The "long range" licence free radio myth
We know that every manufacturer wants to gain the competitive edge over the others. But some companies have starting putting really unbelievable range claims on their packaging and brochures.
mountain to mountain!
Lets start with the facts. Licence free (pmr446) radios are limited in a number of ways to allow them to be classed as licence free. One of the requirements is that the radio is limited to 0.5w (half a watt) RF output power. Anything more than that would require the appropriate Ofcom radio licence for use in the UK.
One of the schools we've looked after for a number of years got in touch to show me this amazing new product that blew their minds, it was a twin pack of licence free radios. I really wasn't too sure what was supposed to be so exciting about them, was I missing something really obvious? She then pointed out to me the 'estimated range' info on the packaging. Up to 12km range. For under £100, for a pair of radios!
The customer felt like we'd been dishonest and sold them expensive radios that no way go 12km!
So, here's the thing. There is no way those licence free, or any licence free radio for that fact will go 12km in real work conditions.
So what's behind the 12km range claims?
Well, 90% of licence free radios are what we call 'leisure radios'. They've been designed for occasional use, for example when camping, or mountaineering. Not for everyday use. The batteries and general build quality aren't up to it. Only 'business radios' have been designed to be used all day every day. Back to the 12km range claims, this is based on a line of sight estimation. So you need to have 12km of open space, no trees, no buildings, nothing. One of the only places this can be tested is from the top of one mountain to another. In this situation even 12km is a push but can be achieved when you have nothing but fresh air in between radios.
As soon as you start introducing other items between you and the other radio the range gets less and less. Say even a rural school will struggle to get more than 0.5km range from this type of radio.
So unless you're wanting a set of radios to go mountaineering with, then unfortunately there is no way you'll even achieve a tenth of that 12km marketed range.
RF power output is physics, there aren't any magical shortcuts manufacturers can use to get so much extra range, both £30 to £180 licence free radios will all give you roughly the same range, about 0.5km outdoors.