Frequency channels and radio station operating modes.

The overwhelming majority of modern radio stations work in simplex or half duplex mode. In this case, reception and transmission are simultaneously impossible. The inclusion of the transfer is carried out by pressing the tangents. When releasing tangents, the station goes to reception mode. Transmission and reception frequency form the frequency channel and in the general case can be different.

If the frequency of transmission and reception coincide, the channel is called simplex. If the frequency of transmission and reception is different, the channel is duplex, and the mode of operation of the radio station is half duplex. In mode full duplex (That is, when the transmission and reception are carried out simultaneously and you do not need to press the tangent) Only full-duplex radio stations can work on the duplex channel, which are not common due to high cost.

The parameters of different channels can be programmed in the radio station. Depending on the radio station model, the number of channels may vary from 1 to 100 or more.

Types of equipment.

Radio stations included in the system of land mobile radio communications can be divided into groups in the following categories:

Operating conditions.

Professional radio stations (Motorola, Vertex):
As a rule, comply with the requirements of the military standard for impact resistance, the effects of vibration, dustlessness. Have a minimum of controls, the parameters are rigidly programmed and cannot be changed by the user. It is numbered for a long service life in harsh environments.

Commercial and amateur radio stations (Yaesu, Alnico):
Have a "friendly" design. Not designed to work in extreme conditions. Parameters can be installed by the user. Radio station stations have an extended set of user functions.

It should be noted that some models occupy an intermediate position and cannot be uniquely attributed to a specific class.

Place installation.

Portable (wearable) radio stations:
Output power0.5-6 W, battery capacity 600-155 mAh. Typical Supply Set: Transceiver (Station Actually), Antenna, Battery, Charger.

Automotive radio stations:
Output power 10-60 W, power on the onboard network (13.8 V). Typical Supplies: Transceiver (actual station), Mounting kit, power cable, automotive microphone with mount. Automotive antenna, in most cases, comes separately.

Stationary radio stations:
As a rule, automotive stations have the ability to stationary installation. Additional equipment: power supply unit 220 V, stationary antenna, antenna cable. For convenience, a desktop dispatch microphone can be used.

Professional, commercial and amateur stations, as a rule, do not differ in the main radiotechnical parameters (frequency ranges, output power, sensitivity). The selection of this or that type of equipment is determined by the operating conditions and the necessary set of functions.

The choice of the type of radio network is determined by the existing frequency resource, the number of users and the specifics of their work. In traditional control systems, the dedicated frequency channel is fixed for each group.

Such a method of organizing radio communications is quite effective in cases where the total number of system subscribers is small, and the necessary radiocrying zone is limited. The main advantage of the radio system is simplicity and low cost. The disadvantages include the inefficient use of the frequency spectrum and a small set of service functions. Dispatch radio networks are most often used to organize technological or service radio.

Simplex radio networks.

In the simplest case, the radio network is a group of radio stations operating at one frequency (on one simplex channel) Fig. 2. All radio stations users hear each other and cause the necessary subscriber to voice. With this method of organization of communication, the number of radio stations is usually small (2-20).

Portable, automotive and stationary radio stations can be used in the radio network. All of them are equivalent. Of course, the range of communication between the automotive (stationary) stations is higher.

Groups of subscribers in the simplex radio network.

Quite often in the radio system requires divided subscribers to groups. The easiest solution to this task is to identify each group of its frequency, which in most cases it is impossible due to a limited frequency resource. The most acceptable solution is the division of groups on tonal or digital pilot signals (Fig. 3).

Until now, my experience with amateur radio was limited exclusively by work on shortwave bands (3-30 MHz). However, radio amples are also available to VHFs 2 meters (She is "Two", 144-146 MHz) and 70 centimeters (430-440 MHz). Work in these ranges has some nuances. If you just acquire a VHF and chop CQ on a call frequency from the balcony, then most likely get no successful experience. That's what the underwater rakes are in the VHF and how to avoid them, then it will be discussed.

A bit of theory

It is required to say a few words about terminology, because it is a little confused.

Ultrakotovoy waves (VHF) called a huge frequency range from 30 MHz to 3000 GHz. It includes the ranges of meter waves (MV, the wavelength is 1-10 meters, or in frequencies - from 30 to 300 MHz) and decimeter waves (DMV, the wavelength is 10-100 cm, the frequency of 300 MHz to 3 GHz). MV are also known under the name of the Volume, very high frequencies (VHF, Very High Frequency). Similarly, another name of DMB - UHF, ultra-high frequency (UHF, Ultra High Frequency). In English, the terms VHF and UHF are often used. In Russian, the Abbreviation of the HFF and UHF for some reason did not very much, and often say VHF, having in view of both bands. Further on the text under the VHF will be due to exclusively radio amateur VHF and UFH bands.

