Crystal Radio Engineering
a web book by Kenneth A. Kuhn
updated March 9, 2015

This is a collection of articles that form a text book on designing crystal radios.  The primary focus is to illustrate to engineering students how to apply concepts of engineering to solve a problem.  It takes a lot of in-depth research to be good at what one does.  The main part of this book deals with understanding the required concepts to build a good basic crystal radio.  Advanced concepts (to be written and posted last) will deal with a number of improvements that can be made to the basic design.

Here is a link to an excellent site for crystal radio information: This is a site in Birmingham, AL that has a number of resources and links to other resources.  This is an excellent site with links to other crystal radio sites.  Be sure to check the Ben Tongue link for a number of practical articles.

Here is a source for parts I found using a Google search  This company specializes in parts for crystal radios and sells variable capacitors, diodes, crystal earphones, etc.  I have not bought from them before so I do not know how good they are but I might try them someday.

The following are links to the pdfs for each chapter.  If a link is not active then the chapter is not complete -- I am working as fast as I can to finish and post those so check back often.  The following is only a guide for now.  As the book develops I will likely add chapters or merge some chapters.  Many of the chapters are still incomplete and more material will be added as I have time.  I am trying to post all I have at the moment, however incomplete, so that students in the communications class, EE421, can use this to help with their crystal radio projects.

Inductor Design Spreadsheet  This is an Excel spreadsheet that guides you through the process of designing an inductor.  













audio_transformer.pdf -- new as of April 13, 2008



loop_antennas.pdf -- new as of April 17, 2008



A chapter on making various measurements of your system is planned.  Some other chapters or additional information is planned to connect all the chapters together smoothly.  Right now the connections are rough -- but this is a work in progress.