How Do CB Radios Actually Work?

CB radios have been around for a long time, and even though smartphones and other modern forms of digital communication have eaten into their usefulness a little bit, they’re still an indispensable and self-contained method of communicating over relatively short distances.

They’re certainly convenient, and affordable, and a great option in any prepper’s toolbox. But, just how do CB radios actually work?

CB radios work by converting electricity into radio waves, which can then be received by other sets, which will turn them into sound through the use of a speaker.

That’s a really short, version of how they function, but we don’t need to take a huge, deep dive into radio signals for you to better understand and appreciate how a CB radio works.

And by better understanding how it works, you’ll have an easier time using one to its full capability. Keep reading, and I’ll tell you more about it…

CB Radios Send, Receive, and Convert Radio Signals Over Short Distances

CB radios are basically a type of self-contained transceiver, as a combination of a transmitter and a receiver.

Obviously, this means they are capable of both sending and receiving radio waves, or radio signals. But CB radios are one of the most low-powered varieties of radios that civilians have access to, and accordingly, they are only good over short distances.

Typically, a CB radio can only effectively send and receive these signals over 5 to 10 miles, oftentimes a lot less depending on local terrain, atmospherics, and other factors.

That’s okay, because this is still plenty of distance for lots of useful functions, including gathering information on traffic data and accidents, coordinating movements and vehicle convoys, etc.

CBs Transmit Across 40 Channels

You might know that there are a great many radio frequencies out there, and all of them spread out across different bands, from high to very high frequency, and even ultra-high frequency.

But CB radios only transmit across a relatively tiny slice of this spectrum, as mentioned above. This is important to understand because you won’t be able to speak to anybody who isn’t on a CB radio, or at least anyone that cannot access those same frequencies. Likewise, larger and more powerful ham radios can talk on frequencies that you won’t be able to hear.

In the grand scheme of things, CB radio is somewhat limited, and depending on where you are, the airwaves can get quite cluttered, but it is usually more than adequate for its intended use.

CBs Communicate Between 26 and 28 MHz

Because CB radios are low-powered, and they are generally quite limited in what they can achieve, they only operate across a pretty narrow frequency range.

Nominally, this is between 26 and 28 megahertz, but if you want to get exact, the 40 frequencies are spread between 26.965 and 27.405 megahertz, typically spaced 10 kHz apart.

All CB Radios Consist of the Same Basic Components

CB radios are commonly thought of as truck radios, or truck driver radios, but this really describes an entire category of equipment and its nominal use case as detailed above.

However, whether you’re dealing with a handheld CB, one mounted in a vehicle, or even one that is a base station in your home or some other location, they will all have the same components and depend on them for proper function.

Transceiver

This is the heart and soul of the CB radio. The transceiver is the component that is responsible for translating received signals into electrical signals, or sounds, that you hear. It is also responsible for turning electrical signals into radio signals that you send, that other users will hear on their side.

Power Supply

CB radios, like all radios, need a power source, and the nature of the power source depends on the installation. Those mounted in vehicles will run off of battery power, like everything else in the car, or for older vehicles, off of the vehicle’s generator.

CBs that are carried by hand will use battery packs, and larger sets that are kept at home or elsewhere can run off of AC/DC, or else off of any other power generation technology you might be using if your house isn’t connected to the grid.

Chassis

The chassis, sometimes called the case, is the hard shell that holds the transceiver, outputs, and jacks, and often times the control panel as well.

Controls

All CB radios, no matter how advanced or how primitive, will have controls to operate them. These controls include volume, gain, tuning, channel selector, and various other settings.

Mic

Mic, or microphone, is the part that you key when speaking into it in order to transmit your voice over the airwaves.

Antenna

The antenna is the other most important part of a CB radio and is responsible for physically sending and receiving the signals from the transceiver.

Antennas might be omnidirectional or unidirectional, but choosing the right one, setting it up properly, and tuning it for correct function is absolutely essential to good radio performance. Without an antenna, your signal will go nowhere!

Speaker

You already know what a speaker does. Whether it is installed in an all-in-one handset, built into the case, or a separate, standalone speaker, this is what you’ll hear other CB users’ voices on when receiving – assuming you are tuned in!

The Antenna Receives and Transmits Signals from the CB

When you key your CB Radio and then talk into the mic, assuming your components are set up correctly, powered, and functional, your voice will be converted into a radio signal that will then be emanated by your antenna.

A good antenna will produce a better, cleaner, and nominally stronger signal that is easier to receive by another set.

At the same time, it will also pick up other CB radio signals and transmit them to the transceiver, which will then convert them back into electrical energy that will come out of your speaker as someone’s voice, or whatever other sound was transmitted.

Again, we can delve into the actual science of this, but that is a long, long conversation!

SSB, or Single Sideband, CBs Have Better Range and More Channel Options

There are some specialized CB radios out there that are commonly referred to as SSBs, or single sideband CB. These CBs tend to be more powerful, clearer, and offer superior performance compared to standard CB radios, with the downside of greater expense.

But even better, they can use additional channels through the use of two sidebands, which will effectively double the number of usable channels your radio can access, a total of 80!

One shortcoming, though, is that if you’re accessing these sideband channels, you’ll only be able to communicate with other SSB radios, not standard CBs.