Do I need any special permission to use walkie-talkies?

In an amicable way, the buyer must register his radio station at the local Radio Frequency Center, but this registration is optional and lies entirely on the buyer's conscience. No special permits are required as the 433-434 MHz range on which the portable radios sold in our stores operate is not licensed.

How to tune the walkie-talkies to each other and start a conversation?

On each walkie-talkie participating in the conversation (there can be as many as you like), it is necessary, using the buttons (or menu), to set the channel number and subcode. If the values ​​of these parameters on all radio stations are identical, then they will be able to receive each other's transmissions. To start broadcasting, you need to press the PTT (push to talk) button and, without releasing it, say a message into the microphone - the rest of the participants will hear it. Releasing the PTT key switches the radio to receive mode.

How can several subscribers talk at the same time?

To do this, their radio stations must be tuned to the same channel and subcode.

How to improve the quality and range of communication?

Some radios support various types of interchangeable antennas (for example, JJ FreeQuency GIGA), extending the range up to 16 km. Others can be connected to an external car antenna. Antenna change is the only solution to improve the quality and range of communication. It is clear that we do not touch upon the geographical features of the area.

Is it possible to make sure that no one can overhear the conversation?

The vast majority of radio stations operate on any of the 69 unlicensed 433 MHz channels. To communicate with other radios, they must be tuned to the same channel and subcode. Subcodes or subchannels are used to skip messages using a different code. In order to avoid interfering with other users in the conversation, there are 3519 combinations of channels and subcodes. Some radio stations are equipped with the ability to encrypt speech (analog scrambling) with varying degrees of security: from the simplest methods (spectrum inversion) to complex ones, with a large number of coding options.

What are the additional functions of radios?

• CTCSS- group codes. Using the CTCSS reception mode allows you to receive signals only with the corresponding code to which the radio station is tuned in, ignoring all other signals.
• VOX- the function of activating the transmission by voice. The radio will automatically start transmitting when the microphone detects your voice (or other noise). The mode can be used with the built-in microphone or with a headset and eliminates the need to press the talk button.
• MONI- radio broadcast control function. The radio starts monitoring the specified channels. When a signal arrives on one of these channels, the radio station starts broadcasting.
• SCAN- channel scan function. The radio station tunes in order to all the channels within its range, on which the broadcast is currently taking place.
• ROGER BEEP- transmission end signal. The radio plays a beep when the speaker releases the talk button.
• CALL TONE- the function of selecting a call melody.
• Vibrating alert

What is the babysitting function?

It may also be referred to as the "local observation mode" by various manufacturers. This mode is very similar to the VOX mode (voice or noise activation of the walkie-talkie), with the difference that it ignores small short sounds and uses only the highest microphone sensitivity level. When the local monitoring mode ("babysitting" function) is on, the radio station, having fixed the sound, will broadcast for some time. If the sound continues, then the broadcast continues. As a rule, this mode is used to monitor sleeping children: you can leave one radio station next to the child's bed, and take the other with you.

Terms asked

Nowadays, the C-BI (CB - citizen band) radio communication is gaining more and more popularity among motorists.... It is especially relevant for those who often travel long distances. These are truck drivers on trucks, and travelers, and other people whose activities or recreation are associated with frequent trips.

Modern radio stations in the 27 MHz range are very diverse in their dimensions, technical characteristics and layout. Devices with a remote front panel are also common. In some designs, all controls and displays are located on the tangent. In other words, the industry produces products that can satisfy the most fastidious customer.

We will talk about how to properly install and connect a radio station in a car, and also touch on the topic of antenna tuning.

Table of contents:

Antenna installation

It is customary to begin the installation of a communication device in a car with the installation of the antenna. Flush antennas require good contact with the metal of the car body (body). This is necessary for the correct radiation pattern. The attachment point of the bracket must additionally be protected from corrosion with any preservative. Ordinary Movil will do. If possible, the antenna rod should be positioned as close to the center of the roof as possible. This is especially true for antennas with a magnetic base.

Please note: Placing on a boot lid or rear bumper will result in malfunction and distortion of the beam lobes. This means that the maximum gain will not be distributed correctly and the antenna will only work effectively in certain directions. For example, if an antenna with a magnetic base is located at the rear of the car roof, then its maximum efficiency (both receiving and transmitting) will be directed towards the front of the car.

