From Vacuum Tubes in Wireless Communication by Elemer E. Bucher. 1918. Makes for an interesting contrast with the radio schematic published just 4 years earlier, as shown here http://clk.works/that-background-image/ Dunno, I like the one that needs alcohol to work.
For some reason a scam artist has locked on to our phone number and keeps leaving this message. The message is just wrong at so many levels it’s funny in a pathetic sort of way. Nothing to do with anything really, just more fluff for the website.
Still fun though to think about the days when a pentode-triode tube was cool… And remember in 60 years someone will look back at your quaint designs with op-amps, microprocessors, etc., and think WTF how did they make anything work back then?