Having experimented with the communication range depending on the terrain and having made a number of conclusions for myself, I focused on working in a network of Internet relays LPDnet.

It is also worth mentioning the first experience of working through a crossband. One afternoon I unsuccessfully called Kolya RN3KK on 433.500 (before that, calls were made at a pre-agreed time) and Sergei RN3KU answered me. At that time, he had a Yaesu FT-8800R and could easily listen to two frequencies at once. Word for word and he suggested that I make a crossband 433.500<-->145.500 so that I can call RN3KK there. There were already real radio amateurs there, of whom you still see quite rarely on 433 to this day. In general, having called RN3KK on 145.500 several times, I did not hear him, but other radio amateurs answered. After telling me who I am, where I’m from and what I work from, they told me that Kolya RN3KK hasn’t been here (145.500) on FM for a very long time, but works in SSB on 144.300. Communication with Kolya RN3KK failed that day, but I met Sergei RN3KU, who later crossbanded me several times to the frequency of the local Echolink. For which I thank him very much!

It was possible to work in LPDnet without problems only from the balcony, because... there were the best indicators for reception/transmission. Climbing around the site LPDnet, I found many descriptions on the manufacture of antennas, but one caught my attention - the Kharchenko antenna.

And it attracted me, first of all, because of its ease of manufacture (it is made from one piece of wire), has a pronounced directivity (when using a reflector) and a good gain (8-10 dB).

There were no particular problems in the manufacture of the antenna itself, except that there was nothing to make a reflector from. The antenna sheet was first made from copper wire with a cross-section of 1.5 mm 2 , but later began to be made from wire with a cross-section of 2-2.5 mm 2 because it is more rigid and does not bend under light loads. Also, the thickness of the vibrator material affects the broadband.

I hung the antenna on the balcony window, since it looks strictly in the direction of one of the LPD links. Among other things, the window plays a role rotating device– by opening and closing it, you can change the direction for reception/transmission. Perhaps the power supply to the antenna is not supplied correctly - in Kharchenko’s works and in the figure above, the feeder is supplied along one of the “arms” of the antenna, but in mine from below and immediately to the center. Distortion of the radiation pattern and large SWR values ​​are quite likely, but more on that later.

At that time, my main problem was connecting this antenna to the radio station. The cable is simply soldered to the antenna, but it is attached to the radio station via an SMA connector (in my case). I described how to solve this issue in an article entitled “ Method for crimping an RG-8X cable with an SMA connector for an RG-58 cable " As a result, my connection looked like this:

In general, the reception/transmission situation has changed dramatically for the better - I sometimes accepted the link up to 9++, and opened it with 0.5W. Before installing this antenna, I had not heard Andrey RL3QAM, when he, being at the threshold of the building where the link was installed, was broadcasting from his portable laptop with an elastic band. That day I was able to talk to him on the direct channel with 100% intelligibility. However, problems arose with soldering the cable to the antenna sheet - over time, the contact came off. This was solved by better re-soldering and careful fastening of the cable to the window frame, so as not to create a load when opening/closing the window. There was also a problem at the junction of the RG-8X cable with the RG-58 - the transition from a thick cable to a thin one. Sometimes there was a bad contact, and if the SMA connector was frequently unscrewed/screwed on, the contact in the connector itself deteriorated, until the cable disconnected from the connector at the moment of unscrewing. All this negatively affected reception/transmission.

The solution came in the form of an SMA (male)-BNC (female) adapter. The problem was to get it at that time, but now it’s on Ali.

A piece of RG-58 is bitten off and thrown away. The remaining cable is stripped and crimped with a BNC connector (Ali has straight or angled ones).

There are different BNC connectors - for different cables, with different types fastenings (crimping, soldering, screw), straight and angular. It is not difficult to crimp a cable with a connector with a screw fastening, but in any case, soldering will always be more reliable and better. But for experiments this will do.

Straight connectors are crimped in the same way:

As a result, everything looks much more beautiful and reliable:

After using such an adapter, problems with bad contact where the cable was attached to the station connector disappeared. Various other adapters also exist, such as SMA-PL.

