What is Morse code and its principles of transmission and reception technology

Morse code is a signal code that is sometimes on and sometimes off. This signal code expresses different English letters, numbers, punctuation marks, etc. through different arrangements. It was invented by American Alfred Weir, who was assisting Samuel Morse in inventing the Morse telegraph (1835).

Morse code is an internationally used symbol in telegraph communication. It uses various combinations of signals of different lengths to represent certain letters, numbers and punctuation marks. When writing, short signals are generally represented by dots ".", pronounced as "的"; long signals are represented by dashes "-", pronounced as "达". In order to distinguish dots and dashes and to distinguish individual characters or groups of characters, there are strict regulations on the length of dots and dashes and the reading of various intervals: 1 dash is equal to the length of 3 uninterrupted dots; in a character, the interval between dots, dashes, and dots is the length of 1 dot; the interval between adjacent characters is the length of 3 dots; the interval between adjacent words or two adjacent words is the length of 5 dots,

To be proficient in sending or copying Morse code, you must memorize each code symbol. Digital code symbols are relatively easy to master, and letters and punctuation marks can be classified and remembered according to the combination rules. When you can read the character represented by a code symbol without thinking, you can start copying and receiving Morse code. When practicing, you can first mix letters, numbers and punctuation marks into a group of 5 words. Each group of codes should have 1 to 2 numbers or punctuation marks, and the rest are letters. Then copy and report to each other according to the bottom of the report, and then listen to the oscillator sending and copying. Copying and receiving must be gradual from slow to fast, but avoid practicing high-speed sending and receiving before the lower-speed sending and receiving are consolidated.

