On 3/13/19 7:10 AM, William Donzelli via cctalk wrote: > Be careful handing out the praise. The idea of adding a external > signals and biases to crystal detectors was an old trick from the > 1920s. No one really knew what was going on, and no one really used > this technology, simply because performance was beyond horrid - even > original Audions worked better.
Sure--I recall reading an article from an issue of QST from the 1920s that reported an "oscillating crystal". One has to believe that negative resistance in solid materials had to have been discovered several times. There is a web site, http://www.sparkbangbuzz.com/ that demonstrates that a strip of galvanized steel can make a quite successful negative-resistance device, including several transmitters. The fellow even shows how to make a memristor using some brass and sulfur. --Chuck