Transistor Museum Oral History Joe D'Airo Trans-Aire Transistor Radio Page 5

A Transistor Museum Interview with Joe D’Airo

Transistor History at Trans-Aire Electronics Inc

Trans-Aire and “Raytheon BLUES”

Raytheon was a major producer of germanium transistors in the early to mid 1950s, and a striking feature of many of these devices was the iridescent blue paint used to coat the metal transistor cases. Transistor manufacturing processes from this timeframe were poorly understood and resulted in low production yields – Raytheon, GE and other transistor manufacturers of the 1950s had large quantities of scrap, which were leftovers that failed the testing activities set up to screen and characterize devices. Shown above left are four Raytheon 1950s germanium transistors that were salvaged by Joe from the Trans-Aire facility where he worked in the 1960s. According to Joe, “This picture shows some Raytheon devices which were marked with their appropriate function. The part on the left is partially painted yellow, which indicated that it was suitable for IF stages. Its original Raytheon part number is visible. The rest of the parts were sorted from fallouts from that part number family.” Note the stamped “IF” for Intermediate Amplifier, “DR” for Driver, and “PA” for Power Amplifier. This is how Trans-Aire identified these re-tested fallouts for specific radio circuit use. The photo at lower left shows the circuit board of the Saxony Six-Transistor radio shown at upper right. Note the use of three Raytheon BLUES in this radio. (See this Transistor Museum link for more information on Raytheon Blue transistors). The Saxony radio shown at upper right was sold with several other brand labels, including “Harlie” and also in various transistor counts including “Ten Transistor”. The actual company name “Trans-aire” appeared very infrequently on these radios. You can see one example above, which is an enlargement of the Saxony radio name plate.

Go To D’Airo Oral History, Page 6

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