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It is a protocol, implemented in a computer program, used for weak-signal radio communication between amateur radio operators. The protocol was designed, and a program written initially, by Joe Taylor, K1JT. The software code is now open source and is developed by a small team.
A trunked radio system is a two-way radio system that uses a control channel to automatically assign frequency channels to groups of user radios. In a traditional half-duplex land mobile radio system a group of users (a talkgroup ) with mobile and portable two-way radios communicate over a single shared radio channel, with one user at a time ...
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 ...
Before the rubber ducky, antennas on portable radios usually consisted of quarter-wave whip antennas, rods whose length was one-quarter of the wavelength of the radio waves used. [1] In the VHF range where they were used, these antennas were 0.6 or 0.9 m (2 or 3 feet) long, making them cumbersome. They were often made of telescoping tubes that ...
The Baofeng UV-5R [note 1] is a handheld radio transceiver manufactured by the Chinese manufacturer Baofeng. This model was the first dual band radio (VHF/UHF) to be successfully distributed by a Chinese brand. [citation needed] It is inexpensive and relatively simple to use (though tedious to program without computer software).
In hand-held radios, an LED indicator may glow green, yellow, or orange to indicate another user is talking on the channel. Hand-held radios usually have a switch or push-button to monitor. Some modern radios have a feature called "Busy Channel Lockout", which will not allow the user to transmit as long as the radio is receiving another signal.
A radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. Radio waves are electromagnetic waves with frequencies between about 30 Hz and 300 GHz. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating current, the ...
450–470 MHz: UHF business band, General Mobile Radio Service, and Family Radio Service 2-way "walkie-talkies", public safety; 470–512 MHz: Low-band TV channels 14 to 20 (shared with public safety land mobile 2-way radio in 12 major metropolitan areas scheduled to relocate to 700 MHz band by 2023 [13])