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An amateur radio propagation beacon is a radio beacon, whose purpose is the investigation of the propagation of radio signals. Most radio propagation beacons use amateur radio frequencies. They can be found on LF, MF, HF, VHF, UHF, and microwave frequencies. Microwave beacons are also used as signal sources to test and calibrate antennas and ...
Radio amateurs may engage in satellite and space craft communications; however, the frequencies allowed for such activities are allocated separately from more general use radio amateur bands. Under the International Telecommunication Union's rules, all amateur radio operations may only occur within 50 kilometres (31 mi) of the Earth's surface.
Morse code is called the original digital mode. Radio telegraphy, designed for machine-to-machine communication is the direct on / off keying of a continuous wave carrier by Morse code symbols, often called amplitude-shift keying or ASK, may be considered to be an amplitude modulated mode of communications, and is rightfully considered the first digital data mode.
The use of "ham" meaning "amateurish or unskilled" survives today sparsely in other disciplines (e.g. "ham actor"). The amateur radio community subsequently began to reclaim the word as a label of pride, [15] and by the mid-20th century it had lost its pejorative meaning. Although not an acronym or initialism, it is often written as "HAM" in ...
Amateur television (ATV) is the transmission of broadcast quality video and audio over the wide range of frequencies of radio waves allocated for radio amateur (Ham) use. [1] ATV is used for non-commercial experimentation, pleasure, and public service events.
The 13 centimeter, 2.3 GHz or 2.4 GHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio and amateur satellite use on a secondary basis. The amateur radio band is between 2300 MHz and 2450 MHz, and thereby inside the S-band. The amateur satellite band is between 2400 MHz and 2450 MHz, and its use by satellite ...
American radio amateurs may use a maximum of one watt of radiated RF power, on any ham frequency authorized for data emissions, to control RC models. [10] Canadian radio amateurs may use any amateur frequency above 30 MHz for the control of RC models. [11] Plus or minus 5 MHz is a common repeater frequency offset in the 70 cm band.
Reliable radio control uses bands dedicated to the purpose. Radio-controlled toys may use portions of unlicensed spectrum in the 27 MHz or 49 MHz bands, but more costly aircraft, boat, or land vehicle models use dedicated radio control frequencies near 72 MHz to avoid interference by unlicensed uses. The 21st century has seen a move to 2.4 GHz ...