The phrase "high technology" is perhaps one of the more overused descriptions in our technical vocabulary. It is a phrase generally reserved for discussion of integrated circuits, fiber optics, satellite systems, and computers. Few people would associate high technology with vacuum tubes. The notion that vacuum tube construction is more art than science may have been true 10 or 20 years ago, but today it's a different story. The demand on the part of industry for tubes capable of higher operating power and frequency, and the economic necessity for tubes that provide greater efficiency and reliability, have moved power tube manufacturers into the high-tech arena. Advancements in tube design and construction have given end users new transmit­ ters and RF generators that allow industry to grow and prosper. If you bring up the subject of vacuum tubes to someone who has never worked on a transmitter, you are likely to get a blank stare and a question: "Do they make those anymore?" Although receiving tubes have disappeared from the scene, power tubes are alive and well and are performing vital functions in thousands of divergent applications. Solid-state and tube technologies each have their place, each with its strengths and weaknesses. Tube design and development, although accompanied by less fanfare, is advanc­ ing as are developments in solid-state technology. Power tubes today are designed with an eye toward high operating efficiency and high gain/bandwidth properties.