Antenna cable placement

When laying the antenna cable, start by laying it on the roof. In order not to spoil the paintwork, it is better to purchase special self-adhesive pads. The cable will rest on them without touching the roof surface. However, it should not be too tight.

It is advisable to run the cable inside the passenger compartment through the trunk lid (or the fifth hatchback door), and not through the side doors. Inside the passenger compartment, the cable should be pulled under the skins, while it is undesirable to attach it to the standard electrical wiring harnesses. It is better to place it separately. Secure the cable with nylon ties.

Important: Avoid strong bends, kinks and deformation of the cable.

The length of the cable supplied with the antenna is usually 3.5-5 meters, so make sure it is long enough. It is not recommended to lengthen or cut the cable - this can lead to a violation of its coordination with the antenna and deteriorate its technical characteristics.

Placement and connection of the radio station

Position the device so that it will not obstruct access to controls, limit visibility and distract the driver. At the same time, the ease of control of the device should be ensured. If it is difficult to find a suitable place for installation, then preference should be given to devices with a remote front panel. It is always easier to place a small-sized panel, but the block can be fixed in any convenient place. The only requirement is that you cannot put it in places where it will be heated from various sources.

All radio stations are designed to be supplied with a voltage of 12-13.8 V. It is advisable to lead the power wires from the battery. Moreover, both positive and negative. This will eliminate unwanted interference, which the 27 MHz band is already clogged with, especially in urban conditions. The supplied power cable already contains a noise filter and fuses. If it becomes necessary to lengthen the wires, it is most preferable to use soldering and insulation with heat shrink tubing. It will not be superfluous to hide them in a plastic corrugation.

The power cable is routed neatly, without twisting or deformation, using nylon ties to secure it.

Please note: You should not power the radio station from a standard cigarette lighter, and especially from lampshades, because their wiring may not be able to withstand the current drawn by the transmitter. This should not be taken lightly, since there are many cases of car fires.

It is also a good idea to install an additional power switch in the cabin. This is easy to implement using a relay and a button, or to purchase a ready-made switch. The latter must be designed for a current of at least 20 A. You can place such a switch anywhere, but remember - it must be fixed, and not dangling from wires.

Antenna tuning

Antenna tuning is a very important procedure and should not be bypassed. The efficiency of work and the quality of radio communication will depend on this. It is best if a specialist does it, but with minimal equipment, some types of antennas can be tuned on their own.

Tuning the antenna consists in bringing it into resonance with the frequency of operation. The frequency at which the drivers work is 27.135 MHz (channel 15).

To configure you need:

• The SWR meter is an instrument for measuring the standing wave ratio. Simply put, this parameter indicates the quality of the antenna and radio match.
• a piece of cable with “UHF-male” connectors at both ends (made independently) with a length of no more than 0.5 m. In what follows, we will call it an “adapter”.

The measurement is carried out according to the following algorithm:

1. connect the antenna connector to the "ANT" socket of the SWR meter;
2. connect the adapter to the antenna socket of the radio station, and the other end to the "TX" socket of the SWR meter;
3. turn on the radio and set the frequency to 27.135 (or channel 15);
4. press the "PTT" button on the tangent and watch the readings of the SWR meter arrow

IMPORTANT: NEVER TURN ON THE RADIO STATION WITH ANTENNA DISCONNECTED!

The normal value is in the range 1-2, the closer it is to one, the better. If the value is normal, disconnect the SWR meter, connect the antenna to the radio and use it to your health.

If the value is greater than 2, the actions are as follows:

1. write down the resulting SWR value;
2. set the frequency to 27.405 (or channel 40)
3. press "PTT" and look at the readings of the device.

If the SWR becomes lower, this indicates that your antenna resonates at higher frequencies and the rod needs to be made a little longer. To do this, we loosen the fastening of the pin to the base (usually 2 hexagon screws) and slightly extend the pin. It must be remembered that in this case the adjustment possibility is small.

