Amazon.com description: Product Description: Behind the Front Panel by David Rutland, an electronics engineer with over 25 years of experience in the design of vacuum tube circuits, explores the whys and wherefores of the components and circuits of the first broadcast radios. By using simplified descriptions and illustrations, supplemented by 25 photographs of actual radio component parts, he provides a readable explanation of what goes on inside the old battery radios. His story begins with the invention of the radio tube at the turn of the last century and concentrates on the engineering design and development through the 1920’s. Design examples are taken from over 45 actual radios manufactured in the decade that saw broadcast radio start as a national pastime and end as a national necessity. This book is a classic in radio history. This edition is carefully re-mastered from the original and published by the California Historical Radio Society.