“Many collectors forget that Depression-era radio manufacturers were businesses. The ability to meet and even anticipate market demands was a key to survival — as it continues to be today.” (Lead paragraph from the original article)
RCA finally granted the use of the superheterodyne patent to other companies in July of 1930. Jackson-Bell introduced this type of receivers at the beginning of 1931.
The links in the column at left will take you to this article and the Jackson-Bells midget radios story.
The links below will take you back to the Blogs page should you wish to read a different article.