The earliest Morse code was dots and dashes that represented numbers. The numbers corresponded to words, and you had to look up a code book to find out which number corresponded to each word. The dots, dashes, and pauses were typed on a single key.
Although Morse had invented the telegraph, he lacked the technical expertise to do it. He made a deal with Alfred Vail to help him build a more practical device. Alfred Vail came up with a scheme that would allow each letter and punctuation mark to be sent independently of each other, using dots, dashes, and pauses. They agreed to put this scheme for identifying different symbols into Morse's patent. This is now known as American Morse code, and it was used to send the world's first telegraph.
The code can be sent as a radio signal with a steady, intermittent tone, usually called a continuous wave, or CW. It can be an electrical pulse in a telegraph wire, or a mechanical or visual signal (such as a flash of light).
Generally speaking, any code that can represent written characters as a variable-length signal can be called Morse code. But now the term is used to refer specifically to two Morse codes for English letters and symbols: American Morse code was used for wired telegraph communications; the International Morse code, still used today, uses only dots and dashes (no pauses).
Telegraph companies charged according to the length of the message to be sent. Commercial codes were carefully designed to form groups of five characters, which were sent 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 codes can be sent individually in Morse code. In Internet lingo, we also speak of some of the most commonly used Morse commercial codes. The Q code and Z code are still used in amateur radio: they were originally used for operators to communicate information such as communication quality, frequency changes, and telegraph numbers.
On January 8, 1838, Alfred Vail demonstrated a telegraph code using dots and dashes, which was the predecessor of Morse code.
As a standard for encoding information, Morse code has had a long life that no other coding scheme has surpassed. Morse code was used as an international standard for maritime communications until 1999. When the French Navy stopped using Morse code in 1997, the last message sent was: "Attention all, this is our last cry before we are silenced forever!"
American Morse Code
A virtually extinct code, American Morse code uses a different set of dots, dashes, and unique spacing to represent numbers, characters, and special symbols. This Morse code was designed primarily for ground operators to transmit over telegraph wires rather than over radio waves.
This ancient, staggered code was designed to match the way operators answered the phone. Unlike today, you can hear the code tones from a speaker or headphones, you can only hear the clicks from a mechanical generator on these earliest telegraph machines, or even from the sending key: this key is set to slave mode when not sending a signal and is responsible for making sounds.
Most of these operators worked for railroads and later Western Union Telex. Like many young people at the time, the teenage Edison was such an operator.
Modern International Morse Code
Today, International Morse Code is still used, although it has become almost entirely the domain of amateur radio enthusiasts. Until 2003, the International Telecommunication Union (ITU) managed the work of amateur radio licenses for Morse code proficient people around the world. In some countries, some bands of amateur radio are still reserved for sending Morse code signals only.
Because Morse relies only on a smooth, unpitched radio signal, its radio communication equipment is simpler than other methods, and it can be used in high-noise, low-signal environments. At the same time, it only requires a very narrow bandwidth and can also help two operators with different native languages ​​communicate, who would encounter great difficulties in telephone communication. It is also the most commonly used method in QRP.
In the United States, until 1991, in order to obtain an amateur radio license issued by the FCC to allow the use of the high-frequency band, it was necessary to pass the Morse code transmission and reception test of five words per minute (WPM). Prior to 1999, a proficiency level of 20 WPM was required to obtain the highest level of amateur radio certification (Extra Class); on December 13, 1999, the FCC lowered this requirement for the Extra Class to 13 WPM.
The 2003 World Radiocommunication Conference (WRC03, a biennial special frequency allocation conference hosted by the ITU) decided to allow countries to choose whether to require Morse code in the management of amateur radio licenses. Although there is still a written requirement in the United States and Canada, some other countries are preparing to completely remove this requirement.
Skilled amateurs and military radio operators can often receive (transmit) Morse code at speeds of more than 40 WPM. Although traditional telegraph keys are still used by many amateurs, semi-automatic and fully automatic electronic keys are increasingly used today. Computer software is also often used to generate and decode Morse code radio wave signals.
Now in the text message ringtone of mobile phones, manufacturers such as Nokia still add the Morse code of the sentence "SMS (···——···)". Since its launch in 1967, Hong Kong's TVB has played the Morse code audio of "NEWS TODAY" in the background music for every news report.
Time control and representation method:
There are two "symbols" used to represent characters: dash (-) and dot (·), or called Dah and Dit or long and short respectively. The length of the dot determines the speed of the message and is used as a reference for the message time. The following is a diagram of time control: Morse code table
Morse code: —— ——— ·—· ··· · / —·—· ——— —·· ·
Here, "—" represents a dash and "·" represents a dot. This is the exact time the message above was sent ("=" means signal is on, "." means no signal, each is the length of a dot):
===.===...===.===.===...=.===.=...=.=.=...=.......===.===.==.=...===.==.===A
dash is usually three dots long; the interval between dots and dashes is one dot long; the interval between characters is three dots long; the interval between words is seven dots long. Beginners are often taught to send characters with short intervals between dots and dashes, short and fast, and to exaggerate the intervals between symbols and words. This method is easier to learn in comparison.
People familiar with Morse code often speak or spell it like this to each other [the "long sound (Dah)" is pronounced as "awe"]: ——
——— ·—· ··· · / —·—· ——— —·· ·
DahDah DahDahDah DiDahDit DiDiDit Dit, DahDiDahDit DahDahDah DahDiDit Dit.

A：·—
B：—···
C：—·—·
D：—··
E：·
F：··—·
G：——·
H：····
I：··
J：·———
K：—·—
L：·—··
M：——
N：—·
O：———
P：·——·
Q：——·—
R：·—·
S：···
T：—
U：··—
V：···—
W：·——
X：—··—
Y：—·——
Z：——··

数字

0: —————
1: ·————
2: ··———
3: ···——
4: ····—
5: ·····
6: —····
7: ——···
8: ———··
9: ————·

Punctuation

“.”: ·—·—·—
“:”: ———···
“,”: ——··——
“;”: ——·—·—·
“?”: ··——··
“=”: ——···—
“'”: ·————·
“/”: ——··—·
“!”: ——·—·——
“-”: ——····—
“_”: ··——·—
“"”: ·—··—·
“(”: ——·——·
“)”: ——·——·—
“$”: ···—··—
“&”: · ···
“@”: ·——·—·

Non-English Latin letters

æ：· —·— à：
·——·—
ç：—·—··
ch：————
ð：··——· è：·—··— é：··—·· ñ：——·—— ö：———· þ：·——·· ü：·· ——Special symbols (same symbol)

