- North American broadcast television frequencies
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The North American broadcast television frequencies are on designated television channels numbered 2 through 69, approximately between 54 and 806 MHz. Traditionally, the frequencies are divided into two sections, the very high frequency (VHF) band and the ultra high frequency (UHF) band. The VHF band is further subdivided into two more sections, VHF-Lo (band I) and VHF-Hi (band III). In between lie allocations for other services including the FM broadcast band (band II), bands used for land mobile radio, radio remote control, civil service agencies, amateur radio, and aircraft navigation aids and voice communication (airband).
Contents
On many FM radios, the audio for channel 6 can often be picked-up by turning the tuner dial below the lower FM band edge, at 87.75. The volume is low as the frequency deviation for TV audio is only ±25 kHz, versus ±75 kHz for FM broadcasting. The lower sideband of HD Radio signals on 88.1 also overlap slightly from 87.9 to 88.0.
The FM audio carrier is 4.5 MHz above the VSB video carrier, and the total channel bandwidth is 6 MHz. The video carrier is nominally 1.25 MHz above the lower channel edge. In some cases, analog TV stations are assigned carrier frequency offsets of +10 or −10 kHz to minimize RF interference with distant stations on the same channel (see NTSC for more details). Positive-offset station will therefore end in .26, while negative-offset stations will end in .24, and are usually denoted with a plus or minus sign immediately after the number (such as 8+ or 37−). While offsets are rare in digital TV, positive-offset stations end in .3380556, while non-offset stations end in .30944056 (rounded to .31).
Analog stations must be separated by at least one unused channel except for non-adjacent channel pairs 4 and 5, 6 and 7, and 13 and 14.
Wireless microphones and medical telemetry devices already share some of the TV bands, but transmit at a very low power. In early 2010 the Federal Communications Commission (FCC) banned these from using the 700 MHz band in the U.S., effective June 12.[citation needed]
Changes and variations
Channel 1 was removed early on as a community television reservation and given to amateur radio and other uses. Channels 70 through 83 were removed from the bandplan in the 1980s to make way for AMPS mobile phone service. These channels were mainly used in the U.S., and mainly for broadcast translators, some of which continued in operation if their frequencies were not used by cellular. Channel 37 is allocated to radio astronomy and may not be used by any station.
In the U.S., channels 52 through 69 are being reallocated for other purposes as the transition to digital television broadcasting is completed for low-power TV stations. All full-power analog broadcasts ended in June 2009, and all temporary full-power digital broadcasts moved back down to the lower channels. While most other countries abandoned VHF due to its poor suitability for TV broadcasting and allocation for Digital Audio Broadcasting, the FCC chose to cut high-UHF channels instead, because frequency-use rights could be auctioned for a greater price.[citation needed]
Channels 14 through 19 are used for two-way radio in major cities on a non-interference basis, although the transition to digital television (DTV) has caused problems in certain instances when a previously unused channel has begun to be used for DTV broadcasts. The same holds true for wireless microphones and medical telemetry devices in that band.
In most regions, new digital television stations are placed on UHF (14 to 51, except 37 and sometimes 14 and 20) or high-VHF channels (7-13), although others are used in some of the more crowded media markets. With virtual channel numbering, many digital televisions group digital channels with their corresponding analog broadcasts. For example, the first digital TV stream of a station that broadcasts analog TV on channel 4 will usually appear as 4-1 or 4.1 on a DTV receiver, even though the digital transmissions may be on channel 38. Several digital subchannels can be multiplexed together, so 4-1 through 4-5 might be used by one station. Subchannel 0 (e.g., 4-0) designates the analog broadcast. In the U.S., all channels from 7-36 and 38-51 are frequently used for digital TV broadcasts. However, VHF 2 to 6 are rarely used by DTV broadcasters due to ongoing problems with impulse noise, and channel 6 being an adjacent channel to the FM broadcast band. Additionally, VHF performance is poor for mobile TV, with ATSC-M/H being the standard finalized and approved in late 2009.
