the story of valves - Once upon a time

the story of valves elektor november 1984 Once upon a time... the story of valves Before the arrival of the transistor all amplifiers, transmitters, receivers, etc., were made with valves. In the eyes of many "modern" people valves were (and are) fragile and unreliable and had a short lifespan. Not all that long ago, however, there was no alternative. Before the valve there were simply no amplifiers, and the transistor was only invented in 1948. But think about this: without FM transmitters (which contain valves) would there be any point in having a compact transistorised FM receiver? 11-24 What exactly is a valve? Many of our more mature readers know, of course, but some of the youngsters may think something along the lines of: "Oh yes, one of those old-fashioned fragile glass things with all sorts of complicated-looking bits and pieces inside". This definition is not strictly wrong but it leaves out rather a lot. True, a valve is made of glass but, in spite of its appearance, it...