The address is not that important other than it is in Carlingford. The only signals are from the Artarmon/Gore Hill/Willoughby triangle of main transmitters.
The main problem is that the antenna is designed for channels 2 - 11 and possibly UHF but the image does not show the whole antenna.
Considering that channel 2 analog has not been transmitted since the end of 2013 and there is no UHF transmissions from the main transmitters, more than 50 % of the antenna is designed for channels which are no longer used.
The antenna should be replaced with a band 3 only antenna which is designed for channels 6 - 12 such as the Hills DY10 http://www.hillsantenna.com.au/common/HillsAntenna/files/DIGITEL_FLYER.pdf or http://www.matchmaster.com.au/digital-tv-antennas/03mm-dr3010/
Once one of these antennas has been installed, and the signal levels and error rates measured, if necessary a masthead amplifier containing a filter for VHF high band, particularly if multiple outlets are used.
An installer must have a digital field strength meter or do not use them.
Off-topic, but a protip for anyone who cares about their privacy: with just a reasonable guess, it took under a minute to get the exact address.
mirakation, you might like to edit your post. Folks, be careful what you post online...