Receiving and sending radio signals require certain technical tools. If you do not swipe at something extremely complicated, then you can stop your attention on the CBS antenna. It is not difficult to make it with your own hands , at the same time it provides good opportunities for work.
How it all began?
What is CBC? This designation is used as an abbreviation for the English phrase "civilian range." It is used to designate affordable and unlicensed short-wave radio communications occupying the 27 MHz band. Depending on the country, the rules for its use may regulate work to a minimum or even be absent. Radio communications may be wearable, transportable or stationary. From professional stations (and a large number of amateur ones) they differ in price and number of available functions. In the simplest versions of this range, you can only receive and transmit audio information over relatively short distances over rugged and wooded areas. You can work to eliminate natural noise or pay attention to increasing the covered distance. But let's not rush yet.
Where do they apply?
CBS radios have a fairly wide application. They are fairly reliable and affordable means of communication, which allow for the interaction of the store with a warehouse, trucks and so on. CBC radios are also used in small fleet - boats and yachts. At the same time, the range of work on water increases significantly due to the fact that there are no serious obstacles.
The greatest use of the CBS range was found as representatives of mobile communications. An example is the devices installed in cars. Portable devices are a bit trickier. The fact is that the CBS range has a wavelength of 11 meters. And the ideal antenna for it should be about 2.7 m in size. On portable devices, they have to be shortened 10-20 times. As a result, a rather large weight, low efficiency in transmitting data to a compact antenna and low efficiency of amplitude noise reduction. But thanks to the fairly significant wavelength of the CBS antenna, it can work even if there are significant obstacles. It is well suited for rough terrain and forests.
Helpful information
CBC radio station allows you to contact the police, ambulance, fire and emergency services thanks to special dispatchers. It should be noted that such an opportunity is not always there. Channel 9C is allocated for this purpose. But, alas, in practice this can only be found in Moscow and St. Petersburg. In the rest of the territory, it is better to use channel 15C, through which you can establish communication with drivers on the tracks. Additionally, at 19C you can pick up on ham radio. All of these people can be called for help. The main thing is that there would be enough power to send and receive a response signal. And now let's look at how to make an antenna with your own hands.
Theoretical training
So, for our homemade put forward a number of requirements:
- It should at least partially provide protection against atmospheric and industrial interference.
- It is necessary to take care of the "ground" for the normal reception of signals.
- To transmit data to the antenna, it must be configured.
If we talk about the design, then there are two main options: horizontal and vertical execution. Each of them has its own characteristics. To find the optimal solution, the antenna is often placed at 45 degrees. Vertical execution is considered more complex, but also better. It requires higher resistance than horizontal. In addition, the latter option is more dependent on the distance to the ground - the further it is, the higher the resistance. To meet various design requirements, several possible designs will be considered. If desired, without greatly complicating everything, they can be improved. So, how to make an antenna with your own hands?
Very simple option
We will make from improvised materials. From the purchase - only UNF connectors and RG-58 cable. The antenna sheet will be equal to the wavelength. By adjusting to resonance, it can be shortened and made a little longer. If the transmitter is coaxial, then the power must be balanced. The easiest way is to use low-frequency ferrite (from 400 to 2000 NN). When creating a C-B antenna with your own hands, a transformer from a computer power supply can act in its role. It should be noted that standard yellow rings are not suitable, therefore, two turns of cable must be wound around the core. And here one question becomes relevant. Namely - which cable for the antenna to choose? Suppose that we need an optimal solution in the price / quality coordinate system. In this case, you can pay attention to the usual piece of wire 20,75. It is divided into two conductors that are soldered together. The total length should go eleven meters. Moreover, the observance of equality of arms is not a critical moment. As an insulator, you can use a plastic ring - for example, from a baby rattle.
Dipole Walkie Talkie
With your own hands, a C-B antenna of this type can be easily made. After all, a dipole is considered very easy to learn and implement. You can create a device suitable for long-term maintenance-free operation. In addition, it can work well in not the most favorable conditions. What is a dipole? In fact, this is the simplest and at the same time the most common antenna, presented in the form of a symmetrical vibrator. The simplest implementation option is a straight-line conductor, the length of which is equal to half the wave, powered by high-frequency currents from the generator. In simple words, take two identical pieces of wire, stretch sequentially in space. In the center of this design, a cable is connected, from which the signal is transmitted from the dipole to the transceiver and back.
DIY antenna can be done vertically or horizontally. The first option is more suitable for establishing local communication, and the second - long-distance. If the dipole is at an angle, then both options are available.