The main problem with them is their availability in stores and their prices. The original ones from Yaesu are an order of magnitude more expensive than these unnamed ones.

The next problem that had to be solved was power problem. It consisted in the fact that my portables were powered by rechargeable batteries. Batteries tend to discharge, and charging the batteries requires time during which the radio must be turned off. The time was 10-14 hours. Those. During this time I was unable to receive or transmit anything. Having noticed on the VX-177 the label for the charging connector as “EXT DC”, which meant “external power”, I thought about this very external power, or rather about the source. The original charger was only suitable for charging the battery, although in reception mode the station could also work from charging, but they wrote on the Internet that charging should not be used for other purposes. Someone tried it and the chargers died. And then, listening is one thing, but transmitting and listening is another. On the Midlands 500, operation from anything other than batteries was not provided, except that charging was possible not through the glass, but through the microphone connector. They wrote about this, but that's another story.

After talking on this topic with Kolya RN3KK and Andrey RL3QAM, I came to the conclusion that the simplest power source is a converted power supply from a computer. I just had one like this without need. After a visit to RN3KK, I had a disassembled power supply with big amount bitten wires, a jumper to turn on the power supply and marked places for soldering. Having soldered + and –, I started experimenting.

I decided to connect to the station not through the charging connector, but directly to the battery terminals. I just didn't have a suitable plug at hand. To do this, I first determined where the + and where – are on the battery, and then connected the power using “crocodiles”.

The station turned on and showed a voltage of 12V. Well, sometimes 11.9V.

Everything would be fine, but when receiving signals from the speaker, in addition to the speech of the correspondents, some kind of buzzing and buzzing could be heard and made intelligibility very difficult. In addition, the power supply itself made a crackling noise.

On the advice of Andrey RL3QAM, since he had experience in remaking computer power supplies to power his links, two capacitors and one ROLL stabilizer were purchased (I don’t remember the markings, but it’s not visible in the photo...).

After a visit to Andrey RL3QAM, I had a power supply with soldered-in air conditioners to filter out interference from the power supply itself and a stabilizer to reduce the output voltage to 9V (just in case). This radically corrected the situation - the buzzing and crackling in the station dynamics disappeared, but the crackling in the power supply itself did not disappear. In any case, thanks to Andrey for your help!

I did not power the VX-177 with this power supply for very long, because... Somewhat later, the option of using another computer power supply appeared, but in any case, using a power supply is much more convenient than using batteries that need to be charged. And later, somewhere I got hold of an ancient computer power supply unit, which, after modification, which consisted of soldering a jumper, installing a power switch, biting out all unnecessary wires and soldering wires of the required length to + and - 12V, worked completely silently (only the fan was spinning) and gave 10-11V. Also, subsequently I used the connection of the station through the corresponding connector using a plug. For this power supply unit we should thank Kolya RN3KK, to whom the old power supply unit was given for experiments. Later Kolya reported that the crackling power supply was like a time bomb.

But the experiments with nutrition did not end there. Somehow I came across a pair of used lead-acid batteries from a UPS. The batteries were CSB GP 1272 with a capacity of 7.2 Ah, with a voltage of 12V. The idea to try such a battery as a power source came at a time when the power was turned off for a long time. Yes, there is a native one accumulator battery, but with intensive use it will fail faster, and a new one costs much more than CSB GP 1272 or similar. So, why not, if you are at home, but without electricity (temporarily), use such a battery? In general, the experiment was successful - the station was powered by such a battery without any problems, and at 5W of power everything worked fine, there was no significant voltage drop. True, the batteries were already worn out, and they were enough for 30 minutes of transmission. I purchased a couple of these new batteries and Charger from 220V for them. Later these batteries were very useful to me, but at that time it looked like this:

The downside was that the battery could not be discharged below 10.8V, otherwise the lead plates would already be destroyed. In order to know the current voltage, you had to either look at the built-in voltmeter of the VX-177 and not see any other information on the display, or, as was done, connect a separate voltmeter and always see the current voltage level. True, the battery in the multimeter had to be changed quite often.

