Search results
Results from the WOW.Com Content Network
Naval air traffic controller communicates with aircraft over a two-way radio headset A variety of portable handheld two-way radios for private use. A two-way radio is a radio transceiver (a radio that can both transmit and receive radio waves), which is used for bidirectional person-to-person voice communication with other users with similar radios, [1] in contrast to a broadcast receiver ...
Typical walkie-talkies resemble a telephone handset, with a speaker built into one end and a microphone in the other (in some devices the speaker also is used as the microphone) and an antenna mounted on the top of the unit. They are held up to the face to talk. A walkie-talkie is a half-duplex communication device. Multiple walkie-talkies use ...
The earliest known manual for the PRC-6 was the preliminary manual printed by Raytheon in 1949. [3]The AN/PRC-6 was designed and used by the US military during the Korean War, and was in use by the US Marine Corps as late as 1972.
Specialized Mobile Radio (SMR) may be an analog or digital trunked two-way radio system, operated by a service in the VHF, 220, UHF, 700, 800 or 900 MHz bands. Some systems with advanced features are referred to as an Enhanced Specialized Mobile Radio ( ESMR ). [ 4 ]
For example, a walkie-talkie or a DECT phone or so-called TDD 4G or 5G phones requires only a single frequency for bidirectional communication, while a cell phone in the so-called FDD mode is a full-duplex device, and generally requires two frequencies to carry the two simultaneous voice channels, one in each direction.
A mid-1940s alarm clock radio with AM radio stations only A typical 1980s clock radio featuring a digital clock/alarm and an analogue FM/MW/LW receiver. A clock radio is an alarm clock and radio receiver integrated in one device. [18] The clock may turn on the radio at a designated time to wake the user, and usually includes a buzzer alarm.
I've moved the following strangely-formatted additions here to talk since they are out of place in the walkie-talkie article.--Wtshymanski 23:12, 23 May 2007 (UTC)Wireless Communication . Prior Inventions. The invention of the walkie-talkie is preceded by the discovery of radio and the invention of wireless communication.
Digital clocks typically use the 50 or 60 hertz oscillation of AC power or a 32,768 hertz crystal oscillator as in a quartz clock to keep time. Most digital clocks display the hour of the day in 24-hour format; in the United States and a few other countries, a commonly used hour sequence option is 12-hour format (with some indication of AM or PM).