As you can be known, the KV is refracted in the ionized layers of the atmosphere and return to the Earth. Thanks to this, radio communications are possible for thousands and even tens of thousands of kilometers. VHF does not work so much. They are possible sporadic-E and tropospheric passage, but these phenomena are relatively rare. Therefore, the relationship to VHF is usually possible for small distances, typically about 100 km. When using "exotic" types of communication (for example, through satellites), it is possible to hold QSO and significantly long distances. But such types of ties deserve their own separate articles, so so far forget about them.

Let the VHF are not suitable for long-distance connections, but there are no equal in terms of stability. If there is a connection to the VHF, then it is 24/7, regardless of the passage, and without any feten, thunderstorms, and so on. In addition, there are no problems with a high level of noise on the air and "Palapami".

The presence between correspondents barriers (high buildings, mountains, and so on) prevents radio communications to VHF. However, in urban conditions, radio communications are possible by reflecting the radio signal from buildings. Suppose your balcony is east and close is a high building. This building can play the role of the reflector, with which it will be possible to contact the correspondent in the West. Also, the obstacles can also be circumvented with the help of repeaters that we will talk about below.

Addition: Later I learned that the VHF could "bypass" the mountains due to the effect called Knife-Edge diffraction. The effect is described in more detail in the fourth volume "Antenna Systems and Radio Propagation" of The Arrl Handbook for Radio Communications 2019.

The wavelengths in VHF bands are significantly less than per square meter. Due to this VHF antenna is more compact. As a result, wearable and automotive radio are very popular. In addition, the directional antennas with a large gain of the intensive size can be constructed to the VHF.

To all of the above, it should be added that the VHF is usually operating in FM. This is not that it was very fundamentally, but is another difference from the KV, where SSB is used.

Choose transceiver

For VHF, there are fairly cheap waters of Chinese production, for example, from Baofeng. But with such races you are waiting for a whole number of inconveniences - the low quality of the microphone and the dynamics, the cut functionality and inconvenient for the amateur targets interface, a small battery life, the small strength of the hull, and so on. But worse than all that such radiations are often not designed to work with an external antenna installed on the roof or balcony, and the antenna on the radio itself extremely ineffective.

The problem lies in the fact that Baofeng'i are not full-fledged analog transceivers, but are built on the basis of the integrated circuit RDA1846 (datashet). This scheme has a relatively small dynamic range by blocking. This means that if you connect the outer antenna to the radio, the receiver will most likely be blocked by powerful signals from local television and radio stations. Theoretically, it is solved using additional filters. But from a practical point of view, it is much easier to take advantage of the walkie-talkie from another manufacturer, for example, Yaesu, Icom or Kenwood.

Important! With a good probability of any radio communications with some Baofeng UV-5R you will not spend. Tested on a personal bitter experience.

When choosing a transceiver, it will not be superfluous to search for reviews on the model you are interested in. Many radio amateurs lay out such reviews on YouTube. The list of recommended youtube channels earlier I led to a note pass the quest for the call sign and register RES. If the new transceiver does not fit into your budget, it makes sense to familiarize yourself with the ads for the sale of used transceivers, for example, on the bulletin board QRZ.RU.

That is how I acquired my walkie-talkie, Kenwood Th-D72a (Manual):

This is not a new, but very high-quality device. It is especially interesting because it is almost the only one present Full Duplex by the radio. That is, while you pass in the range of 2 m, the radio can continue to receive and reproduce the signal on the second channel in the range of 70 cm (when the DUP function is turned on). This is especially convenient when working with the "exotic" types of communication themselves.

Also in the radio there are GPS, support for APRS and certainly some other useful functions in which I have not yet understood. Like most portable radio stations, Kenwood Th-D72a works at no more than 5 W. As we will be convinced soon, it is quite enough to work at the VHF.

Fun Fact! Despite the fact that the radio is no longer produced, Kenwood continues to produce firmware updates for it.

Given the uniqueness of the radio, the fact that the owner sold it along with the KSC-32 charger, the SMC-34 tangent, a spare battery and a cover, and also extremely Attractive price, buying was perfect without any thought. The transaction passed without problems - the device came quickly and in a completely good condition.

Making an antenna

Deafolt antennas of most portable radio stations are not suitable for anything. Antenna Kenwood Th-D72a - no exception. An Antenna Analyzer EU1KY shows the following CWS graphics:

When building such graphs, it is necessary to hold onto the body of the antenna analyzer. The fact is that for normal operation the antenna needs a human body acting on the role of a counterweight. If you do not hold onto the housing, the graphics will turn out even worse. As you can see, the resonance is blinking a little on a twice, just on "some" 15 MHz, and at 70 cm, the CWS does not fall below 2.4. In general, the antenna is quite bad.

It was decided to make a full-size antenna on a range of 2 meters and place it on the balcony. First, there will be no questions about its effectiveness to such an antenna. Secondly, it will be possible to safely work on a twice in winter, being warm and comfortable. Thirdly, the safety technique during the transfer next to the antenna should not be people. Now it is not as critical as I work for 5 watts. But in the future I can get the transceiver and more powerful.

