Walkie Talkies: specifications, types

— Portable. As the name implies, these walkie-talkies are designed primarily for use as portable devices. They are light, small in size, self-powered (from interchangeable batteries or original rechargeable batteries, see below). All this allows you to easily carry them with you for a long time, and they can also be equipped with additional accessories for easy portability (for example, the ability to connect a headset or a clip for clothes). The disadvantages of portable radios include relatively low power and range compared to stationary ones, as well as the need to monitor battery status: if it is impossible to change a dead battery or recharge the battery, the device becomes practically useless.

— Stationary. This type includes walkie-talkies that are not designed for use as portable ones. Most of them are designed for installation in vehicles: cars, ships, aircraft. Stationary models do not have significant restrictions on dimensions and weight, which allows them to provide more power and more extensive features than portable ones. They receive power from the vehicle's on-board network and do not have their own batteries (for more details, see "Power from the on-board network") — thus, you do not need to monitor the state of the battery. The disadvantage is that the mobility of such devices is li...mited by the actual movements of the vehicle.

According to the type of communication, all modern walkie-talkies are divided into analogue and digital. Here is a detailed description of each option:

— Analogue communication. The simplest, from a technical point of view, way of working: the sound received by the walkie-talkie microphone is "embedded" into the radio signal directly, without converting to digital format. Accordingly, the main advantages of analogue radios are the simplicity of design and low cost. The key disadvantages of this option are the relatively low sound quality, which, moreover, strongly depends on the actual signal power: the weaker the signal, the worse the audibility and the higher the level of interference. In addition, the connection itself is not protected from eavesdropping: any user in the range of the walkie-talkie, having tuned in to your range and channel, will be able to hear your conversations. On the other hand, this can be both a disadvantage and an advantage — for example, if we are talking about a CB range car radio, often used to communicate with unfamiliar people. And you can protect the channel from listening, for example, using a scrambler.

— Digital communication. With this communication format, the analogue audio signal (electrical oscillations) is first converted to digital (a sequence of zeros and ones), and only then is sent to the transmitter. In the receiver, accordingly, everythin...g happens the other way around: the digital-to-analogue converter restores the original sound from the stream of numbers. Digital walkie-talkies are noticeably more complicated and more expensive than analogue ones, but they have a number of advantages over them. First, the signal is much better protected from interference. Secondly, its quality does not change when the power changes: the receiving party either hears the sound in its original quality (even at the minimum signal level), or hears nothing at all. Thirdly, the digital format allows the use of various additional features, such as text messages. And fourthly, in such walkie-talkies it is much easier to implement eavesdropping protection. So, within the same range, hundreds or even thousands of channels can be provided, with random selection and periodic switching between them (a similar technology is used in mobile networks and Wi-Fi equipment). And interconnected devices can "agree" on a common unique encryption key — as a result, an outsider will not be able to decrypt digital data, even if he finds a communication channel.

The frequency range supported by the radio for both reception and transmission.

— CB (27 MHz). Abbreviation for "Citizens' Band" (sometimes spelled "Civil Band"), i.e. "civil range". One of the most widely used modern ranges, in particular in the CIS, in many countries CB radios do not require licensing. The technical features of the range are such that it is poorly suited for urban development, but provides good communication outside the city. As a result, such walkie-talkies are widely used in vehicles, especially among truck drivers — they allow you to exchange information at a distance of up to 5 km and warn other drivers about the traffic situation in advance. Also this range is used by many emergency services for direct reception of information.

— LPD (433 MHz). An abbreviation for "Low Power Device", which fully describes the features of walkie-talkies for this range. They have low power consumption and often do not require special batteries (ordinary batteries will do). At the same time, due to the high frequency, LPD models behave well in urban conditions, with dense buildings and an abundance of other sources of electromagnetic interference — the communication range can reach 2-3 km. This range is used mainly in Europe and the CIS, in many countries models for it do not require licensing.

