Thanks for this!
Very interesting.
Murrurundi uses the same UHF 36 frequency as Sugarloaf (and also WIN Wollongong), and the interference issue suggests to me it’s being fed off air (probably from UHF 49 at Rossgole near Scone).
But the thing that perplexes me is IF the cause of the inteference is the “input” signal at the Mt Helen site, then I don’t see why a rescan is required - unless NBN is moving from UHF 36 also, which would seem unnecessary in this case.