What is the principle of Morse code?

Morse code (also translated as morse code) is an intermittent signal code, which expresses different English letters, numbers and punctuation marks through different arrangement orders. It was invented by American Alfred Weil in 1837. Morse code is an early form of digital communication, but it is different from modern binary codes that only use zero and one or two states. Its codes include five types: dot, dash, pause between dots and dashes, short pause between each character (between dot and dash), moderate pause between each word and long pause between sentences. [1]

S.O.S is an international morse code distress signal, not an abbreviation of any single word. In view of the frequent occurrence of shipwrecks at that time, it was often impossible to send out distress signals in time and organize rescue as quickly as possible, resulting in great casualties and property losses. In 198, the International Radiotelegraph Convention officially identified it as an international universal distress signal. The combination of these three letters has no practical significance, just because its code "...-..." (three dots, three dashes, and then three dots) is the most easily sent by the sender and easily recognized by the receiver.

Morse code plays an important role in early radio, which is necessary for every radio communicator. Due to the progress of signal technology, countries stopped using Morse code in p>1999. However, because it occupies the least bandwidth and has a technical and artistic characteristic, it is widely used in real life.

morse code is composed of two basic signals and different intervals: short dot signal ",reading" di "; Hold the long signal "-"for a certain time and read "Da". Interval time: drop, 1t; Ta, 3t; Tick tock, 1t; Between characters, 3t; Between words, 7 t. [3]

Morse code in 1837 was a number of dots and dashes. Numbers correspond to words, and you need to look up a code table to know the number corresponding to each word. You can tap points, strokes and pauses with an electric key.

Although Morse invented the telegraph, he lacked relevant expertise. He signed an agreement with Alfred Weil to help him make more practical equipment. Alfred Weil conceived a scheme in which each character and punctuation can be sent out independently of each other through dots, strokes and pauses in the middle. They agreed to put this scheme of marking different symbols into Morse's patent. This is now known as American Morse code, which was used to transmit the world's first telegram.

this code can be transmitted by a radio signal with a smooth tone and intermittent intervals, which is usually called "Continuous Wave" and abbreviated as CW. It can be an electronic pulse in a telegraph wire or a mechanical or visual signal (such as a flash).

Generally speaking, any coding method that can express written characters with variable-length signals can be called Morse code. But now this term is only used to refer to two Morse codes representing English letters and symbols: American Morse codes are used in wired telegraph communication systems; The international Morse code still in use today only uses dots and dashes (without pauses).

the telegraph company charges according to the length of the letter to be sent. The commercial code carefully designed a group of five characters to send as a word. For example: byoxo (are you trying to crawl out of it? ）； LIOUY（Why do you not answer my question? ）； AYYLU（Not clearly coded, repeat more clearly.）。 These five-character abbreviations can be sent separately in Morse code. In network terms, we will also say some of the most commonly used Morse commercial codes. Q-abbreviations and Z-abbreviations are still used in amateur radios: they were originally used to exchange information such as communication quality, frequency change and telegraph number between operators; In addition, manufacturers will still add the Morse code of "SMS (...-...)" to the ringtone of mobile phones, while in Hong Kong's wireless TV, since it was opened in 1967, the audio of "NEWS TODAY" will be played in the background music for every news report.

As a practically extinct code, American Morse code uses different dots, dashes and unique spaces to

represent numbers, characters and special symbols. This Morse code is mainly designed for ground telegraph operators to transmit by telegraph wires, not by radio waves.

This ancient and staggered code is designed to match the answering mode of the telegraph operator. Unlike now, you can hear the tone of the code from speakers or headphones. You can only hear the clicking sound from a mechanical generator of these earliest telegraphs, or even answer it from the sending key: this key is set to passive mode when not sending signals, and is responsible for making sound.

most of these operators serve the railway or the future Western Union transmission. Like many young people at that time, Edison, a teenager, was such an operator. [2]

Modern

Modern international Morse code was invented by Friedrich Clemens Gerke in 1848 and used for telegraph communication between Hamburg and Cuxhaven in Germany. After 1865, after a few modifications, it was standardized by the International Telegraphy Conference in Paris, and later it was named International Morse Code by the International Telecommunication Union (ITU).

Today, the international Morse code is still used, although it has almost completely become the patent of amateur radio enthusiasts. Until 23, ITU managed the work of obtaining amateur radio licenses for Morse code professionals all over the world. In some countries, some bands of amateur radio are still reserved only for sending Morse code signals.

