You may ask why I wrote this book. There are many, many personal reasons as with any author I suppose. The first two reasons and probably the most important are my love of flying and my love of radio engineering. This may sound rather dull but I love flying in any machine be it balloon, glider, propeller aircraft, microlight through to airline jets and the experience of it. The more I do it the more I feel I understand it. A relative once asked me, ‘how does an aircraft fly?’ I thought for a while, of how to try and explain the fundamentals of physics and aerodynamics which I feel privileged to have had a fundamental education in. After further thought I realized how I take it all for granted like the vast majority of the people, and despite this education and the sound engineering principles, I still find that flying defies all our instinct and it truly is difficult to explain. I also find the whole topic of radio propagation equally magical. Again, how can it work when we cannot see it? How can signals travel through apparent nothingness. How can we predict it? The physical equations are all there to describe it in great detail, however it too defies a layman’s logic.