We design a dipole
Before you start to do something, you need to calculate what we need. It should be understood that the geometric length of the dipole will be slightly less than that calculated by the formula. Why? This is due to the process of generating capacitive current at the ends of the antenna, which is equivalent to increasing its length. The exact length of the dipole (which takes into account the shortening factor) can be calculated using formulas that will not be given here, since technological means can be used in the form of simulation programs to achieve this. As such, MMANA was used. So, it turned out that the top point should be at a height of three meters, the center - 2.5, and the bottom - 2 m. The length of the shoulders is 2.57 m, the wire selected to create the antenna has a diameter of 2 millimeters. This design has a resistance of approximately 75 ohms. This is equivalent to SWR = 1.5. You can select a balancing device to power the antenna. It is essentially a balancing transformer. Why is it so, and not, say, through a coaxial cable? The fact is that a dipole is a balanced antenna. And she will not be able to eat from the cable, because it is an asymmetrical line.
Assemble the antenna
So, for creation we need:
- Plumbing plastic coupling. Suitable with a diameter of 50-55 sentiments.
- Socket SO-239.
- Plumbing plugs commensurate with the previously selected coupling.
- Screw-ring in the amount of three pieces.
- Three nuts and six washers.
In the coupling, a plug for fastening is made in 6 millimeters and for a 16 mm connector. Then you can connect or assemble the balloon. We will imagine that you do not want to buy. Therefore, we take a ferrite ring with a permeability of 600, a piece of wire with a cross section of 0.5-1 mm. We fold the wire three times and begin to wind it around the ring. After the full-fledged coil of the C-B antenna is ready, the winding is fixed with an insulating tape or clamps. We mount the balloon into the workpiece, after which we solder the connector. The design is almost ready. It remains to measure the required number of wires for the best antenna to fix them on the workpiece. Thickness does not play a role here. As an example, you can take three meters of 1.5 mm. By the way, although the program has calculated that it is optimal - 2.57, it is better to take a little extra. Therefore, three meters. We solder everything - and our antenna is ready.
Customization and individual specific points
Since the dipole is a symmetrical antenna, the length of the shoulders should be the same. When creating the first devices, it is advisable not to deviate from these parameters. And it’s better to take a little more than the calculations indicate, because you can always cut it off, while welding is much more difficult. As a result, you can get a fairly simple and versatile antenna. You can collect it in an hour. Pretty good considering the satisfactory result.
For auto
A modern vehicle must have a radio or even something more. Navigation, television and radio communications are far from a complete list. But very often you have to buy something you want yourself. Or do it. For example, do-it-yourself car antenna for the possibility of radio communications. How to implement this? Conventional antennas will not work. Why? The fact is that vehicles often move during communication sessions. And traditional antennas in this case will have a certain “dead” reception area. Even if you drive in such a way as to prevent this from happening, disconnection will still occur during maneuvering.
Summing up, we can understand that a do-it-yourself car antenna must meet the following requirements:
- To have a high coefficient of performance (after all, CBS is needed not only to listen, but also to transmit information).
- Ensure reliable operation at the selected frequency.
- Fit in the cabin.
- Do not raise questions from traffic cops regarding the completion of the buildings.
The specifics of car antennas
A quarter-wave transmitter can be dropped right away — it's too big. Our CBS radio station in this case will not satisfy its size. But if the machine has a frame structure, then you can take advantage of it. In order to tune the antenna in resonance with the required frequency, a capacitor is used. But what to do with the length? One of the most popular solutions is the design of the antenna in the form of a spiral. Another, not inferior in popularity, method is to make the antenna in the form of a trapezoid. In this case, it is recommended that the length of the CB antenna be as follows: the top face is 56.5 cm, the bottom base is 66.5 cm, the sides are 22.5 cm + 45 cm for connection. As you can see, by making not very significant changes in the design, we were able to get the same thing that was necessary before. Here are just a trapezoidal antenna quietly fits in a car. In general, there is a very large space for the flight of thought.
Conclusion
That's all, the main material has been successfully considered. With your own hands, turning the antenna drawings into a finished device is not difficult. But if there is no experience, then there can be certain problems with this. As they say, the road will overpower the walking one. If you can’t create a CB antenna from the first call, you should not be disappointed. Perhaps something was poorly soldered or poorly executed, forgot to connect a power source or something else. In addition, even if everything is done correctly, it cannot be ruled out that a certain element burned out or was produced with marriage.