In simple terms, a steady carrier frequency is turned on or off by the use of a key, bug, electronic keyer, keyboard thru an interface, or by touching two wires together. Most modern transceivers generate an audio tone of 700 - 800 Hz which is then transmitted by the key.

CW is referred to as Charlie Whiskey, code, Morse Code, telegraphy, and to new Amateurs or those who are working on their code as the "Dreaded Code". Generally, learning the code is not that difficult for most people, some will have to dedicate more time than others.

CW was the first method of transmitting "intelligent" signals through the atmosphere using radio waves and is the first true digital mode of operation. CW has two states: ON or OFF. When ON, the tone is heard and we send characters or special prosigns by varying the length of each ON period and using combinations of short and long ON times to create the characters.

CW transmissions will get through most atmospheric conditions that turn other modes of operation unintelligible. And if your code key breaks, you can tap the two ends of the bare wires together to send the code in an emergency.

The code that most Amateurs use is the International Morse Code, although you will hear other forms that have special characters for the different letters of various alphabets. These specialized forms of code are used by Amateurs in direct contact who speak the same language.

The Art and Skill of Telegraphy by Bill Pierpont, N0HFF (SK 20 Feb 2003)

SuperMorse DOS/Windows
NuMorse Lite V1.0 Windows 3.1/Windows 95
Morse Code 4.11 DOS/Windows3.x/Windows95
MRX Morse Code by VK1EME, Windows 95

Other CW Sites:

Canadian Railway Telegraph History website
Movies that use CW
RAC CW Links Page