Microphone Impedance for Amateur Radio

Older vacuum tube ham radio transceivers tend to use the high impedance microphone whilst the newer solid state ham radio transceivers tend to use the low impedance microphone. Mobile radios tend to use low the impedance microphone. Slang terms such as Hi-Z and Low-Z come from the music industry and refer to impedance. A Hi-Z microphone is, for example, a high impedance microphone.