A report on Morse code

Chart of the Morse code 26 letters and 10 numerals
This Morse key was originally used by Gotthard railway, later by a shortwave radio amateur
Single needle telegraph instrument
Telegraph key and sounder. The signal is "on" when the knob is pressed, and "off" when it is released. Length and timing of the dits and dahs are entirely controlled by the telegraphist.
Morse code receiver, recording on paper tape
Comparison of historical versions of Morse code with the current standard. Left: Later American Morse code from 1844. Center: The modified and rationalized version used by Friedrich Gerke on German railways. Right: Current ITU standard.
A U.S. Navy Morse Code training class in 2015. The sailors will use their new skills to collect signals intelligence.
A commercially manufactured iambic paddle used in conjunction with an electronic keyer to generate high-speed Morse code, the timing of which is controlled by the electronic keyer.
A U.S. Navy signalman sends Morse code signals in 2005.
Cayo Largo Del Sur VOR-DME.
Vibroplex brand semiautomatic key (generically called a "bug"). The paddle, when pressed to the right by the thumb, generates a series of dits, the length and timing of which are controlled by a sliding weight toward the rear of the unit. When pressed to the left by the knuckle of the index finger, the paddle generates a single dah, the length of which is controlled by the operator. Multiple dahs require multiple presses. Left-handed operators use a key built as a mirror image of this one.
Representation of Morse code.
Graphical representation of the dichotomic search table. The graph branches left for each dot and right for each dash until the character representation is exhausted.
Scout movement founder Baden-Powell's mnemonic chart from 1918

Method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called dots and dashes, or dits and dahs.

- Morse code
Chart of the Morse code 26 letters and 10 numerals

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An example of an amateur radio station with four transceivers, amplifiers, and a computer for logging and for digital modes. On the wall are examples of various amateur radio awards, certificates, and reception report cards (QSL cards) from foreign amateur stations.

Amateur radio

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Use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications.

Use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications.

An example of an amateur radio station with four transceivers, amplifiers, and a computer for logging and for digital modes. On the wall are examples of various amateur radio awards, certificates, and reception report cards (QSL cards) from foreign amateur stations.
An amateur radio station in Wales. Multiple transceivers are employed for different bands and modes. Computers are used for control, datamodes, SDR, RTTY and logging.
A young Polish woman with radio antennas in Åland
NASA astronaut Col. Doug Wheelock, KF5BOC, Expedition 24 flight engineer, operates the NA1SS ham radio station in the Zvezda Service Module of the International Space Station. Equipment is a Kenwood TM-D700E transceiver.
The top of a tower supporting a Yagi–Uda antenna and several wire antennas, along with a Canadian flag
A handheld VHF/UHF transceiver
The international symbol for amateur radio, included in the logos of many IARU member societies. The diamond holds a circuit diagram featuring components common to every radio: an antenna, inductor and ground.
Reciprocal agreements by country: CEPT Member Nations IARP Member Nations Members of CEPT and IARP USA and Canada Treaty, CEPT and IARP

The term "ham" was first a pejorative term used in professional wired telegraphy during the 19th century, to mock operators with poor Morse code-sending skills ("ham-fisted").

A US Army Signal Corps radio operator in 1943 in New Guinea transmitting by radiotelegraphy

Wireless telegraphy

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Transmission of telegraph signals by radio waves.

Transmission of telegraph signals by radio waves.

A US Army Signal Corps radio operator in 1943 in New Guinea transmitting by radiotelegraphy
Amateur radio operator transmitting Morse code
Tesla's explanation in the 1919 issue of "Electrical Experimenter" on how he thought his wireless system would work
Thomas Edison's 1891 patent for a ship-to-shore wireless telegraph that used electrostatic induction
Example of transatlantic radiotelegraph message recorded on paper tape at RCA's New York receiving center in 1920. The translation of the Morse code is given below the tape.
In World War I balloons were used as a quick way to raise wire antennas for military field radiotelegraph stations. Balloons at Tempelhofer Field, Germany, 1908.
Guglielmo Marconi, the father of radio-based wireless telegraphy, in 1901, with one of his first wireless transmitters (right) and receivers (left)
German troops erecting a wireless field telegraph station during World War I
German officers and troops manning a wireless field telegraph station during World War I
Mobile radio station in German South West Africa, using a hydrogen balloon to lift the antenna

In radiotelegraphy, information is transmitted by pulses of radio waves of two different lengths called "dots" and "dashes", which spell out text messages, usually in Morse code.

Cooke and Wheatstone's five-needle telegraph from 1837

Electrical telegraph

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Point-to-point text messaging system, used from the 1840s until the late 20th century when it was slowly replaced by other telecommunication systems.