If the SWR has become larger, then this means that the antenna resonance lies below the frequency of 27.135. In this case, you need to shorten the pin by about 1 cm and measure the SWR again. If it becomes less than the value that was obtained in the first measurement, then you are on the right track. Thus, by gradually decreasing the length of the pin, excellent readings can be achieved.

Read the supplied instructions carefully before using the radio.

Approved for use in the country where you live. In the Russian Federation, these are LPD stations with an output power of up to 0.01 watts and PMR with an output power of up to 0.5 watts. Recently (since November 2011), they have been supplemented with CBS walkie-talkies with an output power of up to 10 watts. All these radios are easy enough to purchase, and you do not need to register them. Also in our country it is possible with radio stations of the amateur bands, but only after a rather complicated procedure for obtaining a callsign and category.

Before you tune a station to a particular frequency and operate on that frequency to transmit, make sure that this frequency is within the range in which it is allowed to operate. Fixed dialing stations are usually designed so that they simply cannot be sent to the out-of-band frequency. But there are also exceptions. For example, some of the expensive C-Bi radios have some of the channels that cover the amateur 28-MHz range. It is prohibited to work on these channels for transmission without permits. If the station is an amateur, then it is usually rebuilt smoothly or in small steps, and the set of frequencies and powers in which you are allowed to work depends on the so-called category.

This aspect is also important. If your station is multi-band, and the antenna is designed only for a certain range, it is strictly not recommended to work on it for transmission in other bands, even if you have the right to do so. The radio can be damaged by the output stages of the transmitter.

If the radio station has a smooth tuning along the band using the vernier, tune it to a frequency close to the one to which the other station is tuned. Let the owner convey something. At this time, while working on reception, tune your station more precisely according to the maximum signal (with amplitude modulation), no distortion (with frequency modulation) or natural sounding of the voice (with single sideband modulation). If you have a fine adjustment knob, be sure to use it as well.

An analogue tuning station can be equipped with a so-called digital scale. If there is one, setting the operating frequency is greatly simplified: just get the indicator readings that correspond to this frequency. Equally convenient is the optical scale, which is almost as accurate as the digital one.

Synthesizer stations usually allow this parameter to be entered in several ways. If you know the exact frequency, enter it directly using numbers from the keyboard. Or tune the station with the so-called knob - an electronic-mechanical emulator of the tuning knob. The frequency will be displayed on the screen.

Tune a station with a fixed channel set using the arrow buttons. One of them decreases the channel number, the other increases. The instructions indicate which channel number corresponds to which frequency.

If the station has a fixed tuning on one channel, communication between two such devices is possible only if these channels are the same. Some imported single-channel stations from the early nineties are designed to use replaceable quartz resonators. Be sure to turn off the walkie-talkie before changing them.

Usually there is no space for a CB radio on a car. We fix the bracket on a solid and rigid surface: firstly, vibrations are harmful for the station, and secondly, in an accident it will not break. The rear panel must be ventilated - behind it is the transmitter heatsink. And the panel with the speaker has its own requirements: it cannot be pressed, as this drowns out the sound.

In a passenger car, the stations are usually placed in the receiver socket, on the side of the driver's seat, on a shelf at the front passenger's feet, sometimes they are also mounted on the dashboard. In a truck, they are often mounted above the glass. The usual place of the tangent is next to the station, on a special tongue. No less popular is the rubber band fastening to the salon mirror bracket.

Antenna the station gives it a load - without it, the device can burn out! The main element of the antenna is an elastic metal rod. Its minimum resonant length should theoretically be equal to a quarter of the operating wavelength. For a CB it is about 2.7 m. But such a whip can bend the roof, so antenna manufacturers shorten the rod. The loss of "electrical" length is partially compensated by the matching and extension coils located at the base of the antenna or in the middle of the whip.

The length of the waveguide cable from the antenna to the radio is not arbitrary - it is a multiple of the wavelength divided by twice the dielectric constant of the insulation. The usual length is from 3.6 to 4 m. You cannot lengthen, shorten, pinch or wrap the cable around the antenna, it will not work with such a "beard".

