h, h is the letter in morse code that is four dots.
h, h is the letter in morse code that is four dots.
what letter in morse code is four dots?
h , h
the morse system for telegraphy, which was first used in about 1844, was designed to make indentations on a paper tape when electric currents were received. morse's original telegraph receiver used a mechanical clockwork to move a paper tape. when an electrical current was received, an electromagnet engaged an armature that pushed a stylus onto the moving paper tape, making an indentation on the tape. when the current was interrupted, a spring retracted the stylus and that portion of the moving tape remained unmarked. morse code was developed so that operators could translate the indentations marked on the paper tape into text messages. in his earliest code, morse had planned to transmit only numerals and to use a codebook to look up each word according to the number which had been sent. however, the code was soon expanded by alfred vail in 1840 to include letters and special characters so it could be used more generally. vail estimated the frequency of use of letters in the english language by counting the movable type he found in the type-cases of a local newspaper in morristown. the shorter marks were called "dots" and the longer ones "dashes", and the letters most commonly used were assigned the shorter sequences of dots and dashes. this code was used since 1844 and became known as "morse landline code" or "american morse code".
morse code
the international morse code encodes the 26 english letters a through z, some non-english letters, the arabic numerals and a small set of punctuation and procedural signals (prosigns). there is no distinction between upper and lower case letters. each morse code symbol is formed by a sequence of dots and dashes. the dot duration is the basic unit of time measurement in morse code transmission. the duration of a dash is three times the duration of a dot. each dot or dash within a character is followed by period of signal absence, called a "space", equal to the dot duration. the letters of a word are separated by a space of duration equal to three dots, and the words are separated by a space equal to seven dots. to increase the efficiency of encoding, morse code was designed so that the length of each symbol is approximately inverse to the frequency of occurrence in text of the english language character that it represents. thus the most common letter in english, the letter "e", has the shortest code: a single dot. because the morse code elements are specified by proportion rather than specific time durations, the code is usually transmitted at the highest rate that the receiver is capable of decoding. the morse code transmission rate ("speed") is specified in "groups per minute", commonly referred to as "words per minute".
morse code