With analogue radios, the audio is carried along with the radio signals. As the radios get further apart, the signal degrades and you start to get crackling etc on the audio until eventually it fades out altogether, but this is over a very long distance.

Digital radios carry the audio as data “1s and 0s”. This means that as the signal degrades, the quality of the audio remains absolutely constant until the signal has degraded to such an extent that the 1s & 0s are not longer clear, then the audio stops altogether, just like digital TV when it rains hard or the antenna is slightly out of alignment, there is no fading out, it’s either absolutely clear, or nothing.

For most race tracks the signals from both analogue and digital are powerful enough to cover the whole area, but if the track has an area blocked by trees or drops down into a dip, the analogue signal will go crackly but still be heard by the driver whereas the digital audio might cut off completely until the driver is in a better position.  Digital radios do not have to re-pair to connect (like Bluetooth) so if a signal was lost it will come back automatically and instantly.

Analogue radios use an internally generated tone called CTCSS to identify their signal to other specific radios and thereby eliminate crosstalk with other teams.

Digital radios also identify themselves to other specific radios using a digital coding, again eliminating crosstalk with other teams.

Digital radios can be programmed to do more complicated functions such as when 2 cars are talking to 1 pit crew – they can separate out who hears what. Also you can have say 2 teams, 2 pit crews all on separate channels and yet have a team manager able to talk to everybody at the same time, or just the pit crews. – Very flexible, but complicated to set up!!

Both systems can suffer from interference when other teams are transmitting at exactly the same time on exactly the same frequency. Most sellers do not tell you that!