Modulated continuous wave
Abbreviated "MCW".
"MCW uses a fixed audio tone to modulate a carrier wave."[1]
Instead of use on-off to form the dit-dah's of Morse code, MCW turns a tone on and off.
With transmitters that can transmit in various modes, the setting for MCW might be marked "Tone" (Mike Everette, 22 July 1998 Forum).
| A1 | Continuous wave (CW) |
| A2 | Modulated continuous wave (MCW) |
| A3 | radiotelephone; voice |