page_title: Radio receiver
section_title: Superregenerative receiver
hierarchical_section_title: Radio receiver / History / Vacuum tube era / Superregenerative receiver
caption_attribution_description: English: American radio researcher Edwin H. Armstrong and his new invention, the superregenerative receiver in 1922. This was probably taken at the June 28, 1922 meeting of the Radio Club of America in room 306, Havemeyer Hall, Columbia University, New York, at which Armstrong demonstrated the superregenerative receiver. The receiver used only 3 vacuum tubes (visible), but was as sensitive as existing receivers with 9 tubes. However it didn't prove as useful as the other receiver circuits he invented: the regenerative receiver and the superheterodyne receiver, which is used in virtually every radio and television today. The black metal bell (left) is the horn loudspeaker (modern cone loudspeakers hadn't been invented yet), and the wires on the frame (right) is the loop antenna for the radio. The caption of the photo read: "THE MAN WHO ORIGINATED THE ARMSTRONG CIRCUIT Hertz, Marconi, De Forest - and now Edwin H. Armstrong, head the list of scientists who have made radio, as we know it today, possible. Armstrong has the honor of making three definite contributions to radio. FIRST, he originated the regenerative feedback vacuum tube circuit. SECOND, he originated the super-heterodyne circuit, the most sensitive receiver ever produced. THIRD, he invented the superregenerative receiver, which has just taken the world by storm and which bears his name."
context_page_description: In radio communications, a radio receiver, also known as a receiver, a wireless or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The antenna intercepts radio waves and converts them to tiny alternating currents which are applied to the receiver, and the receiver extracts the desired information. The receiver uses electronic filters to separate the desired radio frequency signal from all the other signals picked up by the antenna, an electronic amplifier to increase the power of the signal for further processing, and finally recovers the desired information through demodulation.
  Radio receivers are essential components of all systems that use radio. The information produced by the receiver may be in the form of sound, moving images, or digital data. A radio receiver may be a separate piece of electronic equipment, or an electronic circuit within another device. The most familiar type of radio receiver for most people is a broadcast radio receiver, which reproduces sound transmitted by radio broadcasting stations, historically the first mass-market radio application.
context_section_description: This was a receiver invented by Edwin Armstrong in 1922 which used regeneration in a more sophisticated way, to give greater gain.  It was used in a few shortwave receivers in the 1930s, and is used today in a few cheap high frequency applications such as walkie-talkies and garage door openers.
  In the regenerative receiver the loop gain of the feedback loop was less than one, so the tube (or other amplifying device) did not oscillate but was close to oscillation, giving large gain.   In the superregenerative receiver, the loop gain was made equal to one, so the amplifying device actually began to oscillate, but the oscillations were interrupted periodically.  This allowed a single tube to produce gains of over 10⁶.
caption: Armstrong presenting his superregenerative receiver, June 28, 1922, Columbia University
exif: {"Thumbnail JPEGInterchangeFormat": "44", "Thumbnail JPEGInterchangeFormatLength": "7836"}