The Pan-American television frequencies are different for terrestrial and cable television systems. Terrestrial television channels are divided into two bands: the VHF band which comprises channels 2 through 13 and occupies frequencies between 54 and 216 MHz, and the UHF band, which comprises channels 14 through 36 and occupies frequencies between 470 and 608 MHz. These bands are different enough in frequency that they often require separate antennas to receive (although many antennas cover both VHF and UHF), and separate tuning controls on the television set. The VHF band is further divided into two frequency ranges: VHF low band (Band I) between 54 and 88 MHz, containing channels 2 through 6, and VHF high band (Band III) between 174 and 216 MHz, containing channels 7 through 13. The wide spacing between these frequency bands is responsible for the complicated design of rooftop TV antennas. The UHF band has higher noise and greater attenuation, so higher gain antennas are often required for UHF.
Terrestrial television
History
The VHF band plan was modified several times before 1948. The last of these changes was the deletion of channel 1, originally intended as a community channel. This allocation of the spectrum was given to two-way land-mobile radio.
UHF channels 70–83 in the United States were reallocated in 1983.
In March 2008, the FCC requested public comment on turning the bandwidth currently occupied by analog television channels 5 and 6 (76–88 MHz) over to extending the FM terrestrial band when the DTT transition was to be completed in February 2009 (ultimately delayed to June 2009). , This proposed allocation would effectively assign frequencies corresponding to the existing Japanese FM radio service (which begins at 76 MHz) for use as an extension to the existing North American FM broadcast band.Could EXB Band Be Your New Home? RadioWorld September 10, 2008
700 MHz band The UHF 700 MHz band comprised the spectrum of UHF channels 52 through 69. Channels 52–69 are no longer available for normal, high-power digital terrestrial television broadcasting in the United States, but some channels are available for use as low-power or translator stations. Wireless microphones and medical telemetry devices shared some of the space on this television band, if transmitting at a very low power. After the migration to digital terrestrial television in 2009, the Federal Communications Commission (FCC) banned all of these from using the 700 MHz band, effective June 12, 2010. The 700 MHz band is now used for public safety communications and wireless broadband providers.
600 MHz band In 2017 the FCC auctioned off all remaining UHF spectrum including and above UHF channel 38. This required the reconfiguration of channel allotment (known in the terrestrial television industry as the channel "repack"), allowing for higher gain small antennas to cover a smaller frequency range. In April 2017 it was decided that channels 38 to 51 would be deleted, but channel 37 remains reserved. Channel repacking proceeded in 10 phases from September 2018 through July 2020.
Channel frequencies
VHF band + VHF low-band (band I) (frequencies in MHz) Channel Lower edge Video carrier ATSC pilot Audio carrier Upper edge 1 44 45.25 44.31 49.75 50 (Gap in band plan used by amateur radio 6-meter band) 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 (Gap in band plan used by aeronautical navigation) 5 76 77.25 76.31 81.75 82 6 82 83.25 82.31 87.75 88
+ VHF high-band (band III) (frequencies in MHz) Channel Lower edge Video carrier ATSC pilot 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 The following table lists terrestrial television channels in the ultra high frequency band as they were allocated in their modern form by the Federal Communications Commission on April 11, 1952. The original allocation included 70 UHF channels (14–83) with 6 MHz separation. In the decades since, many of the channels have been de-allocated and reserved for other purposes. Channels 14–36 are usable UHF channels in the United States after the most recent change was completed in 2020. Formerly allocated channels are indicated with a colored background, and their dispositions are explained in the notes below the table. + UHF band (frequencies in MHz) Channel Lower edge Video carrier ATSC pilot Audio carrier Upper edge 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 37 608 609.25 608.31 613.75 614 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 52 698 699.25 698.31 703.75 704 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 70 806 807.25 806.31 811.75 812 71 812 813.25 812.31 817.75 818 72 818 819.25 818.31 823.75 824 73 824 825.25 824.31 829.75 830 74 830 831.25 830.31 835.75 836 75 836 837.25 836.31 841.75 842 76 842 843.25 842.31 847.75 848 77 848 849.25 848.31 853.75 854 78 854 855.25 854.31 859.75 860 79 860 861.25 860.31 865.75 866 80 866 867.25 866.31 871.75 872 81 872 873.25 872.31 877.75 878 82 878 879.25 878.31 883.75 884 83 884 885.25 884.31 889.75 890
