A Transistor Museum Interview with Joe D’Airo

Transistor History at Trans-Aire Electronics Inc

Oral History – Joe D’Airo

Joe, thanks for providing such detailed material on Trans-Aire to the Transistor Museum™.  Would you please talk about your involvement with Trans-Aire?

 

I helped out at Trans-Aire between the summers of 1965 and 1968. My father was an RF engineer there and he brought me to work because of my interest in electronics.  His name is Leonard J. D’Airo, and he wrote Servicing Transistor Radios, published by Gernsback in 1958.

 

In 1965 Trans-Aire was located in New Hyde Park, NY.  At that time they were in the midst of building 100,000 battery operated table radios and large portables for the US government that were distributed in Vietnam in a cultural friendship program (the radios had a logo with two hands shaking – see photos starting on page 10).  Those radios used GE transistors from the 2N525 family.  They would buy fallouts by the barrel, unmarked, and sort them out themselves.  Later on they did the same with Fairchild “Plastic TO-5” or TO-105 transistors.  To identify the sorted transistors, they were either color-coded, stamped with their intended function, or labeled.

 

When they were cleaning out their engineering lab, I kept a number of their discarded transistors.  Among those were a number of devices with small glass-globe tops.  Thanks to the Semiconductor Museum website, I learned that they were Radio-Reflector RR66 phototransistors, possibly brought to Trans-Aire by Roland Wittenberg, who was involved with both companies. 

 

 

 

Oral History – Joe D’Airo

Other discarded transistors included Raytheon devices painted blue, red, and yellow.  It is likely that these were bought from Raytheon as fallouts, then tested and color-coded by Trans-Aire to keep component costs down.  I found other bulk transistors from the Fairchild 2N718 family, plus samples from General Transistor, Germanium Products, Philco, and others.

 

Trans-Aire built their own testers to sort the transistors.  I recall small slope-front meter boxes with transistor sockets, switches, and a large meter which had the grades marked on its face.  The primary test was for gain or beta, with the “hottest” transistors being assigned for RF (converter) use, the next highest gain were IF transistors, and the lower gain devices being assigned to audio stages.  They must have also tested for open-short, leakage, and breakdown, but I don’t recall specifically.  Some of the parts which failed the transistor test were used as detector diodes.  Sometimes they counted those diodes as transistors, which was common in those days. So a “6-Transistor” radio consisted of (1) converter, (1) IF, (1) audio driver, (2) audio outputs, and (1) transistor used as a diode detector.

 

 

What types of work did you do at Trans-Aire in the mid 1960s?

 

It was fun.  I went to work with my father in the summers when school was out, also some Saturdays.  Mostly I worked in the stockroom, but also helped out in the engineering lab. 

 

Go To D'Airo Oral History, Page 4

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