— PMR (446 MHz). Abbreviation for "Private Mobile Radio" — "private walkie-tal...kie". This range is in many ways similar to LPD (see above): in particular, it is intended primarily for urban conditions, it is used mainly in Europe and the CIS, and walkie-talkies under PMR can be used without a license in many countries.

— FRS (462-467 MHz). It stands for "Family Radio Service", which is "walkie-talkie for family use." It is one of the varieties of the UHF band (see below), it has low power consumption on the one hand and relatively short range on the other. Generally refers to the "urban" bands, similar to LPD and PMR (see above), however, unlike them, it is used mainly in North and South America; in Europe and the CIS, such walkie-talkies require licensing at best, and in some countries they are generally prohibited for use.

— VHF. Abbreviation for "Very High Frequency" — "very high frequency", this range covers frequencies 134 – 174 MHz. VHF radios have good range and signal penetration, suitable for both urban and rough terrain, but such devices require a rather long antenna for reliable operation. As a result, VHF is widely used in professional radio communications, in particular maritime and taxi services, but in many countries such walkie-talkies can only be used after registration and/or obtaining a license.

— UHF. The "Ultra High Frequency" range is "super high frequency", most often this definition means frequencies of the order of 400 – 470 MHz. It is a kind of analogue of VHF: it is widely used in professional walkie-talkies and requires licensing in many countries. At the same time, UHF, due to its high frequency and short wavelength, has good penetration and does not require long antennas, which makes it more suitable for compact "city" type radios.

In addition to the above, it is worth noting two points regarding the licensing and registration of walkie-talkies of all ranges. Firstly, license-free conditions often describe not only the range, but also a number of other technical specs (primarily this concerns the power of the transmitter and the type of antenna, see more about both below). Secondly, in different countries (even within the same region), the legislation relating to radio communications can differ significantly — as a result, a model that is freely sold in one country may be subject to registration or even be banned from use in another. And for professional models, a license may be required not only for a walkie-talkie, but also for a specific frequency. Therefore, before purchasing a walkie-talkie, it makes sense to separately clarify the relevant provisions of the law.

The frequency range over which the walkie-talkie is capable of transmitting. This parameter is usually indicated if it does not completely match any of the standard radio operating ranges (see “Frequency Range”). For example, the transmission range is often specified for VHF and UHF models, as these bands themselves are quite wide, and individual walkie-talkies can only use a subset of these frequencies. The opposite option is also possible - wide-range models, whose specs go beyond the standards.

The frequency range in which the radio can receive transmissions. It is usually indicated if it does not coincide with one of the standard ranges of the radio; see "Transmission frequency range" for details.

The number of walkie-talkies in the standard delivery set, usually 1 or 2. Pairs are most often supplied for beginners and/or non-professional users: by purchasing such a kit, you immediately get everything you need for two-way radio communication. Very rarely there are sets for 3 or more walkie-talkies.

The maximum communication range that a walkie-talkie is capable of providing when used with the same model.

Speaking of range, note that usually its perfect value is indicated in the specs. And it is achieved only under a combination of certain conditions: the complete absence of obstacles (houses, trees, etc.) and interference in the passage of radio waves (for example, due to increased solar activity or the presence of powerful transmitters nearby), full battery charge, optimal air temperature , high-quality transceiver at the other end of the line, etc. In fact, the communication range, usually, is much lower. Therefore, when looking at this parameter, it is worth taking a certain margin.

The maximum power at which the radio transmitter is capable of operating. This parameter is one of the most important: it determines both the range of the device (see above) and the features of its use and registration (for more details, see "Frequency range"). For most models of the "amateur" (conditionally) class, the power level does not exceed 2.5 watts. More powerful walkie-talkies are, usually, professional models of the VHF and UHF bands (for more details, see "Frequency range").

Many modern walkie-talkies have several power settings, most often two — low (Low) and high (High). The first option is useful if the the other walkie-talkie is at a short distance: the transmitter will not consume excessive power, respectively, the battery will last longer. If the distance is large, you may need the “High” mode, in fact, the full power of the transmitter.

