Editing Citizens band radio (section)

==Frequency allocations==
CB radio is not a worldwide, standardized radio service. Each country decides if it wants to authorize such a radio service from its domestic frequency authorizations, and what its standards will be; however, similar radio services exist in many countries. Frequencies, power levels and modes (such as [[frequency modulation]] (FM), [[amplitude modulation]] (AM), and [[single-sideband modulation]] (SSB), often vary from country to country; use of foreign equipment may be illegal. However, many countries have adopted the American channels and their associated frequencies, which is generally in AM mode except some higher channels which are sometimes in SSB mode. In September 2021 the FCC approved the use of FM on CB radio.<ref>{{cite web |title=Citizens Band (CB) Scanner Frequencies and Radio Frequency Reference |url=http://www.radioreference.com/apps/db/?aid=7731 |website=radioreference.com |access-date=2015-10-08 |df=dmy-all |url-status=live |archive-url=https://web.archive.org/web/20150914173859/http://www.radioreference.com/apps/db/?aid=7731 |archive-date=2015-09-14}}</ref>

=== Standard channels ===
The standard channel numbering is harmonized through the [[Federal Communications Commission|FCC]] ([[United States|USA]]) and the [[European Conference of Postal and Telecommunications Administrations|CEPT]] ([[Europe]]).{{efn|Channels 23&nbsp;[27.235&nbsp;MHz], 24&nbsp;[27.245&nbsp;MHz], and 25&nbsp;[27.255&nbsp;MHz] are not on the same radio frequencies in the [[European Conference of Postal and Telecommunications Administrations|CEPT]] standard.}}<ref name="legifrance.gouv.fr">{{cite web |url=http://www.legifrance.gouv.fr/affichTexte.do?cidTexte=JORFTEXT000000325971&categorieLien=cid |title=Arrêté du 31 mars 1992 relatif aux caractéristiques techniques et aux conditions d'exploitation des postes C.B. |website=legifrance.gouv.fr |access-date=8 May 2018 |url-status=live |archive-date=1 July 2017 |archive-url=https://web.archive.org/web/20170701032657/https://www.legifrance.gouv.fr/affichTexte.do?cidTexte=JORFTEXT000000325971&categorieLien=cid}}</ref>

See also [[CB usage in the United States#Channel assignments|channel assignments for CB use in the United States]].
{| class="wikitable" align="center" text-align="right"
|+ CB Radio Channels ([[Federal Communications Commission|FCC]])<ref name="95.407">{{cite web |url=http://frwebgate.access.gpo.gov/cgi-bin/get-cfr.cgi?TITLE=47&PART=95&SECTION=407&YEAR=2000&TYPE=TEXT |title=(CB Rule&nbsp;7) On what channels may I operate? |website=frwebgate.access.gpo.gov |access-date=8 May 2018 |url-status=live |archive-url=https://web.archive.org/web/20090214183927/http://frwebgate.access.gpo.gov/cgi-bin/get-cfr.cgi?TITLE=47&PART=95&SECTION=407&YEAR=2000&TYPE=TEXT |archive-date=14 February 2009}}</ref>
|- style="text-align:right"
! Ch.
! Frequency
!
! Ch.
! Frequency
!
! Ch.
! Frequency
!
! Ch.
! Frequency
!
! Ch.
! Frequency
|- style="text-align:right"
| 1
| 26.965&nbsp;MHz
|
| 9
| 27.065&nbsp;MHz
|
| 17
| 27.165&nbsp;MHz
|
| *25
| 27.245&nbsp;MHz
|
| 33
| 27.335&nbsp;MHz
|- style="text-align:right"
| 2
| 26.975&nbsp;MHz
|
| 10
| 27.075&nbsp;MHz
|
| 18
| 27.175&nbsp;MHz
|
| 26
| 27.265&nbsp;MHz
|
| 34
| 27.345&nbsp;MHz
|- style="text-align:right"
| *3
| 26.985&nbsp;MHz
|
| *11
| 27.085&nbsp;MHz
|
| *19
| 27.185&nbsp;MHz
|
| 27
| 27.275&nbsp;MHz
|
| 35
| 27.355&nbsp;MHz
|- style="text-align:right"
| 4
| 27.005&nbsp;MHz
|
| 12
| 27.105&nbsp;MHz
|
| 20
| 27.205&nbsp;MHz
|
| 28
| 27.285&nbsp;MHz
|
| 36
| 27.365&nbsp;MHz
|- style="text-align:right"
| 5
| 27.015&nbsp;MHz
|
| 13
| 27.115&nbsp;MHz
|
| 21
| 27.215&nbsp;MHz
|
| 29
| 27.295&nbsp;MHz
|
| 37
| 27.375&nbsp;MHz
|- style="text-align:right"
| 6
| 27.025&nbsp;MHz
|
| 14
| 27.125&nbsp;MHz
|
| 22
| 27.225&nbsp;MHz
|
| 30
| 27.305&nbsp;MHz
|
| 38
| 27.385&nbsp;MHz
|- style="text-align:right"
| *7
| 27.035&nbsp;MHz
|
| *15
| 27.135&nbsp;MHz
|
| *23
| 27.255&nbsp;MHz
|
| 31
| 27.315&nbsp;MHz
|
| 39
| 27.395&nbsp;MHz
|- style="text-align:right"
| 8
| 27.055&nbsp;MHz
|
| 16
| 27.155&nbsp;MHz
|
| *24
| 27.235&nbsp;MHz
|
| 32
| 27.325&nbsp;MHz
|
| 40
| 27.405&nbsp;MHz
|-
|}

