CW

From HFUnderground

Stands for Continuous Wave, another way of saying that the station is transmitting morse code. This mode is still used in certain Military organizations (like the Russian Air Force, Russian Navy) as well as amateur radio communications.

Emission designator for true CW is N0N. Morse code telegraphy (actual tone) is A1A. Modulated CW (MCW) transmitted over an AM or FM voice radio channel is sometimes called "MCW" or "tone-modulated". Emission designators for Morse code modulated over AM is A3A, Morse code over FM is F3A.

Use of CW for automatic identification is widespread across VHF/UHF land mobile radio systems, radionavigation systems, including the ILS, VOR, VORTAC, non-directional beacons (NDB) systems, fishnet radio buoys, aeronautical and marine radio networks, radio beacons of all kinds and basically everything else.

Morse code over a phase-modulated signal is G3A emission.