Empire State Building
Broadcast stations

Broadcasting began at the Empire State Building on December 22, 1931, when NBC and RCA began transmitting experimental television broadcasts from a small antenna erected atop the mast, with two separate transmitters for the visual and audio data. They leased the 85th floor and built a laboratory there. In 1934, RCA was joined by Edwin Howard Armstrong in a cooperative venture to test his FM system from the building's antenna. This setup, which entailed the installation of the world's first FM transmitter, continued only until October of the next year due to disputes between RCA and Armstrong. Specifically, NBC wanted to install more TV equipment in the room where Armstrong's transmitter was located.

After some time, the 85th floor became home to RCA's New York television operations initially as experimental station W2XBS channel 1 then, from 1941, as commercial station WNBT channel 1 (now WNBC channel 4). NBC's FM station, W2XDG, began transmitting from the antenna in 1940. NBC retained exclusive use of the top of the building until 1950 when the Federal Communications Commission (FCC) ordered the exclusive deal be terminated. The FCC directive was based on consumer complaints that a common location was necessary for the seven extant New York-area television stations to transmit from so that receiving antennas would not have to be constantly adjusted. Other television broadcasters would later join RCA at the building on the 81st through 83rd floors, often along with sister FM stations. Construction of a dedicated broadcast tower began on July 27, 1950, with TV, and FM, transmissions starting in 1951. The 200-foot (61 m) broadcast tower was completed in 1953. From 1951, six broadcasters agreed to pay a combined $600,000 per year for the use of the antenna. In 1965, a separate set of FM antennae was constructed ringing the 103rd floor observation area to act as a master antenna.

The placement of the stations in the Empire State Building became a major issue with the construction of the World Trade Center's Twin Towers in the late 1960s, and early 1970s. The greater height of the Twin Towers would reflect radio waves broadcast from the Empire State Building, eventually resulting in some broadcasters relocating to the newer towers instead of suing the developer, the Port Authority of New York and New Jersey. Even though the nine stations who were broadcasting from the Empire State Building were leasing their broadcast space until 1984, most of these stations moved to the World Trade Center as soon as it was completed in 1971. The broadcasters obtained a court order stipulating that the Port Authority had to build a mast and transmission equipment in the North Tower, as well as pay the broadcasters' leases in the Empire State Building until 1984. Only a few broadcasters renewed their leases in the Empire State Building.

The September 11 attacks destroyed the World Trade Center and the broadcast centers atop it, leaving most of the city's stations without a transmitter for ten days until the Armstrong Tower in Alpine, New Jersey, was re-activated temporarily. By October 2001, nearly all of the city's commercial broadcast stations (both television and FM radio) were again transmitting from the top of the Empire State Building. In a report that Congress commissioned about the transition from analog television to digital television, it was stated that the placement of broadcast stations in the Empire State Building was considered "problematic" due to interference from nearby buildings. In comparison, the congressional report stated that the former Twin Towers had very few buildings of comparable height nearby thus signals suffered little interference. In 2003, a few FM stations were relocated to the nearby Condé Nast Building to reduce the number of broadcast stations using the Empire State Building. Eleven television stations and twenty-two FM stations had signed 15-year leases in the building by May 2003. It was expected that a taller broadcast tower in Bayonne, New Jersey, or Governors Island, would be built in the meantime with the Empire State Building being used as a "backup" since signal transmissions from the building were generally of poorer quality. Following the construction of One World Trade Center in the late 2000s and early 2010s, some TV stations began moving their transmitting facilities there.

As of 2021, the Empire State Building is home to the following stations:
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