The number of channels on which the radio can operate. Each channel is essentially a fairly narrow subband within the main operating band (see "Frequency range"). The division into channels allows several groups of users to work simultaneously on the same territory and in the same range so as not to overlap on the air and not interfere with each other. The more channels provided in the design of the walkie-talkie, the more likely it is to find a free channel and the better it is suitable for working in conditions of intense extraneous radio traffic. This is especially important for powerful "long-range" models. At the same time, simultaneous operation of several groups on one channel is also possible thanks to subcodes (see below).

Single-channel walkie-talkies work on receiving and transmitting in only one channel, two-channel ones have 2 active channels in their arsenal, between which you can switch instantly at the touch of a button. The option with two active channels is suitable for communicating with two users who are not in contact with each other on different frequencies. In advanced models of two-channel walkie-talkies, dual-reception technology is also implemented with automatic switching of broadcasting to the channel on which the transmission is taking place.

Subsonic signals to reduce short-term interference on the air or to ignore radios broadcasting in the same frequency channel without a subtone included. The parameter is set by a special code, which indicates the frequency of the tone mixed with the useful signal. A similar subtone must be set on the receiving device. The sounds of subtones are removed from the signal before being fed into the amplifier and further into the sound system of the walkie-talkie.

— CTCSS. An analogue tone transmitted with a call to separate walkie-talkie users on the same channel and to filter out interference. Various radios may use 38, 39, or 64 CTCSS tones at frequencies from 33 to 254.1 Hz. The serial numbers of specific tones are determined by special charts.

— DCS. Radios with the DCS digital subtone system "hear" each other when set on the transmitting and receiving side of the same code. The DCS system offers over a hundred standardized digital codes, which are a three-digit number of zeros and ones at a carrier frequency of 133 Hz. DCS subtones effectively divide the communication frequency according to the "friend or foe" principle, cutting off unauthorized users, interference or noise on the air.

— CTCSS\DCS. Walkie-talkie models that combine analogue and digital formats for introducing subtones with the ability to switch between them.

The number of subcodes provided in the design of the walkie-talkie. Subcodes are used to create separate subchannels with different coding within one channel (see "Number of channels"). This allows several groups of users to communicate simultaneously on the same frequency channel without interfering with each other. Thanks to the combination of channel and subcode, the number of subchannels available for communication can be in the hundreds — which is more than enough even in a busy air. In entry-level models with low power, the possibility of using subcodes may not be provided at all as practical uselessness — there are not too many users within their range. But for powerful radios with a long range, the presence of subcodes is very important.

The type of antenna used in the radio.

— Non-removable. As the name implies, such an antenna is permanently attached to the body of the radio. Technically, it is most often possible to remove it, but for this you will need to disassemble the radio; replacement for such an antenna with another, of a different type, is not provided at all.

— Removable. The detachable antenna was originally designed to be quickly detached from the body of the radio, most often without the use of any tools. In addition to ease of transportation and storage, this design often provides the ability to change the stock antenna to a more powerful one, or even connect the walkie-talkie to a separate external antenna — to increase the range.

Note that the legislation of some countries refers the design of the antenna to the parameters that determine the conditions for licensing and registration: for example, walkie-talkies with removable antennas may be subject to licensing, while for completely similar models with non-removable antennas, it will not be required.

— Headset connection. The ability to connect a headset to the walkie-talkie — an earpiece (or headphones) with a microphone. The main purpose of the headset is to free your hands during a conversation. In addition, in noisy environments, an earpiece is often more convenient than an external speaker.

— Bluetooth. Medium-range wireless technology (10 to 100 m, depending on version) for direct communication between different devices. The main and almost the only way to use this technology in walkie-talkies is to connect wireless headsets that allow you to free your hands when talking. Bluetooth can be provided in both portable and fixed radios.

