Propagation from Brazil is currently of technical interest in the Melbourne pre-sunrise and post-sunrise periods!
The signal path is via the "short-route", south from Brazil, over the Antarctic region, then northerly into Melbourne. At 2000 to 2200, this path lies almost in total darkness, but polar absorption limits effective propagation, due to signal blocking on freqs below about 6 MHz.
6180 R. Nacional, Brazilia – this appears at 2030, peaking 2100, through to past 2200, clear channel
9565 R .Tupi network, Curitiba – around 2000, co-channel VOIRI *1930-2030* Russian
11765 R. Tupi network, Curitiba – around 1930 to past 2200, co-channel RFI-Issoudin and VOIRI (*2100 Japanese)
11780 Radiodif. Amazonias, Brazilia – around 2030, to 2300, but schedule seems to vary each day. Clear channel.
Map of terminator on May 16 at 2000
Great Circle path from Brazilia to Melbourne