Modulated continuous wave

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Abbreviated "MCW".

"MCW uses a fixed audio tone to modulate a carrier wave."[1]

Instead of use on-off transmissions to form the dit-dah's of Morse code, MCW turns a tone on and off. The carrier wave is modulated by the tone generator. Because receiving the tone generated by the MCW transmitter is just like receiving a voice transmission, MCW receivers could pick up voice transmissions--and vice versa. "Unlike A1A CW transmissions, A2A MCW morse can clearly be heard on a normal AM radio receiver. It was commonly used by many RDF beacons to send a morse station identifier on a regular basis."[2]

With transmitters that can transmit in various modes, the setting for MCW might be marked "Tone" (Mike Everette, 22 July 1998 Forum).

Greg Moore, 28 Jun 2004 Forum.
Modulated CW is either generated by a tone which modulates the carrier, which is, in essence, simply an AM signal modulated with the tone, and would have no distance advantage over AM. because of the power taken up by the carrier and both sidebands (this is of course, why SSB (Single Sideband) is the voice transmission choice of today, because by suppressing the unwanted sideband and the carrier, one gains 75 percent more power out than with AM phone.
Classification of transmission modes
A1 Continuous wave (CW)
A2 Modulated continuous wave (MCW)
A3 Voice modulation, radiotelephone