— Speech masking (scrambler). The presence of a speech masking feature in the radio: the built-in encryption module (scrambler) encodes the sound and broadcasts an encrypted signal, which is decrypted by the similar scrambler at the receiving end. The main purpose of this feature is to protect against unauthorized listening and interception of “sensitive” information: even if an outsider tunes the radio to the appropriate channel (or subchannel, see “Number of subcodes”), he will hear only a set of meaningless noises. For correct operation in this mode, the scrambler modules for all users must be identical. Also note that speech masking walkie-talkies may be subject to licensing in so...me countries.

— Voice activation (VOX). The ability to control the walkie-talkie with the help of voice: during the silence of the user, the device works for reception, and when the microphone captures the voice, it switches to transmission mode. Usually this feature is implemented through a headset (see above), which allows you to completely free your hands and makes the use of the walkie-talkie as convenient as possible: you do not have to press the button every time to switch to transmission mode. And to avoid accidental activation due to extraneous sounds, many models with VOX have a sensitivity control that allows you to set the volume level for triggering the switch.

— Volume control. The ability to adjust the volume of the speaker, which allows you to choose the optimal volume level depending on the environment. This feature is present in most modern walkie-talkies, with the exception of only the most inexpensive models.

— Auto noise reduction. The function of suppressing noise generated on the air by extraneous sources of interference, when the radio is receiving. Such noises create a signature hissing sound in the speakers (the same one that is heard when the radio is not tuned). It's useless "ethereal garbage", because when talking, it reduces the intelligibility of speech, and when silent, it wastes the battery charge to reproduce a meaningless hiss (which is also unpleasant to hear). The noise suppressor blocks these noises, thus increasing speech intelligibility and providing silence between phrases. Usually, walkie-talkies with this feature provide setting the level of noise suppression — for optimal separation of the useful signal and background noise.

— Channel autoscanning. The ability to operate the radio in automatic channel scanning mode (for more details on the latter, see "Number of channels"). In this mode, the walkie-talkie independently tunes in turn to each channel in search of a transmission signal. Channels without transmitters are skipped, and when a signal is detected, scanning is suspended — for a while or until a special user command. Thus, the user can listen to all active channels and select the desired one.

— Channel monitoring. The ability to operate the radio in the channel monitoring mode. In this mode, noise reduction is completely disabled (see above), and the user can listen to the unfiltered signal on each selected channel. This allows you to evaluate both the traffic load of the channel with calls and the overall level of interference, and select the optimal communication settings.

— Roger-Beep signal. The presence of an automatic end-of-transmission signal on the radio, the so-called Roger Beep. Such devices, when switching from transmit mode to receive mode, broadcast a special sound signal (usually in the form of a short squeak, hence the name), indicating the end of the transmission. This eliminates the need for the user to specify the change of modes himself (for example, with the traditional word "over") — his interlocutors will receive a signal about this automatically.

— Power saving mode. The walkie-talkie has a special mode designed to maximize power saving and allow you to extend the work without recharging the battery (or changing batteries). This feature is especially useful if you have to carry the radio with you for a long time, only occasionally getting in touch. Specific features in different models may vary: for example, some walkie-talkies in this mode are almost completely turned off, only periodically “waking up” and scanning the channel for activity; in others, specific power saving features can be selected as desired by the user.

— Vibration. The walkie-talkie has a vibrating call feature similar to that used in mobile phones: when a signal is received on the selected subchannel, the body of the walkie-talkie starts to vibrate. This feature can be useful in noisy environments where it is difficult to hear the sound signal from the speaker — or vice versa, in silence, when any extra noise is undesirable.

— Keypad lock. The ability to block the keys of the radio from accidental pressing. This allows you to carry the device in your pocket or tight case, without fear that due to an accidental movement, the settings will go wrong, the transmission will turn on, etc. The lock itself is usually controlled in a way that excludes as much as possible the possibility of its accidental release — for example, by simultaneously pressing two buttons.

