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CB Radios, Frequencies, and Channels

We explain the background of CB Radio Frequencies & Channels as well as offer a list for easy identificationHow Did CB Radio Come To Be?

Citizens Band (CB) radio dates back to the 1940s. The Federal Communications Commission (FCC), which still regulates CB, took bands from the UHF band (460-470 megacycles) for personal and business communication, as well as for controlling model aircraft. That makes sense, as less expensive CB equipment offers the general public the chance to communicate with each other short distances over various CB frequencies without the expense, study and then the waiting period for getting an FCC license.

Class A and B radio services were established in 1948, which formed the basis of the Family Radio Service. Ten years later Class D was established, becoming the forerunner of CB radio. CB radio channels have expanded. Class D began with only 23 channels, but more were added to bring CB to the current 40 channels in 1977.

When And Why Did CBs Become Popular?

Back in the 70s, CB became very popular. There was an oil crisis when OPEC, a group of oil producing countries, declared an oil embargo. The U.S. government responded by lowering the national highway maximum speed to 55 mph. The embargo caused fuel shortages and that led to rationing, which made it difficult to locate gas supplies.

That's when CB radio use exploded. Using CBs, drivers could find fuel sources and communicate the location to others. They could also alert others to speed traps. Truckers' wages depend on the miles driven, so their productivity and thus their wages were negatively impacted by the 55 mph speed limit. Truckers protested the lower speed limits by setting up highway blockades, using their CBs to organize and carry out those protests.

A list of CB frequencies and CB radio channels follows. Note that the channel numbers are not necessarily sequential with frequency (e.g. between channels 15 and 16). The gaps exist for radio-controlled (R/C) device frequencies. The frequencies 27.575 and 27.585 are for low-power use.

What Are The CB Frequencies And CB Radio Channels?

The following table presents the CB frequencies, the particular wavebands at which a signal is transmitted. The next columns list the corresponding 40 CB channels and the customary uses of the channels.

NOAA Weather Radio all Hazards channels.

CB Frequency CB Channel Customary Use
26.96500 CB Channel 01 open to all
26.97500 CB Channel 02 open to all
26.98500 CB Channel 03 open to all
27.00500 CB Channel 04 open to all--4x4 channel
27.01500 CB Channel 05 open to all
27.02500 CB Channel 06 open to all
27.03500 CB Channel 07 open to all
27.05500 CB Channel 08 open to all
27.06500 CB Channel 09 Emergency
27.07500 CB Channel 10 open to all--regional roads
27.08500 CB Channel 11 open to all
27.10500 CB Channel 12 open to all
27.11500 CB Channel 13 open to all--marine, RV
27.12500 CB Channel 14 open to all--walkie talkies
27.13500 CB Channel 15 open to all
27.15500 CB Channel 16 open to all (also SSB)
27.16500 CB Channel 17 open to all--North/South Traffic
27.17500 CB Channel 18 open to all
27.18500 CB Channel 19 Truckers--East/West Hwy Traffic
27.20500 CB Channel 20 open to all
27.21500 CB Channel 21 open to all--regional roads
27.22500 CB Channel 22 open to all
27.25500 CB Channel 23 open to all
27.23500 CB Channel 24 open to all
27.24500 CB Channel 25 open to all
27.26500 CB Channel 26 open to all
27.27500 CB Channel 27 open to all
27.28500 CB Channel 28 open to all
27.29500 CB Channel 29 open to all
27.30500 CB Channel 30 open to all
27.31500 CB Channel 31 open to all
27.32500 CB Channel 32 open to all
27.33500 CB Channel 33 open to all
27.34500 CB Channel 34 open to all
27.35500 CB Channel 35 open to all
27.36500 CB Channel 36 open to all (also SSB)
27.37500 CB Channel 37 open to all (also SSB)
27.38500 CB Channel 38 open to all (also SSB, LSB)
27.39500 CB Channel 39 open to all (also SSB)
27.40500 CB Channel 40 open to all (also SSB)

Any authorized CB radio frequency is open to all, but some have agreed-upon special purposes. For instance, channel 9 is for emergency use, and channel 19 is used by truckers to report on traffic conditions. Channel 19 is at the middle of the bands, thus has the best antenna efficiency. Channel 9 is used less often for emergencies since the advent of cell phones, but some rural communities still monitor that channel for emergencies. Those who want information or wish to contribute appropriate information on specialized channels are welcomed, as are listeners.

Listening is an important step for beginners, especially on channel 19. Truckers have their own handles (names) and jargon, and many do not welcome non-truckers on the channel. One way to make yourself unwelcome is to misuse or overuse the jargon, or slang. Either one marks you as an outsider and may be used to justify bullying you off the channel. If you want to get a head start on understanding truckers' slang, that's covered in another section.

What Features To Look For to Improve CB Frequencies and Transmissions

Para Dynamics PDC2 SWR Meter

Nothing's worse than trying to tune into CB channels and only receive muffled voices mixed in with an overwhelming amount of crackling static in return. Though all CB radios have only 4 watts of transmission power (this is mandatory by the FCC), there are certain features available for these radios that can vastly improve reception of CB frequencies and improve your ability to clearly listen to any channel.

Different Features for Different Uses of CB Channels

How you plan on using your CB radio as well as which channels you may be trying to tap into will be the difference in which features you'll find beneficial. These features will help anyone improve the quality of their CB frequencies:

  • RF Gain: With this feature, an operator is able to create filters so that only a strong CB radio frequency and transmission is received. It's handy for two reasons: one, it can block out any weak transmissions so that there is less background noise when you're speaking with someone who has a strong channel signal. The other benefit is that it can be used to help bring in weak signals and improve the clarity of all CB radio channels.
  • Automatic Noise Limiter: Also known as "ANL", this feature improves your reception sound quality as it allows operators to filter out interference, such as static and engine noise. This is particularly evident if you drive a larger truck; a radio with this feature will save you a lot of annoying static noise.
  • Instant Channel Functions: Some radios will allow users to quickly jump to two of the most popular CB channels: #9 (the emergency CB channel) and #19 (a channel for truckers).
  • Weather Reporting: Through this feature, your radio will be able to tap into any local NOAA radio stations so that you can receive real-time weather updates. Not only is this handy for truckers, but it's equally useful for RV or motor home drivers as well.
  • PA Functions: Your radio can transform into a public address system, though a PA horn (which is usually sold separately) must be mounted on top of your vehicle or under the hood.
  • Backlit Displays: If you plan on driving extensively during the darker hours of the day, then this feature is an absolute must-have. Though only commonly included in the more expensive models, it's a worthwhile investment.
  • Squelch Control: This feature frees the operator from constantly being forced to listen to background static by setting a specified break-point at which your radio will output a signal. The radio will only activate if a CB frequency or transmission is received.

What is SSB?

Single sideband modulation (SSB) more efficiently uses transmitter power and bandwidth. For an in-depth explanation, refer to Wikipedia's page on SSB.

What's Above And Below The CB Channels?

Above the band at 27.430, 27.450, 27.470, 27.490, 27.510, and 27.530 MHz are channels for the Business Radio Service. That service is part of the VHF and UHF two-way radio bands. They are reserved for commercial use by companies and educational, religious, and health institutions.

The federal government has from 27.540 up to 28.000 frequencies. CB and ham users with modified equipment often use frequencies 27.575 and 27.585 illegally, as well as frequencies from 26.480 to 26.960, which belong to the U.S. military. The Civil Air Patrol, part of the U.S.A.F., is assigned 26.620 MHz, although now the CAP uses VHF frequencies more often. The 10-meter amateur radio (ham) band runs from 28.000 to 29.700 MHz.

What Are Illegal CB Radio Frequencies?

Frequencies of 28.000 MHz and higher are out of the CB channel range and into the domain of licensed Amateur Radio (ham) operators who use it exclusively for Morse code. If you own a modified export CB radio (such as the Galaxy), the 19 high setting puts you at 28.085 MHz - forbidden territory. If you're talking on that frequency, you'll be very noticeable (between the dots and dashes of Morse code) to the Official Observers (OOs) of the Amateur Radio world. To notify you, they'd have to break their own band rules, as voice communication is not allowed at that frequency even for licensed amateur radio operators. They'll likely not hesitate to report you and provide audio/video evidence to the FCC. The FCC then contacts trucking companies and can fine them, which has led to the truckers being fired. To avoid that problem, simply stay within the 40 authorized channels.

What Are Bootleg Frequencies?

CB radios can be modified for use in Amateur Radio's 10-meter range, which is legal only for licensed operators to do. CB radios approved for use in the U.S. are marked "FCC Approved." Everyone, even ham radio operators, legally are supposed to use FCC approved CB radios for channels 1-40. Even those are possible to modify, but it is more difficult than modifying a non-approved one.

What Is Freebanding And Why You Should Think Twice Before Doing It

"Freebanding" sounds exciting, a bit like the Wild West, but don't be enticed.

Freebanding or "outbanding" on random frequencies or channels is a term used to describe an operator who is illegally using these frequencies or channels within the 11 meter (above or below the 10 kHz) frequency.

Many of the channels outside of the 10 kHz CB radio frequency are "private" channels that only those with proper authorization and licensing are permitted to use, but these licensing requirements and restrictions haven't stopped everyone from illegally tapping into these channels.

Unauthorized frequencies include the international call frequencies of 27.555 and 26.285. International call frequencies have been established to provide a common meeting place for long distance operators to initiate or respond to calls from other stations. It's not used for conversation (QSO), as those who make contact then move to other frequencies. So, if you're jawboning on those frequencies, you'll be as welcome as fire ants at a picnic. Listening is OK, but talking is not. Beware, the FCC cracks down on such illegal use of frequencies, citing and fining scofflaws.

Freebanding is against FCC regulations for two key reasons:

    1. Many CB radio channels must be kept open in case an emergency situation does arise.
    2. Illegal linear amplifiers and transmitters made for tapping into these channels are poorly constructed and cause a "splatter" or harmonic distortion on a CB frequency, which disrupts important communications

How Do Users Freeband on CB Radio Frequencies?

Freebanding CB radio operators typically access illegal channels through one of two means:

    1. Operators acquire an export CB radio that are legal in other countries but illegal in the United States
    2. Operators modify amateur radios specifically to freeband

Despite the FCC banning the marketing and sale of any CB radios that they've deemed easily modifiable, clever operators are still able to rig up almost any amateur radio to reach these "off limit" frequencies.

Why Do People Freeband on CB Radio Channels?

The 40 CB channels in the United States can become overcrowded at times, which drives many CB radio operators to use frequencies that are above or below the permissible CB frequencies. A radio frequency that is below the citizens band, for example, is often quiet and seemingly underutilized; however these frequencies are strictly reserved for use by designated radio services, such as government agencies.

Many freebanding CB radio operators tap into an unauthorized CB channel just for the thrill of it. Whether it's to receive news from a different part of the country or from around the world, or just for the excitement about being somewhere they shouldn't be, these freebanders run the risk of being caught by the FCC or any law enforcement agency.

What Penalties do Freebanders Face?

The FCC will first likely issue a Notice of Apparent Liability (or "NAL") which, if a violator responds quickly and resolves the issue, many not result in any fines. However, if someone continues their unauthorized use of CB frequencies, they can face a number of penalties including:

  • A $10,000+ fine
  • The seizure of radio equipment
  • Suspension of any licenses obtained in other regulated FCC services

So how do you stay out of trouble with your CB radio? Stay within the 40 CB channels and don't modify or purchase a radio from a less than reputable dealer. The best way to ensure that you remain CB radio "legal" is to invest in an American-made legal FCC certified CB unit, and don't make any drastic or unnecessary repairs or upgrades without consulting the FCC.

Where Can I Find Out More About The Rules That Govern CBs And CB Use?

The Federal Communications Commission (FCC) established policies and regulations concerning virtually every aspect of the use of CBs. The complete reference can be found at the government site in Subpart D. The following highlights are a few of the important issues addressed in that lengthy document. One concerns emergency communications. Also visit this link to the FCC website that discusses rules for operating a CB radio.

As mentioned, CB channel 9 is for emergency and traveler information, but operators need to be aware that, "You must at all times and on all channels, give priority to emergency communication messages..." [95.406.c] So, if you have an emergency, you are permitted to break into any channel; if you hear an announcement about an emergency, you must stop communicating and allow that emergency message to get through. That seems like common sense, right?

Some issues involve usage regulations, such as: No CB transmitter is permitted to transmit non-voice data. Also harmful interference is not permitted, and that is defined as: "Any transmission, radiation or induction that endangers the functioning of a radio navigation or other safety service or seriously degrades, obstructs or repeatedly interrupts a radio communication service operating in accordance with applicable laws, treaties and regulations."

Other issues addressed are more technical, for instance, CB transmitters must be maintained within a frequency tolerance of 0.005%.

No CB unit is allowed to have the capability to increase transmitting power to any level in excess of the limits specified in 95.639 (4 W carrier power; 12 W peak envelope TP).

No add-on device, internal or external, that extends the transmitting frequency capability of a CB transmitter beyond its original capability will be manufactured, sold, or attached to any CB station transmitter.

Exact external controls and devices that are permitted to be attached to a CB are enumerated in 95.669.

