North American broadcast television frequencies: Wikis

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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 lies the FM broadcast band (band II) used for frequency-modulated radio transmissions and a VHF radio band typically used by civil service agencies, amateur radio and aircraft (often called the 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. WRGB attempted to keep this even after putting its digital signal on 6, but it caused destructive interference with the ATSC DTV signal, despite having opposite radio antenna polarizations. The lower sideband of HD Radio signals on 88.1 also overlap slightly from 87.9 to 88.0.

The FM audio carrier is always 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 FCC banned these from using the 700MHz band in the U.S., effective June 12.

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.A., 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 56 to 59 (14 being seen on 65). ATV is also used on the other amateur bands above 450 MHz.

VHF original bands (historical)

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
2 66 67.25 71.75 72 TV ch. 4
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

VHF bands

VHF low-band (band I)
(Current channel assignments)
 Channel   Lower edge   Video carrier   ATSC carrier   Audio carrier   Upper edge 
1* 44 45.25 n/a 49.75 50
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 
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
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
700MHz band (until June 2009 US only, Canada & Mexico: no change)
 Channel   Lower edge   Video carrier   ATSC carrier   Audio carrier   Upper edge 
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
800MHz band (until 1980s)
 Channel   Lower edge   Video carrier   ATSC carrier   Audio carrier   Upper edge 
70 806 807.25 - 811.75 812
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
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).

See also

  • TV stations in the United States:

External links

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