Search results
Results from the WOW.Com Content Network
A schematic of a superhet AM receiver. Note that the radio includes an AGC loop in order to maintain the RF and IF stages in their linear region, and to produce an audio output not dependent on the signal power received. Here we show block diagrams for typical superheterodyne receivers for AM and FM broadcast respectively.
The term All American Five (abbreviated AA5) is a colloquial name for mass-produced, superheterodyne radio receivers that used five vacuum tubes in their design. These radio sets were designed to receive amplitude modulation (AM) broadcasts in the medium wave band, and were manufactured in the United States from the mid-1930s until the early 1960s.
A simple crystal radio with no tuned circuit can be used to listen to strong AM broadcast signals. An early form of envelope detector was the crystal detector, which was used in the crystal set radio receiver. A later version using a crystal diode is still used in crystal radio sets today.
The ZN414 is a low cost, single-chip AM radio integrated circuit. Launched in 1972, the part was designed and supplied by Ferranti, but was second sourced from GEC-Plessey. The ZN414 was popular amongst hobbyists, as a fully working AM radio could be made with just a few external components, a crystal earpiece and a 1.5 V cell.
One potential disadvantage of the grid leak detector, primarily in non-regenerative circuits, is that of the load it can present to the preceding circuit. [36] The radio frequency input impedance of the grid leak detector is dominated by the tube's grid input impedance, which can be on the order of 6000 ohms or less for triodes, depending on ...
Plate detector circuit with cathode bias. Cathode bias RC time constant three times period of lowest carrier frequency. C L is typically around 250 pF.. In electronics, a plate detector (anode bend detector, grid bias detector) is a vacuum tube circuit in which an amplifying tube having a control grid is operated in a non-linear region of its grid voltage versus plate current transfer ...
The radio signal from the antenna and tuned circuit passes through an amplifier, is demodulated in a detector which extracts the audio signal from the radio carrier, and the resulting audio signal passes again through the same amplifier for audio amplification before being applied to the earphone or loudspeaker.
Block diagram of a crystal radio receiver Circuit diagram of a simple crystal radio. A crystal radio can be thought of as a radio receiver reduced to its essentials. [3] [39] It consists of at least these components: [22] [40] [41] An antenna in which electric currents are induced by radio waves.