Notes Channel 1 (shaded violet above) was removed for the land mobile service. One San Francisco station, KAXT-CD, was assigned Channel 1 as a virtual channel in 2017, but broadcasts on UHF channel 22. Similarly, in Mexico, since October 25, 2016, all Azteca Uno stations are assigned virtual channel 1.1. Channel 37 (shaded pink above) is reserved for radio astronomy in the United States, Canada, Bermuda and the Bahamas; thus there are no television stations assigned to it. Mexico, Colombia, Chile, Peru, Brazil and Argentina informally observe a ban on transmitters using the channel. One New York City station, WNWT-LD, was assigned Channel 37 as a virtual channel in 2019, but broadcasts on VHF channel 3. Channels 38 through 51 (the 600 MHz band, shaded yellow above) have been displaced in the US by the Broadcast incentive auction. On August 22, 2011, the United States' Federal Communications Commission announced a freeze on all future applications for broadcast stations requesting to use channel 51,FCC Public Notice DA-11-1428A1:
Rcd PDF (deadlink) Microsoft Word document (deadlink) PDF format (deadlink) Plain Text format (deadlink) to prevent adjacent-channel interference to the A-Block of the 700 MHz band. Later that year (on December 16, 2011), Industry Canada and the CRTC followed suit in placing a moratorium on future television stations using channel 51 for broadcast use for the same reason. Channels 52 through 69 (the 700 MHz band, shaded brown above) in the United States have been reallocated following the conversion to digital TV on June 12, 2009, although some low-power and translator stations may still be in use on these channels. The frequencies used by UHF channels 70 through 83 (shaded blue above) were reallocated to the Land Mobile Radio System (Public Safety and Trunked Radio) and mobile phones in a CCIR worldwide convention in 1983. With the advent of digital television in 2009, stations are allowed to identify themselves by a virtual channel that may not necessarily be the same as the station's RF channel. Virtual channels 1, 37, and 70 to 99 can be assigned via PSIP even though there is no corresponding physical station on that RF 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 83 translate to rarely used cable TV channels 100 to 139 (add 56). Cable-ready channels 6, 95, 96, and 97 have audio carriers which overlap FM radio stations (87.7, 95.7, 101.7 and 107.7). Cable-ready channels 57 to 61 overlap the 70cm amateur radio band and can be used for amateur television. Cable-ready channel 64 is within the Family Radio Service and General Mobile Radio Service (GMRS) band.
Historical band plans + VHF low-band (bands 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 / FM 44 45.25 49.75 50 Experimental (TV ch. 1) 2 / 1 50 51.25 55.75 56 Amateur band, TV ch. 2 (Break in band plan) * / 2 60 61.25 65.75 66 TV ch. 3 3 66 67.25 71.75 72 TV ch. 4 (Break in band plan) 4 78 79.25 83.75 84 TV ch. 5, TV ch. 6, 5 84 85.25 89.75 90 TV ch. 6, non-commercial educational FM radio (Break in band plan) 6 96 97.25 101.75 102 FM broadcasting 7 102 103.25 107.75 108 The band 44–56 MHz was modified in May of 1940; before, it was assigned to TV channels 1 and 2; after the modification, it was assigned to FM broadcasting and TV channel 1.
+ 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) (Break in band plan) 9 180 181.25 185.75 186 TV ch. 8 10 186 187.25 191.75 192 TV ch. 9 (Break in band plan) 11 204 205.25 209.75 210 TV ch. 12 12 210 211.25 215.75 216 TV ch. 13 (Break in band plan) 13 234 235.25 239.75 240 Military 14 240 241.25 245.75 246 (Break in band plan) 15 258 259.25 263.75 264 Military 16 264 265.25 269.75 270 (Break in band plan) 17 282 283.25 287.75 288 Military 18 288 289.25 293.75 294
Cable television
Harmonically-related carriers (HRC) Harmonically-related carriers (HRC) is a system for assigning television channel numbers to bands of frequencies over a cable television network. William Grant, in his book,Cable Television, 2nd edition, GWG Associates, Schoharie, NY, 1988, page 82 states: "By harmonically relating the carrier frequencies themselves it is … possible to improve system performance. This does not reduce the beats produced, but positions them within the system transmission spectrum, such that they are more tolerable. In effect, all signal carriers are spaced precisely at 6 MHz apart, and thus, all beats generated are at 6 MHz increments.
Since the television signals are vestigial sideband modulation, if the beat products can be manipulated to fall on or near the Radio frequency carriers themselves, they are much less offensive."
Incrementally-related carriers (IRC)