What is CW?

CW stands for Continuous Wave and is commonly associated with Morse code transmissions. In amateur radio, CW refers specifically to the method of transmitting information using the on/off keying of a radio signal, where the signal is turned on for a short duration (dot) or a longer duration (dash). This technique allows for effective communication over long distances, particularly in situations where other forms of modulation may be less clear.

Morse code, which uses a series of dots and dashes to represent letters and numbers, was historically significant in radio communication and continues to be popular among amateur radio operators today. Operating in CW mode is efficient and requires minimal bandwidth, making it advantageous in crowded frequency bands.

The other options, while related to various aspects of radio or electronics, do not accurately describe CW in the context of amateur radio. For instance, electromagnetic propagation refers to the way radio waves travel through the atmosphere but does not pertain specifically to the CW mode. Similarly, a technique for coil winding and a digital mode used on 2 meter FM do not align with the traditional understanding of CW as it relates to Morse code.