How a Two Way Radio Operates

Walkie talkies are the simplest example of a two-way radio.

Unlike the broadcast radio found in your car that only receives signals, two-way radio both transmits and receives. The most common types are walkie talkies, Family Radio Service, CBs and amateur radio. Because two-way radios both transmit and receive, they work a little differently than the car radio.

Uses of Two -Way Radios

Since two-way radios can both transmit and receive they are a popular form of communication. Many families with younger children have opted for Family Service Radio, an improved walkie talkie system, on family outings to places like amusement parks because they are simpler for a small child to operate than a cell phone. These improved walkie talkies are also very popular with businesses where different departments can communicate with each other.

Receiving

The most commonly used mode of a two-way radio is the receive mode. When receiving, the radio is listening for a certain radio frequency. When a signal is detected, it is received on the units antenna, where is is routed to a amplifier and a circuit called a mixer. The mixer takes another fixed radio frequency and mixes it with the one that was received, the result is a lower radio frequency, usually called a I.F. or intermediate frequency.

This intermediate frequency is amplified and fed to another mixer, which will convert the IF down to an audio signal. The audio signal is amplified and fed to a volume control and then to a speaker or headphone jack for the user to listen to the audio.

Transmitting

Transmitting is receiving in reverse. Users normally have to push a button, called a transmit button, to place the radio into a transmit mode. Once the radio is in transmit mode, you talk into the microphone. Your voice audio is then amplified and sent through a mixer, turning it into an intermediate frequency.

The IF is then amplified and routed to another mixer, the frequency of which was chosen for the selected channel that you wish to transmit on. The resulting frequency is now a radio frequency that is sent to another amplifier and then routed to the radios antenna, where it propagates out to the atmosphere and to your intended user.