The scheme of a suitable antenna from the RG58 cable was found in the blogs of Australian radio amateurs John, VK2ZOI and Andrew, VK1NAM:

Antenna is an ordinary dipole, only located vertically. Unlike KV, the VHF is required to monitor polarization. Usually, radio amateurs are used to VHF vertical polarization, therefore, a vertical dipole is required. The cable lived plays the role of the upper arm of the antenna, and the outer side of the cable screen is the role of the lower shoulder. A cutting throttle is nine cable turns on a 25 mm frame.

Fun Fact! Sometimes the VHF work in the telegraph and SSB, while it is customary to use horizontal polarization. However, most modern VHF transceivers support only FM. Telegraph and SSB are mainly supported in transceivers capable of working on both square meters and to VHF. As examples of such transceivers, Yaesu FT-991A and ICOM IC-7100 can be called. Digital communication types also work with the difference that they are used for long-distance connections, and therefore polarization is not important.

At first, a hostility was made:

The antenna was made slightly longer than indicated in the diagram, and then cut down at a minimum of the KSV on the range:

As you can see, the antenna has a relatively good resonance and 70 cm. In this range, it works on the third harmonic. This is not the best antenna for 70 cm, at least for the reason that the choke choke is completely not designed for this frequency. In particular, when writing the antenna in a couple of meters of coaxial cable, the CWW graph varies significantly. But if necessary, the antenna allows radio communications and in this range (verified!).

After adjusting the antenna, it was entirely placed in PVC pipe. From both ends, the pipe was closed by pieces of the sponge, and on top - covered with a lid. I printed the lid on a 3D printer, but with the same success would fit the cover from kefir or a piece of fiberglass. All holes, except the lower, were sealed with epoxy. I did not stick the bottom hole in case, if the antenna still somehow gets moisture. With this scenario it will be smoking.

The antenna was fixed on the balcony in the same way as previously fixed the OPEK HVT-400B sq-antenna:

Unlike KV, the RG58 cable does not like to power the antennas. Instead, it is necessary to use RG213 or cable with even less loss. When using 10 meters RG58, the signal attenuation by 144 MHz is 1.82 dB, and 450 MHz is 3.65 dB. In RG213, it is 0.86 dB and 1.73 dB, respectively. However, if the cable is short, just a pair of meters, then RG58 will come down.

We go on ether

Verified frequency in the range of 2 meters - 145.500 MHz. Just come, and make a common challenge like a square. Not always respond. But if so without much fanaticism to be called in the morning before work and in the evening after, then people answer regularly. Of course, provided that you use a normal transceiver, an effective antenna, and the correct cables, as described above.

At 70 cm everything is more interesting. The official common challenge is 433.500 MHz. However, this frequency falls into the LPD-range 433.05-434.79 MHz and in Moscow there is a strongest interference. An alternative frequency is 432.500 MHz. But this frequency falls into the interval of 430-433 MHz, which is forbidden to use within a radius of 350 km from the center of Moscow. As far as I could find out, among Moscow radio amateurs there is an agreement to use 436.500 MHz as a call frequency. You can also try the so-called "pharmacy" frequency, 436.600 MHz.

Fun Fact! Like on the KV, the VHF meets radio chuligans, many of which behave on the air, let's say, incorrectly. My vital philosophy - if you met such a person on the air, I don't talk about anything with him and make sure that you cost as much as possible in frequency :)

Experiments show that in urban conditions the range of 2 meters works noticeably better than the range of 70 cm. Although radio communications can be carried out and there, and there. I also do not exclude that the case in my antenna, which is not particularly intended for work by 70 cm.

We work through repeaters

Often radio communications on VHF are conducted through repeaters. The repeater is a device that accepts your signal at one frequency and repeats it to another. Usually the repeater antenna is set somewhere high, where it can take a signal from many radio amateurs, and the transmission from the repeater is carried out at high power. This is one of the reasons why above it was said that 5 W is quite enough to work at VHF. The task comes down to reach the repeater. And it will already provide you with good power and coverage area.

Often repeaters "open" using a specific tone. The tone is a low-frequency signal that mixes to your voice when transmitted. The main tone transfer standards are CTCSS and DCS.

The tone is not a password to the repeater. It is rather protection from the fool. Suppose a certain radio amateur is at an equal distance between two repeaters using the same frequencies. With a tone, one of the repeaters can understand that the radio amateur refers to it, and take the signal. The second repeater that uses another tone will understand that the message is not addressed to it, and ignore the signal. Without a tone, the radio amateur would work simultaneously on two repeaters, and, without having not wishing, interfered with the work of colleagues.

The easiest way to know about the current local repeater, asking for local radio amateurs about them. You can also search for the directories of repeaters, at least on the same QRZ.ru. But information in the catalogs is often either outdated or simply incorrect.

