At the end of the Second World War DCA was keen to move air/ground radio communications into the Very High Frequency band because of the much better clarity of transmissions. One difficulty was the bulk of the radio transceivers of the day, meaning that only large aircraft could carry radio.

In an attempt to design a radio transceiver small enough to be fitted in light aircraft, Amalgamated Wireless Australia (AWA) produced the VAC-1 Air Mite. The unit also included an intercom function. The receiver covered the frequency band 112-122 Mcs (MHz), whilst the transmitter had two crystal controlled frequencies. It was therefore important to know what frequencies would be required for a particular flight so that the correct crystals could be installed beforehand. The unit drew 3 amps from a 12 volt battery installed separately in the aircraft.

One of these radios was installed in a DCA Tiger Moth in 1948 (below). Testing by DCA revealed that although the transmitter output was only 0.25 Watt the unit was capable of maintaining reliable two-way communications at 30NM range from 3,000 ft or above. The unit was demonstrated to aircraft owners and operators at the Wagga Flying School in April 1949.

Despite this, light aircraft were still operating into the major capital city airports without any radio at all into the 1960s using visual signals for control.