Circuit Wireless Microphone

Circuit Wireless Microphone

Wireless microphone, as the name implies, is a microphone without a physical cable connecting it directly to the sound recording or amplifying equipment with which it is associated.

More commonly known as a Radio Microphone, there are many different standards, frequencies and transmission technologies used to replace the microphone's cable connection and make it into a wireless microphone. They can transmit, for example, in radio waves using UHF or VHF frequencies, FM, AM, or various digital modulation schemes. Some low cost models use infrared light. Infrared microphones require a direct line of sight between the microphone and the receiver, while costlier radio frequency models do not.

Some models operate on a single fixed frequency, but the more advanced models operate on a user selectable frequency to avoid interference, and allow the use of several microphones at the same time.

Layout Wireless Microphone

individuals and organizations claim to be the inventors of the wireless microphone. Reg Moores developed a radio microphone that was first used in "Aladdin on Ice" in 1949.

John F. Stephens developed an FM wireless microphone for a Navy musical show in 1951 on the Memphis Naval base. Each of the principal players/singers had their own microphone/transmitter. Subsequently, the Secret Service had Stephens modify his invention to be used in government "bugging" operations.

Herbert "Mac" McClelland, founder of McClelland Sound in Wichita, Kansas, fabricated a wireless microphone to be worn by baseball umpires at major league games broadcast by NBC from Lawrence-Dumont Stadium in 1951. The transmitter was strapped to the umpire's back. Mac's brother was Harold M. McClelland, the chief communications architect of the U.S. Air Force.

Shure Incorporated claims that its "Vagabond" system from 1953 was the first. In 1957 German audio equipment manufacturer Sennheiser, at that time called Lab W, working with the German broadcaster Norddeutscher Rundfunk (NDR) exhibited a wireless microphone system. From 1958 the system was marketed through Telefunken under the name of Mikroport.

The first recorded patent was filed by Raymond A. Litke, an American electrical engineer with Educational Media Resources and San Jose State College, who invented the wireless microphone in 1957 to meet the multimedia needs for television, radio, and classroom instruction. His U.S. patent number 3134074, originally filed January 8, 1960, and granted May 19, 1964, is for the world's first portable and practical wireless microphone. At last, a dependable and wireless microphone with clarity, sound, and range proved to be as good as a microphone which used cords and cables. Two types were made available for purchase in 1959: hand-held and lavalier. Litke coined the term “lavalier microphone”, including the word in his patent application. The main transmitter module was a cigar-sized device which weighed seven ounces. The Federal Communications Commission (FCC) granted Litke 12 frequencies at his approval hearing.

Also called the Vega-Mike after Vega Electronics Corporation which first manufactured it in 1959, the midget device was first used by the broadcast media at the 1960 Democratic and Republican National Conventions. It allowed television reporters to roam the floor of the convention to interview participants where Presidential candidates Kennedy and Nixon were the first celebrities to use the wireless microphone. The American Broadcasting Company (ABC) completed testing in 1959, prior to the conventions. Television anchor John Daly was exuberant with his praises for Litke's invention during a TV news broadcast in July 1960. The wireless microphone was first tested at the Olympic trials held at Stanford University in 1959.