Radio

Radio is the use of radio waves is to carry information, such as sound, by systematically modulating some property of electromagnetic energy waves transmitted through space, such as their amplitude, frequency, phase, or pulse width. When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form.

Radio systems need a transmitter to modulate (change) some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation (which can be frequency modulation or phase modulation). Radio systems also need an antenna to convert electric currents into radio waves, and vice versa. An antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual stations to be selected. The electromagnetic wave is intercepted by a tuned receiving antenna. A radio receiver receives its input from an antenna and converts it into a form usable for the consumer, such as sound, pictures, digital data, measurement values, navigational positions, etc. Radio frequencies occupy the range from a 3 kHz to 300 GHz, although commercially important uses of radio use only a small part of this spectrum.

Memphis, Tennessee

Memphis is a city in the southwestern corner of the U.S. state of Tennessee and the county seat of Shelby County. The city is located on the fourth Chickasaw Bluff, south of the confluence of the Wolf and Mississippi rivers.

Memphis had a population of 653,450 in 2013, making it the largest city in the state of Tennessee, the largest city on the Mississippi River, the third largest in the greater Southeastern United States, and the 23rd largest in the United States.

The greater Memphis metropolitan area, including adjacent counties in Mississippi and Arkansas, had a 2014 population of 1,317,314. This makes Memphis the second-largest metropolitan area in Tennessee, surpassed by metropolitan Nashville.

Memphis is the youngest of Tennessee's major cities, founded in 1819 as a planned city by a group of wealthy Americans including judge John Overton and future president Andrew Jackson. A resident of Memphis is referred to as a Memphian, and the Memphis region is known, particularly to media outlets, as "Memphis & the Mid-South".