A number of commercial trunking systems operate in South Australia. Many businesses are now moving away from their own dedicated conventional radio networks, and opting to use a hired commercial trunking system.

The advantage of these networks are that the coverage is often greater than from a conventional UHF or VHF simplex or repeater network, the commercial user does not have to worry about maintenance costs and a small degree of privacy is offered by many of the digital networks.

Many of these trunking systems operate using digital modulation systems, which a scanner cannot demodulate the audio. However with the use of a very inexpensive TV tuner USB dongle, a PC and some software, most of these networks can be monitored.

Software that will you will need to get started includes;

SDR # - to set the TV tuner dongle to trunking frequencies

Unitrunker - needed to monitor the trunking network and view activity on the system

DSD Plus - required to demodulate the digital audio

An excellent tutorial for getting these programs to work together can be found at the RTL-SDR website.