damage appearance car. Therefore, antennas that are shorter in length are often used, but they are less sensitive, convert the energy of the electromagnetic wave worse, and supply less voltage to the input of the radio receiver. That is, a short antenna worsens the reception and quality of playback of a radio program, or even makes reception of some radio stations (especially remote ones) impossible.

This circumstance led to the need for short, but quite effective antennas that would ensure successful radio reception in a car. To solve this problem, active antennas were created - short antennas with high sensitivity.

An active antenna is an electronic device that combines a conventional antenna (whip or dipole) and a radio frequency amplifier. Such an antenna can receive a weak signal and provide the same radio operation as regular antenna increased length. Also, active antennas can perform some other functions, which are described below. But first of all, you should look at what types of active antennas exist today.

Types of active antennas

On the market you can find antennas that differ in design, installation location, type of installation and functionality.

Based on their design, antennas are divided into two main types:

Whip - a metal pin of one length or another is used as an antenna. In modern antennas, the pin has a plastic protective sheath. Typically external antennas are of this type;
Dipole - reception is carried out on a symmetrical dipole, spaced apart pins of the same length. The circuit is typical for interior antennas.

Depending on the location where the antenna is installed, there are:

External - mounted on the roof, in the front or rear fender, etc.;
In-cabin - mounted inside the cabin, on the windshield or rear window.

Both types of antennas have their advantages and disadvantages associated with the presence of a metal body. As you know, metal does not transmit radio waves, so the body of the car serves as a screen; inside the cabin, the electromagnetic field strength is several times lower than outside. Therefore, interior antennas are mounted on the front window. However, the body serves as additional protection from interference (especially coming from cars located in adjacent traffic and behind), while external antenna accepts all interference.

Depending on the type of antenna installation, there are:

Interior - on double-sided tape;
Mortise antennas are external antennas that are rigidly installed in the body or in a special container (retractable antennas);
On a magnetic base - usually external antennas for quick installation on the roof.

The main function of an active antenna is to amplify the signal, but modern antennas may have various additional functions:

Switching between ranges;
Changing sensitivity - “City” mode with lower sensitivity and “Highway” mode with increased sensitivity;
Anti-interference protection.

Also, active antennas can be divided into several groups according to their purpose and operating ranges:

Antennas for one or two bands - usually FM or AM/FM;
TV antennas;
Universal antennas - for all bands from AM to TV.

All active antennas, regardless of type, have a similar design and a common operating principle.

Design and principle of operation of active antennas

Structurally, any active antenna consists of five main parts:

Antenna (pin or dipole);
Amplifier (in a plastic case);
Antenna cable (supply cable);
Wire or separate power supply cable (optional);
Ground connection wire.

In-cabin antennas usually have a dipole design. Dipoles are made in the form of so-called canvases - flexible conductors in a plastic shell that can be mounted on glass. The panels come out directly from the housing in which the amplifier is located; this entire structure is attached to the windshield using double-sided tape.

An active antenna works quite simply: the signal isolated on the canvases is sent to an amplifier, after which it is fed through a cable to the antenna input of the radio/cassette player. The amplifier requires power and grounding to operate. Power can be supplied by a separate two-wire wire, or it can also be done according to the standard scheme - connecting the ground wire to the body (to any bolt located next to the antenna) and the second wire to the “+” of the battery.

Compact antennas with quick installation(on a magnetic base) usually do not have a separate ground, and are powered from the cigarette lighter. Such antennas are small in size and easy to install, but they provide less gain and are generally worse even compared to in-cabin antennas.

Features of installation and operation of an active antenna

The installation of an external antenna, especially a mortise one, should be trusted to specialists; an internal antenna can be installed independently. Installing the antenna in general case boils down to this:

Select the optimal location of the antenna on the windshield or rear window;
Glue the antenna body and antenna sheets using the supplied double-sided tape (the adhesive is already applied to the sheets, covered with a protective film);
Degrease the glass in the area where the antenna body and panels are glued;
Connect the grounding wire to the car body (to any bolt or directly to a part of the body that has been cleared of paint);
Connect the supply cable to the antenna input of the radio/TV;
Connect the power cable in any convenient place to the “+” power source (the best option is to the radio terminal).

Particular attention should be paid to the location where the antenna is installed; here you need to follow several recommendations:

Antenna sheets should be located at a distance of no closer than 5 cm from the edges of the window (this reduces the shielding effect of the car body);
The ground wire should be as short as possible;
The power cord should be connected as close to the radio/cassette player as possible.

It is necessary to place the canvas parallel to the edge of the window, and here there are two options:

Along the upper edge of the window, the canvases are elongated;
In the corner of the window - the canvases are located at a right (or so - depending on the geometry of the glass) angle.

At correct connection After turning on the ignition, the LED on the antenna housing will light up. Active antenna does not change the operation of the radio and in the simplest case does not require any additional actions. If the antenna has additional functionality, then you may need to switch the “City”/“Highway” modes or select bands - how to do this is usually indicated in the instructions.

