PREFACE Truly of the making of many books there is no end and in view of the large number of radio books already existant and advertised as in the process of preparation or printing, perhaps some justification is necessary for the appearance of another. My apologia is a simple one, and possibly one engendered by ideas and aspirations not unfamiliar to all other radio amateurs. Since connecting up my first receiving apparatus in 1908 I have longed for the appearance of a certain type of radio book a book issuing preferably from the pen of an amateur, radiating the true amateur spirit of inquest and investigation, a book chockfull of practical information and suggestions for new things to do and instructions for going about it, in a word, a book which would at once ignite the spark of my enthusiasm and furnish the material for its combustion. Such a book has never appeared, nor ever shall for the great majority of us, for we have all our own ideas as to what the ideal radio book for amateurs should be like. But intercourse extending over a number of years with kindred spirits and frequent discussions with them on this subject has induced the belief that in the main our ideas converge in a common channel. This book represents my conception of the direction and breadth of this channel. I have always looked upon the book-making business with a great deal of fear and hesitation, clearly recognizing 5 6 PREFACE the seriousness of addressing such a vast audience and the power of the pen for the dissemination of good or evil information. Particularly is this true of a book of this nature, whose readers are for the most part non-technical and in no position to judge the theoretical soundness of the suggestions and methods exploited, yet who are at the same time full of enthusiasm and ready to spend time and money upon almost any suggestion offered. My original plan therefore was to defer the book-writing for the growth of a few gray hairs, but this plan has aborted due to the encouragement of friends, the interest of the publishers, and my own feeling that in view of the present widespread popular enthusiasm a more auspicious time for publication will probably never arrive. With elementary treatments of the theory of radio communication on the one hand, and with systematic engineering texts on the other, my book obviously enters into no competition. It is addressed mainly and first of all to the amateur to the amateur in both the commonly accepted meaning of the word and in the true French sense of a lover, or admirer. This latter may be regarded as the legitimate amateur a serious-minded individual with perhaps some technical propensities...