Channel 37
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In the Americas, TV channel 37 occupies a band of UHF frequencies from 608 to 614 MHz. In the United States and Canada, channel 37 has never been used by any over-the-air television station, as it was reserved in 1963 for radioastronomy. The FCC ban on such stations took effect at the beginning of 1974, though it is unclear which stations (if any) were already assigned to use 37.
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[edit] Allocation issues
Reservations non-exclusive
- The Canadian CRTC also enacted such a ban on channel 37.
- It appears that Mexico may also observe a similar ban on the use of this TV channel, if only informally.
- Most NTSC System-M countries in the Carribean have an informal ban on channel 37 as well.
Since July 2000, channel 37 may also be used in the U.S. for medical telemetry equipment on a co-primary basis. This equipment must emit no more than one watt of effective radiated power, and is for use in hospitals and other such facilities.
- The power level permitted by the FCC is many times more than the amount allowed for Part 15 unlicensed broadcasting.
This seemingly low power level can be troublesome for radioastronomy, because it depends on detecting extraordinarily low signal strengths. Any use of the same frequencies raises the noise floor, thereby decreasing the signal-to-noise ratio, and making the work more difficult.
Channel 1 was also removed from the TV bandplan in the late 1940s, channels 70 to 83 by the 1980s mainly for AMPS mobile phones, and soon 52 to 69 for emergency services and mobile TV. Certain of channels 14 through 20 are used for landmobile communications in some large metro areas in the U.S.
[edit] In popular culture
Channel 37 is sometimes seen in fiction, the same way phone numbers with the "555" telephone exchange prefix are used.
[edit] Outside the Americas
Outside North America, channel 37 is active: in the Philippines (UNTV Channel 37); in the UK (many transmitters used by the Five network actually broadcast on channel 37); and in France and Ireland, among other countries. However, frequency allocation for TV channels is different in these countries, and channel 37 is not the same frequency as it is in the Americas (ITU region II).
[edit] External links
- TV Technology: "The Last Empty Channel"
- A short article on channel 37 and channels above 69, which were supposed to have been phased out in the 1970s: [1]
