📡 What Is “CW,” “Morse Code,” or Simply “Code”?

Today, we call it CW—short for Continuous Wave—but this mode of radio communication has deep roots in the earliest days of Amateur Radio.

🕰️ A Brief History

Originally known as radiotelegraphy, CW descends from 19th-century landline telegraphy and carries forward a rich culture of abbreviations, procedures, and operator etiquette. In the early days of wireless, Morse code was sent using spark gap transmitters, producing broad, inefficient signals known as damped waves. These were soon replaced by vacuum tube oscillators, which generated a much purer tone—hence the name Continuous Wave.

📻 CW in Modern Amateur Radio

For the first decade or more of ham radio, CW was the only way to communicate. Today, it remains a beloved mode among operators who value its simplicity, reliability, and legacy. Modern transceivers use solid-state components and microprocessors to support a wide range of modes:

• CW (Morse code)

• Voice (AM, FM, SSB)

• Image (SSTV, fax)

• Digital data (FT8, PSK31, RTTY, and more)

Whether you’re chasing DX or enjoying a quiet QSO, CW offers a timeless connection to the roots of radio.