Most stereo-capable video recorders made through the 1980s and early 1990s had a "simulcast" recording mode where they recorded video signals from the built-in TV tuner and audio signals from the VCR's audio line-in connectors. This was to allow one to connect a stereo FM tuner that is tuned to the simulcast frequency to the VCR's audio input in order to record the stereo sound of a TV program that would otherwise be recorded in mono. The function was primarily necessary with stereo VCRs that didn't have a stereo TV tuner or were operated in areas where stereo TV broadcasting wasn't in place. This was typically selected through the user setting the input selector to "Simulcast" or "Radio" mode or, in the case of some JVC units, the user setting another "audio input" switch from "TV" or "Tuner" to "Line".