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A radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. Radio waves are electromagnetic waves with frequencies between about 30 Hz and 300 GHz. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the ...
The TR-1 is a superheterodyne receiver [2] [11] with four n-p-n germanium transistors and one diode. It contains a single transistor converter stage, followed by two intermediate-frequency amplifier stages. After detection, a single-transistor stage amplifies the audio frequency. All amplifier stages use common emitter amplifiers. Stages are ...
The receiver in most systems also used two inductively coupled circuits, with the antenna an "open" resonant circuit coupled through an oscillation transformer to a "closed" resonant circuit containing the detector. A radio system with a "two circuit" (inductively coupled) transmitter and receiver was called a "four circuit" system.
For instance, if a radio wave passing a given location has a flux of 1 pW / m 2 (10 −12 Watts per square meter) and an antenna has an effective area of 12 m 2, then the antenna would deliver 12 pW of RF power to the receiver (30 microvolts RMS at 75 ohms). Since the receiving antenna is not equally sensitive to signals received from all ...
The transistor both amplifies and rectifies the amplitude modulated (AM) radio signal. Since the base-emitter junction acts as a diode it conducts only on the positive half-cycles of the carrier wave, blocking the negative half cycles, rectifying the carrier to extract the audio modulation signal from the radio wave. The collector current is an ...
English: The image gives six circuit diagrams (schematics) for balanced line antenna tuners of the tuned-transformer type, discussed in the Wikipedia article "Antenna Tuner" or "ATU". It is an edited version of the original by JNRSTANLEY uploaded 2014-10-15.
A mast radiator or mast antenna is a radio tower or mast in which the whole structure is an antenna. Mast antennas are the transmitting antennas typical for long or medium wave broadcasting. Structurally, the only difference is that some mast radiators require the mast base to be insulated from the ground.
A monopole antenna is a class of radio antenna consisting of a straight rod-shaped conductor, often mounted perpendicularly over some type of conductive surface, called a ground plane. [1] [2] The current from the transmitter is applied, or for receiving antennas the output signal voltage to the receiver is taken, between the monopole and the ...