A group of people who are using walkie-talkies to talk to one another have to tune in to the same frequency band, which is called a channel.
Their radios are all "receiving," so their microphone/loudspeaker units are working as loudspeakers and probably hissing with static, a bit like a conventional radio that's not tuned into any particular station.
When someone wants to to talk to the others, they hold the push-to-talk button on their handset.
Their radio goes quiet as their loudspeaker switches over to a microphone.
As they talk into it, their words are converted into radio waves and beamed out on the prearranged channel (typically at a frequency around 460 MHz). Since radio waves are part of the electromagnetic spectrum, they travel at the speed of light (300,000 km/second or 186,000 miles/second ),
so the waves are picked up almost instantaneously by the other handsets.
The radio waves are converted back into fluctuating electric currents and the loudspeakers use those to reproduce the sound of the talker's voice. When the talker has finished, he or she says "over" (meaning my bit of talking is finished) and releases the push-to-talk button.
The radio now switches back into listening mode and someone else can talk.
Unlike a normal radio, which will only pick up broadcast voices or music from a radio station, a walkie-talkie is a two-way radio: you can both talk and listen (send and receive).
The main drawback is that the same frequency channel is used for both things, so only one person can talk at a time.
When communication devices work this way, they're described as half-duplex (a single channel allows communication in only one direction at any one time), as opposed to full-duplex (where you can talk and listen at the same time, as on a telephone).
Play Games With Your Walkie Talkies Code Words
HIDE & SEEK
Each player has a walkie talkie. Take it in turns to hide. The ‘seeker’
presses the CALL button. By listening to where the sound is coming
from (the ‘hiders’ walkie talkie), the target should be easily located!
You can limit the amount of times the CALL can be pressed to make
it a more difficult game.
TREASURE HUNT
Ask an adult to hide something for the ‘hunter’ to find. It should be
in an area where you can both see each other, but at a distance apart
where you would normally need to shout to talk. The adult calls out
clues using the walkie talkie that guide the ‘hunter’ to the treasure;
‘to the left’, ‘above your head’, ‘under the leaves’ or ‘look behind the
tree’ etc. Older children can play this without an adult supervising.
PRETEND PLAY
Using just your imagination, it’s fun to pretend you are in the jungle
or halfway up a mountain! Tell headquarters (HQ) what you are doing
and where you are. Where else could you be using your walkie talkie?
SECRET CODES
Make up secret codes so that only the person on the other walkie talkie
knows what you are talking about! Have fun by changing names and
places with your own code words. For example, Mum could be called
‘V’ or ‘target one’, Dad could be called ‘W’ or ‘target two’ and a
neighbour could be called ‘X’ or ‘target three’. As long as both you and
your friend understand the rules it will be easy to talk in code. You can
also create substitute versions of everyday words. For example, you
could substitute the words ‘birthday’ with OLD, ‘present’ with DONKEY,
and ‘party’ with DANCE. So, you might say (in code) ‘I am going to
take the OLD DONKEY to the DANCE!’ If only a few people know the
substituted words, it can be a good way to keep your communication
secret. Do not forget to write your code words down so you do not
forget them!