To summarize, I would like to note the fact that, somehow, without noticing it myself, I tried to make base station... and it worked. External antenna, power supply from 220V, PTT....

In most cases, when it comes to antennas, people think of large “dishes” that are installed outside a window or on the roof of a house. However, it is worth understanding that this is far from the case. The fact is that the size of the antenna depends on what frequency and wavelength it will catch. Naturally, if you want to catch a satellite signal in order to broadcast several dozen television channels, then you will need a larger antenna. But you don’t always need such a signal. That is why it is worth considering such a thing as a 433 MHz antenna. This device is very different from the antennas you are used to seeing on windows and roofs. It is very small and, as can be seen from the name, does not receive the longest signal waves. Why might such waves be useful? Most people don't pay much attention to them, but if you like to fill your home with various remote-controlled items, then you'll definitely need more than one 433 MHz antenna. If you learn to use their properties, you will be able to create things in your apartment such as a radio socket or even a pet feeder with remote control. Interested? Then read the article below and you will find out what this antenna is, how to use it, where to buy it, and most importantly, how to make it yourself if you don’t want to spend money on a purchase.

What kind of antenna is this?

So, first of all, you need to understand what a 433 MHz antenna is. As you can already understand, this is a device that allows you to tune a certain device to a specific frequency in order to then interact with it. By installing an antenna in a specific device, you can then send a signal to it at a specific frequency to activate and control that device. This is very useful feature in any home, as you can significantly simplify many processes. However, not everyone can do something similar - you need to be well versed in this area in order to tune the devices to the desired frequency. But if you set a goal for yourself, you can definitely achieve it. You just have to try hard, and you should start by studying this particular antenna, since it is one of the most important elements. You should definitely know that the 433 MHz antenna comes in three types: whip, helical and etched. printed circuit board. How are they different? Which one is better to choose? This is exactly what will be discussed next. It's up to you to learn what each of these antennas are and figure out which one is best for your specific purpose.

Whip antennas

How can you get a 433 MHz antenna at your disposal? It’s quite easy to make it yourself, but you can also buy a ready-made one, which will cost you a little more, but will save you a little time. In any case, you first need to decide which type you want to get. And the first type we will talk about is a whip antenna. Its main advantage is that it has the best specifications compared to other types. That is why people almost always make a choice in its favor. Moreover, it is much easier to do it yourself. So overall, this is the best 433 MHz antenna, whether you make it yourself or buy it in a store. However, you shouldn’t think that she’s perfect. If this were the case, then there would simply be no need for other types. That is why it is necessary to separately consider the disadvantages that this type of antenna has so that you are aware of all the features before making a purchasing decision.

Disadvantages of whip antennas

The first disadvantage that 433 MHz whip directional antennas have is their susceptibility to environmental influences. The problem is the very strong reflection and interference that occurs if you try to use the antenna indoors. Thus, it is more suitable for portable devices rather than home appliances, since in homes, due to the small amount of space, obstacles such as furniture and walls, the signal may be distorted, lost and not reach the target device. So first of all, you should think about the purpose for which you are going to use the antenna, and then decide whether to buy it. However, this is not the only drawback of whip antennas, which initially might seem ideal. It turns out that the pin in this antenna must be almost (or completely) parallel to the ground plane on which the structure itself is located. As you can easily understand, this is very difficult to implement in small household appliances. Therefore, you may have already figured out that 433 MHz whip directional antennas are best suited for various portable devices of more or less large size or those on which the antenna can be installed externally. It is not recommended to use such antennas at home. But what should replace them then? As far as you remember, there are two more types of such antennas, so it’s time to pay attention to them.

Helix antennas

The easiest thing you will get is a homemade whip antenna at 433 MHz, however, as you may have noticed above, it is not ideal. Therefore, it is worth paying attention to other types, for example, a helical antenna. How is it different from a pin one? Firstly, it also has good technical characteristics, so in this regard you can use both the first and second types with complete peace of mind. What about interference? It turns out that they are also present in a spiral antenna in enclosed spaces, and sometimes they are even stronger than in whip antennas. Therefore, it remains to look at the last parameter - compactness. As you remember, whip antennas, due to their design, must either be placed on the device body or inside it, but at the same time there must be quite a lot inside the device free space, which is difficult to achieve when it comes to small household appliances. And in this parameter, the helical antenna bypasses the whip antenna, because it is extremely compact and will allow you to make almost every device in your home radio-controlled. Naturally, a homemade 433MHz directional antenna made this way will take you much longer, but if you are looking to buy an antenna, then you should definitely look at the helix versions as they can come in handy and help you out a lot.

