Shall an electron tube or a semiconductor device be used?

A wide variety of electron tubes is now available to satisfy the needs of almost every application, but new types are still appearing as the field of electronics continues to enlarge. Also available are many kinds of semiconductor devices, although they are not as numerous as the types of electron tubes. With such a large range of operating characteristics available in both classes of electron devices, a designer of electronic equipment often is obliged to consider both types and make a choice of either an electron tube or a semiconductor device. The proper selection may not be immediately apparent, although each kind of electron device has a number of distinctive characteristics which can serve as aids in arriving at a reasonable decision.