K

K
K : The symbol used in CW (Morse) and digital modes for "please respond" or "any station respond". The KN prosign is used to invite a specific station only to respond.

Key : A simple mechanical device used to send morse code

Keyer : An electronic circuit intended to interface an amateur CW transmitter to a paddle switch. While multiple variants exist, typically the keyer will send dit's when the paddle is held in one position and dah's in the opposite position. As the timing of the Morse dots and dashes is automatically controlled, code speed is more consistent than that sent manually using a straight key.

Kilo: Metric system multiplier x1000. Also Phonetic alphabet letter K

 Kilohertz (KHz) : one thousand Hertz (Hz) or one thousand cycles per second.