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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.
Due to its location in the centre of the shortwave spectrum, this band provides significant opportunities for long-distance communication at all points of the solar cycle. 30 metres is a WARC band. "WARC" bands are so called due to the 1979 special World Administrative Radio Conference allocation of these newer bands to amateur radio use ...
The 15-meter band (also called the 21-MHz band or 15 meters) is an amateur radio frequency band spanning the shortwave spectrum from 21 to 21.45 MHz. The band is suitable for amateur long-distance communications, and such use is permitted in nearly all countries.
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 ...
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications. [1]
Automatic Packet Reporting System (APRS) is an amateur radio-based system for real time digital communications of information of immediate value in the local area. [1] Data can include object Global Positioning System (GPS) coordinates , non-directional beacon , weather station telemetry, text messages, announcements, queries, and other telemetry .
A typical Yagi antenna used by a Canadian radio amateur for long distance communication Boeing 707 used a HF antenna mounted on top of the tail fin [8] The main uses of the high frequency spectrum are: Military and governmental communication systems; Aviation air-to-ground communications; Amateur radio; Shortwave international and regional ...
Note that different countries have different rules; for example, in the United States, the two-meter band is 144–148 MHz, while in the United Kingdom (and most of Europe) it is 144–146 MHz. Repeater frequency sets are known as "repeater pairs", and in the ham radio community most follow ad hoc standards for the difference between the two ...