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:
http://www.crystalradio.net/crystalplans/index.shtml
http://www.crystalradio.us This is a
site in Birmingham, AL that has a number of resources and links to other
resources.
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.
Here
is a source for parts I found using a Google search
http://www.midnightscience.com/catalog5.html#part2
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.
title.pdf
introduction.pdf
component_sources.pdf
rf_field_strength.pdf
antenna_and_ground_system.pdf
simple_radios.pdf
mathematical_model_of_wire_antenna.pdf
resonant_circuit.pdf
antenna_matching.pdf
designing_inductors.pdf
tapping_inductors.pdf
diode_detectors.pdf
audio_transformer.pdf -- new as
of April 13, 2008
headphones.pdf
speakers.pdf
loop_antennas.pdf -- new as of April 17,
2008
a_simple_crystal_radio.pdf
advanced_topics.pdf
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.