Amateur radio

Gilbilisco, Stan, ed. 1994. Amateur Radio Encyclopedia. Blue Ridge Summit, PA TAB Books. 

So little current flows across a glass electrode that it was not practical when discovered in 1906. One of the first people to use a vacuum tube amplifier to measure pH with a glass electrode was an undergraduate, W. H. Wright at the University of Illinois in 1928, who knew about electronics from amateur radio. Arnold Beckman at Caltech invented a portable, rugged, vacuum tube pH meter In 1935, which revolutionized chemical instrumentation.16... 

MMbb ti/htoL For this reason, the circuitry for these networks is sometimes called a duplexer, another carry-over from communications language a duplexer in an amateur radio transceiver is a circuit which switches the antenna between the transmit and the receive modes. 

Local radio stations, cell phone repeaters, amateur radio transmitters, military radars... 

There are at least nineteen Orbiting Satellite Carrying Amateur Radio (OSCAR). These artificial communication satellites have been launched by individuals. 

Society of Amateur Radio Astronomers http //www.radio-astronomy.org... 

Radio applications are widespread and include commercial radio, amateur radio, marine radio, aviation radio, radar, navigation, and microwave. 

Amateur radio licensing is governed by the FCC under strict federal regulations. Individuals of any age may be granted a license to operate amateur stations for personal use. To obtain a license, one must demonstrate an understanding of pertinent FCC regulations as well as knowledge of radio-station operation and safety considerations. 

Silver, H. Ward. ARRL Ham Radio License Manual All You Need to Become an Amateur Radio Operator. Newington, Conn. American Radio Relay League, 2010. Informative text for one interested in becoming a ham radio operator. 

Simple radio telescopes can be built very inexpensively by amateurs using commercially available parts without modification. An old analogue television set and an ultra-high-frequency (UHF) antenna can be used to detect the Crab Nebula, and amateur radio equipment can be used to detectjupiter. 

A discussion of receivers would not be complete without considering some of the causes of interference. Often the receiver owner thinks that a certain signal, such as an amateur radio signal, is causing the difficulty. This may or may not be the case. The origin of the interference may be at any of the three following locations ... 

Maximum power for amateur radio mobile units. 

The need for backup communications for each business function. Options include messengers, telephones, portable microwave, amateur radios, point-to-point private lines, satellite, and high-frequency radio. 

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