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Morse code can be transmitted in a number of ways: Originally as electrical pulses along a telegraph wire, but later extended to an audio tone, a radio signal with short and long tones, or high and low tones, or as a mechanical, audible, or visual signal (e.g. a flashing light) using devices like an Aldis lamp or a heliograph, a common ...
Acoustic telegraphy (also known as harmonic telegraphy) was a name for various methods of multiplexing (transmitting more than one) telegraph messages simultaneously over a single telegraph wire by using different audio frequencies or channels for each message. A telegrapher used a conventional Morse key to tap out the message in Morse code ...
Morse code abbreviations are not the same as prosigns.Morse abbreviations are composed of (normal) textual alpha-numeric character symbols with normal Morse code inter-character spacing; the character symbols in abbreviations, unlike the delineated character groups representing Morse code prosigns, are not "run together" or concatenated in the way most prosigns are formed.
The primitive spark gap radio transmitters used during the first three decades of radio (1886-1916) could not transmit audio (sound) and instead transmitted information by wireless telegraphy; the operator switched the transmitter on and off with a telegraph key, creating pulses of radio waves to spell out text messages in Morse code. So the ...
MCW can be generated by any AM or FM radio transmitter with audio input from an audio oscillator or equivalent audio source. [1] [2] When an SSB transmitter is modulated by Morse code of only a single audio frequency, the resulting radio frequency emission is J2A or J2B and therefore is CW by definition, not MCW. [3]
A receiver is tuned to a Morse code signal, and the receiver's intermediate frequency (IF) is f IF = 45000 Hz. That means the dits and dahs have become pulses of a 45000 Hz signal, which is inaudible. To make them audible, the frequency needs to be shifted into the audio range, for instance f audio = 1000 Hz.
Fldigi (short for Fast light digital) [4] is a free and open-source program which allows an ordinary computer's sound card to be used as a simple two-way data modem.The software is mostly used by amateur radio operators who connect the microphone and headphone connections of an amateur radio SSB or FM transceiver to the computer's headphone and microphone connections, respectively.
The Alexanderson alternator works similarly to an AC electric generator, but generates higher-frequency current, in the very low frequency (VLF) radio frequency range. The rotor has no conductive windings or electrical connections; it consists of a solid disc of high tensile strength magnetic steel, with narrow slots cut in its circumference to ...