The VHF bandplan was modified several times before 1948. The last change was the transfer of channel 1, originally intended as a low-power (less than 1,000 watts) LPTV community channel, to two-way land-mobile radio and the six-meter amateur radio band. [1] Amateur television (ATV) is used on four channels in the 420-450 MHz (70-centimeter) amateur band; UHF TV channel 14 starts at 470 MHz. These ATV channels are popular for repeater output and direct communications and are seen over-the-air with a cable-ready tuner set to channels 57 to 60 (14 being seen on 65). ATV is also used on the other amateur bands above 450 MHz. ATV is also known as HAM TV or Fast Scan TV.
VHF bands
VHF low-band (band I) Channel Lower edge Video carrier ATSC carrier Audio carrier Upper edge 2 54 55.25 54.31 59.75 60 3 60 61.25 60.31 65.75 66 4 66 67.25 66.31 71.75 72 5 76 77.25 76.31 81.75 82 6 82 83.25 82.31 87.75 88 Note the upper edge of analog TV 6 slightly overlaps FM channel 200, 87.9 MHz. That FM frequency is used by KSFH, various low power pirate stations, and broadcast translator station K200AA (the only USA repeater licensed to use that frequency).
Analog TV 6 audio can be heard on 87.7 or 87.8, but with lower sound volume and therefore fidelity due to differences in the FM specifications between TV and FM radio. Some low-power analog TV stations (see here) operate on TV 6 with the intent of being heard on FM radio at 87.7 MHz.VHF high-band (band III) Channel Lower edge Video carrier ATSC carrier Audio carrier Upper edge 7 174 175.25 174.31 179.75 180 8 180 181.25 180.31 185.75 186 9 186 187.25 186.31 191.75 192 10 192 193.25 192.31 197.75 198 11 198 199.25 198.31 203.75 204 12 204 205.25 204.31 209.75 210 13 210 211.25 210.31 215.75 216 UHF band
UHF band Channel Lower edge Video carrier ATSC carrier Audio carrier Upper edge Notes 14 470 471.25 470.31 475.75 476 15 476 477.25 476.31 481.75 482 16 482 483.25 482.31 487.75 488 17 488 489.25 488.31 493.75 494 18 494 495.25 494.31 499.75 500 19 500 501.25 500.31 505.75 506 20 506 507.25 506.31 511.75 512 21 512 513.25 512.31 517.75 518 22 518 519.25 518.31 523.75 524 23 524 525.25 524.31 529.75 530 24 530 531.25 530.31 535.75 536 25 536 537.25 536.31 541.75 542 26 542 543.25 542.31 547.75 548 27 548 549.25 548.31 553.75 554 28 554 555.25 554.31 559.75 560 29 560 561.25 560.31 565.75 566 30 566 567.25 566.31 571.75 572 31 572 573.25 572.31 577.75 578 32 578 579.25 578.31 583.75 584 33 584 585.25 584.31 589.75 590 34 590 591.25 590.31 595.75 596 35 596 597.25 596.31 601.75 602 36 602 603.25 602.31 607.75 608 37 608 609.25 - 613.75 614 Channel 37 is reserved for radio astronomy in the United States, Canada, Bermuda and the Bahamas, thus there are no television stations assigned to it in these countries. 38 614 615.25 614.31 619.75 620 39 620 621.25 620.31 625.75 626 40 626 627.25 626.31 631.75 632 41 632 633.25 632.31 637.75 638 42 638 639.25 638.31 643.75 644 43 644 645.25 644.31 649.75 650 44 650 651.25 650.31 655.75 656 45 656 657.25 656.31 661.75 662 46 662 663.25 662.31 667.75 668 47 668 669.25 668.31 673.75 674 48 674 675.25 674.31 679.75 680 49 680 681.25 680.31 685.75 686 50 686 687.25 686.31 691.75 692 51 692 693.25 692.31 697.75 698 Channel Lower edge Video carrier ATSC carrier Audio carrier Upper edge 52 698 699.25 698.31 703.75 704 In the USA, these channels have been reallocated to Part 90 Land Mobile Radio Service. 