“The Voice of the Crystal has a stellar reputation amongst radio geeks, and for good reason. This guide to building radios is filled with great ideas and utterly awesome projects.” – Gareth Branwyn, Make Magazine
“Fascinating stuff indeed! Highly recommended for the keen constructor – especially those wanting an interesting challenge!” – Rob Mannion, editor, Practical Wireless Magazine
“The Voice of the Crystal is essentially a guidebook to the art of building radio receivers from scratch. “Scratch” doesn’t mean components purchased at Radio Shack, or lifted from abandoned gear. This is “scratch” in its most elemental sense — discarded glass, scrap metal, you name it. (This book) takes the concept of elementary radio to an entirely new level.” – Steve Ford, Managing Editor, QST Magazine
“ I confess when I first saw the book and read the subtitle, I surmised that this book might be too much of a “niche item,” something only for subspecialists of a dying art. But this book is broadly educational in a way I never expected. Whether or not you plan to build your own crystal set, this book is a delightful read. Frankly, I couldn’t put it down. I can’t think of a better way for a fledgling scientist–young or not so young–to make a beginning at learning the secrets of nature.” – Sheldon Greaves, The Citizen Scientist
About The Voice Of The Crystal
To many, crystal radio construction means purchasing electronic components. However, the very best tinkerers can build their own! In The Voice Of The Crystal, author H. P. Friedrichs reveals how to construct all of the necessary components “from scratch”.
Inside this volume you will find 185 pages of practical information on the fabrication of electronic components suitable for use in building crystal radio sets. Basic theory and simple analysis is combined with dozens of examples of historical practice, work by contemporary experimenters, and construction details for many instruments fabricated by the author himself.
Inside are discussions and plans for three different homemade headphones, (including one fabricated from cigarette lighter parts,) detectors, fixed capacitors, a rotary variable condenser, single layer, spider web and basket coils, and a precision double-slider coil. Throughout, the author shares his thinking and practical experience in the construction of these devices. The Voice Of The Crystal is profusely illustrated, containing well over 120 photos and hand-prepared illustrations.
See also H. P. Friedrichs’ Instruments of Amplification.
The Voice Of The Crystal – Table Of Contents
The Challenge * Safety First * Basic Theory * Essential Characteristics Of A Good Headphone * The “Gallows” Headphone * The “Tin Can” * Headphone * The “Cigarette Lighter” Headphone * Essential Characteristics Of A Good Detector * Practical Detector Designs * The “Boom” Detector * Essential Characteristics Of The Condenser * The “Paper Tube” Condenser * Practical Variable Condensers * The “Roofing Metal” Condenser * Essential Characteristics Of The Coil * Thoughts On Practical Coils * Practical Variable Inductors and Coils * The “Crank” Coil * Thoughts On Simple Tuners * Some Thoughts On Antennas And Grounds * Sample Circuits And Assorted Ideas * Useful Formulas and Data * Where To Find Materials * Reference