) writes:
The heterodyne design (expecially the super heterodyne design) was a big
advancement in radios many years ago,wasen't it?
cuhulin

It was a big advance, but it was practically contemporary to the crystal
radio. Howard Armstrong received the patent for the regenerative receiver in
1914. He received the patent for the superheterodyne receiver in 1920.
His superregenerative receiver patent was issued in 1922. His FM patent
came significantly later.

19 years after Marconi spans the Atlantic, and there's a patent for
the superheterodyne receiver. Considering that wasn't a way station
towards future innovation, unlike the regenerative receiver, it
came about a pretty long time ago. Broadcasting as we know it hadn't
come about, if we listen to KDKA's claim of being the first.

Unless you build a receiver using some early concept, you basically
can't use a receiver without benefitting from Armstrong's work.

Michael