 Continuous wave - Key clicks: Encyclopedia II - Continuous wave - RadioVery early radio transmitters used a spark gap to produce radio-frequency oscillations in the transmitting antenna; these signals had a characteristic rapidly damped amplitude during each pulse of radiated energy. When alternators and later electronic oscillators became available, the signal strength remained constant during each code element, leading to the description of this technique as "continuous" waves.
An unmodulated carrier has no bandwidth and conveys no information; the act of keying the carrier on and off produces a finite ...
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