> As I say, I just switch them on really. Ok. It sounds like you're mostly talking about military communications. For a very restricted set of short distance c

> As I say, I just switch them on really. Ok. It sounds like you're mostly talking about military communications. For a very restricted set of short distance communication a pre-configured HF radio set with a pre-matched antenna may be pretty straightforward to use, but buying a brand new HF rig and getting it to communicate hundreds of miles is a lot more than just "switching them on". There's more to HF communications then you seem to realize. In the amateur service there are power restrictions, and modulation restrictions. If conditions are suboptimal there is then the issue of filtering or signal processing.