Month: December 2022

On the Cover The Telefunken 201, a field-effect device using a sprayed-zinc coating as the control electrodet. In this issue

On the Cover “The Ear of the World”. In this issue  

On the Cover “Speed” – brand tube ad. In this issue

On the Cover Atlantic-Pacific “Solenoid” tube, 1923. In this issue

On the Cover Philips poster from 1930. In this issue

On the Cover The classic 2K25 oscillator reflex klystron. In this issue

On the Cover The well reputed EL84/6BQ5 output tube. In this issue

On the Cover Old-time “image” advertisement for Mullard tubes. In this issue

On the Cover Cover of a 1932 booklet from the Arcturus Radio Tube Company. In this issue

On the Cover Part of a collection of WWII tubes at the Evans Signal Laboratory, a unit of the Signal Corps Engineering Laboratory in New Jersey. In this issue