57T280

Pages 762 and 763 of the Fall 1929 Sears Roebuck catalog lists Silvertone tubes for the first time, with a totally new type number, for example 57T280 = UX280. Research has not yet provided a manufacturer of these tubes or a factory location and Tyne's "Saga of the Vacuum Tube", page 362 states: "No information available" for Silvertone. It is presumed that these tubes were made by the Sonatron Tube Company, with an address in Chicago and in New York and it is also known that Sonatron acquired three smaller companies in 1929, before they themselves were acquired by National Union in September 1929 (Tyne page 359) Silvertone tubes continued to be available for some years and tube boxes with both Sears Roebuck and Silvertone printed in them are relatively common in the US. Sears Roebuck Archives state that the company "ended its association" with Silvertone (radios and or tubes is uncertain) in 1972.were .