HF not so reliable anymore.
Well I hate to disillusion you Didiman but the systems isn't quite as reliable these days as it was. Even the RFDS have acknowledged that the bulk of their callouts now come via phone and not HF in remote areas. They went to Selcall systems on HF and ditched the old two tone ECD a couple of years ago.
Between that and the rash of sunspot activity that seems to be on the increase again (thank you el nina) HF is taking a beating.
Having said that you can still get to just about any of the bases around Oz via HF, the signal just isn't always as strong and clear as it used to be. On some occasions it is marginal at best. The beauty of it being an open communication system though is that is likely somebody can hear you even if your intended station can't. If your satellite based phonecall fails then you have a problem.
I always went for HF communications and will probably continue to do so because I have a fairly significant investment in the equipment (and it's what I know). These days though I'd also carry a SatPhone because the technology has reached a point where it's robust, reliable and cheap. Just like HF used to be. Also the cost of acquiring and licensing HF equipment these days is at least four times that of a SatPhone (new to new comparison) and that equates to a LOT of phonecalls via satellite paid for in breaking even.
Can't remember the last time a satellite couldn't be acquired on InmarSat, that wasn't down due to maintenance (a very infrequent event anyway). Thousands of users worldwide rely on the system and it's still going strong for good reason. Not sure what is happening with Iridium.
Also as someone earlier pointed out. If you have to bail out in a hurry you can grab the SatPhone. Not usually so easy with the HF gear as it tends to be a fixture in the vehicle.
Satphone technology is, and always will be, much simpler to use and clearer than HF can ever hope to be. HF can, and does, get through when all else fails. Choose your poison. Each has plus and minus points.
Another 5c worth. Didn't mean to hijack the thread. Just felt a need to clear up this myth about the wonders of HF.
Cheers,
Iain