It is clear that to work through the repeater, the radio must be adjusted accordingly. Consider this setting on a specific example. A familiar waters says that in your city there is a repeater with an entrance at a frequency of 145.050 MHz and a transfer by 145.650 MHz (channel R2), tone 88.5 Hz. You use Kenwood Th-D72a. Asks how to get to the repeater?

Press VFO and exhibit the frequency of 145.650 MHz. We go to Menu → Radio → Repeater → Offset Freq, we enter here 0.6 MHz, that is, the difference between frequent transmission and reception of the repeater. Click the green button F, and then SHIFT (located on the symbol of the sprocket, to the left of zero). Plus comes on the screen. It means that when transmitted to the current frequency will add the previously indicated Offset Frequency. But we need the frequency to be deducted. Press F again, then SHIFT. The plus sign was replaced by minus. You can check that everything works, as you need, quickly pressing and releasing PTT. During transmission, the frequency should automatically vary on 145.050.

Customize tone. To do this, press TONE (located on the figure 8). The letter T is light up. It means that the radio will pass the CTCSS tone, but it will not require it to open the noise (Squelch). If you want the radio to check the tone and when receiving, you can translate it from the T mode to CT mode by pressing TONE. In the same way, you can switch to the use of DCS instead of CTCSS. Next, press the F button. Go to the Tone Freq selection. We indicate 88.5 Hz, we save.

Now so as not to lose settings, press F, and then M.IN. We save in the memory cell. Now you can go from the VFO mode to MR mode and switch between saved channels. It is much more convenient than constantly tune the frequencies and tones manually. If you wish the cell, you can assign a name to Menu → Memory → Name (only works in MR mode). Long press MR, you can switch to the continuous scanning mode of the saved channels.

If everything was done correctly, now you should hear people on the repeater. Check connection to the repeater can be short-clicking PTT. After you release PTT, the repeater will still pass the carrier that you and hear. If there is no carrier, then either the repeater does not accept your signal, or the tone is incorrectly configured, or the repeater does not work. If the carrier is there, then everything is fine.

Fun Fact! With some fraction of luck to the repeater, it is possible to reach the 5th watts on the antenna, located inside the house.

It is clear that when using another radio, the setting will be different. But the principle will be the same, and I think you can easily figure it out.

Conclusion

So, you went to VHF. Now what? You can stop at this and simply communicate for life with the living near the radio amateurs. And you can learn how to use APRS, carry out radio communications via satellites or echolink, take SSTV from the ISS, install your own repeater, experiment with the antennas, filters, amplifiers, digital types of voice (D-STAR, C4FM, DMR), transcers of different manufacturers, and may and homemade. You may even want to try EME, that is, carrying out radio communications with the help of reflection of radio waves from the moon. In general, you have a frequency range. What you will do on it is limited mainly by your fantasy.

73 And before the meeting at VHF!

Addition: Replacing the standard Antenna Kenwood Th-D72A is considered in the Nagoya Na-771 antenna post: how to distinguish the original from the fake. Alternative antenna for the balcony Look in the article

Ranges and frequency of radio

In this article, we will briefly consider which frequencies are allocated for radio communications and which radio stations and which range should be considered when choosing equipment in one way or another. The article is presented in free form, using simplifications in some concepts and details. It does not claim to encyclopedic accuracy, but will give a general idea of \u200b\u200bfrequencies used in Russia and the applied radio equipment.

Consider in which ranges are running And why, in one case, different cases are used Range frequency ranges.

Shortwave Range - 1-30 MHz

Freak of a sq. Range It is used primarily by the military, the Ministry of Emergency Situations, on the fleet, forest and environmental organizations for professional communication over long distances - from 150 to 8000 km.

The main disadvantages of the range of the range is a low noise immunity and the need to use overall antennas with a length of up to several tens of meters. Pros is absolute autonomy, a large range of communication and low cost compared to satellite communications.

Main used Equipment: ICOM IC-78, IC-M802, VERTEX VX-1700, VX-1400, VX-1200 / 1210., Kenwood TK-90, Cordon R-12, Q-Mac HF 90m, Barrett PRC-2090 , PRC-2091, carat, hangar.

Also, within 1-30 MHz, 9 sections of the frequencies allocated for communications are located. The main used radio amateur KV equipment - Transceivers Kenwood, Icom, Yaesu, Elecraft. If for professional sustainable radio communications, the range is usually limited to 8000 km, the radio amateurs often conduct radio transcontinental radio transmission sessions with their colleagues located on the other end of the globe.

Currently, large turns are gaining the market for software-implemented radio - SDR equipment. The software-implemented radio begins to be widely used in amateur communications, military and in commercial areas. To date, Harris and Alcatel Lucent companies have already implemented several successful projects that use equipment based on SDR technology and cognitive radio (radio system capable of receiving information about the features of its own operation and on the basis of this data to correct their work parameters). In the future, SDR technology has every chance of becoming a new standard in the telecommunications market.

