Editing Radioteletype (section)

==History==
[[File:Creed model 6S-2 paper tape reader.jpg|thumb|Punched tape of the type used with teleprinters in a Creed model 6S/2 5-hole paper tape reader]]
[[File:HAL3100.jpg|thumb|Electronic RTTY terminal, {{c.|1980}}]]
Landline teleprinter operations began in 1849 when a circuit was put in service between [[Philadelphia]] and New York City.<ref>RTTY Journal Vol. 25 No. 9, October 1977: 2.</ref> [[Émile Baudot]] designed a system using a five unit code in 1874 that is still in use today. Teleprinter system design was gradually improved until, at the beginning of World War II, it represented the principal distribution method used by the news services.

Radioteletype evolved from these earlier landline teleprinter operations. The US Department of the Navy successfully tested printing telegraphy between an airplane and ground radio station in August 1922.<ref>[https://timesmachine.nytimes.com/timesmachine/1922/08/10/99054387.pdf "Typing in Airplane Received by Radio”], ''The New York Times'', August 10, 1922, accessed August 25, 2011.</ref><ref>{{cite web |url=http://patimg1.uspto.gov/.piw?Docid=01485212&homeurl=http%3A%2F%2Fpatft.uspto.gov%2Fnetacgi%2Fnph-Parser%3FSect1%3DPTO2%2526Sect2%3DHITOFF%2526p%3D1%2526u%3D%25252Fnetahtml%25252FPTO%25252Fsearch-bool.html%2526r%3D2%2526f%3DG%2526l%3D50%2526co1%3DAND%2526d%3DPALL%2526s1%3D1,485,212%2526OS%3D1,485,212%2526RS%3D1,485,212&PageNum=&Rtype=&SectionNum=&idkey=NONE&Input=View+first+page|title=U.S. Patent No. 1,485,212 |access-date=August 25, 2011}}</ref><ref>{{cite web |url=https://www.loc.gov/pictures/item/2002697173/ |title=Teletype radio plane set, used by Navy Dept., to receive typewritten radio messages from Naval airplanes |website=[[Library of Congress]] |access-date=2011-09-05}}</ref> Later that year, the Radio Corporation of America successfully tested printing telegraphy via their Chatham, MA radio station to the RMS ''Majestic''.<ref>[https://timesmachine.nytimes.com/timesmachine/1922/11/14/99099813.pdf "Radio Now As Fast As Wire Messages”], ''The New York Times'', November 14, 1922, accessed November 4, 2010.</ref> An early implementation of the Radioteletype was the Watsongraph,<ref>{{cite web| url = https://patents.google.com/patent/US1847030| title = SYSTEM OF COMMUNICATION; Patent number: 1847030}}</ref> named after [[Detroit]] inventor Glenn Watson in March 1931.<ref>{{cite magazine| url=http://www.time.com/time/magazine/article/0,9171,741192,00.html | archive-url=https://web.archive.org/web/20081215034755/http://www.time.com/time/magazine/article/0,9171,741192,00.html | url-status=dead | archive-date=December 15, 2008 | magazine=Time | title=Science: Radio Writer | date=9 March 1931}}</ref> Commercial RTTY systems were in active service between San Francisco and Honolulu as early as April 1932<ref>{{cite journal
 |author1       = Bailey, A.
 |author2       = McCann, T.A.
 |name-list-style = amp
 |title         = Application of Printing Telegraph to Long-Wave Radio Circuits
 |journal       = Bell System Technical Journal
 |url           = http://www3.alcatel-lucent.com/bstj/vol10-1931/articles/bstj10-4-601.pdf
 |date          = October 1931
 |volume = 10
 |issue = 4
 |pages         = 601–615
 |doi = 10.1002/j.1538-7305.1931.tb02333.x
 |s2cid = 51647863
 |access-date   = 2013-10-28
 |archive-url   = https://web.archive.org/web/20131030004607/http://www3.alcatel-lucent.com/bstj/vol10-1931/articles/bstj10-4-601.pdf
 |archive-date  = 2013-10-30
 |url-status      = dead
}}</ref><ref>"Teletype Now Used on Radio Circuits to Hawaii by R.C.A. Communications, Inc., for All Its Messages", Telegraph and Telephone Age, Oct 1, 1932</ref> and between San Francisco and New York City by 1934.<ref>Anderson, Phil W0XI, "The ABC's of RTTY", CQ The Radio Amateur's Journal Vol.40 No. 11, November 1984: 34-35</ref> The US Military used radioteletype in the 1930s and expanded this usage during World War II.<ref>{{cite journal
 |url          = http://www.nonstopsystems.com/radio/article-AIEE-1948.pdf
 |journal      = AIEE Transactions
 |title        = Military Teletypewriter Systems of World War II
 |year         = 1948
 |author       = Singer, F.J.
 |pages        = 1398–1408
 |access-date  = 2012-04-26
 |archive-url  = https://web.archive.org/web/20130525065703/http://www.nonstopsystems.com/radio/article-AIEE-1948.pdf
 |archive-date = 2013-05-25
 |url-status     = dead
}}</ref> The Navy called radioteletype ''RATT'' (Radio Automatic Teletype) and the Army Signal Corps called radioteletype ''SCRT'', an abbreviation of Single-Channel Radio Teletype. The military used [[Frequency-shift keying|frequency shift keying]] (FSK) technology and this technology proved very reliable even over long distances.