Who are ultrashort-wave hams

    Who are ultrashort-wave hams


    This article is a small add-on to the article about short-wave radio hams.

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    Operator Antennas EA5FUZ

    As we have already found out, radio communicators are engaged in radio communications exclusively in the form of a hobby, because both written and unwritten rules, they are limited in the subject of communication only to talk about radio equipment and antennas, about radio sports, radio wave propagation and weather. This suits radio amateurs, because it is precisely those topics that are guaranteed to be of interest to any of them, and for other purposes, radio detectors, like any other users, use other communication channels that have nothing to do with radio amateurs. What is the difference between VHF and shortwave? Captain Evidence suggests that VHF forces are conducting r / l communications on the ultra-short-wavelength bands, but the complexity of the classification is that if the short-wavelength bands are somewhat similar to each other - yes, everyone has their own propagation characteristics,

    Since the mass appearance of FM radio stations available for amateurs (it could be both original radio amateur models and commercial ones suitable for frequencies), the popularity of local VHF radio communications in FM began to grow, which gave rise to a rather stable myth that short waves are difficult and expensive, and VHF is simple and cheap. And in modern times, when Chinese-made portable FM radio stations became cheap consumer goods and a new category of people with radio amateur licenses obtained only to legalize these same portable radio stations appeared (that is, in fact they have nothing to do with radio jamming, despite the formal presence of a call sign) , this myth has been strengthened even more.

    Indeed, local FM communications are easy for the operator. Easily accessible, as was said, equipment, plus the simplest antenna on the roof, make it possible to join a club of chat lovers on radio and radio themes within a radius of two to three tens of kilometers. Often a local group or individual enthusiasts set up a repeater that provides support even for very weak subscribers - remote operators, motorists and pedestrians with portable radio stations. Then the chatting club spreads over the entire radio coverage of the repeater, which in the case of relatively densely populated regions, or in the case of an abnormally large installation height of the repeater, gives a more or less decent audience for communication, and the communication is commercially reliable, after all, the imperfection of their own equipment is largely compensated by the repeater. Narrow-band frequency modulation itself was pretty good and it was not without reason that it was so popular in commercial communications until it began to be replaced by a number: it uses its occupied frequency band quite efficiently and with proper circuitry allows it to obtain high reception sensitivity, it is tolerant of inaccurate tuning to the correspondent, in it is elementary to mute the receiver in the absence of a useful signal. Therefore, you should not think that FM is something bad. No, FM is just something very affordable at VHF radio. it uses its occupied frequency band quite efficiently and with proper circuitry allows it to obtain high reception sensitivity, it is tolerant of inaccurate tuning to the correspondent, it mutes sound malfunctioning in the receiver in the absence of a useful signal. Therefore, you should not think that FM is something bad. No, FM is just something very affordable at VHF radio. it uses its occupied frequency band quite efficiently and with proper circuitry allows it to obtain high reception sensitivity, it is tolerant of inaccurate tuning to the correspondent, it mutes sound malfunctioning in the receiver in the absence of a useful signal. Therefore, you should not think that FM is something bad. No, FM is just something very affordable at VHF radio.

