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Chart of the Morse code 26 letters and 10 numerals [1]. This Morse key was originally used by Gotthard railway, later by a shortwave radio amateur [2]. Morse code is a telecommunications method which encodes text characters as standardized sequences of two different signal durations, called dots and dashes, or dits and dahs.
The Royal Canadian Corps of Signals (RCCS or RC Sigs; French: Corps des transmissions royal du Canada, CTRC [2]) is a component within the Canadian Armed Forces' Communications and Electronics Branch, consisting of all members of that personnel branch who wear army uniform.
The RTCM (Radio Technical Commission for Maritime Services) maintains specifications specific to EPIRB devices. The alarm signal is defined as an AM signal (A3X and/or N0N emissions), containing a swept tone ranging from 1600 Hz to 300 Hz (either upwards or downwards), with 2-4 sweeps per second. [26] [27]
The QN Signals are Morse code operating signals that were introduced for Amateur radio net operation in 1939 on the Michigan QMN Net to lighten the burdens of net control operators. Originally created by a committee of the Detroit Amateur Radio Association led by Ralph Thetreat, W8FX. [ 1 ]
Mayday is an emergency procedure word used internationally as a distress signal in voice-procedure radio communications.. It is used to signal a life-threatening emergency primarily by aviators and mariners, but in some countries local organizations such as firefighters, police forces, and transportation organizations also use the term.
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. [1]: 26‑1 As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. [2]
Naval flag signalling undoubtedly developed in antiquity in order to coordinate naval action of multiple vessels. In the Peloponnesian War (431 – 401 BCE) squadrons of Athenian galleys were described by Thucydides as engaging in coordinated maneuvers which would have required some kind of communication; [1] there is no record of how such communication was done but flags would have been the ...
The most basic radio-navigational aid used in aviation is the non-directional beacon or NDB. It is a simple low- and medium-frequency transmitter used to locate airway intersections and airports and to conduct instrument approaches, with the use of a radio direction finder located on the aircraft.