Antenna on board

If you need a high-quality compact collinear antenna at 433 MHz, then you should definitely pay attention to this type, that is, antennas that are embedded in the board. This means that this type is impossible (or very difficult) to make with your own hands, so they will be considered exclusively as purchased. What are their advantages over the two types described above? First of all, they have good characteristics. Of course, not as impressive as the previous two options, but good enough for everyday use. Their main advantage is their compactness - such antennas can be placed in absolutely any device. But, as mentioned above, their main drawback is that a do-it-yourself dual-band 144-433 MHz antenna on a board is something fantastic. That is why this option will not be considered further for the reason that the rest of the article will be devoted to creating an antenna with your own hands. How difficult is it to do? What will you need for this? You will learn about all this further.

Necessary calculations

But if you decide to make an antenna with your own hands, then you will need a lot of theoretical knowledge on this topic. The fact is that any deviation in the manufacturing process will not allow you to tune the antenna to receive a specific frequency. Therefore, everything must be done very accurately, so it is always recommended to start with calculations. Making them isn't that difficult because all you need to calculate is the wavelength. Perhaps you understand physics, so it will be much easier for you, since you will understand what you are talking about we're talking about. But even if physics isn't your strong suit, you don't necessarily need to understand what every variable means to make the necessary calculations. So, how is the length of a 433 MHz antenna calculated? The most basic equation you need to know is the one that will allow you to calculate the required antenna length. To do this you need first since the length of the antenna is one fourth of the wavelength. Those people who understand physics can themselves calculate the required wavelength for a specific frequency: in this case it is 433 MHz. What needs to be done? You need to take the speed of light, which is constant, and then divide it by the frequency you need. The result is that the wavelength for a given frequency is about 69 centimeters, but at this detailed settings It is better to use more precise values, so it is worth keeping at least two decimal places, that is, the final result is 69.14 centimeters. Now you need to divide the resulting value by four, and you get a quarter of the wavelength, that is, 17.3 centimeters. This is the length your 433 MHz J antenna should be, or whatever style you want to use. Remember that regardless of the type, the length of the antenna must remain the same.

Use of the received data

Now you need to put the data you have gained into practice. Antenna 144-433 MHz can be made different ways, however practical use theoretical information should always be the same. What is it about? First, you should always use a wire that is a few centimeters longer than the desired antenna length. Why? The fact is that in theory everything turns out quite accurately, but in practice everything will not always work as you plan. Therefore, you should always have some reserve in case something goes wrong or the signal is not picked up at the frequency you wanted. You can always easily bite the wire in a specific place once you determine the required length. Secondly, you should always remember that the length is measured from the place where the wire comes out of the base. Thus, the resulting 17 centimeters should be measured from the base of your antenna. Most often you will have to use slightly longer wire as you will need to solder your antenna. A 433 MHz whip antenna will work better the more pins you use, so you'll want to make sure each one is the same length.

Preparation of materials

So, the theory is over, it's time to get down to practice. And for this you will need to take everything you need to create your own antenna. First of all, these are the wire or rods that will make up the main receiving part of your antenna. Secondly, you will need a base for your antenna. It is advisable that it has several holes that you can use to attach pins. If these holes are missing, you will have to either drill holes or solder directly to straight metal, which is not very convenient and will not allow you to correctly calculate the length in advance. Therefore, use a base with pre-drilled holes. Naturally, you will need other things, such as a soldering iron, but everyone knows about this, so there is no point in listing all such items.

