Chuck Colby

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  First Pocket Transistor Radio, The TR-2


The TR-2, Outside and Inside

In early 1954, 12-year-old Chuck Colby of Torrance, California built what is believed to be the first commercial Pocket Transistor Radio, The Colby TR-2.  It used two CK722 transistors. In the above photo of the inside of the Colby TR-2, the CK722 transistor is the blue colored component. The other transistor is missing in this unit as it was used for 35 years by a night duty nurse, and while changing batteries; one of the transistors fell out and was lost. It was returned in 1990 but declared out of warranty. The CK722 was the first transistor that was available to the pubic. Introduced in 1952 at a price of  $21 each, by 1954 the price had fallen to two or three dollars, so it was then feasible to build a low cost transistor radio using them. This transistor is so famous it even has its own website.

TR-2 PC Board

Later in 1954, a company called Regency introduced the second pocket transistor radio, the TR-1. It was quite a bit larger than the Colby unit (3x5x 1.25” versus 3x2.25x.75” for the Colby unit). It sold for $49.99 plus $3.95 for the earphone ($375 in today's dollars) verses $12.99 for the Colby unit, which included an earphone. The Regency unit (website) was designed by Texas Instruments and used 4 transistors. Additional info on early transistor radios can be found here.

Besides fitting into a shirt pocket much easier than the Regency unit, the Colby unit used 2 low cost AAA batteries that were good for 80 hours, verses the very expensive 22.5 volt battery the Regency unit used that only gave 20 hours of use. The main other differences were that the Regency unit had a beautifully designed case and a  built-in speaker whereas the Colby unit used a plain, off the shelf, plastic case and could be used only with an earphone.  Regency, with their worldwide advertising budget, sold ten of thousands of their units, verses the hundreds that Chuck Colby sold  to his friends, family and paper-route customers. But it was a start and made Colby enough money to convince him that Electronics was the field to go into and started him on a life of inventing that have resulting in many firsts over the years.

Almost unbelievably, the first pocket Japanese transistor radios did not appear until 1957 and the Taiwan and Korean versions until the ‘60s. The first Sony portable transistor radio was not produced until 1955 (Sony TR-55) and the first Sony pocket sized unit (Sony TR-63) in 1957.