Wireless fundamentals [antikvár]

PREFACE This book is intended to fill a gap that at present exists between books whose aim is to teach "wireless" to students with no previous knowledge of electricity and those which are written for readers of University standard, equipped with the Calculus and the desire for a rigorously mathematical treatment of the subject. I believe that the scope of the former type is too wide to be embraced, with advantage to the student, within the confines of a single volume, while there is a wide choice of excellent books of the latter kind (a list of such books is to be found in Appendix IV). This book caters for those who find the former type of book on Wireless Fundamentals too elementary in the parts dealing with simple electricity, such as the effects of an electric current, Ohm's law, etc., and yet who find the more advanced books too mathematical and with too little space accorded to descriptions of the more physical and practical aspects of the subject. I have therefore assumed a knowledge of elementary electricity up to Ohm's law. Though sorely tempted on many occasions, I have not used the Calculus but I have attempted instead to keep the physical and experimentál side of the subject to the fore throughout the book. Nevertheless, I have made provision in the Appendices for the student who desires to have the more theoretical parts of the subject treated mathematically. It is hoped, too, that the Appendices will "point the way" to those who are not yet sufficiently equipped in that direction by indicating how certain portions of the subject lend themselves to concise and elegant mathematical treatment while having to be glossed over or stated without proof in a non-mathematical presentation. As wireless is pre-eminently a practical subject, the reader is urged to perform the experiments outlined in the book for himself, and it has been assumed that facilities exist for carrying out this practical work. Where such facilities do not exist it is hoped that the description of the method of the experiment and the results to be obtained are sufficiently detailed to give a clear understanding of what the experiment is intended to