He was primarily known for advocating several technologies designed to improve the sound quality of AM radio.
Later, a part of that system was used to develop the CAM-D AM digital broadcasting technology.
His other notable inventions include maximum ratio combining[1] used in multiple output systems.
with the low frequency components 50 Hz-250 Hz at the remote site then demodulated the 3 kHz carrier at the studio end.
This was then combined with the telephone quality audio and produced a much more natural sounding broadcast ranging from 50 Hz to as high as the telephone line would permit with the exception of the sharp notch at 3 kHz to filter out the carrier.