A relay league is a chain of message forwarding stations in a system of
optical telegraphs,
radio telegraph stations, or riding
courier
A courier is a person or organization that delivers a message, package or letter from one place or person to another place or person. Typically, a courier provides their courier service on a commercial contract basis; however, some couriers are ...
s. Early 19th century methods of this type evolved into the
electrical telegraph
Electrical telegraphy is point-to-point distance communicating via sending electric signals over wire, a system primarily used from the 1840s until the late 20th century. It was the first electrical telecommunications system and the most wid ...
networks of the mid-to-late 19th century.
Radio relay leagues
Radio amateurs have been early in arranging relay leagues, as is reflected in the name of the organization of
American Radio Relay League (ARRL).
Radio amateur message relay operations were originally conducted in the first two decades of the 20th century using
Morse code
Morse code is a telecommunications method which Character encoding, encodes Written language, text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code i ...
via
spark-gap transmitter
A spark-gap transmitter is an obsolete type of transmitter, radio transmitter which generates radio waves by means of an electric spark."Radio Transmitters, Early" in Spark-gap transmitters were the first type of radio transmitter, and were the m ...
s. As
vacuum tube
A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...
s became affordable, operations shifted to more efficient manual telegraphy transmitters, referred to as ''CW'' (
Continuous wave). Messages were relayed station-to-station, typically involving four or more re-transmission cycles to cover the continental
United States
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, in an organized system of amateur radio networks. After
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, voice and
radioteletype implementations of the message relay system were employed.
See also
*
Post rider
*
Pony Express
*
Relay (disambiguation)
References
{{DEFAULTSORT:Relay League
History of telecommunications
Telegraphy