It was an experiment set for International Physics Olympiad. There was a black box with a tunnel diode, inductor and capacitor inside. If the diode would have b

It was an experiment set for International Physics Olympiad. There was a black box with a tunnel diode, inductor and capacitor inside. If the diode would have been impossible to source, another set-up for the black box would have been used instead. Experiment is described here: http://hedgehog.ee/ipho http://hedgehog.ee/ipho