What Is a Radio Scanner? A Beginner’s Guide

What Is a Radio Scanner? A Beginner’s Guide


Radio scanners, more often simply known as scanners, are the most common type of reception equipment used by radio enthusiasts, professionals, and others interested in telecommunications. 

Chances are you've not only used a scanner before, but you use one daily. Virtually every modern car features a built-in AM/FM radio receiver which is able to scan for BBC and commercial radio stations. 

The air around us is buzzing with invisible frequencies that can be decoded and heard using a scanner. If you like to listen to broadcasts beyond what’s available from your car stereo, you can buy a basic radio scanner. Here, we cover what radio scanners are, how they work, and best practices for using one.

What is a Radio Scanner?

Scanners got their name from their function: the internal machinery scans the airwaves for readable frequencies. Anyone with a broadcast transmitter can project whatever they want — music, speeches, other communications — for those with scanners to pick up and listen. 

Generally, scanners are for picking up VHF and UHF transmissions, or Very High Frequency and Ultra High-Frequency transmissions. If you're interested in monitoring shortwave transmissions, you should consider getting a shortwave receiver. Ironically, shortwaves travel further. Picture it: radio waves with high frequencies bounce a lot, so they go shorter, but if they bounce up and down less, they go further.

In the early days, scanners were bulky, temperamental, and could only pick up a narrow range of frequencies. Because of their size, they were stationary devices, not the kind that people nowadays transport or install in their cars. The advent of microprocessors has allowed for making portable scanners that can tune thousands of frequencies. 

What Does a Radio Scanner Do?

Scanners pick up available frequencies on the airwaves. They work by catching ambient frequencies that the user must tune in to hear. Broadcast transmissions are made accessible by tuning to specific channels.

Generally, scanners have three modes of operation: manual scan mode, scan mode, and search mode. 

  • Manual scan mode is something like “seek” on a car radio. The scanner will automatically search for clear and viable channels. These frequencies will come pre-programmed on basic scanners but can be easily re-programmed by the new owner.

  • Scan mode is something like “tune” on the average car radio. You manually scroll up and down through all available frequencies. The fun of this mode is that you never know what you will get. You could pick up a marine transmission sent out to alert nearby vessels to avoid a collision or an emergency transmission relating information about a local emergency.

  • Search mode is for when you don't know what frequency to tune to and want to hear a rundown of all the frequencies in your area. It's more complicated than that, involving threading the needle of a given band between two sets of frequencies. But people use this mode to discover cool new frequencies they can save on their presets.

How Many Types of Radio Scanners Are There?

Different ranges have designated frequencies for public and private uses. The radio scanner’s frequency range indicates what types of transmissions it can receive.

VHF and UHF 

You can buy these basic scanners at an electronic store and use them without much trouble, set-up-wise. 

Very high frequency and ultra-high frequency transmissions are things like civil aircraft bands, military bands, fire and emergency bands, marine bands, hobby radio bands and business radio bands.  You can listen to just about anybody using a radio communications system such as local businesses, hospitals, clubs, train stations, prisons, bus companies, security surveillance, mountain rescue and local football stadiums.

You should be aware that some signals are digitally broadcast and you will need a digital scanner to listen to such broadcasts.  Also some broadcasts, such as UK police signals, are now encrypted to ensure total privacy.

Police Scanners

In the US, there are special scanners for police officers that are preset to toggle between specific channels. You can buy a police scanner in the US, however, there are laws regulating usage, including that it is illegal for citizens to listen to police channels and other private transmissions not intended for public listening.

In the UK, you can no longer listen to police communications.  The UK police now use the TETRA radio system, which is not only encrypted but also digitally broadcast.  The digital age means that the police are now equipped with radios that cannot be monitored.  The encrypted messages are broken down into and transmitted over a number of frequencies to be reassembled at the other end. You would need a very sophisticated scanner system to be able to monitor the separate transmissions of data and reassemble them both ways.

Air Traffic Control Scanner

Air traffic controllers use high-powered scanners to pick up broadcasts from hundreds of miles away - those massive antennas you see shooting out of the top of airports as you land!

Best Practices When Using a Radio Scanner

Visit Scanner Groups on the Internet

If you're unsure how to begin using your scanner. There are dozens, if not hundreds, of communities across the internet dedicated to discussing all things radio. 

On these chat groups, you will find people who can patiently explain how scanners work and give you tips to make the experience more fun.

Know Scanner Use Laws

Each country has laws regarding radio broadcasting and scanning, including regulations for specific types of scanners. For example, Ireland's laws on marine vessel scanners will differ from general UK scanner laws.

In the UK, the two laws you need to mind concern unauthorised interception and disclosure under the Wireless Telegraphy Act 2006.  

Within the UK, there are strict privacy laws to protect private citizens' communications. Make sure you're up to date with your locality's laws, so you're scanning well within the boundaries of the law.

Get the Right Equipment

Your access to various frequencies largely depends on the scanner’s range and whether it can pick up VHF, UHF, and other frequencies. Check the product’s frequency range, also known as coverage, to determine if the scanner covers the bands you want to hear.

Shop Moonraker’s Radio Scanners Today

If you're interested in getting into scanners, shop Moonraker's radio scanners today. Moonraker UK has the broadest and best selection of radio scanners on the market, from scanners, short-wave receivers, to scanner antennas and all the hardware you need to mount them.

You'll find a new world of radio signals as soon as you get your hands on a decent scanner.

Shop Scanners & Receivers Now