Another size and format was that of radio transcription discs beginning in the 1940s. These records were usually vinyl, 33 rpm, and 16 inches in diameter. No home record player could accommodate such large records, and they were used mainly by radio stations. They were on average 15 minutes per side and contained several songs or radio program material. These records became less common in the United States when tape recorders began being used for radio transcriptions around 1949. In the UK, analog discs continued to be the preferred medium for the licence of BBC transcriptions to overseas broadcasters until the use of CDs became a practical alternative.