1) Power Supply
You need one of these. About 95% of homes in the Clarence Valley have a Mast Head Amplifier sitting below the antenna to boost TV signals. Mast Head Amplifier's require a power supply to work. Ensure you have a power supply like the one's shown below.
If you don't have a power supply, you can purchase one from Harvey Norman, Electrical Wholesalers or Myself.
Now that you have a power supply you need to install it. The large power pack side obviously gets plugged into a power point. The smaller 'T' piece fitting plugs into your wall TV outlet. The 'T' piece has a male plug that gets inserted into the wall outlet (labelled "To Amplifier") and a female plug that the cable for your TV gets inserted into (labelled "To Television").
3) TV Tuning
Now that everything is installed you need to tune your TV. Go into the 'menu' or 'settings' (the button on your remote may look like a cog icon). Find 'channels' or 'DTV tuning' and start an auto tune. After the auto tune is complete if your TV didn't find any channels you may need to move the power supply to another TV outlet in the house (your TV doesn't have to also move). Then repeat the auto tuning process. If your house has several outlets you may need to repeat this until you find which TV outlet the power supply needs to be installed in.