Area 50 is a collection of unusual, difficult, or simply lightly documented projects.  Much of the information in Area 50 is intended for experienced hobbyists - not beginners. The information may be incomplete or even incorrect and readers are assumed to have sufficient knowledge of the areas covered to evaluate the suitability and veracity of the information. Many projects will have kernels of information that are useful for other purposes and those will be mentioned at the end of the page.

Be warned, these are not necessarily polished projects! Area 50 is for inspiration only.

High Fidelity Audio Amplifier

Readers' Projects

Dual Tone Generator

Water Hammer Seismometer


What to do with obsolete Clock Chips

The Bug Duster

Phone "Apps." Really just Javascript electronics calculators that I find handy. Double-tap the one you want and it should fill the screen.

Mouse Versions of Apps  for PCs (with little keypad).

Virtual Projects - LTSpice schematics

Low Frequency Active Antenna works at the end of a long coax run.

Schumann Resonance Converter

Prospector's Ionization Chamber

PPS Generator  (1, 10, 100, 1000 PPS)

White Noise Generators

Electronic Mouse/Rat Trap

Portable Radon Detector

Extremely Isolated High Voltage Supply

Low Noise, High Gain Audio Preamplifier

Impulse Power!

What The Heck are these circuits? (scraps of paper with schematics).

Ghost Detector!

RF Isolator Notes are random notes and ideas regarding my Isolator/Circulator. These are just notes, so errors may exist. It looks like I was trying to come up with a version that uses standard resistor values.

MC1466 Replacement Circuit, possibly.

10MHz to 60 Hz frequency divider