:<nowiki>*</nowiki> Channels&nbsp;3, 7, 11, 15, and 19 have adjacent "hidden" channels (see below); channels&nbsp;23, 24, and 25 are numbered out-of-order for their frequency allocations in the United States.

=== Intermediate channels ===
When looking at the FCC/CEPT channel list there are some channels with a spacing of 20&nbsp;kHz instead of the regular 10&nbsp;kHz step. These intermediate frequencies are reserved for the Radio Control Radio Service (RCRS).{{efn|RCRS was formerly known as the Class C Citizens Radio Service until the 1976 changes.}} The RCRS service is commonly used for remote control of model aircraft and boats. It is an unofficial practice to name these channels by their next lower standard channel number along with a suffix&nbsp;"A" (''after''). For example, channel&nbsp;"11A" is 27.095&nbsp;MHz, spaced 10&nbsp;kHz <u>after</u> standard channel&nbsp;11 (at 27.085&nbsp;MHz) is used to provide for part of European railroad's [[Eurobalise]] radio communication with trains.

{| class="wikitable"
! Channel !! Frequency !! Channel !! Frequency !! Channel !! Frequency !! Channel !! Frequency !! Channel !! Frequency
|-
| ''3A'' || 26.995&nbsp;MHz ||  ''7A'' || 27.045&nbsp;MHz || ''19A'' || 27.195&nbsp;MHz || ''11A'' || 27.095&nbsp;MHz || ''15A'' || 27.145&nbsp;MHz
|}

=== SSB use ===
{{Unreferenced section|date=October 2015}}
[[Single-sideband modulation|Single-sideband]] (SSB) operation involves the selection of either the Lower Side Band (LSB) or the Upper Side Band (USB) mode for transmit and receive.  SSB radios also have the standard AM mode for communicating with standard CB radio models. With the original 23&nbsp;CB channels SSB stations commonly used channel&nbsp;16, to avoid interference to those using [[Amplitude modulation|AM]] (SSB stations are authorized to use 12&nbsp;watts, as opposed to 4&nbsp;watts for AM stations) and to more easily locate other SSB stations. With the FCC authorization of 40&nbsp;channels, SSB operation shifted to channels&nbsp;36–40. Channel&nbsp;36 (or 38 for LSB) became the unofficial SSB "calling channels" for stations seeking contacts, with the subsequent conversation moving to channels&nbsp;37–40. CBers with AM-only radios are asked to not use channels&nbsp;36 through 40. In return, SSB stations stay off the remaining 35&nbsp;channels so they could be used by AM stations. This agreement provides interference-free operation for all operators by separating the far more powerful SSB stations from the AM stations. This solution also resolves the confusion created by the false advertising that SSB radios have 120&nbsp;channels compared to only 40 for AM radios.

