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This 1920s TRF radio manufactured by Signal is constructed on a breadboard Tuning a TRF receiver, like this 5 tube Neutrodyne set from 1924 with two stages of RF amplification, was a complicated process. The three tuned circuits, controlled by the 3 large knobs, had to be tuned in unison to the new station.
The Neutrodyne radio receiver, invented in 1922 by Louis Hazeltine, was a particular type of tuned radio frequency (TRF) receiver, in which the instability-causing inter-electrode capacitance of the triode RF tubes is cancelled out or "neutralized" [1] [2] to prevent parasitic oscillations which caused "squealing" or "howling" noises in the speakers of early radio sets.
Audio reproduction quality of TRF sets was limited by the available loudspeakers. "High Fidelity" was not to become a radio marketing concept until the mid-1930s and was not realized until the advent of FM broadcasting. Reaction sets, also known as regenerative receivers, rely on positive feedback to achieve adequate gain. This approach ...
E.H. Scott Radio Laboratories is sometimes confused with H.H. Scott. E.H. Scott was founded in 1925 by Chicago resident Ernest H. Scott. Its first product was the World's Record Super 8, a TRF (tuned radio frequency) design with typical harness wiring with 16 gauge silvered solid core copper wire employed in an array configuration that was typical to radios at the time. This construction ...
The Neutrodyne receiver, invented in 1922 by Louis Hazeltine, [133] [134] was a TRF receiver with a "neutralizing" circuit added to each radio amplification stage to cancel the feedback to prevent the oscillations which caused the annoying whistles in the TRF.
Repair and restoration of vintage amateur radio equipment may involve replacing vacuum tubes, reforming electrolytic capacitors if needed, replacing any faulty resistors, replacing two-wire power cords with three-wire cords except on transformerless AC/DC radios, and receiver alignment as necessary.
The RCA model R7 Superette superheterodyne table radio. This is a list of notable radios, which encompasses specific models and brands of radio transmitters, receivers and transceivers, both actively manufactured and defunct, including receivers, two-way radios, citizens band radios, shortwave radios, ham radios, scanners, weather radios and airband and marine VHF radios.
Hallicrafters founder Bill Halligan and his personal SX-28 depicted in a 1944 magazine ad. In July 1940, the Hallicrafters Company announced the SX-28 "Super Skyrider", the result of a development effort by 12 staff engineers and analysis of more than 600 reports that included input from U.S. government engineers, commercial users, and amateur radio operators.