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.

Napa

Napa may refer to:

Places:

People:

Other uses:

NAPA may stand for:

Los Angeles

Los Angeles (ⁱ/lɒs ˈændʒəlᵻs/ loss AN-jə-ləs or loss AN-jə-liss) (Spanish for "The Angels"), officially the City of Los Angeles and often known by its initials L.A., is the second-largest city in the United States after New York City, the most populous city in the state of California, and the county seat of Los Angeles County.

Situated in Southern California, Los Angeles is known for its mediterranean climate, ethnic diversity, sprawling metropolis, and as a major center of the American entertainment industry. Los Angeles lies in a large coastal basin surrounded on three sides by mountains reaching up to and over 10,000 feet (3,000 m).

Historically home to the Chumash and Tongva, Los Angeles was claimed by Juan Rodríguez Cabrillo for Spain in 1542 along with the rest of what would become Alta California. The city was officially founded on September 4, 1781, by Spanish governor Felipe de Neve. It became a part of Mexico in 1821 following the Mexican War of Independence. In 1848, at the end of the Mexican–American War, Los Angeles and the rest of California were purchased as part of the Treaty of Guadalupe Hidalgo, thereby becoming part of the United States. Los Angeles was incorporated as a municipality on April 4, 1850, five months before California achieved statehood. The city experienced rapid growth with the discovery of oil.

National Automotive Parts Association

The National Automotive Parts Association (NAPA), founded in 1925, is a retailers' cooperative distributing automotive replacement parts, accessories and service items in North America.

Operations

There are over 6,000 NAPA Auto Parts stores across the United States. 1,110 NAPA stores are owned by Genuine Parts Company, and the remainder are independently owned. 15,000 NAPA AutoCare repair facilities are in operation which provide vehicle maintenance and repair services.

Outside the United States, NAPA operates in Canada through the UAP (United Auto Parts) division of Genuine Parts Company and NAPA Autopro repair facilities in Canada, Mexico and other locations throughout the Caribbean and Latin America.

In April 2013, Genuine Parts Company acquired Exego Group, a leading automotive parts and accessories distributor in Australasia. The company sells automotive accessories and parts under the Repco name in Australia and New Zealand.

Products and services

Radio advertisement

Commercial radio stations make most of their revenue selling "airtime" to advertisers. Of total media expenditures, radio accounts for 6.9%. Radio advertisements or "spots" are available when a business or service provides valuable consideration, usually cash, in exchange for the station airing their spot or mentioning them on air. The United States Federal Communications Commission (FCC), established under the Communications Act of 1934, regulates commercial broadcasting, and the laws regarding radio advertisements remain relatively unchanged from the original Radio Act of 1927, enacted to deal with increasing problems of signal interference as more and more stations sprung up around the country.

History

The first radio broadcasts aired in the early 1900s. However, it wasn't until 1919 that radio stations began to broadcast continuously, similar to the modern practice. In the United States, on November 2, 1920, KDKA Pittsburgh became the first radio station to receive a commercial license from the government. KDKA engineer Frank Conrad may have been the first to broadcast a radio advertisement on his own experimental station in 1919 when he thanked a Pittsburgh music store on the air for supplying him with phonograph records, although that was for trade, not cash.