While a SSB radio has three possible "modes" (AM, LSB, USB) it can operate in, operation is still limited to the same 40&nbsp;channels. Some manufacturers tried to sell more radios by claiming that with three different modes possible for each channel, it was the equivalent to 120&nbsp;channels.{{Citation needed|date=October 2020}}  Reality is far different: Attempting an SSB conversation while an AM conversation is in progress results in jammed communications for everyone. In general, each channel can only support one AM conversation and no others; if no AM conversation is in progress, two SSB conversations can share one channel without interference if one is in LSB and the other in USB mode. For a particular conversation, everyone must be tuned to the same channel and same mode in order to talk with each other.
Starting in October 2021 the FCC has approved FM for CB in the US.

=== Country-specific variations ===
{{Main|Personal radio service}}
The [[European Conference of Postal and Telecommunications Administrations]] (CEPT) adopted the North American channel assignments, except channel&nbsp;23, frequency 27.255&nbsp;MHz; channel&nbsp;24, frequency 27.235&nbsp;MHz; and channel&nbsp;25, frequency 27.245&nbsp;MHz.<ref name="legifrance.gouv.fr"/> However, legal CB equipment sold in Europe does follow the North American channel designation. Some member countries permit additional modes and frequencies; for example, [[Germany]] has 40&nbsp;additional channels at 26&nbsp;MHz for a total of 80. The [[United Kingdom]] has an additional 40&nbsp;channels between 27.60125 and 27.99125&nbsp;MHz, also making 80&nbsp;channels in total. Before CEPT, most member countries used a subset of the 40&nbsp;U.S. channels.

In [[Russia]] and [[Poland]], the channels are shifted 5&nbsp;kHz down; for example, channel&nbsp;30 is 27.300&nbsp;MHz.{{citation needed|date=November 2011}} Many operators add a switch to change between the "zeroes" (the Russian/Polish channel assignment) and the "fives" (the international/European assignment). Most contemporary radios built for those markets can do "fives" as well as "zeroes" out of the box. Since roughly 2005–2006, Russia and Poland have adopted use of the standard US channel offset as well as the older channel plan, for two overlapping "grids" of channels.

Russia uses an alphanumeric designation for their CB channel plans, because several "grids" or "bands" of 40&nbsp;channels each are used, along with both AM and FM mode.  Russian CB allocations follow the CB band 26.965–27.405&nbsp;MHz (designated as band&nbsp;C), as well as 26.515–26.955&nbsp;MHz (designated as band&nbsp;B) and 27.415–27.855&nbsp;MHz (designated as band&nbsp;D). Some radios refer to the "mid band" (standard CB band) as "band&nbsp;D" which shifts the letters up one (making 26.515–26.955&nbsp;MHz "band&nbsp;C" and 27.415–27.855&nbsp;MHz "band&nbsp;E".

For the convenience of users of the grid were marked by letters. Classic is considered the marking when the main range is designated letter&nbsp;"C". The most common description of the channel is considered to be similar to the following: (C9FM or C9EFM or C9EF or 9EF).

In it:

* the first letter («C») is indicated by a grid that contains a set of 40&nbsp;channels. If the first letter is not specified, it is considered that it is («C»). For example, (C9EF, 9EF)
* hereinafter ("9") – the channel number. Sometimes less than 10&nbsp;channels are designated 2&nbsp;digits. For example, (C9EF, C09EF)
* behind it – an optional designation («E») for "European" or mandatory («R») for "Russian" size frequency nets. For example, (C9EF, C9F, C9RF)
* end – the used modulation («FM») or («F»), («AM») or («A»). e.g. (C9EFM, C9EF, C9EAM, C9EA)

An example of correct designations: C9EF, C9EA, C9RF, C9RA

The 25–30&nbsp;MHz band (including the CB allocations and frequencies above and below the 26.5–27.860&nbsp;MHz band) is heavily used for taxi cab and other mobile two-way communications systems in Russia, Ukraine and other former USSR country states.

