Definition
A radio signal transmitted as an uninterrupted, constant-amplitude, constant-frequency wave. To carry information, a continuous wave is interrupted (keyed) into short and long pulses representing Morse code, or modulated by varying its amplitude or frequency.
Plain English
A steady radio signal that just keeps going at the same strength and pitch. On its own it carries no information, so it is either switched on and off in a pattern (like Morse code) or altered slightly to carry voice or data.
Context Anchor
Seen in radio communication and navigation discussions, especially when describing Morse code station identifiers or older non-voice radio signals.
Derivation
From Latin continuus (uninterrupted) and Old English wafian (to wave). The name simply describes what the signal is: an unbroken wave, in contrast to a pulsed or interrupted transmission.
Why Pilots Care
Allows correct identification of certain non-directional beacons and legacy radios still found in training and vintage aircraft.
Analogy
Think of a steady whistle. If you turn the whistle on and off in short and long bursts, you can make a code, but the sound itself is still just one steady tone while it is on.
Intuition Check
Continuous wave does not mean a radio message that never stops. It means the wave itself is steady while it is being transmitted; it can still be switched on and off to send code.
Example Sentence 1
The VOR identifies itself by interrupting its continuous wave to send the station's three-letter Morse code ident.
Example Sentence 2
The pilot switched the receiver to continuous wave mode to copy the beacon's identification.