Point-to-point text messaging system, used from the 1840s until the late 20th century when it was slowly replaced by other telecommunication systems.

Cooke and Wheatstone's five-needle telegraph from 1837
Morse Telegraph
Hughes telegraph, an early (1855) teleprinter built by Siemens and Halske
Sömmering's electric telegraph in 1809
Revolving alphanumeric dial created by Francis Ronalds as part of his electric telegraph (1816)
Pavel Schilling, an early pioneer of electrical telegraphy
Diagram of alphabet used in a 5-needle Cooke and Wheatstone Telegraph, indicating the letter G
Morse key and sounder
GWR Cooke and Wheatstone double needle telegraph instrument
A magneto-powered Wheatstone A. B. C. telegraph with the horizontal "communicator" dial, the inclined "indicator" dial and crank handle for the magneto that generated the electrical signal.
Professor Morse sending the message – WHAT HATH GOD WROUGHT on 24 May 1844
Foy–Breguet telegraph displaying the letter "Q"
Wheatstone automated telegraph network equipment
A Baudot keyboard, 1884
Phelps' Electro-motor Printing Telegraph from circa 1880, the last and most advanced telegraphy mechanism designed by George May Phelps
A Creed Model 7 teleprinter in 1930
Teletype Model 33 ASR (Automatic Send and Receive)
Major telegraph lines in 1891
The Eastern Telegraph Company network in 1901
German Lorenz SZ42 teleprinter attachment (left) and Lorenz military teleprinter (right) at The National Museum of Computing on Bletchley Park, England

At the sending station, an operator would tap on a switch called a telegraph key, spelling out text messages in Morse code.

A variety of radio antennas on Sandia Peak near Albuquerque, New Mexico, US

Radio

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Technology of signaling and communicating using radio waves.

Technology of signaling and communicating using radio waves.

A variety of radio antennas on Sandia Peak near Albuquerque, New Mexico, US
Radio communication. Information such as sound is converted by a transducer such as a microphone to an electrical signal, which modulates a radio wave produced by the transmitter. A receiver intercepts the radio wave and extracts the information-bearing modulation signal, which is converted back to a human usable form with another transducer such as a loudspeaker.
Comparison of AM and FM modulated radio waves
Frequency spectrum of a typical modulated AM or FM radio signal. It consists of a component C at the carrier wave frequency f_c with the information (modulation) contained in two narrow bands of frequencies called sidebands (SB) just above and below the carrier frequency.
Satellite television dish on a residence
Satellite phones, showing the large antennas needed to communicate with the satellite
Firefighter using walkie-talkie
VHF marine radio on a ship
Parabolic antennas of microwave relay links on tower in Australia
RFID tag from a DVD
Satellite Communications Center Dubna in Russia
Communications satellite belonging to Azerbaijan
Military air traffic controller on US Navy aircraft carrier monitors aircraft on radar screen
ASR-8 airport surveillance radar antenna. It rotates once every 4.8 seconds. The rectangular antenna on top is the secondary radar.
Rotating marine radar antenna on a ship
A personal navigation assistant GPS receiver in a car, which can give driving directions to a destination.
EPIRB emergency locator beacon on a ship
Wildlife officer tracking radio-tagged mountain lion
US Air Force MQ-1 Predator drone flown remotely by a pilot on the ground
Remote keyless entry fob for a car
Quadcopter, a popular remote-controlled toy
Television receiver

In the mid 1890s, building on techniques physicists were using to study electromagnetic waves, Guglielmo Marconi developed the first apparatus for long-distance radio communication, sending a wireless Morse Code message to a source over a kilometer away in 1895, and the first transatlantic signal on December 12, 1901.

Replica of Claude Chappe's optical telegraph on the Litermont near Nalbach, Germany

Telegraphy

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Long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message.

Long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message.