Civil Range - 27 MHz

Conditionally called "Range of 27 MHz". The frequency range is 25.6-30.1 MHz (officially allowed plot - 26.965-27.860 MHz). Another name is Sibi Range from the English abbreviation CB - Citizen Band.

Truck range on radio This is the 15th channel, with a frequency of 27.135 MHz, in amplitude modulation mode (AM). The channel is actively used by truckers, for communication on the tracks. In large cities, filing SI BI RAZ 27 MHz, used by car enthusiasts, for the exchange of information about the road atmosphere. In different cities, various channels are used for urban communication. For example, in Krasnoyarsk it is a channel 40, with a frequency of 27.405 MHz, in Kemerovo 27th channel, frequency - 27.275 MHz. Frequency modulation (FM) is used at the frequencies of urban autochannels.

Also, small taxi and cargo transporters, a quick response group of security enterprises and utilities enjoy the radio stations of this range. Despite the price availability of equipment, and the fact that, according to the Decree of the Government of the Russian Federation of October 13, 2011 No. 837, 12 MHz bandwidth Not subject to registration, it is necessary to take into account the fact that the civil range is subject to great atmospheric and industrial interference and use radioCB range For commercial purposes, it is not suitable for enterprises where qualitative radio communication needs. Filing SI BI BY RANGE, in view of a small radius of action and relatively large dimensions, they did not receive special distribution and are used, mainly with loading and unloading works or on the parking lots of trucks.

Most of the CB ranges available in Russia are represented in our online store.

Filing SI BI Range Buy which you can in our online store are presented in separate catalog .

Low-Band range - 33-57.5 MHz

This is the lower section of the VHF range of mobile radio communications.

Due to the large influence of industrial interference in cities and interference from TV broadcast transmitters, this range is used mainly in rural areas. Main users, since the USSR, ambulance station and agricultural enterprises. To date, most world manufacturers stopped the production of radio stations for these frequencies. Equipment for the LOW-BAND range, currently offered domestic manufacturers - Granite and VEBR companies. In warehouses, you can still find radio stations from eminent brands: Motorola GP340, GM360., VERTEX STANDARD VX-3000L. The only of the available foreign manufacturers of the range of 33-57.5 MHz remains Alinco, Inc. The company offers a DJ-V17L wearable radio and automotive (basic) DR-135LH and DR-M06R radio stations.

Avia Range - 118-137 MHz

Air ships carry out radio exchange among themselves and with ground services in this frequency range. In contrast to most other types of VHF communication, amplitude modulation is used. Popular Equipment for Airlines -

wearable Aviation Range:

156,8375-174 MHz - mobile and fixed ground bond.

In accordance with the basic law "On Communication" of July 07, 2003 No. 126-FZ, for the organization of radio communications in this range, it is necessary to obtain permission to the FSUE "GRSCH". If you need to receive frequencies, we can provide advisory and accompanying support in obtaining permits.

High interference and good signal passage provided the range of 136-174 MHz is the most popular among users and equipment manufacturers. Our store presents the majority of popular radio stations and antennas VHF bands. RadioVHF Range In our store are presented in separate catalog .

River range - 300 MHz

Used to communicate on inland waterways.

Warning frequencies Located in the range of 300,0125-300,5125 MHz and 336,0125-336,5125 MHz.

River range Comes with pre-installed channels isolated to communications with ships and coastal services, for certain purposes.

Frequencies of channel racies - Their numbers and appointments are set "instructions on the organization of ship radio communications in the basin (region), approved by the River Fleet Service of the Ministry of Transport of the Russian Federation and coordinated with local authorities for radio communications. So, the main channels are:

Channel 2 (300.05 MHz) - for communication between the courts;

Channel 3 (300.1 MHz) - to communicate with gateway dispatchers;

Channel 4 (300.15 MHz) - to communicate with other rechfoot services;

Channel 5 (300.2 MHz) - to call ships, coordination of the order of discrepancies and overtaking when maneuvering and transmitting disaster signals.

Channel 25 and 43 (336.2 MHz and 300,125 MHz) are generally accepted for communication between yachts.

All radio stations installed on ships on the inland waterways must necessarily have the admission of river register of Russia (RDR) and the certificate of the Ministry of Communications, regardless of their affiliation and on whether these radio stations are the main or additional equipment.

According to the frequency distribution approved by the International Telecommunication Union (ITU), the frequencies in the range of 156-162 MHz are used for communication between the courts (rivers and the sea). The river range is 300 MHz, used only in Russia and the choice of the proposed equipment on this range is small. Popular river radio stations: Radioma-300, Vertex Standard VX-451 / VX-454, VGA VG-304, Argut A-36.

VHF range - 400-470 MHz

In foreign sources, the range is denoted as UHF, the name of which is formed from capital letters Ultra High Frequency.

Features of the propagation of UHF frequencies allow you to recommend this range for use in a dense urban building, in the mountains. Under the conditions of the forest area of \u200b\u200bthe radio station at 400 MHz, inferior to radio stations of the range of 136-174 MHz.