— On/off button sound. The ability to turn on and off the beep that sounds when each button is pressed. An audible signal serves as a convenient confirmation of a full press; on the other hand, it may not be appropriate in some situations.

— GPS module. It implies the presence of a built-in module for receiving GPS data from satellites, which allow you to determine the exact location of the user. The accuracy of work largely depends on the number of satellites that see the receiver at a particular moment, and weather conditions, but, usually, it ranges from one to ten metres. The functions of the portable radio with built-in GPS may vary depending on the specific model. So, the device can simply display the exact position at the moment on the screen (latitude, longitude, altitude), as well as the direction and speed of movement. More advanced models with a large screen can show locations on a map or, for example, transmit the user's coordinates to the dispatcher.

The number of ringtones provided in the design of the radio. The more such melodies, the wider your possibilities for choosing the most pleasant call signal.

— Ni-Cd. Nickel-cadmium batteries have strength, reliability, and resistance to low temperatures, which makes it possible to use walkie-talkies with such battery in cold weather. Also, Ni-Cd batteries tolerate high charging currents well, which significantly speeds up the process. Their main disadvantage is the so-called "memory effect": if the battery is started to charge without being completely discharged before, its capacity decreases. The original capacity can then be restored, but this requires certain tricks. In addition, Ni-Cd batteries are considered environmentally hazardous. As a result of all this, today they are very rare.

— Ni-Mh. Nickel-metal hydride batteries were developed as a replacement for nickel-cadmium batteries (see above), in order to eliminate their main disadvantages. Such batteries hold voltage well (it decreases only when the charge is almost completely exhausted), resistant to low temperatures, environmentally friendly and almost not affected by the "memory effect" - it only appears when stored in a partially charged state for more than a few days. As a result, Ni-Mh batteries have become quite widespread in walkie-talkies. Among their disadvantages, one can name a slightly shorter life cycle than that of Ni-Cd, a significantly longer charging time and unsuitability for storage in a discharged form.

— Li-Ion. Lithium-ion batteries are by far the most common type of batteries for portable electronics, including radios. They...have good capacity with small size and weight, they charge quickly, and most importantly, they are not affected by the “memory effect”. At the same time, Li-Ion batteries are quite sensitive to low temperatures, and they are more expensive than "nickel" types (see above).

— Li-Pol. Lithium-polymer batteries are actually an improved version of lithium-ion batteries (see above) - with the same advantages, they have even more compact dimensions and lighter weight. However, the main drawback - sensitivity to cold - also remains, and the price may be even higher than that of Li-Ion. As a result, this type of battery is quite rare among walkie-talkies, mainly in premium models.

It is worth noting that among the walkie-talkies there are models with both built-in and replaceable batteries. In the latter case, the batteries can be the size of standard AA or AAA batteries. This allows, if necessary, to replace them with conventional disposable batteries or other batteries of the same size. Technically, you can even install batteries of a different type in such a walkie-talkie - for example, replace the complete nickel-metal hydride batteries with more advanced lithium-ion ones. However, if the kit comes with a charging stand (see below), you cannot use it for a "non-native" type of battery, because. different types of batteries have significantly different charging modes. In the above example, this will mean that only the bundled Ni-Mh batteries can be charged on the stand, and Li-Ion will require a separate charger.

The capacity of the radio battery, in other words, the amount of energy that the battery can store. It is standardly measured in ampere-hours: 1 Ah means that the battery, when fully charged, is capable of delivering a current of 1 A for 1 hour. In portable electronics, measurements are typically made in a thousandth of a milliamp hour (mAh).

In general, the higher the battery capacity, the longer the radio is able to work; however, this is true only under otherwise equal conditions. In fact, due to differences in the specs of individual models (range, transmitter power, etc.), their power consumption can also vary significantly, and even situations when a model with a smaller battery capacity of two walkie-talkies will have greater battery life can happen. This is especially noticeable when comparing compact models of "urban" ranges and powerful "long-range" radios that require a lot of energy. Therefore, for walkie-talkies, the battery capacity itself is rather an auxiliary parameter — the operating time in different modes provided by this battery is of decisive importance (see below).

