Electronic Design's Eighth Annual Transistor Data Chart, following last year's pattern, has been specially tailored to meet the specific needs of the design engineer. Contrary to existing lists which group transistors by manufacturer or in numerical se-quence (fine for salesmen, of limited use to engineers), the 1960 Data Chart has its 1088 transistors from 31 manufacturers or-ganized into six application categories:
- Audio—mostly general purpose types, under 1-w power rating.
- Power devices—1 w and above
- High frequency—types ranging up to and above the vhf range
- High-level switching—devices intended to handle high currents
- Low-level switching—low power devices for switching signal circuits
- Special types—low noise, high power/high frequency and others.
By this system of listing transistors, the design engineer is offered a rapid method of selecting a particular type based on parameter value. One word of caution: Quite a few similar number types, made by several companies, were submitted with different characteristics due to the non-conformity in test methods among manufacturers. (Electronic Design, July 8, 1960, p. 57)
Interest in transistor history is still strong. I received e-mail from two engineer/historians, Jack Ward and Bob McGarrah, and both have excellent transistor web sites (www.antique radio.com/ward_history_12-98.html; www.concentric.net/~Rmcgarra/). Ward is trying to find contacts at early transistor-oriented companies: National Union, Germanium Products, Hydroaire, Marvelco, and Sonotone. Contact him at www.ck722.com (focused on the early Raytheon CK722 transistor) if you can offer insight on any of these (or other transistor) companies.