Each book in "The Radio Boys" series by "Allen Chapman" included a short foreword by Jack Binns, who had gained fame as the radio operator aboard the Republic when it sank in 1909. In this edition, Binns commented on the "super-regeneration" circuit recently invented by E.  H. Armstrong, which would be briefly heralded as a major advance in receiver design. (Note that super-regeneration is different from the similarly named "super-heterodyne" circuit). However, super-regeneration turned out to be limited in selectivity, so it actually was rarely used by radio manufacturers, who a few years later would introduce receivers using the more sophisticated super-heterodyne circuits, also largely the invention of E. H. Armstrong. (Armstrong would later develop the wideband FM system still used by broadcasting stations today.)
The Radio Boys at the Sending Station, Allen Chapman, 1922, pages v - vi:



    SINCE this volume was written an epoch making invention has been announced to the radio world. It is the super-regenerative system developed by E. H. Armstrong, the wizard of Columbia University. This system is bound to revolutionize the art of wireless communication in every branch, and is in itself the most important discovery since Marconi put into operation the first crude form of wireless apparatus.
    I am mentioning this fact because there is the romance of youth overcoming every obstacle placed before it tied up in the history of Armstrong's remarkable achievements, and the story of this romance should stand forward as an incentive to American boyhood.
    Fifteen years ago when radio amateurs first began to send out wireless telegraph messages, the federal authorities in Washington were at a loss to devise some means that would regulate them. It was then that a bright official conversant with radio said: "Put 'em down below 200 meters, and they'll soon die out."
    He knew perfectly well that it was almost impossible to operate on those low wave-lengths with the apparatus in existence at that time--hence his sardonic proposal. The amateurs however, refused to "die out." Faced with the inexorable regulation, they set to work to devise apparatus which would operate successfully. Among them was E. H. Armstrong, a youth who at that time was attending Columbia.
    It was a really lucky thing for the world that the official in Washington thought of his clever scheme to kill the amateurs, because it provided just the incentive needed to set Armstrong to work. The result has been that within ten years he has produced three epoch-making inventions, any one of which would have been a remarkable life achievement in itself.
    Such, briefly is the story of one radio boy overcoming difficulties, but of course in this case it is a real story. It emphasizes the fact that even in these highly developed and organized times there is always an opportunity for boys to improve upon existing conditions, and since this is the theme of the adventures of "The Radio Boys," I am very glad to write the foreword to the series.
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