A few months ago, I was asked by Chris Wells, PARS President, if I
would be interested in “coming up” with a club “construction project”.
Something simple and safe, such as a regenerative receiver, low-voltage
“Space Charge” receiver or self-powered crystal radio set.
One unique crystal radio design in particular has held my interest for
several years now. I stumbled upon it on the Internet and have since
wanted to build and experiment with it. That circuit is known worldwide
as the “Mystery Crystal Set” of Australia.
First appearing in 1932, it has since captivated many radio enthusiasts.
Countless Mystery Sets have since been constructed and variations
of it have evolved. It has been studied, “reverse-engineered”
and countless discussions and conversations have ensued over its
simplistic, remarkable and unorthodox electrical circuit design and
how it operates.
It is my sincere hope that PARS club members will also be intrigued
by the Mystery Crystal Set radio, enough to want to build and experiment
with one of their own creations.
Certainly, there are numerous ways that the Mystery Set circuit can
be physically implemented – a few such versions are included herein.
It should prove quite interesting to see what variations club members
come up with in their own unique designs and then to compare notes
and performances.
I hope you find this project to be fun, exciting and able to transport
you back to a much simpler time and the early magic of radio!
Joe Patrick - PARS member - 2011

Mystery Crystal Set.PDF1.51 MB