The antenna can be attached to the spillway, but then it will "shoot" mainly towards the roof of the car. The best antenna is the one embedded in the middle of the roof: the cable and connections will always be dry, and the operating diagram is almost circular. But not everyone will dare to hole the roof, which is why antennas on a magnetic base are so popular. Alas, they do not have good ground contact - and the efficiency is lower. By the way, the thickness of the rubber pad under the antenna base affects the performance of the system. And one more thing: you need to re-install the antenna exactly in the place where it was tuned, otherwise the standing wave ratio (SWR) will change.

Nutrition usually connect through the cigarette lighter, but it is more correct to take the "plus" from the backup fuse or a separate outlet. There are many electrical devices in the car that create interference: the high-voltage part of the ignition, xenon headlights, a generator, various relays, etc. Therefore, it is advisable to put a filter on the supply wire, for example, ferrite "latches". They are put on closer to the radio station. There are also special adapters - such, for example, is produced by KB "Berkut".

An antenna is a resonant radiator. Until you set it up correctly, it will not really work. Choosing it, we proceed from the operating frequency indicated in the passport - for the CB it is 27 MHz. We use a SWR meter to match the antenna with the walkie-talkie. We connect it between the radio station and the antenna cable. We turn on the radio station on the working channel in frequency modulation (FM) for the transmission mode - and see what the SWR is. If it is more than 3.0, the station may burn out.

To tune the antenna change the length of the pin, achieving a SWR close to unity. The pin has to be either shortened or extended. Sometimes it makes sense to additionally adjust the location for the antenna on the roof. After tuning to the main channel, we check the VSWR on adjacent channels - above and below. If the parameter changes, then the antenna is working. If a station (for example, ALAN 9001 or VEKTOR Navigator) has a built-in SWR meter, it can be used to control the alignment directly during operation in different grids.

The local communication range with a tuned antenna depends on its height above the ground. This distance can be roughly calculated using the empirical formula: Dmax = 4.1 (√ h1 + √h2), where Dmax is the maximum possible communication distance in kilometers under the condition of line of sight; h1 and h2 are the antenna heights from the ground in meters. Natural and artificial obstacles in the signal path shorten this distance. Glades, open water, and working from higher elevations can increase the range. Solar activity fills the range with additional buzz and talk from around the world. (Specialists expect special troubles at the maximum solar activity in 2012!) Recall: the signal from FM is heard farther than from AM, and SSB - single-sideband modulation - is the longest range.

It is impossible to improve communication with amplifiers. The heavy-duty station only "dusts", making it difficult to work on adjacent channels. Power from 4 to 10 W is sufficient to operate at a distance of 10-15 km between machines - but this is usually the limit of what is possible. For comparison: my record for local communication with a power of 4 W is about 46 km.

The article is written for beginners, those who are going to tune the antenna for the first time to work on the channel (frequency) they need. Those who have already repeatedly engaged in antenna tuning are unlikely to find anything useful for themselves in the article.
The article describes the main points of tuning simple single-band antennas - automotive inset, on a magnetic base, base 1/4 GPU, 1/2 (half-wave), 5/8 (five eighths).

What you need to tune the antenna

SWR meter
A device that shows the ratio of the forward (coming from the radio to the antenna) and backward (reflected from the antenna) wave in the cable.
Indirectly, this device shows that the output characteristic impedance of the radio station is equal to the resistance of the cable, and it is equal to the impedance of the antenna. You can read about what wave impedance is and how it differs from that shown by a conventional tester in the article:.
The SWR meter (SWR meter) can be purchased (the issue price is about 1000 rubles) or for a while you can ask any of your friends who have it.

Radio station
The SWR meter does not work without a radio station.
The more "grids" there are in the radio station, the wider the frequency range the radio station can tune, the easier it will be to tune the antenna to the desired frequency (channel).
With a radio station with 40 channels at 27 MHz, it is possible to tune the antenna, but it is very difficult, with a radio station that has 400 or 600 channels, it is much easier to do this.

Roulette or ruler
It will be required to measure the antenna web and determine how many centimeters to shorten or lengthen.
In principle, you can do without a tape measure or a ruler and perform the adjustment just step by step, by slightly shortening or lengthening the antenna web.

