As most of the Amateur Radio community know there is HF APRS on the 30m band. Well there is a trial currently happening (again) on the 20m band. This was started up a few weeks ago by Ray VK2TV. Now depending on what packet radio equipment you have (TNC) the frequency that you will need to monitor will vary depending on the tones used by your TNC/Sound Card/Tracker. Most TNC's are either 1600/1800Hz but some older ones (like the PK-232) use 2110/2310Hz. So if you start listening around 14.105MHz USB you can then fine tune form there!
Now as the HF band conditions haven't been too good! you may not hear much! but be persistent… Currently there is only two fixed stations active that is Ray VK2TV-4 & myself VK7HSE. I'm just using a PK-232MBX TNC to monitor if sufficient traffic starts to use this the I'll integrate this into my I-Gate so that traffic that I hear will be passed to the APRSIS system.