In the range, frequency bands are highlighted for professional use, for radio amateurs and for non-limited use by all those who wish.

Frequency of racieswhose work, in accordance with the basic law "On Communication" of July 07, 2003 No. 126-FZ, is possible only if there are permits:

420-430 MHz - mobile and fixed ground communication;

430-440 MHz - Radio Digital Range;

440-470 MHz - mobile and fixed ground bond.

If it is necessary to obtain frequency ratings, we can provide consulting and accompanying support in obtaining permits.

The ranges of the range that, according to the Decree of the Government of the Russian Federation of December 31, 2004 No. 896 do not require permits - permitted Range Range (Deceptible frequencies):

433,075-434,775 MHz - LPD ("Low Power Device") Range. Standard frequency grid of 69 denominations, with a step of 25 kHz;

446,00625-446,09375 - PMR (PRIVATE Mobile Radio) Range. Standard Mesh Frequencies of 8 channels, with a step between channels of 12.5 kHz (for accurate tuning, the radio should be able to restructure the step of 6.25 kHz).

And we continue.

Fourth level - portable VHF / UHF radio stations

With this, many are offered to lay the basis of their radio farmbecause your initial radio amateur license allows you to use these frequencies. This makes sense, right?

No, and no, if you first have not learned the question. The license for one level above the initial allows work on the SV-RAM, and it is necessary to concentrate from the very beginning of its training.

From the translator:

• In the Russian Federation, work on amateur areas UHF / VHF ranges is permitted by the fourth radio amateur category, and work in addition to VHF / UHF and on short and medium waves - the third category. An exemplary analogue of the Russian fourth category in the United States is technician, and the third (and second) - General. In each country, the approach to the distribution of categories is different, follow the advice on reconciliation with local legislation.

When you explore the use of KV, VHI questions you will click like seeds. Again, this is my opinion. But after many years of using radio communications, I see that such an approach is more rational for the long-term perspective. Most portable radio stations are VHF / UHF range stations. If short, it means that they work in the area of \u200b\u200bdirect visibility.

From the translator:

• UHF / VHF is two ranges, they are written together as the designation of dual-band radio stations or in the case when they have a radio station of any of two ranges;
• VHF - The service interval of this range extends in the interval of 136-174 MHz, the radio amateur area on it - 144-146 MHz, in some countries - 144-148 MHz. The commodity name is "two meters", "two-meter" (along the wavelength in the radio amateur area). In some countries, on this range there is a limitless MURS standard;
• UHF - the service portion of the range occupies 400-520 MHz. The amateur portion - 430-440 MHz. The commodity name is "70 cm", "Semesey" (along the wavelength in the amateur portion). On this range, as a rule, there are at least one unless-free standard in any country, whether LPD, PMR, FRS, GMRS, PRS, SBRS, KDR, and the like. Specify the nuances of local state regulation in the field of radio communications;
• Often questions arise, on what range will be better in the forest in the forest. This largely depends on the range, but from the antenna installed on the radio station, see Note below about the antennas;
• There are portable on LB ("Low-Band", 30-80 MHz) and SIB, but they are less convenient in practice by virtue of a significantly larger wavelength and, accordingly, larger antennas, see the antennas note below;
• The expression "area of \u200b\u200bdirect visibility" means that the interlocutor can be seen in binoculars, not necessarily a naked eye to ensure good communication conditions. In the general case, the radius of the line of sight is determined by the crirness of the planet Earth - how much is the distance from your location to the horizon line, you can contact another radio station on such a distance. If it stands at the ground level. If your interlocutor is just like you, standing on Earth and keeps a portable at the head, then you can contact him at a distance from you to the horizon and from the horizon line to the interlocutor. It is important to remember that this is possible only in ideal conditions - smooth steppe (or waste), or a water surface. If you are on the tower or balloon, then the range of possible radio communications increases even more, as the horizon line is removed from you.

If you can see a person, you can contact him. In this way. There are no magic portable radio stations with a radius of communication of 50-100 miles. These radio stations are often used with the repeater to increase the communication radius.

So what is the portable for you?

First of all, it is a cheaper radio station. But you get what they paid for, take note. You may buy what will work well, and never experience any problems. Maybe. I consider the purchase of high-quality goods by manifestation of common sense, if it really will have to rely on his work. I hate advise the following samples, but if you have a skinny wallet, and there was a need to close some need, that is, several popular models.

• Baofeng UV-82
• Baofeng UV-5R

What do I think about them? In medical terms it is like a leukoplasty on a serious wound. They only give you the illusion that you have a radio. The best thing in them is that they are not sorry to throw them out. This is not the best advertisement, probably. My group decided that we need a realistic approach and a single standard of spare parts, antennas and batteries, and not the intercession of stations and parts that do not join with each other.