[[New Zealand]] and [[Japan]] have unique allocations compared to any other country. New Zealand authorizes use of their New Zealand specific 40&nbsp;channel 26.330–26.770&nbsp;MHz [[frequency plan]] in addition to the "standard" 40&nbsp;channel 26.965–27.405&nbsp;MHz frequency plan for a total of 80&nbsp;HF CB channels. New Zealand has adopted the Australian UHF CB System as well.<ref>{{cite web |url=http://www.uhfcb.com.au/New-Zealand-PRS.php |publisher=UHF CB Australia - New Zealand PRS |department=News |title=Repeater Locations & Information |website=www.uhfcb.com.au |access-date=8 May 2018 |url-status=live |archive-url=https://web.archive.org/web/20180312193015/http://uhfcb.com.au/New-Zealand-PRS.php |archive-date=12 March 2018}}</ref>

Japan's CB allocation consists of 8&nbsp;voice and 2&nbsp;radio control channels with a maximum power output of 500&nbsp;mW. AM mode is the only mode permitted and antennas must be non-removable and less than 199&nbsp;cm (78&nbsp;inches) long. In Japan, the 26–28&nbsp;MHz range is allocated to fishery radio services and these frequencies are heavily used for marine communications. Japan's "double side band fishery radio" or "DSB Fishery Radio Service" covers 26.760&nbsp;MHz-26.944&nbsp;MHz, 27.016&nbsp;MHz, and 27.524-27.988&nbsp;MHz. However, frequencies such as 27.005&nbsp;MHz AM are widely pirated in Japan with very high power transmitters. This causes interference to the authorized low-power 1&nbsp;Watt DSB (1&nbsp;Watt AM) fishery radio service. Instead of 26–27&nbsp;MHz, Japan has authorized several UHF FM CB-type [[personal radio service#Japan|personal radio service]]s in the 348&nbsp;MHz, 420–422&nbsp;MHz and 903–904&nbsp;MHz bands.

# 26.968&nbsp;MHz – Japanese CB Channel 1
# 26.976&nbsp;MHz – Japanese CB Channel 2
# 27.040&nbsp;MHz – Japanese CB Channel 3
# 27.080&nbsp;MHz – Japanese CB Channel 4
# 27.088&nbsp;MHz – Japanese CB Channel 5
# 27.112&nbsp;MHz – Japanese CB Channel 6
# 27.120&nbsp;MHz – Japanese CB Channel 7
# 27.144&nbsp;MHz – Japanese CB Channel 8 – Calling Channel

# 27.048&nbsp;MHz – Japanese Remote Control R/C Frequency
# 27.136&nbsp;MHz – Japanese Remote Control R/C Frequency
# 27.152&nbsp;MHz – Japanese Remote Control R/C Frequency

[[Indonesia]] has the usual 40&nbsp;channels at 27&nbsp;MHz, plus a unique 60-channel VHF allocation from 142.050 to 143.525&nbsp;MHz. Unlike most other countries, CB operators in Indonesia are required to have a CB-specific license (similar to GMRS licensing in the United States, albeit it cannot be used by other immediate family members and only valid for 5 years). An alphanumeric callsign, like it's amateur radio counterpart, would then be issued. <ref>{{cite web |url=http://www.postel.go.id/content/ID/regulasi%5Cfrekuensi%5Ckepmen%5Ckm%20nomor%2077-2003%20krap.pdf |title=An Indonesian government decision regarding CB, with frequency charts |archive-url=https://web.archive.org/web/20160120224026/http://www.postel.go.id/content/ID/regulasi/frekuensi/kepmen/km%20nomor%2077-2003%20krap.pdf |archive-date=2016-01-20 |df=dmy-all}}</ref>

In [[Brazil]], CB channels were upgraded from 23 to 60 channels starting in 1979 and again in 1980 to {{ill|lt=80 channels|Serviço Rádio do Cidadão#Frequência e canalização|pt|vertical-align=sup}} (from 26.965&nbsp;MHz to 27.855&nbsp;MHz).

