In North American broadcast television frequencies, channel 1 was a former broadcast (over-the-air) television channel which was removed from service in 1948. During the experimental era of TV operation, Channel 1 was moved around the lower VHF spectrum repeatedly, with the entire band displaced upward at one point due to an early 40 MHz allocation for the FM broadcast band. After FM was moved to its current frequencies in 1946, TV Channel 1's last assigned band was 44 to 50 MHz. This allocation was short-lived. Land Mobile Radio and television broadcasters shared the same frequencies until 1948, which caused interference. This shared allocation was eventually found to be unworkable, so the FCC reallocated the Channel 1 frequencies for public safety and land mobile use and assigned TV channels 2–13 exclusively to broadcasters. Aside from the shared frequency issue, this part of the VHF band was (and to some extent still is) prone to higher levels of radio-frequency interference (RFI) than even Channel 2 (System M). As Mexico signed on its first station in 1950 and Canada's first station went on-air in 1952, the historical Channel 1 (System M) is exclusively a U.S. allocation artifact. History Channel 1 was allocated at 44–50 MHz between 1937 and 1940. Visual and aural carrier frequencies within the channel fluctuated with changes in overall TV broadcast standards prior to the establishment of permanent standards by the National Television Systems Committee. In 1940, the FCC reassigned 42–50 MHz to the FM broadcast band. Television's channel 1 frequency range was moved to 50–56 MHz (see table below). Experimental television stations in New York, Chicago, and Los Angeles were affected.<ref>"Threat to Television Is Feared in Frequency Modulation Order", New York Times, May 21, 1940, p. 23. "Gives Du Mont Right to Television Here", New York Times, July 21, 1940, p. 28.</ref> Commercial TV allocations were made by the Federal Communications Commission (FCC) under the NTSC system on July 1, 1941. Channel 1 was located at 50–56 MHz, with visual carrier at 51.25 MHz and aural carrier at 55.75 MHz. At the same time, the spectrum from 42 to 50 MHz was allocated to FM radio. Several commercial and experimental television stations operated on the 50–56 MHz Channel 1 between 1941 and 1946, including one station, WNBT (now WNBC, channel 4) in New York City, which had a full commercial operating license. In the first postwar allocation in the