Radio Australia has changed their schedule but this page still shows the
old schedule.

http://www.abc.net.au/ra/tuning/unitedstates.htm
Overnight 19:00 - 04:00 12080 13630 15160 15515 17715 17795 21740

I take this to mean that they are on all of these frequencies during
this time. This is has been wrong for months at least as they have been
on 21,740 22:00 to 24:00 UTC and now it looks like 23:00 to 24:00 hours.

I went to their web site and down loaded their frequency schedule and
only found one listing for 21,740 on page three that states 22:00 to
00:00 UTC.

http://www.abc.net.au/ra/tuning/shortwave_window.htm

--
Telamon
Ventura, California