Double-ganged Mystery Crystal Set
copyright © 2006 by
Larry J Solomon
Here's another great performer based on the Mystery set. This one
uses a 500 pF döppelganger.
C1, C2 - 500 pF double-ganged air-variable capacitor
C3 - .001 uF capacitor
D - 1N34A diode or rock crystal
L1 - 50 turns #24 awg
L2 - 25 turns #24 awg wound in tandem with middle of L1
The Coil is air-spaced on each end of L1. L2 is close-wound with L1
after 12 turns of L1. Coils are wound in same direction. Coil form is
2.625 inches high by 2.375 inches in diameter. Although a high
impedance headphone is shown, the
set can be directly connected to the magnetic phono input of an
amplifier instead of the headphones.