Audio Frequency (AF): Audio Frequency (AF) refers to the range of frequencies that the human ear can detect. This range typically spans from 20 Hz (Hertz) to 20 kHz (Kilohertz). Sounds within this range are audible to humans and include everything from the lowest bass notes to the highest treble notes in music. In amateur radio, AF is important for understanding the audio signals that are transmitted and received, particularly in voice communication modes like AM (Amplitude Modulation) and FM (Frequency Modulation).
Radio Frequency (RF): Radio Frequency (RF) refers to the electromagnetic waves used for transmitting data over long distances. RF encompasses frequencies above 20 kHz, extending into the gigahertz (GHz) range. This includes various bands used for different communication purposes:
RF is crucial in amateur radio as it encompasses the frequencies used for different modes of communication, such as voice, data, and video. Understanding RF helps operators select the appropriate frequency bands for their communications, considering factors like propagation conditions and interference.