If you are investing in a new two-way radio, or if you are simply interested in the topic from a hobbyist perspective, then you might find yourself wondering what the limitations of this technology are. What kinds of things can you pick up using a radio? What kinds of things can you transmit?
And how could you hack this technology in order to do something amazing with a walkie talkie?
How Radios Send and Receive Data
To understand the full potential of radios, it is first useful to understand how they work. And, as the name would suggest, these devices primarily work by using radio signals.
Radio waves are a form of electromagnetic radiation. These are ‘packets of energy’ that essentially travel through the atmosphere and alter the charge in the ambient electrons, causing tiny oscillations. While we think of radio waves as being relatively ‘old’ technology, they are actually extremely powerful – capable of travelling at the speed of light and easily circling the globe more than 7 times a second!
Not only that, but because electromagnetic pulses use electromagnetic fields as their ‘medium’ (rather than particles like air or water), they are capable of travelling through space. This is why organizations like SETI use radio waves to attempt communication with extra-terrestrials!
When using two-way radio or a police scanner, we will listen out for fluctuations in this electromagnetic field that exist within certain frequencies (called bands). These are then converted to alternating currents by antennae, which in turn are then converted to spoken language, music, and other forms of communication.
Analogue radio works through slight changes to the frequency within a certain band, while digital radio utilizes ones and zeroes (stops and starts) in order to packet the data.
Hacking Radio Waves
So how can slight changes to a radio wave be interpreted as words and voice? Well actually, this works in just the same way as files on a computer – which are also interpreted from 0s and 1s (in this case representing the states of millions of switches).
A close analogy that humans use would be morse code. These are simply sounds that start and stop, but we are able to decode those signals into words and messages. Radio works in the very same way. The only difference is that this information is able to travel much further than morse code, and to contain far more complex messaging.
So, what can you send over radio? Well… anything really!
While most of us think of things like HAM radio, or digital police scanners, the truth is that radio can send video and even computer programs. The best example perhaps is Bluetooth, which is actually a data transmission protocol that moves through radio. If ‘radio’ is speech, then ‘bluetooth’ is English. Traditionally, television will also use radio waves!
So, why can’t you get television on your walkie talkie?
Of course, the limitation here is primarily with the hardware – which has neither the capability to decompile the amount of information necessary for images, nor a means of displaying it!
But if you really wanted to, as a hobby, there would be nothing stopping from creating a system that allowed you to send videos from a baby monitor to a computer. And in all likelihood, knowing the internet, someone probably already has!