Cable radio or cable FM is a concept similar to that of cable television, bringing radio broadcasting into homes and businesses via coaxial cable. It is generally used for the same reason as cable TV was in its early days when it was "community antenna television", in order to enhance the quality of over-the-air radio signals that are difficult to receive in an area. However, cable-only radio outlets also exist. The use of cable radio varies from area to area - some cable TV systems don't include it at all, and others only have something approaching it on digital cable systems. Additionally, some stations may just transmit audio in the background while a public-access television cable TV channel is operating in between periods of video programming. From the late 1970s to the late 1980s, before the advent of MTS Stereo television broadcasts, an additional cable decoder was offered to cable TV subscribers, which was connected to the FM antenna terminal of a radio receiver and broadcast audio simulcasts of television broadcasts on certain frequencies, but separately transmitted in FM stereo, along with traditional local radio stations at their specific frequencies, utilizing the cable system's own taller receiving antenna for maximum audio clarity. For instance, MTV's audio would be offered on a cable radio frequency, thus the video being played in monaural sound on cable would have its television audio muted, and the stereo audio instead heard through the radio receiver. A related secondary meaning of the term is any automated music stream - the usual format of cable-only "stations". United States The first "commercial" cable radio station in the United States was CABL-FM 108 in California, on the Theta Cablevision system, serving West Los Angeles and surrounding areas. It went live on January 1, 1972, and was run by Brad Sobel, playing what he called "progressive top 40". CABL-FM 108 came into being after Sobel's original venture, K-POT, a bootleg FM station at 88.1 MHz, was silenced by the Federal Communications Commission (FCC) in November 1971. The illicit station ran for three days until it was shut down, and the event made the front page of the Los Angeles Times and the Los Angeles Herald-Examiner. Because Theta Cablevision charged extra for its FM hookups, CABL-FM 108's potential audience was between 4,700 and approximately 25,000 (based on information provided by Brad Sobel in an article in Billboard), out of Cablevision's approximately