    Local communication is, of course, good, but most radio amateurs are not interested in sitting in the same swamp, listening to the same stories of the same correspondents day after day, but making the most distant communications, because that is what sporting interest, which to a large extent consists of radio amateurism. Speaking of VHF, they often talk about the practically optical, rectilinear propagation of radio waves that practically do not diffract from obstacles like the horizon. However, communication over the horizon is still possible. Ranges of meter waves and, to a large extent, ranges of decimeter waves, receive the possibility of anomalously distant propagation, when the medium - the atmosphere, receives a temperature inversion and, especially, more or less pronounced temperature layers, in which refraction of radio waves occurs and their waveguide propagation. Probably the most obvious analogue will be an optical fiber in which light is fairly reliably held by reflection from the boundaries of the media - and in the tropospheric layers, radio waves are held by the boundaries of the layers. Such conditions arise, depending on the geographical region, infrequently and unwarranted, therefore they are not used in commercial communications, but radio detectors with simple equipment, usually limited by communication ranges of the order of two to three tens of kilometers, get the opportunity to operate the stations several hundred kilometers, and if you're lucky , then up to a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. Probably the most obvious analogue will be an optical fiber in which light is fairly reliably held by reflection from the boundaries of the media - and in the tropospheric layers, radio waves are held by the boundaries of the layers. Such conditions arise, depending on the geographical region, infrequently and unwarranted, therefore they are not used in commercial communications, but radio detectors with simple equipment, usually limited by communication ranges of the order of two to three tens of kilometers, get the opportunity to operate the stations several hundred kilometers, and if you're lucky , then up to a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. Probably the most obvious analogue will be an optical fiber in which light is fairly reliably held by reflection from the boundaries of the media - and in the tropospheric layers, radio waves are held by the boundaries of the layers. Such conditions arise, depending on the geographical region, infrequently and unwarranted, therefore they are not used in commercial communications, but radio detectors with simple equipment, usually limited by communication ranges of the order of two to three tens of kilometers, get the opportunity to operate the stations several hundred kilometers, and if you're lucky , then up to a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. in which light is fairly reliably held by reflection from the boundaries of the media - and in the tropospheric layers, radio waves are held by the boundaries of the layers. Such conditions arise, depending on the geographical region, infrequently and unwarranted, therefore they are not used in commercial communications, but radio detectors with simple equipment, usually limited by communication ranges of the order of two to three tens of kilometers, get the opportunity to operate the stations several hundred kilometers, and if you're lucky , then up to a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. in which light is fairly reliably held by reflection from the boundaries of the media - and in the tropospheric layers, radio waves are held by the boundaries of the layers. Such conditions arise, depending on the geographic region, infrequently and unwarranted, therefore they are not used in commercial communications, but radio detectors with simple equipment, usually limited by communication ranges of the order of two to three tens of kilometers, get the opportunity to operate the stations several hundred kilometers, and if you're lucky , then up to a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. depending on the geographical region, it is infrequently and unwarranted, therefore it is not used in commercial communications, but radio detectors with simple equipment, usually limited by communication distances of the order of two to three tens of kilometers, get the opportunity to operate the stations several hundred kilometers, and if you are lucky, then one and a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. depending on the geographical region, it is infrequently and unwarranted, therefore it is not used in commercial communications, but radio detectors with simple equipment, usually limited by communication distances of the order of two to three tens of kilometers, get the opportunity to operate the stations several hundred kilometers, and if you are lucky, then one and a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. then up to a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon. then up to a half to two thousand. In ordinary time, when the troposphere is relatively homogeneous and has a more or less calculated temperature gradient, this effect is not observed, and communication is really possible only to the horizon.

    To increase the range of the repeater, you must raise it as high as possible. So radio satellites appeared. Unfortunately, earlier launched satellites with highly elliptical orbits, which provided at the peak of radio coverage of almost the entire hemisphere and several hours of radio visibility, have long failed. Everything that works now or is planned to be launched is LEO low-flying, low-power kubsats with altitudes of the order of 500-700 km, whose radio visibility usually does not exceed fifteen minutes, and the radio coverage radius is about two to three thousand kilometers, making transcontinental communications impossible for most. Rumors are circulating about the launch of a geostationary amateur satellite, or rather, that a commercial transponder will be allocated for radio amateur entertainment, but so far this has not become a fait accompli, discussing this does not make much sense. According to the types of payload, satellites can be roughly divided into FM repeaters, linear transponders and packet digipiters. Satellites with FM repeaters are very popular with beginners, because they do not require any serious equipment to start. Theoretically, you can work on a portable with a complete or, preferably, an extended rubber band, but in practice this is unlikely and succeeds more as an exception. Typical equipment of a novice satellite lover is a portable directional antenna and a portable radio receiver. Theoretically, you can work on a portable with a complete or, preferably, an extended rubber band, but in practice this is unlikely and succeeds more as an exception. Typical equipment of a novice satellite lover is a portable directional antenna and a portable radio receiver. Theoretically, you can work on a portable with a complete or, preferably, an extended rubber band, but in practice this is unlikely and succeeds more as an exception. Typical equipment of a novice satellite lover is a portable directional antenna and a portable radio receiver.