The maximum time the radio can operate in standby mode on a single battery charge. In this mode, the radio is on, but power consumption is minimal; for details on its features, see "Features - Power Saving Mode". The longer the time in standby mode, the longer, relatively speaking, the radio can be carried with you without missing a call (although at the end of such carrying energy for a full-fledged radio exchange may no longer be enough).

It should be considered that the standby time is indicated for perfect conditions, when the walkie-talkie does not use any features for the entire time of operation, except, in fact, to maintain itself in mode. Accordingly, in fact, the battery life time will be lower - in the interval between standby time and talk time, closer to one or the other value, depending on how intensively the radio is used.

The maximum operating time of the radio in talk mode — i.e. with continuous radio traffic and approximately equal distribution of time between work for reception and transmission. You should pay special attention to this parameter if you plan to communicate intensively. Note that when receiving, much less energy is consumed than when transmitting. And therefore, in fact, the time in the talk mode, even with continuous radio exchange, may differ from the claimed one both downward (with large volumes of transmissions) and upward (when working mainly for reception).

The radio is powered by the on-board network of the vehicle on which it is installed. It is used exclusively in stationary models (see "Type"). This option is convenient, first of all, because you do not have to monitor the state of batteries of the radio: as long as there is voltage in the on-board network, it will work. At the same time, it is not even necessary for the engine to work — the walkie-talkie can also be powered from the vehicle battery (moreover, such devices consume relatively little, and the batteries on modern vehicles are quite capacious). For this reason, stationary models usually do not have their own autonomous power sources at all.

The presence of a microUSB port in the design of the radio.

In this case, this feature means, first of all, that the radio can be charged from any standard microUSB charger, or even a cable connected to the USB port of a computer or network adapter. This is very convenient, given that microUSB is perhaps the most popular connector among modern portable gadgets — smartphones, tablets, etc. Accordingly, there are a lot of accessories for microUSB devices, and finding a charger or cable for such a walkie-talkie will be much easier than for a model with a different type of connector.

Also, the microUSB port can be used to connect the radio to a computer — for example, to manage settings, flashing, etc. However, this feature, unlike charging, is optional and is not found in all models.

The walkie-talkie has an indicator showing the battery charge level. Its presence allows you to monitor the state of the battery, so that the charge does not run out at the most inopportune moment, and also, in some cases, control the charging process. In this case, the role of the indicator itself can be played by both a simple LED that changes colour or mode of operation if it is necessary to charge the battery, or a full-fledged info on the display (similar to those used in mobile phones).

The presence of a special stand with a built-in charger in the delivery set of the radio. This greatly simplifies and speeds up connection to the charger — just install the walkie-talkie on a stand connected to the network in advance. The stand can also be used for storage. Note that only batteries of the "native” (bundled) type can be charged on it; see "Battery type" for details.

The presence of LCD displayin the design of the walkie-talkie. Various service information can be displayed on it: the selected channel and subchannel, operating mode, installed transmitter power, battery status, and much more. This makes the control of the device more convenient and intuitive.

The presence of a built-in backlight in walkie-talkie display (see above). This allows you to use the device even in complete darkness — the information on the display will still be visible. Also, the backlight can be used as an flashlight (kind of) if there are no other light sources and the corresponding feature (see "Flashlight") is not provided in the radio itself. At the same time, the backlight also consumes power and reduces battery life; In order to save power, some models provide the ability to turn off the backlight and/or adjust its duration.

The walkie-talkie has a built-in flashlight — usually in the form of one or more LEDs. This feature is useful at night or when there is insufficient light, such as when you are outdoors at night.