These are some dot-dash combinations with special meanings. They are used by connecting two letters of Morse code into one, so that the interval time required to send them as two letters can be omitted.
AR: ·—·—· (stop, end of message)
AS: ·—··· (wait)
K: —·— (invitation to transmit signal) (usually followed by AR, meaning "it's your turn")
SK: ···—·— (termination, end of communication)
BT: —···— (separator)

special symbols (not the same symbol)

···—·(I will resend the last word)
·· ··(same)
·········(error)
[Commonly used abbreviations] Abbreviations are different from the same symbols. Abbreviations retain the spaces between characters and are not used as one. 8 Good afternoon or Go ahead (depending on context) GE Good afternoon. evening GM Good morning GND Ground （ground potential） GD Good HI Laughter () HR Here HV Have (have) LID Poor operator (Poor operator) MILS Milliamperes (milliamperes) NIL Nothing (Nothing) NR Number (Number) OB Old boy (Old boy) OC Old chap (Old chap) OM Old man （any male amateur radio operator is an OM）(any male amateur radio operator is an OM) OO Official Observer （Official Observer） OP Operator OT Old timer （Old timer） OTC Old timers club OOTC Old old timers club （Old old timers club） PSE Please （Please） PWR Power （Power） QCWA Quarter Century Wireless Association RI acknowledge or decimal point （Acknowledge or decimal point） RCVR Receiver （Receiver） RPT Repeat or wks Sign in WKD Sign in English: report (repeat or report) (depending on the context) RST Signal report format (Readability-Signal Strength-Tone) (receiver indicator) RTTY Radio teletype (radio teletype) RX Receive (receive) SAE Self addressed envelope (self-addressed envelope) SASE Self addressed, stamped envelope (self-addressed, stamped envelope) SED Said (say) SEZ Says (say) SIG Signal (signal) SIGS Signals (signal) SKED Schedule (schedule) SN Soon (soon = soon) SOS (SOS = international) SRI Sorry (sorry) STN Station (station) TEMP Temperature (temperature) TMW Tomorrow (tomorrow) TNX Thanks (thank you) TU Thank you (thank you) TX Transmit (transmitter) U You (you) UR Your or you're (you or you're already) (depending on the context) URS Yours (your) VY Very (very) WDS Words (words) WKD Worked (work) WL Will (will) WUD Would (will) WX Weather (weather) XMTR Transmitter (transmitter) XYL Wife (wife) YL Young lady (used of any female) (young woman) 73 Best regards (best regards) 88 Love and kisses (love and kisses goodbye) (note that it should be used between "opposite sex") 99 go way (asked to leave, not friendly) See entry: Q abbreviation
Talking in Morse code]
To communicate clearly using Morse code, only letters are enough. In order to make communication more efficient, there are many internationally accepted patterns.
This is an example of CW communication between station A (s1) and station B (s2):
s1: CQ CQ CQ de s1 K [Calling anyone (CQ), this is (de) s1, end (K). ］
s2: s1 de s2 K (call s1, this is s2, end) (now the two radio stations have established a communication connection)
s1: SK (goodbye.)
s2: SK (goodbye.)
As an example, the radio stations above did not talk about anything, it just demonstrated a communication situation.
SOS signal for help】
In August 1909, the American ship "Araphawi" was unable to sail due to a broken tail shaft, so it sent an "SOS" signal to the nearby coast and passing ships. This was the first time this signal was used.
In 1912, when the famous Titanic cruise ship was in distress on its maiden voyage, it sent CQD (the British Marconi Radio Company decided to use CQD as a ship distress signal), but because D (—··) was easily confused with other letters, the surrounding ships did not realize that it was a distress signal, and no quick rescue was carried out. The new distress signal SOS (···———···) was used when the ship was about to sink. After the sinking of the Titanic, SOS was widely accepted and used.
In fact, although the SOS signal was established in 1906, British radio operators rarely used the SOS signal, preferring the old CQD distress signal. Titanic's chief radio officer John George Phillips had been sending the CQD distress signal until his junior radio operator Harold Bride suggested to him: "Send SOS, this is a new call signal, and this may be your last chance to send it!" Then Phillips mixed the SOS signal with the traditional CQD distress signal. The distress signal was not received by the Californian until the next morning because she did not monitor the radio 24 hours a day.

