Cogwheel,
Perhaps the aircraft flown by pilots you refer to did not have HF fitted during their training. We have only one aircraft out of 16 on our line which does have a HF comm.
I know there a plenty of PPRuners here who are passionate about perceived falling standards in training. Without trying to make excuses, it is the regulator who decides the standards, not the training establishments. If more detailed theory training in this or other subjects was to be introduced into say the PPL syllabus then sure, areas such as basic radio theory and RF propagation could be covered. But then you would have organisations which advocate ideologies such as "freedom to fly without unnecessary restriction" crying out that the student is being taught information that is not required and incurring extra expense. It will do no good to provide the best theory training as part of a PPL course if the student decides he can achieve the same result cheaper elsewhere.
I seem to recall the briefing offices [RIP]used to produce an HF prediction chart to show the best frequencies for various regioins and times of day. Havent had a look to see if it is part of the available ASA briefing material but I bet it isn't.
[ 30 December 2001: Message edited by: Islander Jock ]</p>