"Cqcqcq, this is bh9emq, the friend station on the call frequency. Please reply, over." One morning, as usual, I took my hand-held short wave radio, set up a portable antenna in the park near the school, turned on the radio to tune to the 14mhz band, and called my Guangdong friends 1300 kilometers away. CQ means seek you; Bh9emq is my call sign and my ID pixabay in the world of radio communication After a while, I was surrounded by people doing morning exercises. They took out their mobile phones to shoot this "original and novel" thing. Then, the patrol police sneaked up to me and asked about my operation license. After checking it, he told me to "pay attention to safety" and left. This is the fifth time I have been mistaken for a "spy". I am an amateur radio enthusiast. My informal name is "ham". The reason why we were not taken away as "spies" is that we are completely legal to transmit radio waves - we need to obtain a radio operation certificate and apply for a license. In China, there are 170000 licensed ham like me, accounting for about 0.01% of the national population, and nearly 3 million people worldwide. Amateur radio is not "amateur" at all. What do ham people do? Ham's activities mainly fall into three categories: communication, competition and emergency communication. Communication is the main activity of amateur radio. In short, amateur radio uses radio waves in the air to communicate with other enthusiasts. The contents and forms of communication are diverse, mainly including voice, image, wireless telegraph (that is, the Morse code in spy films), and digital mode. Enthusiasts generally exchange necessary information and discuss technology. When I was a junior in college, I would stay in the dormitory to operate the radio station as long as I didn't have classes, just to send the signal to further places. Sometimes rare prefixes such as Tonga, Brunei and other countries and regions, major event commemorative radio stations and so on appear on the frequency (the beginning of the call sign of each country and region is "prefix"), for example, The prefix of the memorial platform of the just concluded Winter Olympic Games is by1cra / wo22. The radio equipment in my dormitory is provided by the author When a rare call sign appears in the radio wave, indicating that it comes from those rare areas, a large number of Ham will soon flock to strive for radio connection with it. Many competition enthusiasts take pride in collecting the prefix of the radio station they have connected to, just as we collected the "game king" card when we were young. The proof methods include QSL card, digital connection record of Arrl, etc. When you have enough prefixes, you can report to Arrl and qrz COM and other institutions and websites apply for certificates of corresponding levels. These awards are like medals, which symbolize the technical level of ham operation. The QSL card and commemorative letter I received were taken by the author One evening in the summer of 2019, when I was watching the radio, I suddenly found a signal call from Iceland. I immediately replied to the call sign and the received signal quality, but it lasted for several minutes, and the other party still didn't reply. My heart is burning. At that time, when the sun sets, it is the most efficient time for the ionosphere to reflect short wave signals in the atmosphere. If the signal from distant Iceland misses the "window period" of communication, it is difficult to say when it will be encountered again next time. I hurried to the top of the building to rotate the direction of the antenna, and fine tuned the length of the antenna to resonate with the frequency of the other radio station. Then I ran downstairs and stared at the waterfall of the radio station. My sweat wet the table. Finally, after 15 minutes of "extreme pull", the other radio station finally recovered and received my call sign, and reported my signal quality. The excitement of that moment is still unforgettable. And a Swedish enthusiast whose call sign was provided by the author of 3m3liv In the two years of short wave communication, I have successfully connected with 149 countries and regions. The East is Montenegro, the west is Brazil, the south pole is the south pole, and the north is Norway. There are also some names I have never heard of, such as Isle of man, Ceuta and Melilla. Among several communication modes, I like FT8 digital mode best. FT8 is a digital communication mode that uses computers and radio stations to cooperate with each other. People communicate with remote station friends in the form of sending data packets through radio stations. The principle is similar to fax. Its advantage lies in its strong anti-interference ability and excellent modulation and demodulation mechanism, which can effectively separate the effective signal from the noise. With amateur radio, we can even communicate with astronauts on ISS (International Space Station). However, this extremely tests the comprehensive technical level of radio operators. Astronaut Reid Wiseman (call sign kf5lkt) communicated with ham NASA in June 2014 Generally speaking, if astronauts have amateur communication plans, they will be in ariss in advance Org predicts that enthusiasts around the world need to prepare Yagi antenna and radio equipment with stronger directivity, understand its on orbit operation through satellite monitoring tools, call astronauts within a few minutes of ISS passing over them on the day of connectivity, and finally complete connectivity. Yagi antenna Wikipedia It should be noted that you can't chat with the astronaut, such as asking him "what did you eat at noon", because there are many ham waiting by the radio station. The uncivilized behavior of occupying the frequency for a long time will be despised by the insiders. In the radio circle, it seems that everyone abides by a rule: communication should be concise and efficient without nonsense. In order to improve the communication efficiency, ham also created a set of common English abbreviations: GM = good morning, 73 = best rewards, 88 = love and kisses, etc. If you have a set of equipment that can connect astronauts, you can also receive the returned data from NOAA (National Oceanic and Atmospheric