What is "wireless telegraphy"

Wireless \Wire"less\, a. Having no wire; specif. (Elec.), designating, or pertaining to, a method of telegraphy, telephony, or other information transmisssion, in which the messages, data, etc., are transmitted through space by electric waves; as, a wireless message; a wireless network; a wireless keyboard.

Wireless telegraphy or Wireless telegraph (Elec.), any system of telegraphy employing no connecting wire or wires between the transmitting and receiving stations.

Note: Although more or less successful researchers were made on the subject by Joseph Henry, Hertz, Oliver Lodge, and others, the first commercially successful system was that of Guglielmo Marconi, patented in March, 1897. Marconi employed electric waves of high frequency set up by an induction coil in an oscillator, these waves being launched into space through a lofty antenna. The receiving apparatus consisted of another antenna in circuit with a coherer and small battery for operating through a relay the ordinary telegraphic receiver. This apparatus contains the essential features of all the systems now in use.

Wireless telephone, an apparatus or contrivance for wireless telephony.

Wireless telephony, telephony without wires, usually employing electric waves of high frequency emitted from an oscillator or generator, as in wireless telegraphy. A telephone transmitter causes fluctuations in these waves, it being the fluctuations only which affect the receiver.

n. 1 Telegraphy by radio rather than by transmission cables 2 The use of radio to send signals by Morse code

1. n. telegraphy that uses transmission by radio rather than by wire [syn: radiotelegraph, radiotelegraphy]

2. the use of radio to send telegraphic messages (usually by Morse code) [syn: radiotelegraph, radiotelegraphy, wireless telegraph]

Wireless telegraphy is the transmission of electric telegraphy signals without wires ( wirelessly). It is now used as a historical term for early radio telegraphy systems which communicated with radio waves, although when the term originated in the late 19th century it was also used for a variety of other experimental techniques for communicating telegraphically without wires, such as photoelectric and induction telegraphy.

Wireless telegraphy came to mean Morse code transmitted by radio waves ( electromagnetic waves), initially called " Hertzian waves", discovered by Heinrich Hertz in 1886. The first practical wireless telegraphy transmitters and receivers were developed by Guglielmo Marconi beginning in 1895. By 1910 communication by Hertzian waves was universally referred to as " radio", and the term wireless telegraphy has been largely replaced by the more modern term "radiotelegraphy". The transmission of speech ( radiotelephony) began to displace wireless telegraphy by the 1920s for many applications, making possible radio broadcasting. Wireless telegraphy continued to be used for private point-to-point business, governmental, and military communication, such as telegrams and diplomatic communications, and evolved into radioteletype networks. Continuous wave (CW) radiotelegraphy is regulated by the International Telecommunication Union (ITU) as emission type A1A.

Today, due to more modern text transmission methods, Morse code radiotelegraphy for commercial use has become obsolete. On shipboard the computer and satellite linked GMDSS system has largely replaced Morse as a means of communication. Telegraphy is taught on a very limited basis by the military. A CW coastal station, KSM, still exists in California, run primarily as a museum by volunteers, and occasional contacts with ships are made. Radio beacons, particularly in the aviation service, but also as "placeholders" for commercial ship-to-shore systems, also transmit Morse but at very slow speeds.

The US Federal Communications Commission does still issue a lifetime commercial Radiotelegraph Operator License. This requires passing a simple written test on regulations, a more complex written exam on technology, and demonstrating Morse reception at 20 words per minute plain language and 16 wpm code groups. (Credit is given for amateur extra class licenses earned under the old 20 wpm requirement.) Wireless telegraphy is still used widely today by amateur radio hobbyists where it is commonly referred to as radio telegraphy, continuous wave, or just CW. However its knowledge is not required to obtain any class of amateur license.