are unwanted sidebands caused by the rapid transitions of the key 's on and off states, A capacitor or two can easily damp key clicks b> "softening the transitions (slowing iheni down), but such softening plays havoc with oscillators, so it's rarely used in single-stage designs w hich key die power going to the oscillator Now and then, you can get awa\ wiih it when the oscillator is crystal-controlled, hi a modem multistage radio, keying is much more complex than .1 simple on/off signal, A typical HI- rig has a pretty involved keying circuit which sequences various operations each time you press the key; First, the synthesizer's \ FO put on the matter what the waveform originally looked like, in fact, that's how it's done in virtually all CW-onl\ transmitters.

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