What is a Radio Receiver?
A radio receiver is an electronic device that takes a transmitted signal, extracts the original signal from it and amplifies that signal. The process of extracting the signal is called demodulation. A radio station, for example, will broadcast a signal which is then detected by a radio receiver. The receiver, in turn, will separate that signal from many others and then play it through its speakers. There are several different types of signals that the receiver can be designed to demodulate and decode including sounds, pictures and digital data, to name a few. Alexander Stepanovich Popov designed and implemented the first radio receiver in 1896. It was based on electromagnetic waves, which were proven to exist by James Clerk Maxwell only a few years earlier in 1887. It took only a few more years until the first radio system was able to transmit communications across the Atlantic in 1901. In the time between then and the present day, the radio receiver has seen a great many technological
Radio works by compositing or heterodyning frequencies. You have the frequency of voice or music you want to carry or generate and a frequency you carry it with, called the station, channel, station frequency or carrier wave specifications (e.g. 1120 AM) To get the station you generally have to have a long wire that is “tuned” to an area of frequencie waves. This is based on the thichness or length of the wire and resistance level to electricity. Then you need to use a device that notches out frequcenices in a tight band which is a tuned crystal, tuned coil or capacitor. All of which can band pass or notch out frequencies. Once you tune in a given station you cancel out the frequecy of the carrier (called a beat cancellation) and what you are left with is the desired signal. Finally you need to amplify what is left, which is your voice or music. Then you need to have a device to hear it. At the simplest level is a diode radio or crytal radio. You get a long wire and put it outside like
