For many people you would know a two way radio by the common name of ‘walkie talkie’. You’ve probably all seen someone use a two way radio, whether it is a policeman, a crane operator, a security guard or a truck driver.

Two way radios are used in countless industries  and for some, using two way radios can be a matter of life or death.

Think of your local policeman, if he’s in a dangerous situation he will need to call for backup. Two way radios make communication instant; there’s no dialling a number, waiting for the phone to ring and the other person to pick up. By pushing a button on the radio you will be instantly broadcast to whoever is listening on your frequency.

Traditionally two way radios work on an analog system. They are simplex communication devices which means only one person can talk at a time. Not like your telephone which has

photo credit: ThreadedThoughts

full duplex, This, as you know allows you both to talk to each other at the same time.

Some people might think this is a disadvantage which is why radio manufacturers such as Motorola are now making digital radios which are capable of full duplex operations just like your ordinary telephone – but without the phone bill!

There are two types of two way radios, unlicensed and licenced.

Unlicensed means anyone can use them. A common name for an unlicensed two way radio is a CB Radio (Citizen Band Radio), GPRS (General Public Radio Service) or amateur radio. If you have a CB radio you share the channels you talk on with anyone else who is in range, which means your conversations are never private. You may have to switch channels to get a free channel again. This can be annoying, but there are no ongoing charges with CBs, once you buy the unit you can start talking.

Licenced two way radios are what most commercial industries use. For example police, ports and civil defense to name just a few industries. There are special radios which are able to be programmed to specific frequencies which you lease on a yearly basis. This means that only someone with your radio frequencies can talk to you. This keeps communication fairly private, however some people may still be able to listen in on your conversations if they have the right equipment. You’ve probably all heard of someone with a police radio scanner?

A scanner allows the person to listen, but they can’t communicate back.