Radio Communications 2
Its a bit more involved but skip is an easy way to describe. As there is ground waves and relfected signals of the ionisphere (skip).Basicly the Flying Doctor Radio Service has certain HF channels in the differect bands again usable at different times of the day.
For example the Amateur bands (80meters) 3.5Mhz morning / night, (40 Meters) 7Mhz daytime, (20 Meters) 14.250Mhz afternoon. Just 2 Mhz of so up from HF CB (11meters) >> (10 Meters) 29.600Mhz FM (like uhf CB "FM" but HF great in summer with repeaters throughout Oz and repeaters accessable Overseas. We at times have a ball here driving aroung sydney on 10-30 watts talking via Adelaids 10M FM repeater to other hams in Queensland and WA. Sometimes Amercian repeaters are even accessable. Again 52Mhz (6 Meters) just like ABC TV Frequency here in NSW great summer band with repeaters.
There are too many bands / frequencies to list here.
So in an emergency you would select the most optimum Amateur band or frequency to use. It is not approved to use an amateur radio on the RFDS service but it is possible, I do not advise you to do this.
However in such an emergency I would want to talk to anyone on any frequency to summon help.
Currently we are at the worst HF conditions as we at the bottom of the 11 year sunspot cycle so even HF CB may be suffering this may explain no body answered you. In the comming years you will be able to work another HF user with a piece of wet string as an antenna it does get real fun with very little power talking huge distances. Things arn't real good at the moment for HF.
I believe the foundation course is some study plus a 2 day week end.
Why not give it a go
VK2JLM is my call sign
have a look a The Official VK2JLM Website