and W2XCR television aired their regular broadcasting debut in New York City on April 26, 1931, with a special demonstration set up in Aeolian Hall at Fifth Avenue and Fifty-fourth Street. Thousands waited to catch a glimpse of the Broadway stars who appeared on the six-inch (15 cm) square image, in an evening event to publicize a weekday programming schedule offering films and live entertainers during the four-hour daily broadcasts. Appearing were boxer Primo Carnera, actors Gertrude Lawrence, Louis Calhern, Frances Upton and Lionel Atwill, WHN announcer Nils Granlund, the Forman Sisters, and a host of others. CBS's New York City station W2XAB began broadcasting their first regular seven-day-a-week television schedule on July 21, 1931, with a 60-line electromechanical system. The first broadcast included Mayor Jimmy Walker, the Boswell Sisters, Kate Smith, and George Gershwin. The service ended in February 1933. Don Lee Broadcasting's station W6XAO in Los Angeles went on the air in December 1931. Using the UHF spectrum, it broadcast a regular schedule of filmed images every day except Sundays and holidays for several years. By 1935, low-definition electromechanical television broadcasting had ceased in the United States except for a handful of stations run by public universities that continued to 1939. The Federal Communications Commission (FCC) saw television in the continual flux of development with no consistent technical standards, hence all such stations in the U.S. were granted only experimental and non-commercial licenses, hampering television's economic development. Just as importantly, Philo Farnsworth's August 1934 demonstration of an all-electronic system at the Franklin Institute in Philadelphia pointed out the direction of television's future. On June 15, 1936, Don Lee Broadcasting began a one-month-long demonstration of high definition (240+ line) television in Los Angeles on W6XAO (later KTSL, now KCBS-TV) with a 300-line image from motion picture film. By October, W6XAO was making daily television broadcasts of films. By 1934 RCA increased the definition to 343 interlaced lines and the frame rate to 30 per second. On July 7, 1936, RCA and its subsidiary NBC demonstrated in New York City a 343-line electronic television broadcast with live and film segments to its licensees, and made its first public demonstration to the press on November 6. Irregularly scheduled broadcasts continued through 1937 and 1938. Regularly scheduled electronic broadcasts began in April 1938 in New York (to the second week of June, and resuming in August) and Los Angeles. NBC officially began