Two way radios, or walkie talkies are proving extremely popular with motorcyclists, skiers, mountain bikers and anyone that likes outdoor activity. They are also commonly used at events, football matches, rugby matches and other sporting events for crowd control and security, not to mention the use by doormen for nightclub security. An innovative use of the technology is as baby monitors - up to 3km away!

So How Do They Work?

Two way radios are very simple to operate. Each radio needs to be on the same channel, and when they are, you can communicate via the PTT (Push to talk) buttons. There's no fees or line rental to pay - thats why they are known as license free and offer a huge saving over the price of mobile phone calls.

In addition, PMR446 radios are not anything like mobile phones as they do not require an outside signal or network to operate. When you transmit, the signal is directly picked up (like peer to peer) by another radio in range, and hence you do not need to pay for calls.

Walkie talkies are also different to phones in that you cannot talk and listen at the same time, i.e. they are not full duplex. You have to press the push to talk button to transmit and let go to hear the person talking to you.

So Whats The Range?

The maximum theoretical range is around 5 kilometres, however in real life 1km - 3km is achievable. All PMR446 radios are legally restricted to 0.5w of power, which means that all brands will have around the same range. The range is however reduced when the radio signal has  to pass through solid objects. Indoors the range may drop to as little as 400 metres, depending on the materials used to construct the building.

So Whats PMR446?

PMR446 is the European standard for short range license free radios that can be bought and used by the general public. PMR446 compliant two way radios are made by a wide variety of manufacturers, including Cobra, Entel, Oregon Scientific, HYT, Xtreme, Motorola, Kenwood, Binatone etc. PMR446 is a standard and not a model type, and all PMR446 radios use the same channels, so PMR446 radios of one brand can "talk" to any other PMR446 brand of radio.

So How Many Channels Do These Radios Have?

All PMR446 radios have at least 8 channels. Almost all models also have 38 CTCSS codes as well. These are sometimes known as "sub channels" although what they really do is screen out other radio messages on the same channel from radios not set to the same CTCSS code.

So in theory, there are 304 unique "channels" that you can communicate on.

So What Is CTCSS?

CTCSS stands for "Continuous Tone Coded Squelch System". If a CTCSS tone is selected, a CTCSS sub-audible tone is transmitted along with the regular voice audio by the transmitting radio.

The receiving radio, set to the same CTCSS tone, will only receive audio if it contains that sub-tone. Interference from other users on the same frequency is therefore rejected (unless they are also on the same CTCSS code).

This is a way of allowing groups of users of walkie-talkies on the same channel to avoid hearing messages from other nearby users. It is useful if you find that another company or organisation next door to yours are also using PMR446 walkie-talkies.

At BB-Shopping, the most popular sets of radios that we sell are the Cobra MT725 Value Pack and Oregon Scientfic TP380.