In March of 2009 while shopping for some sensors on ebay, quite on a lark I typed "Crystal Radio" as a search term not really knowing what to expect. My search was not totally random, I have always been interested in radio communications and in radio propagation as a geophysical probe of the ionosphere, (more about that here). Additionally as a child I had once a small "Spy Pen" crystal radio what always facinated me, and as an adult I had given a crystal radio toy kit to my second son who showed much interest in computers and electrical things. He has since gone on to his Master's degree in EE and now works designing computer chips for Intel in Silicon Valley. So, maybe it was the radio?
Vaguely I thought to find a crystal radio or radio kit of some sort to play with, something more serious than a cheap plastic toy. What I found was suprising, so much there. I explored the listings, odds and ends mostly of course, its ebay after all, and a few completed radios new and vintage, and one in partictular which caught my eye. There were several kits by someone calling himself Xtalman including one he calls Dunwoody which seemed to exactly fit my idea, a kit, easy enough for a beginner but serious enough to satisfy a more educated mind. I decided to pull the trigger, the radio was offered "buy it now", so I did! So began my journey into a black hole of interest, somebody really ought to post warnings on all crystal radios.. "WARNING, may cause serious refocusing of lifestyle".
In the time since, I have plunged deeply into the web literature, joined the Xtal Set Society, and built homebrews of my own in addition to purchasing a few sets, (described separately). In the following pages I present each radio with the ideas and motavations that move me to own, admire, and use them. It has become a facinating journey for me which I wish to share so that others may understand and catch the bug for themselves, so that other radio builders may view and comment, with suggestions perhaps for improvement, and so us newbies may heed the WARNING, and STILL take the plunge!
I would love to hear from you if you have comments or questions. Please write me at the following:
CRYSTAL RADIO HANDBOOK.. Available in hardcover to add to your library.....
RADIO LABORATORY.. Know thy radio.....
A Library of Crystal Hookups and Theory:..
A Geological look at Steel Galena...
KGOW1650, a local PEST!!..
JACQUEMARD.. The good Professeur's French Rig for MW/LW..
Acknowledgements:.. (and useful links)
SPARK GAP TRANSMITTER.. A Spark-Gap Transmitter project...
DUNWOODY.. A tale of my entry into the world of Crystal Radio
MYSTERY.. My first homemade, Proton's Mystery
HOME BREW.. A double tuned set / prototyping testbed.
DE FOREST.. A showcase for some lovely vintage components.
BREMER-TULLY.. Bank-wound inductor, vintage components seeking their place..
GLOBAL DX'TER.. Riding on the High Road
FLEMING.. The first electronic detector, Fleming's amazing valve.
MINSTREL BOY.. Triple-tuned link-coupled set veiled in green.
HAMMARLUND.. Double-tuned set with Hammarlund caps.
TEFLON.. High-performance Double-tuned set, Contest Worthy.
TELEFUNKEN.. Another Mystery set, powerd by vacuum technology..
BIG LITZ.. A venture into performance..
WAVE TRAP.. Problems eliminated
PRO WAVE TRAP.. Playing with the big boys now...
AUDIO AMPLIFIER.. For those times when....
LOADING COIL.. A Vintage Variometer finds a happy home.
MINILABS.. A toy Crystal Radio my son made.
SLEEPER #1.. Cheap shot, but it's a radio!
STEINITE.. Vintage radio from the mid-1920's
AMERICAN RADIO STORES.. Another vintage radio from the mid-1920's
BBC COMMERATIVE.. A bit of a mystery this one..