Execution of work

First of all, you need to prepare material for further work. To do this, you need to clean all the pins, tin them and treat them with flux. After this, you need to cut the pins to the required length, but do not forget to leave a little length so that you can then adjust the finished result. Then you need to start soldering - each of the pins needs to be soldered on the back of the antenna, and then take another one that will be attached to the antenna. Its length no longer plays a role, since it will serve as a holder and will not be responsible for receiving the signal. It also needs to be soldered, after which you can already admire the result of your work.

Final steps

Well, your antenna is now ready to use. All you have to do is take the final steps. Trim the excess length of the pins so that the signal is received perfectly. If you have heat shrink, use it. And remember - this is just one example of a homemade antenna. You can also make a helix antenna, but your design of a whip antenna may look completely different. However, calculations to obtain the length of the antenna are relevant in any case, and the steps to create an antenna with your own hands will also differ only in details.

In this publication we'll talk not about how to improve it, but about how to check the result on your knees.
Some radios, such as the popular Midland G5, can be modified even by complete beginners. But any modification must be controlled, otherwise a good thing can be ruined.
For primitive control, the same primitive field indicator is quite enough for us.
To make it, we will need an indicator head with a sensitivity of up to 200 µA (preferably), a pair of diodes, a piece of wire and a soldering iron with solder.
The indicator head can be pulled out of an old broken tape recorder, for example this one. I personally wouldn’t raise my hand to cheat the worker. Or buy it in chip and dip, for example.

Diodes are suitable for example KD 419, KD514 (and generally KD5XX), KD922, GD507, D18, D20 (preferably germanium)

I used the same circuit, only even simpler - without capacitors (I simply didn’t have it on hand at that time). Everything works great, it responds perfectly to the quarter-wave pin, and the Yagi puts the needle at the speed of light.

The length of the antenna wire should be quarter length, i.e. for 433-446 megahertz - about 16.5 centimeters. We don’t need to worry about millimeters; we don’t need the device for precise measurements, but to control soldering, etc. You can even install a cheap telescope antenna for 50 rubles and get a variable length (and a corresponding variable control frequency)

When measuring, do not forget about the polarity of the antenna. If the antenna on the radio is an ordinary pin, it is advisable to keep it coaxial with the indicator antenna and at approximately the same height, otherwise the device may not respond. Also check the operation of the radio at the same distance (before and after modifications)
It is very convenient to use such an indicator to check new homemade antennas. Sometimes it happens that the soldering is bad, or the contact has come loose, or something else. And so - I pointed the antenna at the indicator - and you can immediately see whether it is working or not. It would be useful to remind you that in the absence of an antenna (if it does not work as it should), you can burn the transmitter

Images
the circuit itself

a pair of indicator heads from tape recorders




Photo of my indicator front and back.



There was a resistor on my indicator head, do not pay attention to it (it is visible from the back).

Thanks to this indicator, I have already caught the BNC connector unwinding a couple of times on homemade antennas, as well as poor antenna soldering on the Midland G5.

Several collinear antennas are described below, all of them are designed to be made of aluminum wire with a cross-section of 6 mm square (recloser wire from which the PVC insulation has been removed). Aluminum wire was chosen because aluminum, unlike copper, is more resistant to corrosion and has slightly lower electrical conductivity, i.e. An antenna made of aluminum works no worse than one made of copper, but does not rot under our acid and alkaline rains.

All antennas are made according to the “J elbow and phase-shifting loops” scheme and are bent from a single piece of wire; by default, the antennas are calculated for PMR 446 MHz, but can be easily converted to LPD 433 - 434 MHz.
The width of the short-circuited line forming the J elbow for all antennas is 20mm, the length is also the same 1/4 wavelength or 168mm, only the feeder connection points are slightly different.

Collinear antenna 2 x 5/8 plus 1/2 L

Collinear antenna 3 to 5/8 plus 1/2 L

Collinear antenna 4 to 5/8 L

Collinear antenna 4 x 1/2 L

The antennas are adjusted by selecting the location where the feeder is connected to the J elbow and by slightly trimming the last, topmost element, since only this element is subject to the shortening factor.

