Practical Wireless Encyclopaedia [antikvár]

preface to thirteenth editionA CONSIDERABLE amount of new matter has been added to the present edition, and the text has been entirely reread, amended and where necessary brought up to date.F. J. Cammpreface to twelfth editionThe first edition of this book was published in 1932 and its appearance coincided with the first issue of Practical Wireless. In founding that journal I felt that the large public for which it was intended to cater should at the same time have at hand a really comprehensive volume arranged in encyclopaedic form which would serve the dual purposes of an instruction manual and a work of reference. The reader encountering new terms, or wishing to consult a not easily-remembered formula was thus able, with equal facility, to refer to this encyclopaedia; and, if he desired, for example, to trace a fault in a receiver, to wind a coil, make a transformer, erect an aerial or study short-wave technique, he found upon consulting the subject that those aspects of radio were included in expanded sections. This book was then, and it remains, the only work of its type, and I am naturally gratified to know that it has become the standard work of reference.The justification of the idea which prompted its preparation is provided by its remarkable sales, for in the past eighteen years, during which the market has avidly absorbed eleven editions, over 300,000 copies have been sold. They have journeyed all over the world. Copies can be found on board ship, in radio laboratories, in the radio dens of the Bush, in public libraries, and the libraries of colleges and scientific institutions; in fact, copies are almost as widely broadcast as the radio waves with which the volume treats. The sales have exceeded by tens of thousands those of a best seller in fiction.In a new industry such as radio, changes are rapid. New branches of the science are introduced, and the nomenclature expands with the developments. The task of revising each edition so that it reflected these changes to keep