53 704 705.25 704.31 709.75 710 54 710 711.25 710.31 715.75 716 55 716 717.25 716.31 721.75 722 56 722 723.25 722.31 727.75 728 57 728 729.25 728.31 733.75 734 58 734 735.25 734.31 739.75 740 59 740 741.25 740.31 745.75 746 60 746 747.25 746.31 751.75 752 61 752 753.25 752.31 757.75 758 62 758 759.25 758.31 763.75 764 63 764 765.25 764.31 769.75 770 64 770 771.25 770.31 775.75 776 65 776 777.25 776.31 781.75 782 66 782 783.25 782.31 787.75 788 67 788 789.25 788.31 793.75 794 68 794 795.25 794.31 799.75 800 69 800 801.25 800.31 805.75 806 Channel Lower edge Video carrier ATSC carrier Audio carrier Upper edge 70 806 807.25 - 811.75 812 Reallocated to Land Mobile Radio Service and Cellular Mobile Radio Service in 1982. 71 812 813.25 - 817.75 818 72 818 819.25 - 823.75 824 73 824 825.25 - 829.75 830 74 830 831.25 - 835.75 836 75 836 837.25 - 841.75 842 76 842 843.25 - 847.75 848 77 848 849.25 - 853.75 854 78 854 855.25 - 859.75 860 79 860 861.25 - 865.75 866 80 866 867.25 - 871.75 872 81 872 873.25 - 877.75 878 82 878 879.25 - 883.75 884 83 884 885.25 - 889.75 890 Notes
- Virtual channels 1, 37, and 70 to 99 can be assigned via PSIP even though there is no corresponding physical station on that channel.
- Cable television frequency issues
- UHF channels 14 to 43 translate to common cable-ready channels 65 to 94 (add 51).
- UHF channels 44 to 69 translate to rarely-used cable TV channels 100 to 125 (add 56).
Historical band plans
VHF low-band (band I & II)
1940 U.S. channel assignments (partly deprecated)
(frequencies in MHz)Channel Lower edge Video carrier Audio carrier Upper edge Current U.S. use 1 50 51.25 55.75 56 Amateur band, TV ch. 2 (deprecated) 2 66 67.25 71.75 72 TV ch. 4 (deprecated) 3 72 73.25 77.75 78 Radio-controlled car/plane hobby, TV ch. 5 4 78 79.25 83.75 84 TV ch. 5 5 84 85.25 89.75 90 TV ch. 6, FM radio 6 96 97.25 101.75 102 FM radio 7 102 103.25 107.75 108 FM radio VHF high-band (band III)
1940 U.S. channel assignments (partly deprecated)
(frequencies in MHz)Channel Lower edge Video carrier Audio carrier Upper edge Current U.S. use 8 162 163.25 167.75 168 NOAA Weather Radio (162) 9 180 181.25 185.75 186 TV ch. 8 10 186 187.25 191.75 192 TV ch. 9 11 204 205.25 209.75 210 TV ch. 12 12 210 211.25 215.75 216 TV ch. 13 13 234 235.25 239.75 240 military 14 240 241.25 245.75 246 military 15 258 259.25 263.75 264 military 16 264 265.25 269.75 270 military 17 282 283.25 287.75 288 military 18 288 289.25 293.75 294 military See also
- TV stations in the United States:
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- Channel 2
- Channel 3
- Channel 4
- Channel 5
- Channel 6
- Channel 7
- Channel 8
- Channel 9
- Channel 10
- Channel 11
- Channel 12
- Channel 13
External links
- What ever happened to Channel 1? - J. W. Reiser, based on a Radio-Electronics article of the same name by David A. Ferre.
- Post-transition U.S. digital TV channel assignments as of 1 August 2007
- U.S. cable television channel frequencies
- TVTower.com - Commercial Television Frequencies
Categories:- Bandplans
- North America
- Lists of television channels by region
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