The antennas together with the J elbow, as mentioned above, are bent from a single piece of wire; the “counterweight” going down from the J elbow is then mounted using the twisting method.
When assembling the antenna, all distances are measured from the center of the wire, and not from the boundaries, the measurement accuracy should be no worse than 1 mm.
Please note that the measurement error in the elements of the main antenna fabric is cumulative, that is, if when bending the first knee, counting from the bottom of the J knee, we made an error by +2 mm, then we can correct this by making the length of the phase-shifting loop that follows it less by 2 mm. If the error there is +2mm, then the total error will be +4mm, if we make an error by another 1mm in the next leg, then the total error will already be +5mm, which will inevitably lead to a drop in the antenna gain as a whole at the design frequency.

So that those who want to repeat the antennas can imagine how to bend the antenna, here is a photo of a ready-made antenna 4 x 1/2 L on PMR:

When connecting an antenna, it is desirable that the feeder be diverted at least 1/2L at an angle of 90 degrees to the antenna surface.

The collinear antennas themselves, made of wire with a cross-section of 6 mm square, do not have structural strength and are not able to support themselves, so they are secured to a plastic fishing rod with polyethylene ties. As tests have shown, the plastic of Chinese fishing rods is radio transparent and does not affect the parameters of the antennas.

Phase-shifting loops can be made in another way - in the form of 1 turn, with such a diameter that its circumference corresponds to the length of the phase-shifting loop.

If it is necessary to recalculate one of the presented antennas at 433 MHz, then all its elements are lengthened in proportion to the change in frequency, that is, the length of each element, including the lengths of the J elbow and phase-shifting loops, must be multiplied by 446/433 or 1.030023094688222.

You can install a walkie-talkie in your car using various reasons. This could be a future car trip with friends on vacation, or even a passion for eavesdropping on other people's conversations in a car. But basically such a device is installed either by taxi drivers or truckers. Whatever the reason, a walkie-talkie antenna must be installed for the unit to operate properly.

This installation may seem simple only at first glance. In fact, there are several nuances that need to be taken into account when choosing, manufacturing and installing an antenna.

Types of external transceiver devices

There are two types of antennas for radios in a car:

• mortise:
• with magnetic base.

They are not fundamentally different. The main difference is that a built-in antenna for a walkie-talkie is stationary, while one with a magnetic base is removable; it can be removed or moved to another location.

Built-in antennas

From the name it is clear that they are attached in one place. Therefore, before installing this device, you need to carefully think about where to install it so that it doesn’t interfere and the reception is good. You should also take into account the fact: the antenna for the radio in the car must be attached to the supporting body. If you neglect this postulate and install it, for example, on the hood or wing, that is, on a false mass, the efficiency of the device is lost by 30-40%. Some car enthusiasts are trying to improve this system and try to connect the mass with additional wires to the body. But still the desired effect cannot be achieved in this way. Although sometimes it works, it is extremely rare. As a rule, such an antenna for a walkie-talkie still works quite well for reception, but transmission using such a device is very bad.

Height will be an important factor when installing. The higher the device is installed, the more efficient its operation will be. For example, if you install an antenna in a car bumper, the transmission and reception range is reduced by half.

It is optimal to install the antenna in the middle of the roof. Some craftsmen convince that it can be installed with equal success on a bracket in the corner of the roof. But there are some points that need to be taken into account for expedient installation. If installing a radio is needed only for driving around the city, then the mounting option on a bracket is completely suitable. This will not affect the operation of the device due to the fact that a directional effect will not be created in the city due to additional reflections. If this device is installed for long trips along the highway, then installing the antenna for car radios in the corner of the roof would be impractical.

Installation of a mortise antenna

When installing the antenna in the roof, it is necessary to reinforce the joint with an additional metal plate. This is necessary primarily for greater connection strength.

The canvas itself and the extension coil should be as far as possible from all vertical metal planes that are located parallel to the base of the antenna. The minimum distance between them should be 50 cm. If this factor is neglected, the device will not work properly due to the high reactivity of the space. This nuance should be taken into account when installing antennas for car radios, including trucks.

Antennas with magnetic base

An antenna with a magnetic base, or, as it is popularly called, “magnetic”, can be used on any car. But there are several points that should be observed when installing it.

