What is Morse code?

How does Morse code work?

Every letter, figure and sign is a short pattern of dots and dashes. The timing carries the meaning: a dash lasts three dots, and the silences between signals have fixed lengths too. The ITU, the UN agency for telecommunications, sets the code and its timing in Recommendation M.1677-1.1

Source: ITU-R M.1677-1.1

Speed is counted in words per minute (WPM). The ITU sets no speed unit. Hams use the ARRL's standard word PARIS, which takes exactly 50 units, so one dot lasts 1,200 ÷ WPM milliseconds: 240 ms at 5 WPM, 60 ms at 20 WPM.12

The most common English letters got the shortest codes. E is a single dot and T a single dash, while Q and Y take four signals each.3

The Morse code alphabet

The International Morse code has 26 letters, 10 figures and about a dozen punctuation marks. Each figure is five signals long, so numbers are easy to tell from letters. Tap a letter to hear it.1

The only accented letter in the ITU table is É (··−··). The newest sign is @ (·−−·−·), added in 2004 for email addresses.13 Punctuation, prosigns such as SK (end of contact) and the full table are in the Morse code translator.

Who invented Morse code?

Samuel F. B. Morse and his partner Alfred Vail, in the United States. On May 24, 1844, Morse sent "What hath God wrought?" over an experimental line from Washington, D.C., to Baltimore. The Library of Congress credits Morse with the code; Vail's family argued for decades that Vail designed the alphabet.456

Morse's first plan sent only numbers, which the operator looked up in a code book. Vail's supporters, among them the Franklin Institute, credited Vail with the alphabet of dots and dashes.6 The code we use today is a later European version:

• 1844. The first public message, Washington to Baltimore.4 The American code of this time had dashes of different lengths and uneven gaps. It survived on US railroads as American Morse.3
• 1848. Friedrich Clemens Gerke rewrote the code for the Hamburg–Cuxhaven line: one dot, one dash three dots long.37
• 1865. The International Telegraph Union was founded in Paris on May 17. Its rules made Morse code the international standard.8
• 1906. The Berlin radiotelegraph conference adopted SOS worldwide.9
• 1999. Ships switched to the satellite-based GMDSS on February 1.11
• 2003 and 2007. Europe and then the US dropped the Morse test for ham licenses.1316

Why is SOS the distress signal?

SOS (···−−−···) became the worldwide distress signal in 1906. It is one signal, not three letters: the dots and dashes run on with no letter gaps. The Berlin convention set it from July 1, 1908. Before that, Marconi operators sent CQD.9103

The Titanic's radio operator Jack Phillips sent both, CQD and SOS, in April 1912, according to junior operator Harold Bride.3012 From February 1, 1999, ships call for help through GMDSS, the Global Maritime Distress and Safety System, by satellite and digital selective calling.11 The French Navy had already sent its last Morse message on January 31, 1997.3

SOS works without a radio. You can flash it with a torch or a mirror, or knock it.3 In 1966 Jeremiah Denton, a US Navy pilot held as a prisoner of war, blinked T-O-R-T-U-R-E in Morse during a filmed interview. It was the first clear proof for US intelligence that prisoners were tortured.24

Do you need Morse code for a ham license?

In most countries, no. The 2003 World Radiocommunication Conference let each country decide whether hams must know Morse. Europe's CEPT license dropped the requirement on September 15, 2003. The US cut its test to 5 WPM in 2000 and removed it on February 23, 2007.13141516

Classes and exams in 14 countries are in How to get a ham radio license, and you can practice for the written exam.

Where is Morse code used today?

Mostly by hams, on the air as CW. Aircraft navigation beacons still identify themselves in Morse, and a network of 18 ham beacons sends call signs in Morse around the clock. Phones offer Morse as a way to type for people who cannot easily use a keyboard.17192122

Ships and the US Coast Guard no longer listen for Morse.311 Your call sign in Morse, and how it sounds on air, is in the call sign generator.

How do you learn Morse code?

Learn it by ear, not from a chart. The two methods most hams use are Koch and Farnsworth: both send each letter at full speed from day one, so you learn its sound as a whole instead of counting dots. In Koch's 1936 study, learners knew the alphabet at about 12 WPM after 24 to 28 half-hour sessions.252

The Koch method. Ludwig Koch's learners started at full speed with just two letters. A new letter came only when they made no more than 10% mistakes in a test. He reported the alphabet learned in 12 to 14 hours of practice.25

Farnsworth timing. Letters are sent fast and the gaps between them are stretched, for example 20 WPM letters at an overall 10 WPM. As you improve, the gaps shrink. The method is named after Donald R. "Russ" Farnsworth, W6TTB.23

1. Learn by soundUse a trainer that sends letters at 15–20 WPM with Farnsworth spacing, and write what you hear.
2. Add letters slowlyStart with two and add one when you get 90% of the test right, as Koch did.
3. Practice oftenShort sessions work: Koch's learners practiced in half-hours.
4. Listen to real trafficW1AW code practice and recorded runs, then real contacts on the CW bands.

Where to practice, all free:261427282923

• W1AW, the ARRL's station, sends code practice on air on 1.8025, 3.5815, 7.0475, 14.0475, 18.0775, 21.0675, 28.0675, 50.350 and 147.555 MHz, from 5 to 35 WPM. The ARRL keeps MP3 files of past runs from 5 to 40 WPM.
• LCWO.net (Learn CW Online): a Koch course in the browser, speed practice and MP3 files.
• CW Academy by CWops: free online classes for beginners three times a year, in January–February, May–June and September–October.
• Morse Code Ninja: practice audio, including short stories at 15 to 50 WPM.
• Google's Morse typing trainer, for those who type in Morse on Gboard.

Translate text to Morse code

Type a word or a phrase and you get the Morse code; paste dots and dashes and you get the text. Press Play to hear it, slow the speed, or stretch the gaps the Farnsworth way to practice copying by ear.

The same translator, with the full table of punctuation and prosigns, is on its own page: Morse code translator.

Does a PoC radio use Morse code?

No. A PoC radio sends your voice over the mobile network through a push-to-talk app; there is no Morse mode and no license test. Morse belongs to ham radio, where you need a license to transmit. If you want to talk across a city or a country without an exam, see What is a PoC radio? and What is ham radio?.

Questions

Sources

1. Recommendation ITU-R M.1677-1: International Morse code (2009) · ITU (web archive copy)
2. A Standard for Morse Timing Using the Farnsworth Technique, QEX, April 1990 · ARRL, Jon Bloom KE3Z
3. Morse code · Wikipedia
4. Today in History, May 24: What Hath God Wrought? · Library of Congress (web archive copy)
5. Invention of the Telegraph, Samuel F. B. Morse Papers · Library of Congress (web archive copy)
6. Morse's partner argued he invented famous code, to no a-Vail · HistoryNet
7. Friedrich Clemens Gerke · Wikipedia
8. ITU is born (1865) · ITU History Portal
9. 100 years of the Radio Regulations: 1906 · ITU
10. SOS · Wikipedia