The first electronic amplifier on our planet had the grid at space potential

Patent US879532 - Lee de Forest:


https://worldwide.espacenet.com/publicationDetails/originalDocument?CC=US&NR=879532A&KC=A&FT=D&ND=3&date=19080218&DB=EPODOC&locale=en_EP


How many hundred years ahead of its time.


How similar is the Neumann U47 schematic...


http://downloads.bbc.co.uk/rd/pubs/reports/1954-23.pdf