Any number of specialized switches for sending Morse Code signals. They take the form of straight keys
, semiautomatic keys
, or electronic keyers
The first electrons pressed into the service of digital communications were excited by Samuel F.B. Morse
in 1837, when he pushed down on the handle of his telegraph key and closed a circuit between the District of Columbia to Baltimore Maryland.
"What hath God wrought?"
If only you could know, Sam.
And so there it was: instantaneous communication. Telegraphers' skill was the limiting reagent in data transmission rates. Transmitting and receiving high speed telegraphy
, or any speed telegraphy
, require specialized equipment and unique skill sets.
An essential component of copying high speed telegraphy is really a form of data compression: the ability to "copy behind," or write several characters behind the sender, while mentally keeping up with the constant flow of data. Some telegraphers can copy 50-70 WPM, a speed in which individual dots and dashes are nearly indiscernable. To an untrained, or even moderately trained ear, the stream sounds more like a steady carrier with a lightly modulated amplitude than individual carrier segments.
Once one is fluent in the code, the bandwidth limiter in transmitting is purely mechanical: how quickly can you work the switch and still send intelligable code.
The first, and most familiar type of telegraph key is the straight key
. It is a system of one or more spring-loaded levers, electrical contacts--both within the switch itself and inputs for the telegraph line. There is a handle, and the key is operated by pushing down on the handle to make dots and dashes, or, more correctly, "dits" and "dahs." This is very difficult much over 20 WPM, although I believe the record is in the upper 30s. Someone clue me in if that's wrong. Anyway, as telegraphers became faster and faster necessity invented the semi-automatic "bug," an awesome and gorgeous piece of precision engineering. Using a system of MANY levers and springs, the bug is operated in a side to side motion, rather than the up and down motion of a straight key. A swipe to the right, and the weighted arm bounces off its contact in a perfect "dit" rhythm for as long as you hold the lever to the right. Repeating "dahs" are up to the operator, swiping to the left at the correct rhythm. Bugs are usually the most difficult piece of telegraphy equipment to master, because of the precision timing required to get true dits, dahs and character separation
. Many operators opt to use a bug and don't bother to develop these skills. Listening to their code is torture, and communication is often impossible.
Lastly, fully automatic electronic keyers use a side to side motion to generate both repeating dits AND dahs. They rely on circuitry which produces perfect dit/dah ratios, and double-paddle "iambic" models allow certain shortcuts that create sound economy of motion.
In the hands of a skilled operator, bugs and electronic keyers can relay information faster than most people can type.
I am desirous of ranting on the responsibility we have of keeping Sam's magnificant code a visible part of history, but I have to go to bed. Within the last five years it has been officially abandoned by every organization which relies extensively on radio communication except amateur radio operators. And even many of their ranks think the Morse Code is a waste of time. Most people think Morse Code is a waste of time. But it's not, because of its beauty, bandwidth, unparalled signal to noise ratio, and because it is the father of every 1 and 0 you've ever been involved with.