In Ireland and the rest of these off shore European isles, the non-digital terrestrial transmitted TV signal has a 6Mhz sound subcarrier, continential Europe and the Antipodean colonies use a 5.5Mz subcarrier. In Ireland, other parts of Europe and the Aus, a mix of UHF and VHF transmitter frequencies are used, while in the John Bull's island UHF frequencies only are used.
The simplest solution to your problem is to acquire a cheap local VCR and use it as a tuner. connecting to the SCART/ video audio input of your UK telly which now functions solely as a monitor.
Or find a replacement tuner from an equivalent Aus model.
Or, if you are receive picture but not sound, having the sound carrier retuned from 6 to 5.5 Mhz, but this can lead to other problems such as a buzz on the audio, vision beat problems and cross channel interference and it may not be possible with some of the more modern sets.