Walkie-talkies with this feature have a special protected housing that prevents dust and moisture from getting inside and damaging sensitive electronic components. If you often have to be in adverse conditions, you should pay attention to such walkie-talkies. At the same time, note that the specific degree of protection in different models can vary markedly, and here it is most convenient to evaluate it by IP marking. This marking consists of the letters IP and two numbers; resistance to dust — the first digit, resistance to moisture is described by the second, last digit. You can find the following options for protection against moisture:

— 4. Protection against splashes from any direction. Thus, the walkie-talkie will be fine during rain of medium intensity, regardless of the strength of the wind
— 5. Protection against water jets from any direction. Allows walkie-talkie to endure a combination of strong wind with a downpour.
— 6. Protection against strong water jets and sea waves. It is considered the minimum level of protection that allows use near water.
— 7. The possibility of short-term (less than half an hour) immersion under water to a shallow depth (less than 1 m); continuous operation in immersed mode is not expected.
— 8. The highest level of water protection. Allows long-term (more than 30 minutes) immersion under water to a depth of 1 m or more, and even permanent work in a submerged position. However, note that specific restr...ictions on the use in such walkie-talkies may be different, they must be clarified according to the manuals.

Dust protection values are presented more modestly:
5 — dust resistance without full closure (a certain amount of dust can get inside, but it is small and does not affect the operation of the device)
6 — full protection (dust is not able to penetrate inside the case).

At the same time, there are situations when the manufacturer did not test the device for dust resistance, but limited itself to water protection. In this case, instead of the dust protection number, there is an X, for example IPX7.

The walkie-talkie has a case that allows the device to endure more severe shocks and drops without consequences than models with a conventional case can withstand. You should pay attention to this feature if you plan to use the radio in adverse conditions where there is a corresponding risk — for example, in camping trips, construction, military affairs, etc. Such models have the American military MIL-STD-810 standard. It imposes quite stringent requirements on the test subjects: the level of product resistance to impacts during drops and shakes is checked, vibration tests are carried out, the device is tested in a wide temperature range, in rain, in fog, under the influence of sand, dust, etc. However, the MIL-STD-810 label in "civilian" products does not always mean the highest degree of protection. This is due to the lack of strict regulation of the tests. So, the most ingenious vendors test the gadgets literally on one or two points of the programme from an extensive list and often deliberately do not cover which tests were passed. Accordingly, the specific features of such protection remain reliably unknown. The standard has been live since 1962. Each new version of it is indicated by a letter of the Latin alphabet at the end. The further the letter down the alphabet, the more recent the version of the certificate. Since 2008, the MIL-STD-810G specification has been live everywhere, and in 2019 a new edition of the MIL-STD-810H standard w...as approved.

Special protection against explosive impact.

Availability of explosion protection means that the walkie-talkie well resists not only blows and concussions, but also high temperatures. Thus, such devices are indispensable in conditions of increased explosion and fire hazard, where conventional moisture and shock protection is no longer enough. Walkie-talkies with this feature are widely used in hazardous industries (chemical, oil), in rescue services, the armed forces, etc.

Also note that most of the explosion-proof models presented on the local market comply with the European ATEX standard (safety in an explosive atmosphere). Details regarding ATEX criteria can be found in specific sources.

— Plastic. Inexpensive and at the same time very reliable material. It is believed that it is less durable than metal, but this is only partly true — some types of plastic are quite suitable even for creating shock-resistant cases. At the same time, this material, regardless of the grade, is resistant to moisture and has low thermal conductivity (in other words, it does not “cool” hands in cool weather). Therefore, the vast majority of modern radios are made of plastic.

— Metal. The main advantages of metal over plastic are high strength and reliability. In addition, it has a solid appearance. On the other hand, metal is more difficult to process, more expensive and tends to “cool” hands at low air temperatures. In addition, this material shields radio waves, which creates difficulties in the design of all-metal cases. As a consequence of all this, metal is rarely used in radio bodies, and even in such cases, it is usually a metal edging on a plastic body.