Basic considerations when tuning an antenna

The antenna must be tuned in the place where it will then stand.
That is, the antenna must be tuned in the conditions in which it will be further operated, especially if at a distance closer than 2-3 wavelengths (wavelength = 300 / frequency in MHz (for 27 MHz, the wavelength is about 11 meters)) there are some conductive objects parallel to the antenna web.
If this is a basic antenna, then a mast must already be prepared for it, which allows you to remove and install the antenna, raise and lower all this for adjustment and maintenance.
If this is a car antenna, then the car should be parked in such a way that there is exactly the situation next to it, which will be when driving it at the time of operation of the radio station, that is, there were other cars at a distance of about 5-10 meters, but on the other side there should not be be walls of reinforced concrete houses, garages, you can not stand inside an iron garage or hangar. At the time of measurements during adjustment, the car must have the doors and trunk closed. You should not stand next to the car yourself, the human body absorbs radio waves and thereby introduces losses, affects the operation of the antenna.
There should be no moving conductive objects at a distance of 2-3 wavelengths from the antenna.
All instrument connections must be secure.
You should not keep everything "on weight", with your hands pressing to the contacts somehow stripped pieces of cable that are about to fall out of the connectors or are closed.
Reliable connections are needed so that the readings of the device do not change as they please, do not float and are repeatable. If the readings are not repeatable, then this is no longer the readings of the instruments, but the weather on Mars at the moment of eating the snickers and it is impossible to be guided by such readings.

How to use the SWR meter

We connect the cable to the antenna, the other end of the cable to the SWR meter, to the "ANT" connector, connect the SWR meter "TRANS" to the antenna connector of the radio station.
We turn on the radio station and set the frequency at which we will measure the SWR.
If there is a SWR / PWR switch, move it to the SWR position.
Switch on the SWR meter "FWD / REF" to the FWD position.
We press on the transfer to the radio station and set the arrow at the end of the scale with the regulator sticking out of the SWR meter. Let's release the transfer.
Set the "FWD / REF" switch to the REF position.
Press on the gear and read the SWR reading on the indicator. On most SWR meters, the less the arrow deviates, the lower the SWR, if not deviates at all, then the SWR = 1 or the device is dead. If at all frequencies, in the REF position, the arrow does not deviate, then either you have a good equivalent load connected instead of the antenna, or the device has died, but let's not talk about sad things.

Antenna tuning - step by step

We connect everything to measure the SWR, as mentioned above, the antenna in the working position.
- We set on the radio station the highest frequency that the radio station is capable of issuing, for example, the G channel 40 grid (more precisely, see the instructions for the radio station).
- We measure the SWR, moving down the frequencies through about 20 channels (200 kHz), remember at what frequency (channel, grid) the SWR was minimum and what SWR was at the minimum.

There are now several options:
SWR is large everywhere, the device "scales".
Either you are using the SWR meter incorrectly or you have a break in the cable or antenna.

The SWR decreases smoothly as the frequency decreases, but we did not reach the minimum.
Your antenna is too long. It must be shortened. In shortening it is worth remembering the golden rule: "measure seven times, cut once." It is impossible to stick the shortened back in most cases, so we shorten it a little bit, for C-Bi antennas in the 27 MHz range, a little bit is about 1 centimeter, for LPD or PMR antennas in the 433-446 MHz range, a little bit it is 2 millimeters.

VSWR increases with decreasing frequency.
Your antenna is too short. The antenna needs to be lengthened. How much is better by 20 percent, and then shorten it.

The SWR dropped with decreasing frequency, at a certain frequency it became minimal, and then, as the frequency decreased further, it began to increase again.
This is the most common case.
It means such behavior that everything is fine, the antenna works in the required range, it remains only to tune it to the desired frequency (channel).
If you have this case, then it is advisable to find exactly on which channel the minimum SWR is.

If the frequency at which the minimum SWR was lower than what you need, then the antenna must be slightly shortened, literally by 5 millimeters, if we are talking about the 27 MHz range, after each shortening, look where the SWR is at least now, and shorten it until the minimum The SWR will not be at the frequency you want.

If the frequency at which the minimum SWR was higher than the one you need, then the antenna must be lengthened.