    Since most operators have no more than two hands, one of which is occupied by a radio station and the other has an antenna, they usually use a voice recorder to record a span to make communications without being distracted by keeping a hardware logbook and entering the logbook in a calm environment later. The satellite’s output power is hundreds of milliwatts, so the main difficulty is to receive it, and not to transmit it at all. Of course, if at the same time someone else is transmitting with a much stronger signal (not necessarily due to the transmitter power, because it is more profitable to increase the “gain” of the antenna), then do not shout it down. But when no one bothers, the power of their transmitter, an order of magnitude greater than that of a satellite transmitter (most handhelds - 4 ~ 5W), is more than enough even in the case of an elastic band, not to mention a directional antenna.

    Two satellites are still functioning for relaying digital voice. One of them accepts analog FM, digitizes it and transfers down already by a digit. The second only works in numbers. Technically, they are similar to FM satellites and, with the exception of the need for appropriate equipment, do not differ in terms of operation on them.

    The next step is linear transponders. Theoretically, it is possible to use any modulation within their band, practically only telegraph and telephony are used in SSB, but FM is severely condemned because all the available transponder power, and it is on the order of hundreds of milliwatts, is divided into all relayed signals. Telegraph pulsed signals and single-band suppressed carrier modulation have a low average power. And the frequency modulation has an average power equal to the maximum - regardless of the modulation, the carrier level is constant and maximum, which leads to drawing out all the weak satellite resources to service this carrier to the detriment of other signals. That is why FM is behind the scenes is strictly prohibited. For operation on linear transponders, less common CW / SSB equipment is required, and also requires continuous compensation for Doppler shift. After all, if FM is sufficiently tolerant of tuning inaccuracies and for the entire time of satellite passage it is enough to skip a station a couple of times, then CW and SBB require continuous tuning, without which the correspondent will float in frequency to complete illegibility very quickly. For advanced operators, everything is automated: based on the known TLE (orbit parameters) and the known operator’s location, the satellite’s passage and Doppler offset compensation for each band are calculated, so the rotary device itself directs the antennas to the moving satellite, and the radio itself introduces the correction, eliminating the perceived frequency drift. But the transmission power is still large is not required. An excessively strong signal at the transponder input will disrupt its normal transmission and instead,

    Packet digipiter and BBS are used for both traditional packet communication and the APRS segment, which will be discussed separately.

    The low power of the satellites is associated not with administrative restrictions, but with the weight and size of the payload and the purely technical limitations on its power. For example, a transmitter with ISS, where there are no problems with power, is heard on the whole scale, and cubsat give a couple of hundred milliwatts to the simplest, not the most efficient antennas.

    Satellites, nya!
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    KC2UHB is an experienced amateur radio operator. Here, she kind of hints to us how to properly make a satellite dish from improvised materials and how to use it later. What have you achieved?

    Repeaters, even in space, are active. But amateurs want to try passive, depending only on them, ways to establish long-distance communications. There are two general directions - scattering and reflection. This is a world of large attenuation, so it requires high power, highly directional antennas and low-noise receivers that allow you to stretch weak signals. It’s also a pure sport or, one might say, Proof Of Concept, in which the establishment of radio communications is valuable in itself, and does not mean pleasant chatter for hours, because often it can take several hours to exchange simple callsigns. Most of these connections are made by prior arrangement.

