Iron Pyrites RF Oscillator. Iron Pyrites Negative Resistance Oscillator.
Curve tracer shows negative resistance in the reverse bias portion of the curve.
Curve tracer was modified to apply ac to the device. Success with this experiment has been a very exciting experience for me as it represents the ability to build a simple homemade active semiconductor device. It is almost like making your own homemade transistor. This is an actual realization of some very old, and esoteric 1920's experiments, by W.H. Eccles, Greenleaf Pickard and Oleg Losev, that were so vaguely reported in a few articles that I have often wondered if in fact it had actually been done. Even so, I have always had an extreme fascination with those reports of being able to produce a continuous wave RF signal from a crude semiconductor matarial back in the very early days of radio.