'''CB Radio Channels (ANATEL)'''
{| class="wikitable"
|Channel
|Frequency
|Channel
|Frequency
|-
|1
|26.965
|41
|27.415
|-
|2
|26.975
|42
|27.425
|-
|3
|26.985
|43
|27.435
|-
|4
|27.005
|44
|27.455
|-
|5
|27.015
|45
|27.465
|-
|6
|27.025
|46
|27.475
|-
|7
|27.035
|47
|27.485
|-
|8
|27.055
|48
|27.505
|-
|9
|27.065
|49
|27.515
|-
|10
|27.075
|50
|27.525
|-
|11
|27.085
|51
|27.535
|-
|12
|27.105
|52
|27.555
|-
|13
|27.115
|53
|27.565
|-
|14
|27.125
|54
|27.575
|-
|15
|27.135
|55
|27.585
|-
|16
|27.155
|56
|27.605
|-
|17
|27.165
|57
|27.615
|-
|18
|27.175
|58
|27.625
|-
|19
|27.185
|59
|27.635
|-
|20
|27.205
|60
|27.655
|-
|21
|27.215
|61
|27.665
|-
|22
|27.225
|62
|27.675
|-
|23
|27.255
|63
|27.705
|-
|24
|27.235
|64
|27.685
|-
|25
|27.245
|65
|27.695
|-
|26
|27.265
|66
|27.715
|-
|27
|27.275
|67
|27.725
|-
|28
|27.285
|68
|27.735
|-
|29
|27.295
|69
|27.745
|-
|30
|27.305
|70
|27.755
|-
|31
|27.315
|71
|27.765
|-
|32
|27.325
|72
|27.775
|-
|33
|27.335
|73
|27.785
|-
|34
|27.345
|74
|27.795
|-
|35
|27.355
|75
|27.805
|-
|36
|27.365
|76
|27.815
|-
|37
|27.375
|77
|27.825
|-
|38
|27.385
|78
|27.835
|-
|39
|27.395
|79
|27.845
|-
|40
|27.405
|80
|27.855
|}

[[South Africa]], like New Zealand and the UK, permits the use of two HF CB bands.  South Africa has a 23&nbsp;channel AM / SSB 29&nbsp;MHz CB allocation (called "29 Megs" or "29 MHz CB") from 29.710 to 29.985&nbsp;MHz in 12.5&nbsp;kHz steps. South Africa also permits use of standard CB channels&nbsp;19–27 (27.185–27.275&nbsp;MHz) with AM / SSB permitted. Many radios sold in South Africa feature both the 27&nbsp;MHz and 29&nbsp;MHz bands. A license from [[ICASA]] is no longer required to purchase or use a CB radio in South Africa.

[[Hungary]] allows use of the "low channels" for a total of 80&nbsp;channels (26.515&nbsp;MHz to 27.405&nbsp;MHz).

[[Germany]] authorizes a similar allocation, with 40&nbsp;channels from 26.965 to 27.405&nbsp;MHz and another 40&nbsp;channels from 26.565 to 26.955&nbsp;MHz in regular 10-kHz steps.

The [[Czech Republic]] authorizes 80 channels as well (same as the German 80-channel plan). As in Germany, digital modes are allowed on certain frequencies.{{efn|Channels&nbsp;24&nbsp;[27.235&nbsp;MHz], 25&nbsp;[27.245&nbsp;MHz], 52&nbsp;[26.675&nbsp;MHz], 53&nbsp;[26.685&nbsp;MHz], 76&nbsp;[26.915&nbsp;MHz, and channel&nbsp;77&nbsp;[26.925&nbsp;MHz]}} [[Gateway (telecommunications)|Internet gateways]] and [[radio repeater]]s are allowed on channels 18&nbsp;[27.175&nbsp;MHz] and 23&nbsp;[27.255&nbsp;MHz]. Paging is permitted on channel&nbsp;1 (26.965&nbsp;MHz) and channel&nbsp;80 (26.955&nbsp;MHz) is the recommended call channel for Czech CB radio operators.

Using radios outside their intended market can be dangerous, as well as illegal, as frequencies used by Citizen's Band radios from other countries may operate on frequencies close to, or be used by, emergency services (for example, the Indonesian service around 142&nbsp;MHz operates on frequencies allocated to a public safety network shared with police, fire and EMS services in Ontario, Canada).

In the [[Philippines]], up to present time, the use of 27&nbsp;MHz CB is still banned since the Marcos regime banned it in 1980s. Before it was banned, they use the same allocation as the US. A few operators still illegally utilize the 40&nbsp;CB channels.