Active antenna at correct installation and operation improves radio reception and makes travel more enjoyable. This is a simple, inexpensive and interesting solution that every car owner can afford.

Today, car antennas have different purposes. In times of combat, they receive communications, and in times of peace, they receive navigation information and broadcast channels. Due to the simplicity of the design, you can make a car antenna yourself. More on this later in the article.

This is a special device that receives electromagnetic radio signals and converts them into an electrical signal. To make an antenna for a car with your own hands, you need to decide on the type of modulation, wave range and purpose of the device. These are the three key components that go into the design.

Types of car antennas by purpose

Types of car antennas by installation method

Types of car antennas by mounting location and type of amplification

Based on the type of amplification, the following types of car antennas are distinguished:

At the mounting location:

Operating principle of a vehicle communication antenna

The size of a car antenna directly depends on the range. This is why 27 MHz communication antennas are so large. The most powerful variations can reach two meters in length, however, according to the rules of science, they should be even higher. To adjust the differences between the quarter wavelength and the actual size, there is an extension coil at the base.

On cars, the communication antenna is installed strictly vertically, which is determined by the type of polarization. It is worth noting that all communication antennas are capable of tilting using a lever in certain road conditions, for example, in order to overcome the span of a low bridge or not break in the forest. As a rule, communication antennas are used by owners of large trucks. Installation on jeeps and other cars is allowed, but the appearance will not be very attractive.

Digital car antenna, operating principle

Digital car antennas for TV reception, as a rule, look like police flashing lights, but are made in a different color scheme. There is nothing complicated in their design, they just have to accept a frequency of about hundreds of MHz. For example, the first multiplex in Moscow is located at a frequency of 559 MHz.

Digital car magnetic antennas are usually placed on the roof, and the wire runs directly above the door without any modifications. The signal is characterized by the presence of horizontal polarization; the main task of the device is to receive it from each azimuth.

Radio broadcast antenna

Radio broadcast antennas are both “flashing lights” and short rods, similar to those that receive signals from walkie-talkies, but a little shorter.

Technical characteristics of frequencies of radio, television, navigation, radio communications

Radio communication - SV (about 27 MHz).
Navigation - GPS (about 400 MHz).
Television - DVB–T (up to 900 MHz).
Radio - FM or AM (about 70 - 108 MHz).

Also pay attention to the connector. As a rule, it matches most of the devices for which it is intended, but it would not be a bad idea to check this. There is an opinion that an external antenna receives better, but this only applies to reception in the city. On country roads, the glass of a regular passenger car is not capable of creating serious obstacles. However, interior car antennas are easier to install. It is worth noting that they are lower than external ones, which affects the quality.

You can find various hybrid models in the market. In addition, it is possible to switch reception from city to highway. Their difference is in the features of interference suppression and sensitivity, due to which the reception range outside the city is significantly increased. There are also unique tandems - a pair of similar-looking pins, the first of which is television broadcasting, and the second is radio or communications. Of course, to take full advantage of the kit, you need to have the appropriate receiving equipment available.

Tools, materials and devices to help the master

DIY car antenna, step-by-step instructions

It is worth saying that the car body is constantly in motion. That is why ordinary terrestrial household antennas will have in this case reception dead zones. When maneuvering, there will be quite long periods of time when there will be no reception. This refers to horizontal polarization. With vertical, it doesn’t matter where the signal comes from.

At self-production car antenna, a frame structure is used, which must be laid under the rear window seal of the car. It is slightly narrowed towards the top and has slightly different dimensions than required at a frequency of 27 MHz. That is why there is a capacitor in the center, which is used to tune the car antenna to resonance on the desired channel.

There are two receiving frequencies, for example:

28.2 and 68 MHz
27 and 65 MHz.

The upper resonance occurs for the lower range of radio broadcasting. Car antenna diagram:

You should lay the MGTF wire 0.5 in a trapezoid along the perimeter of the rear window - sidewalls 22.5 + 22.5 and 45 cm, bottom edge 66.5 + 66.5 cm, top edge 56.5 + 56.5 cm.
The pluses are where the wires for the corresponding capacitor will be added and the signal will be removed using the RK-50 cable.
Two wires run vertically to the center, in the middle, of the glass, where a tuning capacitor is attached exactly in the center. The length of each is 45 centimeters. They need to be twisted in a zigzag and placed under an insulating tube.
The cable must be soldered from the side, where the wire is cut off in the middle. There should be no gap on the opposite side.

How to install and connect an antenna

The car antenna is connected via the connector used by the communication equipment. Keep the cable length short.

Advantages of a DIY antenna

Such models are usually installed on the roof of a car and have a greater height than the passenger car itself. In the forest this is a definite plus. Moreover, there is no need to wind the matching device. In this case, ease of design, ease of installation and accessibility to any user are achieved.

In some cases, purchasing a car antenna and installing it is more expensive, more complicated and provides poorer reception quality. There is nothing complicated in the design below and every car enthusiast can try it out.