Antennas for cars are different. They are mainly used to receive FM radio stations or to watch TV programs on mini-devices., equipped with special equipment. in addition, antennas in the car are needed as a navigation channel. In military conditions, car antennas are needed to receive the signal.
Today we will talk about it, how to make an antenna for a car radio in order to listen to FM radio stations, how not to make a mistake when buying a ready-made device, and also you will learn, what types of car antennas exist.
Classification of car antennas
If you want to make a radio antenna with your own hands, then it is not a big deal for you, since such a device has a fairly simple design. The main thing when working is to choose the right range of waves (most often choose FM) and type of modulation. However, we will return to this, and now let's find out, what categories are divided into car antennas.
By their purpose, they are adapted to the reception:
- radio broadcasting in different bands, mainly, this is FM;
- television broadcasting;
- information from the satellite in order to ensure the operation of navigation systems.
There are also communication antennas.
Installation of the device on the car can be carried out:
- with the help of magnets;
- using suction cups;
- mortise method;
- by the method of threaded connection;
- clamp;
- built-in method.
According to the method of placement of the antenna can be external and salon, and by type of amplification - active and passive.
There are a number of classifications, but they are very specific, therefore we will not dwell on them.
The size of the device depends on the range. Example, communication antenna on 27 The MHz is large. The most powerful specimens can have a length of about 2 meters.
To work properly, install the antenna on the machine should be strictly vertical, due to the type of polarization. Of course, the connecting structures may be tilted by a lever or a lamb, so as not to break in certain places, but they are mainly used by drivers of large vehicles.
The digital TV antenna for the car looks like a flasher on a police car, only has a different shade. The device of this design is quite simple, its main task is to receive hundreds of MHz. Most often, the digital installation is placed on the roof of the car with a magnet, the wires are stretched over the door without additional modifications. The signal has a horizontal polarization.
What to look for when buying
Antennas for car radios are also small, but they are a little more television, because the wavelength is higher. Pins of small height are suitable for this purpose, resembling a device for receiving walkie-talkie signals, but their length will be less, than police flashers. So as not to accidentally buy an antenna for a TV instead of a special model for the radio, study its technical characteristics:
- the antenna for the radio is indicated as FM or AM (frequencies 70-108 MHz);
- for television - DVB - T (frequency up to 900 MHz);
- for navigation - GPS ( 400 MHz);
- for radio communication - JI (27 MHz).
Also, be sure to pay attention to the antenna connector. Most often, they should match your device, but pre-check it when buying will not hurt. It is considered, that the car antenna external type catches better, but this only applies to urban work. However, devices for installation inside the car interior are simpler in terms of installation, but they are cheaper, in accordance, and will work worse than external ones.
To date, you can find a variety of hybrid products on sale, which can be used for all the above needs - and watching programs and listening to FM - radio stations, and navigation. There are also models with the function of switching reception from highway to city and vice versa. Such methods differ from each other in sensitivity and features of suppression of obstacles. So, on the highway the reception range can be increased to 80 km.
Common tandem models, equipped with a pair of pins, one of which is intended for watching TV programs, and the second - for listening to radio programs. Of course, to use such devices for their intended purpose, special equipment will be required.
How to make your own antenna for the radio
In that, to Assemble the Antenna for Listening to FM Radio Receivers |, the main difficulty is the constant oscillation of the car body. Therefore, simple household antennas for terrestrial use will not work here and will have deadlocks in terms of reception. For a conventional terrestrial device is exactly the same, from which side the signal will be given, but for that, that is constantly in motion, requires a special approach to assembling your own hands.
Properly assembled car antenna must have the following characteristics:
- not to cause unnecessary questions from the traffic police due to excessive refinement of the case;
- should get up in the cabin;
- provide reliable reception;
- have high efficiency.
A simple quarter-wave vibrator in this case is ill-suited due to such shortcomings:
- it is difficult to manufacture;
- relatively large;
- difficult to mount;
- may interfere with movement.
The best option for a car comes from the frame design, which should be laid directly under the rear window seal. It should be slightly narrowed up, in its center is a capacitor, which tunes the antenna to resonance on a particular channel. There are two receiving frequencies, it may be 27 and 65 MHC or 28,2 and 68 in accordance.
The upper resonance should correspond to the lower range of the radio broadcast. Therefore, we perform the following actions:
- we lay the wires of the MGTF brand 0,5 along the perimeter of the rear window in the form of a trapezoid;
- the pros must be in place of the addition of wires for the matching capacitor and must be recorded by the cable;
- to the central part of glass we spend two wires vertically in the direction to each other and we establish there adjustment of the condenser. The length of the wires should be 45 div. Fold them in a zigzag pattern and place under the insulation;
- solder the cable from the side, where the wire is cut in half, and on the opposite side there should be no such gaps.
Now, when the work is done, you can connect the antenna using the connector, used by communication equipment. The cable should not be too long. Passive antenna, therefore, the signal in the path can be greatly attenuated. If connecting equipment is installed next to the rear window, then it will be better.
Antenna benefits, made with their own hands
The self-made antenna has a number of advantages in comparison with factory model. Of course, they will not have a long range and are excellent to take, as you would like. But you can fit it under your car and not have problems with too much height, which often prevents you from driving normally in hard-to-reach places.
in addition, you will not need to wind the matching device, and this is an extremely difficult job. Because you need to accurately withstand the number and pitch of turns, and also to pick up a wire of the necessary thickness. in addition, all this requires sealing, which will result in you in the purchase of a number of accessories in addition to the antenna itself.
The capacitor for a self-made design is necessary because of the shortened circuit. The coefficient is 0,3. Electrical extension of the frame is performed in the middle of the loops up to the desired size, the capacitor dampens the reactance to match the cable, allowing you to tune everything into resonance. Because the broadband antenna, it can be mounted on the rear window of any car model in almost any case without any major changes. The setting should be made according to the minimum standing wave ratio.
Many motorists have long since mastered, that sometimes buying and installing a factory car antenna is not only a more expensive pleasure, but also difficult in terms of installation in contrast to homemade. And the quality of reception is sometimes worse, than in "homemade". So if you want to please yourself with the melodies of your favorite FM stations while driving, try your hand and make the device yourself. As you can see, it's not that difficult, as it may seem.