> Negative resistance devices are very tricky to use Sure... I'm not an engineer, but I read that tunnel diodes were hailed as the greatest innovation in semi

> Negative resistance devices are very tricky to use Sure... I'm not an engineer, but I read that tunnel diodes were hailed as the greatest innovation in semiconductor of the 1960s, and it was often the only available option in high-frequency applications, but they were almost completely abandoned when integrated circuits became feasible. Leaving the embarrassing situation that the tunnel diodes in lot of vintage Tektronix oscilloscopes are unobtainium. > Bell created a design that was commercially useful and widely applicable This is kind of the point made by the original comment. Arguing about the "first" sometimes is a waste of time, it's better to list all the codiscoverers and discuss their respective contributions.