AT&T laid the first L-carrier coaxial cable between New York City and Philadelphia, with automatic signal booster stations every , and in 1937 it experimented with transmitting televised motion pictures over the line. Bell Labs gave demonstrations of the New York–Philadelphia television link in 1940 and 1941. AT&T used the coaxial link to transmit the Republican National Convention in June 1940 from Philadelphia to New York City, where it was televised to a few hundred receivers over the NBC station W2XBS (which evolved into WNBC) as well as seen in Schenectady, New York via W2XB (which evolved into WRGB) via off-air relay from the New York station.