When you work with a two-way radio or another radio, there are two ways that you can use them. One is to simply follow the instructions, press some buttons, and let them do their thing. This is how most of us will use a walkie talkie for instance. The other way though, is to spend some time to better understand how these devices work, and then to use that knowledge in order to get more use out of them. As a hobbyist, that might mean using a police scanner to listen out for interesting things like HAM radio. As a business owner, it might mean finding ways to make your communication more secure and reliable over your business two-way radio.
One thing that can help is to understand the different types of radio frequency found on these devices. Here’s what you need to know.
Radio Frequencies: The Basics
Radios work by transmitting and receiving messages via radio waves. Radio waves are waves that effectively disrupt the electromagnetic field that is present all over earth, and even in space. This is different from a soundwave for instance, as there is no requirement for a substance (such as air) for the waves to travel through. That way, radio waves have the potential to travel deep into space, at the speed of light.
There are a large range of frequencies that we can consider to be radio waves. They can go as low as 30Hz and as high as 300GHz. Two way radios work by listening to fluctuations in these waves that exist within a certain range of that spectrum (called a ‘band’).
Types of Frequency
So while you have a huge range of frequencies available, there are also specific ranges that have been categorized for different purposes. These are the ‘types of radio frequency’, and they are as follows:
VHF stands for Very High Frequency. These frequencies exist anywhere between 30MHz to 300MHz and are commonly used for businesses. More famously though, they are also used for marine bands: the communication used by vessels and harbours, bridges, locks, and the like. This is Marine VHF Radio.
Licence-Free Radio Frequencies
These frequencies are reserved for license free broadcasting. Most frequencies require a license, which is a measure intended to prevent interference and jamming. However, many users will broadcast without ever obtaining a license.
These frequencies can be found in the ‘UHF’ or ‘Ultra High Frequency’ band, which is anywhere from 300MHz to 3,000MHz.
American FRS and GMRS Radio Frequencies
These frequencies are the ones used by commercial walkie-talkies and typical handheld two-way radio tools. FRS stands for ‘Family Radio Service’ and is a system that has been around since 1996 for personal use.
As said: if you simply intend on buying a walkie-talkie and using it to communicate with friends and relatives, then you won’t need to understand all this. However, if you plan on listening in to interesting chatter via a police scanner, or investing in the right equipment for your business, then it can be useful to know what is what!