Because Morse only relies on a stable and unchangeable radio signal, its radio communication equipment is simpler than other methods, and it can be used in high noise and low signal environment. At the same time, it only needs a very narrow bandwidth, and it can also help two operators with different mother tongues to communicate with each other and encounter great difficulties in traffic communication. It is also the most commonly used method in QRP.

in the United States, until 1991, in order to obtain an amateur radio certificate issued by the Federal Communications Commission (FCC) allowing the use of high-frequency bands, it was necessary to send and receive tests through Morse code with five words per minute (WPM). Before 1999, the highest level of amateur radio certificate (extra class) can only be obtained if the proficiency level is 2WPM; On December 13th, 1999, the FCC reduced this requirement for additional classes to 13WPM.

In p>23, the World Radiocommunication Conference (WRC3, a biennial special conference on frequency allocation sponsored by the International Telecommunication Union) made a decision, allowing countries to choose whether or not to require Morse code in amateur radio license management. Although there is still a written requirement in the United States and Canada, in some other countries, it is being prepared to completely remove this requirement.

Skilled amateurs and military operators can often receive (copy) Morse codes at speeds above 4WPM. Although traditional telegraph keys are still used by many fans, semi-automatic and full-automatic electronic keys are widely used today. Computer software is often used to generate and decode Morse code radio signals.

Morse code is simple and clear, with little ambiguity. The code is mainly represented by two characters: "."and "-",one is long and the other is short, which is widely used in many cases, such as sending distress signals. In the movie "Wind", Moore code is sewn on clothes to spread the news. This method is used in the cartoon "Detective Conan" and "Reasoning Confrontation, New vs Okiya Subaru" (tv511).

when using Moore's password light for help, it is defined as "-"and "."when the light is on for a long time, so you can send all kinds of information, such as help information, through the switch of the flashlight.

If the light is displayed according to the law of "short bright dark short bright dark short bright dark long bright dark long bright dark short bright dark short bright short bright", then it means SOS.

because the molar code of SOS is:--------------------------------------------------------------------------------- This coding is actually very simple, three short, three long and three short.

In addition to beyond the lights, distress signals can also be sent by sound (two different sounds). This way of asking for help is something that we should all understand, and maybe it can come in handy when necessary [4].

In January p>215, Kenji Goto, a Japanese hostage kidnapped by the terrorist organization "Islamic State" (IS), was beheaded. The news shocked the international community. On February 1 of that year, an interpretation film by Japanese netizens was circulated on the Internet, which pointed out that Goto blinked more frequently than haruna yukawa, the hostage on the right. Some Japanese netizens enlarged Kenji Goto's picture, and Japanese netizens decrypted that Goto was through. [

Representation method

There are two kinds of "symbols" used to represent characters: dot (.) and dash (-), or "Dit" and "Dah". The length of the point determines

the sending speed and is taken as the sending time reference. The following is a diagram of time control:

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m or s e (space) c or d e

Here, "-"means a row and "."means a point. This is the accurate sending time of the above message (= indicates that there is a signal,. indicates that there is no signal, and each is the length of a point):

= =. = = = = = ... = = = = = = = = = = = = = ... The interval between dots and dashes is the length of a point; The interval between characters is the length of three points; The interval between words is the length of seven points.

Beginners are often taught to send short, short and fast dotted characters, and exaggerate the interval between symbols and words. Comparatively speaking, this method is easier to learn.

people who are familiar with Morse code often speak or spell like this (where "long sound/Dah" is the sound of "awe"):

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Dahdah Dahdah Dahdah didahdit. They are connected by two-letter Morse code, which can save the interval time necessary to send them as two letters in normal times.

AR: ——— (stop, the message ends)

as: ——— (wait)

k: ——— (invite to send a signal) (generally follow ar, which means "it's your turn")

sk: ——— (terminate.

morse code table

A-All after (used to request repetition after question mark)

AB-All before (same)

arrl-American radio relay league

ABT-About

ADS-Address

. N-Again

ANT-Antenna

ABN-All between

bug-semi-automatic key

C-Yes (yes, Ok)

CLG-Calling

CQ-Calling any station

CUL-See you later

cuz-cause

CW-Continuous wave

CX-condition. Status)

DE-From

dx-distance (some times referers to long distance contact)

ES-And (and)

FB-Fine business (similar to "OK")

FCC-Federal Com. Munications Commission

FER-For

FREQ-Frequency

ga-good afternoon or go ahead (depending on context)

GE-Good even. Ing (good night)

GM-Good morning

GND-Ground (ground potential)

GD-Good (good)

HI-Laughter; (Laughter)

HR-Here (here)

HV-Have (with)

LID-Poor operator

Mills-milliamps (milliamps) < p