Walkie-talkie
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Recreational, toy and amateur radio walkie talkies
A walkie-talkie is a hand-held portable, bi-directional radio transceiver. The first walkie-talkies were developed for military use. Major characteristics include a half-duplex channel (only one can receive and transmit at a time) and a push-to-talk switch that starts transmission. The typical physical format looks somewhat like a telephone handset, possibly slightly larger but still a single unit, with an antenna sticking out of the top. Where a phone's earpiece is only loud enough to be heard by the user, a walkie-talkie's built-in speaker can be heard by the user and those in his immediate vicinity.
History
The first radio receiver/transmitter to be nick-named "Walkie-Talkie" was the backpacked Motorola SCR-300, created by an engineering team in 1940 at the Galvin Manufacturing Company consisting of Dan Noble, who conceived of the design using FM technology, Henryk Magnuski who was the principal RF engineer, Marion Bond, Lloyd Morris, and Bill Vogel. Motorola also produced the hand-held AM SCR-536 radio during the war, and it was called the "Handie-Talkie" (HT).Al Gross also worked on the early technology behind the walkie-talkie between 1934 and 1941, and is sometimes said to actually have invented it.
Uses
Hand-held transceivers became valuable communication tools for police, emergency services, and industrial and commercial users, using frequencies assigned for these services.Walkie-talkies are popular with amateur radio operators. Many manufacturers produce models of hand-held transceivers that transmit and receive on amateur radio frequencies. An amateur radio license is required to use these transceivers, and in some countries may also be required for possession of an amateur radio walkie-talkie.
Inside of a recreational radio walkie talkie
Low-power versions, exempt from licence requirements, are also popular children's toys. Prior to the change of CB radio from licensed to un-licensed status, the typical toy walkie-talkie available in retail stores in North America was limited to 100 milliwatts of power on transmit and the 27 MHz citizens' band channels. Other toy walkie-talkies operate in the 49 MHz band shared with cordless phones and baby monitors; typically these devices are very crude electronically and may lack even a volume control, though they may have elaborate packaging. Unlike telephones, low-cost toy walkie-talkies do not have separate microphones and speakers; the speaker is typically used as a microphone while in transmit mode.
The personal walkie-talkie has now become popular again with the Family Radio Service. FRS operates in the GMRS band, which is also used for business walkie-talkies and mobile radios. While FRS walkie-talkies are also sometimes used as toys, they are also a useful communication tool for business and personal use.
See also
External links
- [Picture of a SCR-536 Handie-Talkie]
- [SCR-300-A Technical Manual]
- http://gordon.army.mil/ocos/Museum To see "U.S. Army Signal Corp Museum," click link "Exhibits and collections management."
- [Today's US Army walkie talkie (UHF)]
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