Administration) meteorological satellite, and then playback the recorded audio to the computer decoding software to get a clear satellite cloud image. You can make a simple "weather forecast" at home. Although amateur radio is a small circle, it is still attracting enthusiasts who love it. Every year, enthusiastic new ham flock to the competition field. Use FT8 mode at home for short wave communication competition - photographed by the author Whether international or regional events, amateur radio competitions run throughout the year. There are events organized by global institutions such as the International Amateur Radio Union (IARU) and the American Amateur Radio Association (Arrl), as well as regional competitions long held by official institutions such as the amateur radio branch of the China Radio Association (Crac). Contestants represent their own countries and regions and compete with ham around the world. They usually connect as many radio stations and regions as possible in the form of single person or group at the same time. I also made a video of my experience of playing amateur radio and sent it to my station B channel "hamzone". I remember a popular message: "it's up to you to contact each other at the end of the world." "Revealing" technology in the face of disaster Amateur radio is a kind of communication resource scattered among the people, which can operate as an independent unit. In a sudden disaster, especially when other modern communication means are destroyed, it is a communication means with the highest survival rate and the strongest self recovery. Amateur radio stations all over the world share frequency resources, and a certain number of radio stations listen to the frequency at every moment. Many amateurs also have good resolution ability for weak signals, which makes it easier to respond to the distress signals sent by the disaster areas. In 2008, the devastating earthquake disaster in Wenchuan, Sichuan paralyzed the communication within nearly 200 kilometers of the epicenter. Coupled with the bad weather conditions, the satellite was unable to take effective pictures, and the information of the hardest hit areas was delayed. Within 12 minutes after the earthquake, ham in Chengdu established an emergency communication network in VHF (very high frequency) / UHF (ultra high frequency) band, quickly learned the direction and situation of major disasters, and drove to the earthquake area with amateur radio equipment. VHF / UHF band is the band used by walkie talkies and car radios. The antenna is easy to erect, plug and play, and can be compatible with military and government radio frequencies upward, and can talk with ordinary consumer walkie talkies downward In the next few days, ham from other parts of Sichuan, Beijing, Henan, Jiangsu, Hong Kong and other places also formed teams to drive to the site of the hardest hit areas, set up a temporary VHF / UHF amateur relay station, and provide communication services for rescue through mobile radio. In Hanwang and other areas, amateur radio has become the platform of the first radio emergency command communication and information release system opened after the earthquake. Later, the American Amateur Radio Association awarded the 2008 humanitarian medal to amateur radio enthusiasts in China and Sichuan Province. The advantages of amateur radio lie in its flexible configuration and relatively standardized organization. When the basic communication cannot work normally due to the disaster, people can still use the local amateur radio to send a lot of information. Last July, a torrential rain broke out in Zhengzhou. The city suddenly lost the Internet, and Internet applications such as payment, taxi and hotel reservation failed almost instantaneously. At that time, amateur emergency frequency was launched immediately as part of the disaster communication network: Zhengzhou radio administration temporarily coordinated four pairs of emergency communication frequencies for ham to cooperate with the actions of flood control and disaster relief departments, provide communication services with the permission of relevant departments, and provide temporary information transmission services for local residents. How to become ham? Many people are unfamiliar with the five words "amateur radio": "radio? Or amateur?" Radio is a technology that uses electromagnetic waves to communicate and transmit signals. It has already penetrated into every corner of our life. In addition to the most easily thought of broadcasting, the successful bus card, Wi Fi and even the satellites connected by heaven and earth are built from radio applications. Called "amateur", it is not "unprofessional", but more like "civil". Hams use their own radio equipment and antenna feed system (referring to the system in which the antenna radiates electromagnetic waves into the surrounding space), make voice calls within the radio frequency band divided by law, send Morse code, discuss technology, communication competition and so on. These activities are purely personal hobbies and cannot be for profit. Radio communication began in 1897. Marconi's radio communication experiment across the Bristol Strait was successful, with a communication distance of 14 kilometers. The first radio transmitter built by Marconi can transmit radio signals through Morse code - Wikipedia Just as the development of cars needs traffic rules to a certain extent, invisible and untouchable radio waves also need to be regulated. In 1903, the amateur radio service was established by the International Telecommunication Union (ITU) through the radio rules. All countries and regions joining the United Nations should negotiate frequency division and communication in accordance with the rules. By 1982, the collective amateur radio stations (units applying for radio stations) that had been silent for many years in China were allowed to resume. In 1992, the amateur business was fully opened. In the following 20 years, the number of amateur radio stations and operators across the country increased sharply by more than two orders of magnitude, and the popularity expanded rapidly. Since then, a large number of amateurs, especially young amateurs, have continuously entered the ranks of ham. Up to now, domestic