Replica of Claude Chappe's optical telegraph on the Litermont near Nalbach, Germany
Great Wall of China
Schematic of a Prussian optical telegraph (or semaphore) tower, c. 1835
19th-century demonstration of the semaphore
Cooke and Wheatstone's five-needle, six-wire telegraph (1837)
A Morse key (c. 1900)
An early Cooke and Wheatstone double-needle railway telegraph instrument at the National Railway Museum
A block signalling instrument as used in Britain in the 20th century
Australian troops using a Mance mk.V heliograph in the Western Desert in November 1940
US Forest Service lookout using a Colomb shutter type heliograph in 1912 at the end of a telephone line
A Baudot keyboard, 1884
A Creed Model 7 teleprinter, 1931
Creed paper tape reader at The National Museum of Computing
The first message is received by the Submarine Telegraph Company in London from Paris on the Foy–Breguet instrument in 1851. The equipment in the background is a Cooke and Wheatstone set for onward transmission.
The Eastern Telegraph Company network in 1901
Alexander Bain's facsimile machine, 1850
Marconi watching associates raising the kite (a "Levitor" by B.F.S. Baden-Powell ) used to lift the antenna at St. John's, Newfoundland, December 1901
Post Office Engineers inspect the Marconi Company's equipment at Flat Holm, May 1897
Western Union telegram (1930)
ITT Creed Model 23B teleprinter with telex dial-up facility
An illustration declaring that the submarine cable between England and France would bring those countries peace and goodwill

The Morse system was adopted as the international standard in 1865, using a modified Morse code developed in Germany in 1848.

Samuel Finley Breese Morse, ca 1845 LOC

Samuel Morse

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American inventor and painter.

American inventor and painter.

Samuel Finley Breese Morse, ca 1845 LOC
Birthplace of Morse, Charlestown, Massachusetts, c. 1898 photo
Daguerreotype of Samuel Morse Professor of Art while at NYU in 1839. One of the earliest existing American photographs by Dr John William Draper
Self-portrait of Morse in 1812 (National Portrait Gallery)
Dying Hercules, Morse's early masterpiece
Jonas Platt, New York politician, by Morse. Oil on canvas, 1828, Brooklyn Museum.
The House of Representatives. Oil on canvass, 1822, National Gallery of Art.
Morse maintained a studio at 94 Tradd St., Charleston, South Carolina, for a short period.
Portrait of Marquis de Lafayette
Portrait of Lafayette
Original Samuel Morse telegraph
Leonard Gale, who helped Morse achieve the technological breakthrough of getting the telegraphic signal to travel long distances over wire
Plaque at the first telegraph office
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Cover of Foreign Conspiracy Against the Liberties of the United States by Samuel F.B. Morse, 1835 edition
Morse's "repeater" circuit for telegraphy was the basis for the Supreme Court's holding some claims of Morse's patent valid.
Effect of repeaters
Portrait of Samuel F. B. Morse taken by Mathew Brady, in 1866. Medals worn (from wearer's right to left, top row): Nichan Iftikhar (Ottoman); Order of the Tower and Sword (Portugal); Order of the Dannebrog (Denmark); cross of the Order of Isabella the Catholic (Spain); Legion of Honour (France); Order of Saints Maurice and Lazarus (Italy). Bottom row: Grand cross of the Order of Isabella the Catholic (Spain)
Statue of Samuel F. B. Morse by Byron M. Picket, New York's Central Park, dedicated 1871
Morse was honored on the US Famous Americans Series postal issue of 1940.
Coat of Arms of Samuel Morse
Captain Demaresque of Gloucester, Massachusetts, Princeton University Art Museum
Portrait of John Adams
The Gallery of the Louvre 1831–33
Portrait of James Monroe, 5th President of the United States (c. 1819)
Eli Whitney, inventor, 1822. Yale University Art Gallery
Chart of Colors, drawn to illustrate his palette of colors

He was a co-developer of Morse code and helped to develop the commercial use of telegraphy.

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Prosigns for Morse code

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Procedural signs or prosigns are shorthand signals used in Morse code radio telegraphy procedure, for the purpose of simplifying and standardizing radio communication protocol.

Earth station at the satellite communication facility in Raisting, Bavaria, Germany

Telecommunications

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Transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems.

Transmission of information by various types of technologies over wire, radio, optical, or other electromagnetic systems.

Earth station at the satellite communication facility in Raisting, Bavaria, Germany
Visualization from the Opte Project of the various routes through a portion of the Internet
A replica of one of Chappe's semaphore towers
Optical fiber provides cheaper bandwidth for long-distance communication.
Digital television standards and their adoption worldwide
here
The OSI reference model

His code was an important advance over Wheatstone's signaling method.

Low-power inductively coupled spark-gap transmitter on display in Electric Museum, Frastanz, Austria. The spark gap is inside the box with the transparent cover at top center.

Spark-gap transmitter

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Obsolete type of radio transmitter which generates radio waves by means of an electric spark.

Obsolete type of radio transmitter which generates radio waves by means of an electric spark.

