[ARC5] Pre-WW2 technology

[James Cole]

I am curious about something I recently read: that the ARC-5 (and immediate
predecessor) was designed in 1938 -  that the basic design of the ARC-5
series was designed well before WW2. What surprises me is that I was under
the impression that in the late 30's superhets were either rare or unknown
(?) and the concept of "miniaturization" i.e., compact design, was
unheard-of. How was it that the ARC-5 (ARA) emerged from this? Was it some
particular engineer? In my view the ARC-5 receivers are models of
ingenuity, and yet they seem to have evolved from...where? - Jim