We like radio stations Yaesu series VX., I. ECU VX-7 Among them is the most preferred. "Sevenka" is a civilian version of the Japanese military portative suitable, and I am pleased with it. It is easily configured in the schedule and has good warranty support, as well as a wide selection of accessories. It is moisture-resistant when diving to one meter and protected from dust. However, it is no longer produced, so we go to other models in the VX series as new radio stations are purchased.

I can not emphasize how important it is to establish the standard of equipment in the team. I just do not understand why people buy some cheap radio stations, chasing the amount instead of buying one that will work when deplets break.

I do not say that I did not use the radio stations of the lower price level. I used, and used others, with whom I regularly communicate. We all came to a single output. If you want, so to speak, to cry out the sediment from the bottom of the barrel, then save your right. If you are persistent, you can find the products of the EUE or other respected manufacturers at a price of a little higher than Chinese cheaps. If you need what will work straight out of the box, and will continue to work in the future ... then you will understand how and why we came to our solution about radio stations.

From the translator:

• The author recommended by the author has in addition to high characteristics, also extensive functionality, completely redundant for most applications. You can recommend another model of ECU, namely FT-60, which works on two amateur bands and allows you to listen to aviators;
• Single-band radio stations of well-known manufacturers are cheaper than dual-band, but they need to choose wisely, focusing on future use and compatibility with the equipment of the current and alleged interlocutors;
• The Chinese make different radio stations - baophengi and chiters Very different from each other. Class higher than baophengcan be called vastoxew, Wouxun. - Their quality is higher, the range of accessories is wide, there is dust and splashing. They stand in one and a half - three times more expensive than the aforementioned.

When buying radio stations you get exactly what they paid for. No matter what radio stations you are bought, you need to change the antennas to more efficiently than standard. Carefully monitor the compatibility of the connector, and this is another consideration in favor of equipment standards inside the group. A set of compatible antennas, accumulators and accessories are better than a bunch of different trash.

From the translator:

• The full length of the antennas in this case is discussed as 1/4 wavelength. For the VHF radio amateur portion, it is two meters, which means a quarter is approximately 50 cm (with nuances that are not discussed here). For amateur UHF, it is 17.5 cm. You can draw conclusions about the convenience of use and risk to break the antenna. Thus, despite the fact that VHF is more effective in forest conditions than UHF, for UHF it is easier to use a more efficient antenna - and in the practical section of the UHF will be more efficient than VHF.
• It is important to remember when choosing equipment, which is often the standard of the limitless range prohibits on the races corresponding to the standard, replace the antennas to more efficiently, and the antennas on these radio shows are fixed, without the possibility of twist-fastened. From this again, a recommendation should be found out to find out local legislation, learn the permitted standards, and weigh everything for and against - whether to use non-limitated stations, or decide to receive a radio amateur license. Perhaps it will be a reasonable choice of single-band radio stations for their group capable of interacting with common non-limzenia in your country.

Fifth level. Mobile radio stations - in transport and installed stationary

I place it after the portatives because, even though mobile and are as if in the middle between the SV-Transceivers and VHF portable, but you can partly replace them with a portable with a trimmed antenna. Mobile radio stations are transmitted at significantly greater power than portatives. My portable gives 5 watts, two-way mobile station 50 watts, and my mobile single-band on VHF is 75 watts. Power, however, not a key point in radio communication, "more" does not always mean "noticeably better."

From the translator:

• The power of the radio station under the conditions of direct visibility of the value almost does not have. If there is a forest between you and the interlocutor, or crossed terrain, then the real range is significantly reduced. Even more it will decrease if there are buildings, hills on the line of sight, they absorb radio waves. Even stronger the objects of industrial infrastructure, power lines, substations, and even simply electrical devices in residential buildings, which create noise, "electronic smoking" on ether. Power can help overcome these interference, but not always. In general, it is better to go to the balcony than to increase the power of the radio station while inside the room;
• There is a dividing formula that in order to increase the distance distance by 2 times - power must be increased 4 times. If the distance is already the limit (see above the horizon), then this increase will not give effect, but only the battery discusses it faster.

I like in mobile stations what I can pull them out of the car and put at home by connecting to a stationary installed antenna, more efficient. It does not contribute to secure, but most people have no idea that they see when they look at any antennas.

Yaesu FT-2900R

The 2900th is my favorite for noisy ethereal conditions, and it gives 75 watts. It is intended only for the VHF range, but if you are ready to understand how different ranges are used, and what is its specific features, it is a stunning radio. It is designed for SUVs, passable transport with open top, as it is sealed. Because of this, it can overheat with long-term work on the transfer, but, at the same time, if it happened, then you need to work on your work skills.

Yaesu FT-8800R

8800 is more popular than the 8900th, since at least the 8900th and there are 6 and 10 meters ranges, but it cannot work in SSB, so most of those who use 6 and 10 meters will not be able to talk to you . 8800 I use in my everyday car and at home as a base node. She can work simplex (radio<-> Radio) and through the repeater. If I bought one radio for UHF / VHF, I would choose it.

