Note
Popular Electronics, Mar 1959, p. 38.
Popular Electronics, May 1961, p. 28. (100 mw version)
Popular Electronics, Jan 1962, p. 110.
Springfield released this unit in March 1959. It is based on the TC-144 series the company released in 1957.
Originally, no model number was given, but in November 1959, an ad in the same style as the original appeared from a company called Elcolab. In this ad the unit was called the RT-27A. Moreover, unlike the "everything is an accessory" model used by Springfield, the Elcolab units were "complete, ready to operate."
In May 1960 Popular Electronics (p. 123) another ad for Springfield.
In November 1961 (p. 130) same ad but for Vanguard Electronic Labs, also in Hollis NY.
By at least June 1962, these units had evolved into a variety of services--CB, CAP, industry, civil defence, and amateur.