1. For more efficient work And correct settings This device should also be installed on a supporting body.
2. Under no circumstances should you change the length of the cable from the antenna. This will make it impossible to configure or will degrade the performance of the device.
3. It is not recommended to roll the cable into a coil; this can also adversely affect the operation of the device. If the cable is longer than necessary, then you just need to carefully lay it around the cabin.
4. The position of the antenna on the roof can be arbitrary. This type is not too demanding on location. But if there is a need to dismantle the device, then the next time you have to use it again, you should try to put the antenna in the same place.

DIY radio antenna

The most simple option The solution to this type of car upgrade would be to purchase an antenna. But it can also be made independently. To do this, you can follow the step-by-step instructions.

1. Take a simple antenna-whip from a radio. All it needs is a foundation.
2. Buy metal knitting needles with a diameter of 3-4 mm.
3. Make an extension coil. It should be on a 10 mm mandrel. For it to work properly, you need to wind 44 turns of PEV 0.41 wire.
4. Next, you should solder the ends of the coil to the brass bushings. This will ensure good contact and create additional structural strength.
5. After this, you need to connect the spokes to the bushings at each end. It is important that both knitting needles are the same length.
6. Next, the SWR meter is adjusted and the spokes and coil are adjusted.
7. Then the antenna for car radios is directly installed.
8. Open the ceiling.
9. Unscrew the standard antenna, unscrew 2 screws, remove the board active amplifier and carefully remove it.
10. Solder a 50 ohm in place coaxial cable. It is important to maintain the order of the veins, mass to mass.
11. All connections should be sealed.
12. Route the coaxial wire under the trim and rug and lead it to the radio.
13. Attach the antenna in place.

If all steps of the algorithm were completed correctly, then the antenna for the walkie-talkie is made with your own hands. You can proceed to the next stage - configuration. But, according to experts, this is a rather complex and delicate process. This is due to many aspects: you need to be able to solder carefully, winding the coil is also not easy to do correctly. As a conclusion: homemade device can only be made by a sufficiently trained amateur. Otherwise good antenna This won't work for a walkie-talkie.

Antenna setup

If the antenna is installed correctly and correctly, then it only needs minor adjustments. But many car enthusiasts approach this process skeptically, thinking that this element of the communication system is not particularly important for the operation of the entire device. And they are deeply mistaken. Not only the reception signal, but also the operation of the device itself depends on how correctly the antenna for the radio is installed and the device is configured. Moreover, if you configure the radio incorrectly, you can damage not only the transistors of the output stage, but also ruin the device itself.

Step-by-step setup instructions

The radio antenna should be configured according to the following algorithm:

• For correct settings, you need to have a device such as an SWR meter.
• The setup process must be done away from structures made of metal, concrete or wood. It is advisable that trees be placed no closer than 15-20 m.
• It is highly advisable to stop the car on a clean, level and dry surface.
• Antenna tuning may also be affected by nearby vehicles with radio antennas. Next, you need to install the SWR meter according to the instructions, that is, between the radio itself and the antenna. In this case, you cannot use an amplifier.
• Measurements with the device must be made on several different channels and at different points. It is advisable to carry out this procedure in different networks. This will allow you to see the real picture of the settings.
• The next step is very important: you should find the minimum SWR indicator, ideally the indicator should be equal to 1, it is advisable to write down where it is located. If it is located at a frequency below the specified one, this means that the antenna needs to be shortened. Accordingly, if it is higher, you need to lengthen it.
• The next step is to shorten or lengthen the antenna, depending on the SWR readings of the device. Lengthening or shortening is the process of adding or, conversely, unwinding turns from the matching coil, and not shortening the antenna with wire cutters.
• After this, you again need to look at the SWR meter. Repeat the procedure until the desired result is achieved. Sometimes in some models it is not possible to achieve the ideal indicator, but this is not a big deal. If the indicator deviates, for example to 1.5, the losses will be equal to 5%. The walkie-talkie will work quite normally even with an indicator of 3. If an amplifier is built into the system, you need to take into account that the minimum indicator should not exceed 2.

If all steps of the algorithm are completed correctly, the antenna for the radio in the car will serve perfectly.