    In the troposphere, there are always heterogeneities that lead to scattering of radio waves. As a rule, this dispersion is negligible, but still it is not zero. Therefore, we take an irradiator, say, of a range of 70 cm, put it in the focus of a parabolic reflector of meters, at least six in diameter, and direct it towards a correspondent with comparable equipment. We bring the power to the irradiator slightly higher than allowed and reliably communicate with the correspondent at any time of the year and at any time of the day at a distance of at least 500 kilometers. Yes, in the event of a temperature inversion in the troposphere, the same distance can be covered by incomparably simpler equipment, but there it is a case, and here is everyday life. However, it’s more interesting to deploy such an antenna to the Moon - reflection from the Moon (EME) is perhaps the most difficult form of communication on VHF, since the signal attenuation is huge, and quite serious equipment is needed to compensate for the attenuation, primarily the antenna. If you go higher in frequency (say, one of the popular EME bands is 10 GHz), then the diameter of the reflector can be significantly reduced. However, with increasing frequency, the problems of frequency stability per se and separately compensation for Doppler shift increase, and indeed centimeter waves require completely different engineering solutions to fundamentally the same issues that are well developed in the meter wavelength range and no longer seem to be something complicated. Nevertheless, at the same 10 GHz, the connection with precipitation dispersion is relatively popular - Rain Scatter. one of the popular EME bands is 10GHz), then the diameter of the reflector can be significantly reduced. However, with increasing frequency, the problems of frequency stability per se and separately compensation for Doppler shift increase, and indeed centimeter waves require completely different engineering solutions to fundamentally the same issues that are well developed in the meter wavelength range and no longer seem to be something complicated. Nevertheless, at the same 10 GHz, the connection with precipitation dispersion is relatively popular - Rain Scatter. one of the popular EME bands is 10GHz), then the diameter of the reflector can be significantly reduced. However, with increasing frequency, the problems of frequency stability per se and separately compensation for Doppler shift increase, and indeed centimeter waves require completely different engineering solutions to fundamentally the same issues that are well developed in the meter wavelength range and no longer seem to be something complicated. Nevertheless, at the same 10 GHz, the connection with precipitation dispersion is relatively popular - Rain Scatter. which are well-developed in the range of meter waves and no longer seem to be something complicated. Nevertheless, at the same 10 GHz, the connection with precipitation dispersion is relatively popular - Rain Scatter. which are well-developed in the range of meter waves and no longer seem to be something complicated. Nevertheless, at the same 10 GHz, the connection with precipitation dispersion is relatively popular - Rain Scatter.

    Typical moon reflection antenna
    It’s a pity that only a pickup piece is visible at the bottom right - it would be easier to estimate the scale of the structure, which rotates both in azimuth and elevation.
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    What else can be scattered or what else can reflect radio waves from? For example, from ionized meteor tracks. We direct the antenna towards the expected meteor shower and for some time continuously transmit our callsign, repeating it at high speed. If you are lucky, then one of our programs will completely reflect on the track and will be accepted by our correspondent - therefore, it is necessary to transmit at a high speed in order to be able to slip through the existence of the ionized trace in a short time, and therefore it is necessary to transmit for a long time so that it is lucky to get such a trace. Then our correspondent just as quickly and for a long time passes the answer to us. The time for which information can be successfully transmitted is very small. Especially use such modes in which the transmission speed is very high, higher than human capabilities. When there were no computers We recorded the telegraphic package on a tape recorder and played it very accelerated - the receiving side recorded the received and played back slowly, so that we can already hear the callsign transmitted by the telegraph. But it may take a very long time to wait until our information can reflect on something, and the result is not guaranteed. Sometimes it is possible to make a connection very quickly, and sometimes even for the whole day, nothing happens - just the same meteor will not appear, from the trace of which we can reflect our signal. For example, one of your parcels was successfully received by your correspondent, but you still can’t get his answer - without this, the connection does not count, you need a full exchange in both directions. At the same time, you can be in correspondence in a specialized chat for meteor fans and know that you are actually communicating,

    You can also reflect the signals from the fuselage of the aircraft. No, seriously, such connections are sometimes made. If the wavelength is less than the object, then it can be reflected, and ultrashort waves are shorter than any plane, if only it was made of a conductor - fortunately for radio detectors, almost all planes are metal, which means you can try it. Sometimes they ask if such a connection does not pose any danger to the aircraft, its systems or passengers. No, there is no danger. Firstly, the electromagnetic field near the aircraft is extremely small - the distance to it is large. Secondly, the aircraft is a Faraday cage, so its insides, including the pax, are reliably shielded by the fuselage. No one is surprised that lightning can get on the plane, and this does not cause him any problems? Also, no one is surprised that nothing happens to airplanes from exposure to their radars - specialized constantly working devices for communicating with the reflection of radio waves from an airplane. So nothing can happen from radio pranks and even more so.

    Aurora, the northern lights are still good. This is an ionized region, which means that you can work by backscattering from it. Inventive radio receivers are ready to use any natural phenomenon or artificial structure for their strange purposes - simply establish radio communications for the sake of establishing radio communications. If this is unclear or uninteresting to you - do not worry, you are just one of the majority of normal people.

    What else can I do on VHF? Sports direction finding, which for some misunderstanding is called fox hunting.