From the translator:

• There are also Chinese mobile stations, such as QYT KT8900, problems with them are the same as with portatives.

The sixth level. Other ranges in the level structure

"Si-bi" of radio stations - avoid cheap working only in FM mode. Buy only capable working in SSB. Each ballback can own Sibishka, but most of them can not work in SSB.

From the translator:

• The radio stations sold in the Russian Federation and the adjacent states of the Range of SIB are working, as a rule, with the modulation of AM and FM - SSB in our edges a very rare beast and expensive. To buy a Sobish radio with SSB, you need to clearly focus on its use, otherwise it is a waste of money.

Unless-free radio stations are both common wagons sold in pairs in plastic packaging, as well as better, from famous firms.

From the translator:

• Unless-free radio stations that meet the standard and fully legal should have a fixed power (LPD - 50 MW, PMR - 500 MW, SI-BB - 4 W in AM and FM and 12 W in SSB), fixed radiation strip to transmission, in some standards and unplaced antenna. It often happens that those who are on sale, offered as non-mighty, do not correspond to these requirements, but no one is strictly followed by this.

I hope that I was able to give you an initial idea of \u200b\u200bthe place of communication in survival.

In contact with

Odnoklassniki.

Permitted VHF frequencies for radio amateurs their appointment

I often meet with questions from radio amateries about the assignment of frequencies on the VHF band. The fact is that the number of frequencies is limited and some of them are reserved for certain types of connections. Also, part of the frequencies are allocated for the needs of the creation of repeaters. For this reason, novice radio amateurs are afraid to take a specialized frequency and get on the ears. To often not respond to these questions, I will give a table for the VHF band.

The range from 144 to 146 MHz is allocated to the radio amateur service on a primary basis. The fourth category radio amateurs have the right to work at these frequencies with a capacity of 5 W, the second and third to 10 W, and the first category by 50 W (for the EME and MC of the Common Categories are allowed to use up to 500 W).

Frequency range (MHz)	Strip width (kHz)	Types of Modulation and Purpose (MHz)
144,000-144,110	0.5 kHz	Only telegraphy. Advantageously telegraph EME. Tube frequency of telegraph 144.05 MHz. Frequency for MC communication without prior arrangement - 144,100 MHz. The frequency band is 144.0025 MHz - 144,025 MHz - mainly for space communication (space-ground).
144,110-144,150	0.5 kHz	Narrowband species. Mostly digital narrow-band types of EME. Center for activity PSK31 - 144,138).
144,150-144,165	2.7 kHz	Telegraph, circuit, digital species. Mostly digital species EME.
144,165-144,180	2.7 kHz	Telegraph, circuit, digital species. Mostly digital views. The delicate frequency of digital species is 144,170 MHz.
144,180-144,360	2.7 kHz	Telegraphy and circuit. Picky frequency OBP - 144,300 MHz. Frequency band for MC bonds without prior arrangement - 144,195-144,205 MHz.
144,360-144,399	2.7 kHz	Telegraph, circuit, digital species. Frequency for FGC441 connections without prior arrangement - 144,370 MHz.
144,400-144,491	0.5 kHz	Narrow-band species - only lighthouses.
144,500-144,794	20 kHz	All kinds. Tailing frequencies: Foci - 144,500 MHz; Teletip - 144,600 MHz; Fax - 144,700 MHz; ATV - 144,525 and 144,750 MHz). Recommended frequency bands for linear transpoders: 144,630-144,600 MHz - Transmission, 144,660-144.690 MHz - Reception).
144,794-144,990	12 kHz	Telegraph, digital species, digital voice communication, digital automatic stations. APPEATICAL ACTIVITY for APIs - 144,800 MHz. Recommended frequencies of digital automatic stations for digital voice communication: 144,8125, 144,8250, 144,8375, 144,8500, 144,8625 MHz.
144,990-145,194	12 kHz	World Cup, digital voice communication - only for repeaters, reception. Ratings of frequency 145,000-145,175 MHz, pitch 12.5 kHz.
145,194-145,206	12 kHz
145,206-145,594	12 kHz	Telegraphy, World Cup, Digital Voice Communication, Digital Automatic Femged Stations ("Echolin"). Verified frequencies: World Cup - 145,500 MHz, digital voice communication - 145,375 MHz. The Center for the Affilitary Emergency Service Stations - 145,450 MHz.
145,594-145,7935	12 kHz	FM, digital voice communication - only for repeaters, transmission. Ratings of frequency 145,600-145,775 MHz pitch 12.5 kHz.
145,794-145,806	12 kHz	Telegraph, World Cup, Digital Voice Communication. Mostly for cosmic communication.
145,806-146,000	12 kHz	All kinds are only for space communications.

It turns out that for direct communication in frequency modulation, frequencies are isolated from 145,206 MHz to 145.594 MHz. Mesh pitch 12.5 kHz. This table is drawn up according to the decision of the GCRF of July 22, 2014 No. 10-07-01.

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