While doing some research on the transition to solid state devices I encountered a really interesting article on the worlds first Transistorized Hi-Fi System. This article provides a nice back-stage view on how electronic design is carried out. Often, success depends on convincing your boss that a certain idea or process is worthwhile. Transistors in the 50s were hard to manufacture, noisy and unreliable, and when they worked it was only at low frequency and very low power. Many engineers were struggling to figure out what the transistor was good for outside of miniature hearing aids or signal conditioning in diode logic circuits. Sure the vacuum tube was large and inefficient, but it could do just about anything that needed doing at the time. Except when you needed thousands of them for a computer, then they weren’t so great.
By the 1960s, the transistor had finally found it’s niche in portable and mobile AM radios, Hi-Fi stereo systems, computers, and telephone repeaters while vacuum tubes continued to carry the day in high frequency radios, RF power amplifiers, and high voltage switches. The transistor had to pick it’s battles against the vacuum tube while new materials and manufacturing processes were being developed. Far from an explosion, the shift to transistors and the obsolescence of the vacuum tube required decades. The CRT display, a giant glass vacuum bottle filled with tin, copper, zinc, cesium, silver, and lead didn’t leave the scene until the first decade of the 21st century, replaced by a flat glass screen full of transistors. But we still have vacuum tubes in our microwave ovens. Last stand, I guess.”