    Personal opinion of the author
    The fact is that for hunting foxes carbines of small caliber with a relatively low-speed bullet are more suitable, otherwise, due to a water hammer, the prey will be damaged and the killing will be in vain and meaningless. It seems infinitely far from humane to try to kill a fox with a portable direction finder, except that she will die of laughter, watching your attempts to do this. Better yet, leave the fox alone, not listening to arguments about “pests,” because the fox is an integral part of the ecosystem, and only humans do real harm when trying to remake the ecosystem for their convenience and ignoring the long-term consequences. Therefore, if you are not going to eat a fox, just leave it alone.

    This is a rare type of radio sport - full-time. Opponents physically get together at the start and compete in person with each other according to the rules, to some extent close to orienteering, only bookmarks are searched with direction finders. This skill, by the way, makes it quite easy to find inappropriate, mistakenly thinking that they are anonymous, and therefore unattainable, and conduct friendly conversations with them, sometimes even without self-harm. However, unlike sports equipment, amateurs also have Doppler radars - they make them themselves or buy ready-made ones. There is also software that allows you to determine the "handwriting" of a signal from an individual radio station. With such an arsenal, the detection and identification of the elusive anonymous are made quite affordable even for private individuals, which is especially valuable in those countries

    Amator packet networks, which were popular among IT enthusiasts rather than radio communications, are no longer the same. About the same thing happened, what happened when it was your ffpedo and these Internet of yours started. Both sysops and users have lost interest, ceased to support networks, and as it seemed, that’s all, apart from individual marginals who are still raising new BBS or stubbornly supporting old ones. But then comrade WB4APR, who came up with APRS, adhered in a timely manner. APRS is usually deciphered as an Automatic Packet Reporting System, although there are often dreamers that change the word Packet to Position. APRS is quite a multifaceted thing, so let's try to consider it from different points of view. Logically, this is a network without a connection. You do not connect to the host, you simply create and send a packet that, depending on the contents and infrastructure settings, it will be processed one way or another. From the point of view of the access method, the network can be divided into a short-wave segment (limited use due to the extremely small bandwidth that does not allow significant traffic), the VHF segment (the most popular), the satellite segment (also VHF, but separated from the ground segment) and the Internet -segment (optional, but if available removes restrictions on the amount of traffic). On HF, the data transfer rate is 300bps, the channel is one for the whole world, therefore for nothing more than use by stations remote from everything, it is not suitable and is not used. On VHF, they usually work with speeds of 1k2 because, firstly, it is a historically established speed, and secondly, the equipment in this mode is quite tolerant of tuning inaccuracies. The type of modulation is called AFSK, You can talk about FSK through an audio device, simply through a regular VHF-FM radio station. There is also a GMSK 9k6 modulation, which is much less widespread due to higher requirements for setting up the equipment and, by and large, the lack of need in most regions of the world. Where there is not enough space, they prefer to use additional frequencies and work on them in parallel with the main frequencies, instead of increasing the speed and losing compatibility with those that 9k6 does not support.

    How does the APRS network work if it is a network without a node connection? A network member creates a packet and transmits it. The packet contains the sender and, nevertheless, the recipient, as well as relay instructions. The recipient may be APRS, i.e. a package for everyone, a package can be a newsletter, i.e. for everyone who has a subscription to receive, or a package can be addressed to a specific recipient, this usually happens when exchanging messages with someone specifically. Of course, like any r / l information, packets are not encrypted and publicly available, just terminals ignore packets not addressed to them, so as not to overload the operator with redundant and unnecessary information. The package for everyone is usually a lighthouse that informs the station that sent it of what the station wants to report to itself, or a lighthouse,

    Also in the package may be some kind of event or alarm point. Packages from weather stations quite unexpectedly contain weather information. Relay instructions specify where (geographically) and / or how many hop to relay the packet, they are usually anonymous and suitable for any relay (digipeater), but sometimes they indicate the specific node through which the packet should go. DJs, as a rule, adequately ignore incorrect relay settings, and also do not miss packets that require an abnormally large number of hopes, in order to avoid the situation when, due to an erroneous or malicious packet, a huge region is busy using its relay relay. All network segments are isolated and use gates to communicate with each other, which, depending on the settings, can pass all traffic, or selectively filter it. The gateway to the Internet segment (APRS-IS) is commonly referred to as an Igate. For example, short-wave aigates never pass APRS-IS> RF traffic, because data from an infinite Internet capacity instantly floods an extremely narrow radio channel, but on the contrary, RF> APRS-IS traffic usually goes without any filtering. For the same reason, satellite gateways (Satgate) also never pass APRS-IS> RF traffic.

