Wikipedia has an entry for Tuned RF receivers that says EH Armstrong
invented the Tuned RF receiver in 1918. I think this is wrong. Armstrong
was in the throes of patenting the superheterodyne circuit at that time.

Hazeltine invented the Neutrodyne, but this was an improvement on the TRF
circuit. Was it just one of those things that logically developed from
wanting a bigger signal for the detector?

73,

Tom