As the authors of this book say, amateur radio is considered by those who practise it to be the most rewarding of all hobbies. Nowadays, amateur radio knows practically no frontiers. Providing conditions permit, it is now possible to 'broadcast' almost anywhere in the world. Use of artificial satellites designated for amateur use and the great diversity of modern equipment make exchanges over vast distances speedy and reliable. Foreign language problems can be eliminated through the use of Morse (CW) transmissions. Alternatively, communication can take place orally, or with fellow enthusiasts as close as the next village, street or town. Comprehensively illustrated with line drawings and photographs, this book aims to provide all the relevant background information to students for the Radio Amateur's Examination, leading to the Amateur Radio Licence issued by the Home Office. It describes in detail what a radio is and how it works, including essential elementary mathematical formulae to explain first principles. All the basic aspects of transistors, modulation, receivers, transmitters, antennas, transmission lines and HF and VHF signals are dealt with in turn. The important subject of measurement, both to ensure that operation is within the power limitations set by the Home Office and that transmission is within the permitted amateur bands, is fully covered. Portable stations operating at less than 5 watts and video transmissions for amateurs are also described.