    “Ordinary” VHF-eyegates basically pass all RF> APRS-IS traffic and filter APRS-IS> RF traffic, usually based on the distance from the Aygate. The fact is that APRS on VHF involves local, local data exchange, so packets from very remote sources (more than a hundred or two kilometers, which is much more than a reliable VHF communication range for an average car or even a simple stationary station) not only do not benefit for operators, but vice versa they are a hindrance, in vain occupying the channel and in vain distracting unnecessary conclusions to the terminal. Since each segment is independent and can simultaneously lock with another segment, the fall of any of them, primarily the Internet, will not lead to the collapse of the network. At the same time, the Internet provides convenience in the form of an infinite (by the standards of information transmitted on radio networks) channel width and allows you to unload a short-wave channel from those who want to participate in correspondence with a very remote correspondent: just create a packet and indicate the recipient of your destination, your packet will be accepted the nearest aiguet, directly or through a DJ chain, then in APRS-IS the packet will be switched to the one that the last heard your correspondent and will transmit the packet there. If everything is in order, ACK will return on the same route. Further, in APRS-IS, the packet will be switched to the Aygate that the last heard your correspondent and will transmit the packet there. If everything is in order, ACK will return on the same route. Further, in APRS-IS, the packet will be switched to the Aygate that the last heard your correspondent and will transmit the packet there. If everything is in order, ACK will return on the same route.

    Due to the fact that 99.9% of APRS traffic gets to the Internet, aggregator sites have become very popular, which collect all the information from APRS-IS and display it in a human-friendly form on top of the map. Some mistakenly think that this is APRS, and that the whole point is to then see their movements on the map (although even for the sake of this it makes sense to venture).


    Why do we need APRS? There are several reasons, besides the obvious that it is an independent network that will survive the power supply when everything else collapses, and also that it is a network through which you can send a message asking for help or send an alarm point. Therefore, the main reason: APRS is the only source of reliable information about local activity, especially on VHF. Locals do not understand this, because they already know what and where they have repeaters. But what about the visitor? And if the visitor does not speak your language? And you yourself, when someone is visiting? It’s good practice to send beacons to APRS informing everyone about local transponders. It’s also nice to send messages about yourself, as if inviting you to make a connection. If the operator p / st supports the QSY function, then it is enough to press one button, to tune in to the repeater (or to you, why not?) and immediately make a connection. If you are a licensed radio receiver and it seems to you that you do not need APRS, then this only seems so to you. Throughout the radio-amateur-developed world, APRSs are maintained in excellent condition and the radio coverage of the network is almost continuous, even if they do not really have it in their place and need it just like you do at home.

    If, however, APRS on VHF is not available to you due to the complete and unconditional lack of infrastructure - build your own aigate, and if you are in the vast expanses of the earth or ocean - use short waves or try to work through satellites. Purely technically, the easiest way is to work through ISS, in addition, you can often hear operators who correspond with messages there. Such messaging, by the way, counts toward certain diplomas as well as voice communication, for example.

    Over the past few years, various Digital Voice systems have begun to gain popularity. Unfortunately, there are a lot of standards, but all of them are directly incompatible with each other. DV means a clean, interference-free communication, as long as communication is possible at all, and then after a short “gurgling” its sharp break. The payback for this is the “robotic” voice characteristic of the first GSM phones. Simultaneously with the voice, your identifier is transmitted (callsign, if we are talking about the originally radio amateur "number", or abstract ID, if we are talking about the originally commercial systems, which radio amateurs also liked). This allows the system to correctly recognize you when you are roaming. Since the voice is now just a data stream, wide open spaces appear for modifying the radio interface (for example, TDMA - is it a joke, so that physically one amateur transponder provides simultaneously and independently two logical channels), and for processing the stream itself. The simplest and most obvious is the creation of reflectors or conversation groups that you can connect to from any repeater in the world. The second is the ability to transcode the voice of one standard into another so that users of incompatible standards can talk in the same reflector, again, each from any repeater in the world. Third - the ability to create multi-standard amateur transponders that can manually or automatically switch to any of several popular incompatible standards. Here already traditional radio communicators-communicators meet with IT specialists, from whose dedicated work such grandiose projects take place,

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