Interesting. I had heard many years ago that they broadcast from Grovedale but just presumed the information to be incorrect - you are right that the signal wouldn’t have been anywhere near as good into Melbourne from out there. Do you know more about where abouts they were located? I had been told it might have been somewhere near the library off Heyers Road.
Seems odd that a high-power AM TX site such as that would have been newly constructed for a narrowcaster after 3GL went off-air. But then, it also seems odd that 3GL would have invested in a new TX site knowing an FM conversion was likely imminent. Would love to get to the bottom of that.