Audio/Video Glossary - Impedance MatchingVideo signals should be treated with care and accuracy, as proper RF* signals, since they occupy a very large spectrum of frequencies - from almost DC (0 Hz) up to several Megahertz. Video generally uses 75 Ohms cable and lines. Input and output impedance (a form of resistance) must be matched to 75 Ohms. If the output impedance of the video source, or the input impedance of the receiver, or the cable carrying the signal, are not properly matched to 75 Ohms, a series of problem may arise. Signal level will not be kept to standard, high frequencies will get lost and fine detail and color information will be lost. In addition, instability, oscillations apparent as snow, component heat-up and ghost images may also appear. In the digital domain, cable mismatch may create an instant signal breakdown (see Cliff Effect*).