What to do if the minimum SWR is at the desired frequency, but this minimum value is still high

This suggests that the antenna does not work exactly as intended by the manufacturer or the antenna is rubbish, however, there is no need to immediately talk about sad things.
If this is a car's in-line antenna, then maybe it "lacks mass", that is, the contact with the mass is bad.
If this is a car antenna on a magnet, then it may also "lack mass", for example, the paint layer is too thick.
Or your car antenna is located where it should not be installed - next to the elements of the metal roof rack, next to the additional light that you hung on the trunk, you generally magnetized it to the hood or trunk, bumper or wheel rim.
Maybe you fixed the mortise antenna on the aluminum rails of the trunk, which you have on the roof, but the trunk turned out to be not aluminum but plastic, or does not have reliable contact with the mass of the car, or is not long and wide enough to act as a mass for the antenna.

If the antenna is on a magnetic base, try to look for another place where to "slap" it, try from the corner of the roof, in the center of the roof, from a different angle.
RF currents do not flow quite like direct current, where the tester shows excellent contact, for RF this may be a bottleneck.

If the antenna is a mortise, see if you have thoroughly cleaned the place where the antenna ground contact is attached.
If you fixed the in-line antenna on the trunk or some kind of fastener on the drain, try to improve the contact with the ground. There were cases when the author of the article took 2 pieces of wire 0.5 mm thick without insulation, wound it on a bracket on which a mortise antenna hanging on a drain or trunk was fixed, threw them into different corners of the roof of a car along the gutters and the SWR decreased from 3 to 1, then there is an antenna starting to work perfectly (naturally, the signal on the air also improved).
Throwing extra wires, tearing paint and then pouring sealant or looking for other ways to improve the mass or installation point - it's up to you, this is your antenna and your car.

If you do not have a car, but a basic version of the antenna, then the treatment here is actually exactly the same, namely: maybe you need more "mass", or maybe you need to climb into the antenna design with a soldering iron.
First, we make sure that there is enough mass - the pipe is the base, it is also the main counterweight, the mass for antennas of type 5/8 (five eighths) and 1/2 (half wave) should be at least 1/4 of the wavelength, that is, for 27 MHz it is about 2 meters 75 centimeters. More is better; less - you have to lengthen it with a wire thrown over the roof.
Although it sometimes happens that everything is done well, and the antenna is not tuned, this was the case with a friend of the author of the article, 1/2 did not want to tune. It seems to be in frequency, but the SWR is not 1 or even 1.2 or 1.5 - it turned out that someone "climbed into the antenna" before him and cut off the coil loop installed inside the antenna.
It is also very likely that the stretched optics of your provider or the mast of the collective antenna are interfering with your base antenna nearby.

How much to cut and what is the ruler for?
The dimensions of the antennas depend linearly on frequency.
If the antenna is full-sized, then how much you need to shorten or lengthen it in order to get to the desired frequency directly depends on the ratio of the current frequency where it resonates and the desired frequency where you would like the antenna to resonate.
Let me explain with an example:
we have a quarter, let its length be 267 centimeters, it resonates (SWR is minimal) turned out to be at a frequency of 27.0 MHz (channel 4, sect C), we want the antenna to work at 27.275 MHz.
We consider the K differences in frequencies:
27.0 / 27.275 = 0.9899175068744271
Multiply the current antenna length by this K:
267 * 0.9899175068744271 = 264.3
and we get the length that the antenna should have in order to earn 27.275.
We calculate how much to cut:
267 - 264 = 3 cm.
But!
It is not necessary to cut immediately exactly 3 cm. Do not forget that the antenna is not only a spike, it is also counterweights. Everything affects.
So you can separate the order of the first cut - either 3 cm or 5 mm.
Next, we proceed step by step.
For the above example, you can cut off 1.5 cm, find resonance again, and proceed further based on the result obtained.

Lastly, although it probably should have been written first:
Basic rules for installing antennas
The antenna should be placed no closer than one wavelength to other conductive objects, especially those that will be parallel to the antenna.
The higher the antenna is mounted, the better.
It is clear that for car antennas at 27 MHz, these rules are simply impossible to follow, therefore car antennas are compromise, so do not demand miracles from them.

If, nevertheless, you have no time, there is no desire to deal with the intricacies of measuring the SWR, look for a SWR meter, tune the antenna yourself and you are in Novosibirsk, for example, you can contact here: