Citizens Band Radio, or CB, as it’s more commonly known, is a type of Personal Radio Service. CB operation does not require a license, so anyone can use it, unlike the most commonly used radio by hobbyists (“Ham radio”), which requires an amateur radio license.
This CB land mobile radio system allows short-distance person-to-person bidirectional audio communications, on 40 channels near 27 MHz in the high frequency (shortwave) band. CB Radio is covered under Part 95 of the Federal Communications Commission (FCC) rules.
Although neither a license nor call sign is required for using CB, it’s still common practice to have a “call sign”, or “CB handle” (Betty Ford, former First Lady of the United States used the handle “First Mama” for instance). Taking this into consideration, the FCC (an American government agency in charge of regulating radio communications in the U.S.) now allows users to create their own handles.
This article will go over the basics of CB and important details every technology geek should know. For example, a seemingly small thing, like the right tuning or frequency knowledge, can change your user experience dramatically.
Through this article, everyone can start their citizens’ band journey easily.
CB Radio Etiquette
Some CB radios can go into low power mode, to preserve battery, which helps operate a device longer. In addition, some common etiquette is required when using CB radio to prologue the battery life even more. For example, users shouldn’t talk with another CB station for more than 5 minutes continuously and must wait at least one minute before starting another communication. This way everyone can have their “turn”.
Some CB radios have a built-in feature, called “Roger beep”, which gives feedback upon releasing the button. Since this makes a loud beeping sound, which everyone can hear, a lot of people prefer to keep it off, to avoid annoyance.
What is a CB Radio & Its History
The history of CB began in 1945 in the United States. At that time, the FCC introduced several personal radio services, including the Citizens Band Radio Service. These personal CB radios were similar to what everyone knows as walkie-talkies, but they all had different purposes, ranges, and audio qualities.
The CB radio service was introduced to allow citizens to use a radio band for solely personal matters (for example, they’re widely used in family businesses, and radio-controlled model airplanes). Citizens band radio became a hit, and quickly reached the heart of the public, most commonly used by the US Coast Guard and farmers.
At first, two classes were introduced, the “A” and “B” classes, which were more or less the same, with the main difference being that CB service Class B radios operated on a smaller frequency range. In 1958, CB Class D was created on 27 MHz. It wasn’t until this class, that the band became what is known today as “Citizens Band Radio”.
In the early days, there were only 23 channels available for CB radio users, 22 of which were taken from the former amateur service. The additional channel 23 was shared with radio-controlled devices.
With Class D becoming the “face of citizens radio”, Class A became the forerunner of the General Mobile Radio Service, and Class B became the now distant ancestor of the Family Radio Service. While there are several other classes available, these were the ones that created the foundation for PRS.
During the ‘60s, the CB radio service became highly sought-after among small businesses, truck drivers, and hobbyists. After being taken over by specialists, the weight, size, and price of the CB radio began to fall, allowing more of the public to access this device.
The improved affordability, made many boaters install CBs instead of the still expensive VHF Marine Band. As a result, due to its growing popularity among marines, CB radio introduced “marine CBs”, including a weather band.
CB Channels & Frequencies
A CB’s transmitter power output is limited to 4 watts and they have a range of approximately 3 miles depending on the terrain and weather conditions. This can be improved by matching the antenna height to reach the 1:1 SWR (Standing Wave Ratio).
A higher SWR ratio means parasitic feedback on the antenna, which cancels the outgoing signals. In certain cases tuning the RF power amplifier stage helps to reach even longer distances, but it has to stay below the FCC’s 4 watts limit.
Like many other land mobile services, multiple devices can share a single frequency channel, but only one can transmit at a time. Because of this, users on a channel must take turns talking, using the “push to talk” button. When the button isn’t used, the radio constantly stays in receive mode, and only activates its transmitters when pushing the designated button.
The Citizens Band Radio Service operates on 40 shared channels (between 26.965 MHz and 27.405 MHz) in AM, FM, or Single Side Band (SSB) mode. Each channel number refers to a specific carrier frequency.
Some devices even have the capability to separate the carrier into low, mid, and high sections. With this solution, another 40 channels are made available. Since the range and quality of AM radio is somewhat lacking, while SSB has a greater range and higher audio quality, therefore is more widely used on higher-end CBs. However, you can only communicate with other SSB radios when in SSB mode.
The reason for the limited 40 channels is simple. All other frequencies belong to other operators. Above the frequencies of CB are channels for the Business Radio Service (which is part of the VHF and UHF bands).
Frequencies 27.540 to 28.000 are controlled by the federal government, and 26.480 to 26.960 belong to the U.S. military. Above that, on the 26.620 MHz are the Civil Air Patrol, and a part of the U.S.A.F., although today the Civil Air Patrol uses VHF more often. And right above all of these, the 10-meter Ham device runs from 28.000 to 29.700 MHz.
CB frequencies and their channels are not assigned to specific individuals or organizations. You can operate a CB radio on all 40 channels and frequencies designated by the Federal Communications Commission.
Any of the 40 designated channels allocated by the FCC can be used for emergency communications and traveler assistance, which is one of the primary uses for CB. As a result, you must always give priority to emergency communications on all channels. Furthermore, CB channel 9 is strictly reserved for emergency use only which was given this intention by the FCC in 1969.
While CB is intended for short-range use only (the FCC prohibits attempts to communicate with a CB station over 155 miles away), there is a way to increase range by bouncing or “skipping” the signal off the ionosphere. This method, called “shooting skip” allows CB users to skip a signal thousands of miles away. However, it’s important to know that signals can skip naturally depending on the tropospheric conditions, therefore it’s not unusual to send or receive CB transmissions across the country, or even the world, unintentionally.
Citizens band radio service became one of the most popular two-way radio systems for the individual consumer and some of the best CB radio examples are high in demand. Those in need of short-range radio communications, such as plumbers, carpenters, construction workers, who needed to communicate between the job site and the office quickly got used to this band as the most practical way of radio communication yet.
Apart from specialists using this service, it also became a popular hobby in many countries. A lot of users of handheld devices (families, friends, hunters, hikers, etc.) have migrated to the higher frequency 49 MHz and the UHF Family Radio Service over time.
In most places around the world, CB channel 19 is the unofficial traveler frequency used to share important information and knowledge, and in cases of emergency. If you use CB while traveling, it’s smart to check which CB channels are reserved for emergencies and travelers.
The reason that these channel numbers were reserved for emergency communications is that tuned circuits (particularly an antenna) work best in the middle of the band. These signals are transmitted and heard the farthest, in the highest quality possible.
Overall, CB radio channels can be used to share all kinds of content, but mainly, CB communications are utilized for work and emergencies (a lot of police stations, government agencies, construction workers, and travelers use this device and a CB station as their main way of communication).
Anyone can have the ability to operate a CB as permitted by the FCC. And while it has gone “out of style” over the past decade, everyone carrying out activities that involve them getting off the grid, or spending a lot of their time on the road still relies greatly on this somewhat “outdated” technology.
CB Radio Antennas
There are multiple kinds of antennae spanning from fixed to portable, which they use in cars for example. Considering that 27MHz is a relatively long wavelength, the choice of antenna has a considerable impact on the performance of the device.
The most commonly used mobile antenna is one that everyone has seen at one point: a quarter-wave vertical whip. This is mounted on the vehicle body and often has something on it to enhance its flexibility when striking nearby objects.