Radio receivers are electronic circuits that detect, demodulate and amplify transmitted signals. These signals are then converted into forms usable for the consumer such as sound, pictures, digital data, measurement values, navigational positions, etc. Radio receivers come in various types and among these are audio and high fidelity audio receivers, satellite television receivers, and crystal radio receivers or radio sets.
An AV receiver is a type of receiver which uses an amplifier, a preamp/processor, and an FM/AM tuner. Along with audio and high fidelity audio receivers, this type of receiver is the most commonly used type especially by home stereo listeners and audio and home theatre system enthusiasts. The increased need in better audio is brought about by the increasing number of high definition television and home theatre systems found in the market. On the other hand, there are also the satellite television receivers which can be considered as the most widely used radio receiver in the world today. This type of radio receivers is used to receive television programming from communication satellite found din the outer space. Given the fact that almost all homes in the world have at least one television set at home, it is no wonder that this type are the most popular and widely used.
The simplest type of radio receiver is the crystal radio receiver or popularly known as radio set. This receiver is used in the reception of modulated AM/FM signals. The first examples of this type are the radio transistors which are quite popular during the days of grandparents. Today, the reception of AM/FM signal is also integrated as special function for cassette players, DVD/CD players, MP3 CD, USB key players. Radio receivers are communications receivers, specialized-used receivers, measuring receivers, and scanners are other types of radio receivers commonly used. All these types are used for the purpose of entertainment but are also essentials among different companies for business and security purposes.
The discovery of radio receivers was attributed first to the discovery of electromagnetic waves by James Clerk Maxwell in the 1850’s. Electromagnetic waves were then demonstrated by Heinrich Hertz in 1887 by using a spark gap equipment to transmit and receive radio waves. However, it was Alexander Stepanovich Popov who designed the world’s first radio receiver first seen at the All Russia Exhibition in 1896. His experiment demonstrated how a wireless device can detect an electromagnetic signal flowing through the air and can convert this into usable form-which is the same concept that brought us now the cellphone.
Radio receiver technology in the present continuously moves forward. Receiver technology has improved greatly from the discovery of electromagnetic waves to the discovery of transistors and radio sets. Nowadays, this technology continues to move gradually but regularly. Converting signal to digital stream manipulated mathematically is now widespread and is popularly known as Digital signal processing. Different soft wares are also being used in order to be able to do other functions which are normally performed by an analogue intermediate frequency stage.
A great leap in the fields of science and technology has already been made by radio receivers. Communication and entertainment have been easily accessible to consumers through the use of receivers. From the simple transistors, receivers have evolved to different entertainment equipment and gadgets such as radio sets, television set as well as cellphones which also have become an integral part in the lives of many individuals around the world.
Mr. Gil works for a construction firm in New Zealand. His crew uses a Baustellenradio Bosch, a radio set designed for use in environments like construction sites. During work or free time, they listen to the radio set for news.


































