a web book by Kenneth A.
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
http://www.crystalradio.us This is a
site in Birmingham, AL that has a number of resources and links to other
http://www.1n34a.com/ 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.
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.
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
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
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,
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.