A copy of Part 95, Subpart D of the FCC rules, current at the time of packing the transmitter, must be furnished with each CB transmitter marketed. If you got your CB used, you may not have received a copy, but you can access it at Ignorance of the rules is, as usual, not an excuse.

What Are The 10 Codes?

Back when CB radios first started, they had tubes, and tubes had to "warm up" before transmitting. So, after keying the mic, the user had to pause a few seconds or that part of his or her transmission would be lost to the listener. Thus, the so-called 10 codes were developed to automatically insert that necessary pause at the beginning of the transmission (during the time it took to say the "10" part of the code, before the important informational part of the code was given). Modern equipment doesn't have that problem, so the trend for modern day users is to drop the 10 codes altogether and use ordinary language for communication. For those still enamored with the "secret" language of 10 codes, the following are a few examples of some popular ones. A more complete list can be found on our CB Lingo page.

  • 10-4--Message received
  • 10-9--Repeat message
  • 10-10--Transmission completed, standing by
  • 10-17--Urgent business
  • 10-20--Identifying location (shortened to: "What's your 20?")
  • 10-27--I'm moving to channel _____
  • 10-33--Emergency traffic at this station
  • 10-38--Ambulance needed at _____
  • 10-45--All units within range please report
  • 10-62--Unable to copy, please use phone
  • 10-99--Mission completed
  • 10-100--Bathroom break
  • 10-200--Police needed at _____

What is CB slang?

Besides the 10 codes, you'll hear slang on the radio, which can vary by the region that you're in. The following are some examples of CB slang.

  • Ace--Important CBer
  • Ancient Mariner--AM or FM user
  • Backdoor--Vehicle behind
  • Beam--Directional antenna
  • Big Mama--9 Ft. whip antenna
  • Boat Anchor--An old tube rig or a radio that's unrepairable
  • Chicken Coop--Weigh station
  • CW--Morse code
  • Double Key--Two stations talking at the same time
  • Foot warmer/heater/kicker/wearing socks--Linear amplifier
  • Fox Charlie Charlie--FCC
  • Fox hunt--FCC hunting for illegal operators
  • Gallon--1000 W of power
  • Haircut Palace--Bridge or overpass with low clearance
  • Mobile--CB radio station in a car or truck
  • Play dead--Standby
  • Prescription--FCC rules
  • QRM--Noise, interference on the radio
  • QSO--Conversation
  • Set of dials--CB rig
  • Smile and comb your hair--Radar trap ahead
  • Twin Huskies--Dual antennas

Worldwide, Where Can I Legally Use My CB Radio?

You can use your CB radio within any area of the world where radio services are regulated by the FCC, including: the 50 states and the District of Columbia (DC); the Caribbean area, including Puerto Rico, Navassa Island and the U.S. Virgin Islands; and various Pacific areas. In other parts of the world, you can use your CB with their legal equipment and rules.

Are Different Frequencies Used Around The World?

Although many countries have the same CB frequencies as the U.S., there are some differences in frequencies, power levels and modes (e.g. AM, FM, SSB), and the use of equipment not intended for that country could be illegal.

Canada's General Radio Service matches U.S. frequencies, modes and power levels. Therefore, no adaptations are required for using CB gear when traveling between Canada and the U.S.

The European Conference of Postal and Telecommunications Administration (CEPT) that coordinates telecommunications adopted the U.S. channels, but use FM rather than AM mode. Other European countries have additional channels. Germany, for example, gets 80 channels by adding the 26 MHz frequency.

Some other countries, such as Japan and New Zealand, have frequency assignments that don't match those of any other countries. If you use your CB equipment in countries that don't match our frequency, mode and power requirements, you would be operating outside the laws of both that country and the U.S.

For a chart listing various countries, bands, bandwidths, modes, power and antenna system specifications, see this page listing CB frequencies around the world.

Other Considerations Operators Should Make

One key consideration that operators must make when operating these radios is the size of the unit. Contrary to what some believe, a larger radio doesn't mean that you'll receive better CB radio frequencies (remember, legal CB radios are only allowed 4 watts of output power!). There are a wide variety of small radios that will take up only a small portion of space and are a perfect addition to trucks, RVs and passenger vehicles.

Another major consideration that operators must think about is the CB antenna. Many assume that a top notch radio must have a fabulous antenna, but many are poorly set up and lead to poor reception. For the best functionality, a quality antenna that's installed properly will always give CB operators the best sound quality, regardless of how expensive or inexpensive the unit may be.