Editing Regenerative circuit (section)

===History===
[[File:1915 Armstrong Tickler regen receiver.gif|thumb|1915 Armstrong regenerative receiver]]
The inventor of [[FM broadcasting|FM]] radio, [[Edwin Armstrong]], filed US patent 1113149 in 1913 about regenerative circuit while he was a junior in college.<ref>{{Citation |title=The Armstrong Patent |date=May 1922 |journal=Radio Broadcast |location=Garden City, NY |publisher=Doubleday, Page & Co. |volume=1 |issue=1 |pages=71&ndash;72 |url=https://books.google.com/books?id=VMcnAAAAYAAJ&pg=PA71 }}</ref> He patented the superregenerative circuit in 1922, and the [[superheterodyne]] receiver in 1918.

[[Lee De Forest]] filed US patent 1170881 in 1914 that became the cause of a contentious lawsuit with Armstrong, whose patent for the regenerative circuit had been issued in 1914. The lawsuit lasted until 1934, winding its way through the appeals process and ending up at the [[Supreme Court of the United States|Supreme Court]]. Armstrong won the first case, lost the second, stalemated at the third, and then lost the final round at the Supreme Court.<ref>{{Harvnb|Morse|1925|p=55}}</ref><ref>{{Harvnb|Lewis|1991}}</ref>

At the time the regenerative receiver was introduced, [[vacuum tube]]s were expensive and consumed much power, with the added expense and encumbrance of heavy batteries. So this design, getting most gain out of one tube, filled the needs of the growing radio community and immediately thrived. Although the superheterodyne receiver is the most common receiver in use today{{Citation needed|reason=direct conversion is the standard for the vast majority of single chip receivers used in bluetooth, wifi, LTE, SDRs etc, but which is most common?|date=January 2024}}, the regenerative radio made the most out of very few parts.

In World War II the regenerative circuit was used in some military equipment. An example is the German field radio "Torn.E.b".<ref>{{langx|de|Tornisterfunkgerät}} = [[Joint Tactical Radio System#JTRS Handheld, Manpack & Small Form Fit (HMS)|Manpack]] radio</ref> Regenerative receivers needed far fewer tubes and less power consumption for nearly equivalent performance.

A related circuit, the ''superregenerative detector'', found several highly important military uses in World War II in  [[Identification friend or foe|Friend or Foe]] identification equipment and in the top-secret [[proximity fuze]]. An example here is the miniature RK61 [[thyratron]] marketed in 1938, which was designed specifically to operate like a [[Triode|vacuum triode]] below its ignition voltage, allowing it to amplify analog signals as a self-quenching superregenerative detector in [[radio control]] receivers,<ref>{{cite web |url=http://www.mif.pg.gda.pl/homepages/frank/sheets/138/r/RK61.pdf |title=''Subminiature gas triode type RK61'' data sheet |publisher=[[Raytheon|Raytheon Company]] |access-date=20 March 2017 |archive-date=20 March 2017 |archive-url=https://web.archive.org/web/20170320233833/http://www.mif.pg.gda.pl/homepages/frank/sheets/138/r/RK61.pdf |url-status=dead }}</ref> and was the major technical development which led to the wartime development of radio-controlled weapons and the parallel development of [[radio-controlled models|radio controlled modelling]] as a hobby.<ref name=Honnest-Redlich>George Honnest-Redlich ''Radio Control for Models (1950)'' p. 7</ref>

In the 1930s, the [[superheterodyne]] design began to gradually supplant the regenerative receiver, as tubes became far less expensive. In Germany the design was still used in the millions of mass-produced German "peoples receivers" ([[Volksempfänger]]) and "German small receivers" (DKE, Deutscher Kleinempfänger). Even after WWII, the regenerative design was still present in early after-war German minimal designs along the lines of the "peoples receivers" and "small receivers", dictated by lack of materials. Frequently German military tubes like the "RV12P2000" were employed in such designs. There were even superheterodyne designs, which used the regenerative receiver as a combined IF and demodulator with fixed regeneration. The superregenerative design was also present in early FM broadcast receivers around 1950. Later it was almost completely phased out of mass production, remaining only in hobby kits, and some special applications, like gate openers.