Since amateur radio communication does not require high Morse code transmission and reception speed, the font must be formal and clear when copying, and the letters should be capitalized. The number "0" should be slashed to avoid confusion with the letter "o".

Morse code can be sent by hand or by electronic keys (automatic keys). For hand keys, each dot and dash is sent by pressing the electric key manually, while for electronic keys, it is sent automatically by electronic devices, and only the number and connection of dots and dashes need to be controlled manually.

How can we send out each dot and stroke well? For enthusiasts who use electronic keys, the dots and strokes can be automatically sent out by the electronic keys according to the specified ratio, while enthusiasts who use manual keys must do the following:
1. Adjust the electric key. For beginners, the spring of the electric key should be adjusted tighter, and the distance between the upper and lower contact points should be larger, generally not less than 1 mm. As the sending speed increases, the distance between the contact points of the electric key can be gradually reduced, and the spring can be gradually adjusted to be looser. The electric key should generally be placed about 5 cm away from the front edge of the table; 2. Have a correct key holding posture. If it is a flat key, the index finger and middle finger should be placed together and bent into an arc and placed on the plane of the key button, the thumb naturally rests on the left side of the index finger, and the ring finger and little finger naturally bend toward the palm. If it is a ball-type key button, pinch the waist of the key button with the thumb and middle finger, the first joint of the middle finger "kneel" on the bottom plate of the key button, and the index finger is bent into an arc and placed in front of the spherical surface of the key button. The ring finger and little finger are still naturally bent toward the palm, and the forearm is roughly parallel to the key beam; 3. The force must be applied correctly, which is the key to sending a good message. When sending a dot, the method of applying force should be: after holding the key, lift the wrist up to a position that is about level with the back of the hand or slightly higher than the back of the hand, then quickly and forcefully press the key so that the upper and lower contacts touch each other, and then the wrist returns to its original state, thus completing a dot. The basic method of applying force when sending a stroke is the same as when sending a dot, except that after the wrist is pressed down, the contact time of the upper and lower contacts of the key is kept for a certain length (i.e. 3 points), and then the wrist returns to its original state. Whether it is sending a dot or a stroke, when sending at a low speed, one mainly uses the strength of the wrist, and the slower the speed, the greater the range of wrist movement should be. As the speed of sending increases, the range of wrist movement gradually decreases. The proportion of finger force increases. When the speed of sending exceeds 100 small codes per minute, the sending of a dot is mainly completed by the shaking of the fingers.

The practice of sending and receiving must strictly follow the principle of starting from easy to difficult and from slow to fast. First send a single dot and a single stroke (EEEEE TTTTT) and then send multiple dots and strokes (EEEEE IIIII SSSSS HHHHH 55555 TTTTT MMMMM OOOOO MMMMM 00000 (number zero)). After mastering the essentials of sending and receiving dots and strokes, you can start practicing simple dot and stroke connections (AAAAA UUUUU VVVVV 44444 NNNNN DDDDD BBBBB 66666 WWWWW JJJJJ 11111 GGGGG 99999) and then practice complex dot and stroke connections (RRRRR KKKKK PPPPP XXXXX YYYYY QQQQQ LLLLL FFFFF CCCCC ZZZZZ ????? ///// 33333 77777 22222 88888). The above exercises are basic exercises. After the foundation is laid, you can practice sending and receiving regular messages or communication terms. Whether you use hand keys or electronic keys to send and receive codes, dots, dashes, and dot-dash connections, they must be clear, regular, and meet the specified length and spacing standards. The spacing between characters and groups (words) should be clear and uniform. Mastering the Morse code sending and receiving technology is a necessary condition for CW communication, and it is also a required subject for high-level operation certificates in my country. Therefore, every amateur radio enthusiast should strive to master it.