 | This article includes a list of general references, but it lacks sufficient corresponding inline citations. (January 2024) |
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.
Until 1948, Land Mobile Radio and television broadcasters shared the same frequencies, 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.