Those of you who're interested in obscure engineering history might like to read up on Oleg Losev[1] who developed and built solid-state negative resistance rad

Those of you who're interested in obscure engineering history might like to read up on Oleg Losev[1] who developed and built solid-state negative resistance radios and amplifiers long before the first practical transistors. [1] https://en.wikipedia.org/wiki/Oleg_Losev?wprov=sfla1 https://en.wikipedia.org/wiki/Oleg_Losev?wprov=sfla1