Low-power inductively coupled spark-gap transmitter on display in Electric Museum, Frastanz, Austria. The spark gap is inside the box with the transparent cover at top center.
Pictorial diagram of a simple spark-gap transmitter from a 1917 boy's hobby book, showing examples of the early electronic components used. It is typical of the low-power transmitters homebuilt by thousands of amateurs during this period to explore the exciting new technology of radio.
Hertz's first oscillator: a pair of one meter copper wires with a 7.5 mm spark gap between them, ending in 30 cm zinc spheres. When 20,000 volt pulses from an induction coil (not shown) was applied, it produced waves at a frequency of roughly 50 MHz.
Circuit of Hertz's spark oscillator and receiver
Circuit of Marconi's monopole transmitter and all other transmitters prior to 1897.
Transmitter (bottom) and receiver (top) of the first "syntonic" radio system, from Lodge's 1897 patent
Inductively coupled spark transmitter. C2 is not an actual capacitor but represents the capacitance between the antenna A and ground.
Circuit of Poldhu transmitter. Fleming's curious dual spark gap design was not used in subsequent transmitters.
Telefunken 100 kW transoceanic quenched spark transmitter at Nauen Transmitter Station, Nauen, Germany was the most powerful radio transmitter in the world when it was built in 1911
Heinrich Hertz discovering radio waves with his spark oscillator (at rear)
Hertz's drawing of one of his spark oscillators. (A,A') antenna, (J) induction coil
Hertzian spark oscillator, 1902. Visible are antenna consisting of 2 wires ending in metal plates (E), spark gap (D), induction coil (A), auto battery (B), and telegraph key (C).
Hertz's 450 MHz transmitter; a 26 cm dipole with spark gap at focus of a sheet metal parabolic reflector
Jagadish Chandra Bose in 1894 was the first person to produce millimeter waves; his spark oscillator (in box, right) generated 60 GHz (5 mm) waves using 3 mm metal ball resonators.
Microwave spark oscillator demonstrated by Oliver Lodge in 1894. Its 5-inch resonator ball produced waves of around 12 cm or 2.5 GHz
Demonstration inductively coupled spark transmitter 1909, with parts labeled
Amateur inductively coupled spark transmitter and receiver, 1910. The spark gap is in glass bulb (center right) next to tuning coil, on top of box containing glass plate capacitor
Standard Marconi inductively coupled transmitter on ship 1902. Spark gap is in front of induction coil, lower right. The spiral oscillation transformer is in the wooden box on the wall above the Leyden jars.
Telefunken 25 kW long distance transmitter built 1906 at Nauen Transmitter Station, Nauen, Germany, showing large 360 Leyden jar 400 μF capacitor bank (rear) and vertical spark gaps (right)
Tesla's inductively coupled power transmitter (left) patented 2 September 1897
Braun's inductively coupled transmitter patented 3 November 1899
Stone's inductively coupled transmitter (left) and receiver (right) patented 8 February 1900
Marconi's inductively coupled transmitter patented 26 April 1900.
Ship radio room with 1.5 kW Telefunken quenched-spark transmitter
Tuned circuit of transmitter. (top) quenched gap, (center) oscillation transformer, Leyden jars
Quenched spark gap from transmitter, left. The handle turns a screw which puts pressure on the stack of cylindrical electrodes, allowing the gap widths to be adjusted.
Cross section of portion of quenched spark gap, consisting of metal disks (F) separated by thin insulating mica washers (M) to make multiple microscopic spark gaps (S) in series
A powerful quenched-spark transmitter in Australia. The 6 cylinders in front of the Leyden jars are the quenched spark gaps.
A typical rotary spark gap used in low-power transmitters
Small rotary spark transmitter, 1918
1 kilowatt rotary spark transmitter, 1914.
Fessenden's 35 kW synchronous rotary spark transmitter, built 1905 at Brant Rock, Massachusetts, with which he achieved the first 2 way transatlantic communication in 1906 on 88 kHz.
US Navy 100 kW rotary gap transmitter built by Fessenden in 1913 at Arlington, Virginia. It transmitted on 113 kHz to Europe, and broadcast the US's first radio time signal.

So spark-gap transmitters could not transmit audio, and instead transmitted information by radiotelegraphy; the operator switched the transmitter on and off with a telegraph key, creating pulses of radio waves to spell out text messages in Morse code.

A commercially manufactured paddle for use with electronic keyer to generate Morse code

Continuous wave

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Electromagnetic wave of constant amplitude and frequency, typically a sine wave, that for mathematical analysis is considered to be of infinite duration.

Electromagnetic wave of constant amplitude and frequency, typically a sine wave, that for mathematical analysis is considered to be of infinite duration.

A commercially manufactured paddle for use with electronic keyer to generate Morse code

Information is carried in the varying duration of the on and off periods of the signal, for example by Morse code in early radio.