Search results
Results From The WOW.Com Content Network
Morse code. Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called dots and dashes, or dits and dahs. [3] [4] Morse code is named after Samuel Morse, one of the early developers of the system adopted for electrical telegraphy .
American Morse code. American Morse Code — also known as Railroad Morse—is the latter-day name for the original version of the Morse Code developed in the mid-1840s, by Samuel Morse and Alfred Vail for their electric telegraph. The "American" qualifier was added because, after most of the rest of the world adopted " International Morse Code ...
A telegraph key or Morse key is a specialized electrical switch used by a trained operator to transmit text messages in Morse code in a telegraphy system. Keys are used in all forms of electrical telegraph systems, including landline (also called wire) telegraphy and radio (also called wireless) telegraphy. An operator uses the telegraph key to ...
Telegraph Sounder. A telegraph sounder is an antique electromechanical device used as a receiver on electrical telegraph lines during the 19th century. It was invented by Alfred Vail after 1850 to replace the previous receiving device, the cumbersome Morse register [1] and was the first practical application of the electromagnet.
Morse code mnemonics are systems to represent the sound of Morse characters in a way intended to be easy to remember. Since every one of these mnemonics requires a two-step mental translation between sound and character, none of these systems are useful for using manual Morse at practical speeds. Amateur radio clubs can provide resources to ...
An 1860s-era siren. [2] A siren is a loud noise-making device. Civil defense sirens are mounted in fixed locations and used to warn of natural disasters or attacks. Sirens are used on emergency service vehicles such as ambulances, police cars, and fire engines. There are two general types: mechanical and electronic.
Morse receivers. The first radio receivers used a coherer and sounding board, and were only able to receive continuous wave (CW) transmissions, encoded with Morse code (wireless telegraphy). Later transmission and reception of speech became possible, although Morse code transmission continued in use until the 1990s.
Wireless telegraphy. A US Army Signal Corps radio operator in 1943 in New Guinea transmitting by radiotelegraphy. Wireless telegraphy or radiotelegraphy is transmission of text messages by radio waves, analogous to electrical telegraphy using cables. [1] [2] Before about 1910, the term wireless telegraphy was also used for other experimental ...