Search results
Results from the WOW.Com Content Network
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.
Today's radios are usually uneconomical to repair because mass production and technological improvements in numerous areas have made them so inexpensive to buy, while the cost of human labor and workshop overheads have increased greatly in comparison. Typical insides of an antique radio, showing the vacuum tubes.
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.
Majestic's trademarked slogan was "The Mighty Monarch of the Air" and its advertising in 1930 touted a 40 percent market share of U.S. and Canada radio sales. [15] Prices ranged from $126.50 to $235 in 1930 (equivalent to $1,890–$3,500 in 2020), with installment purchase plans offered by retail dealers. [15]
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.
The (American version) radio's main receiver covers 30 kHz through 60 MHz, 142 MHz through 152 MHz, and 420 through 450 MHz (plus 1240 through 1300 MHz with the "X" model). The sub-receiver tunes between 118 and 174 MHz, and from 220 to 512 MHz (VFO ranges).
The receiver functions as a tuned radio frequency (TRF) receiver. The radio frequency (RF) signal from the tuned circuit ( bandpass filter ) is amplified, then passes through the high pass filter to the demodulator , which extracts the audio frequency (AF) ( modulation ) signal from the carrier wave .
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.