I have a shed cupboard full of valves. Old ones from the 40’s and 50’s and couple salvaged from 60’s radios before transistors took over the world. As a kid I was into radios in a big way, and used to scribble radio schematics on the spare pages of my school jotters. I even built them at home, with a soldering iron, a “breadboard” and a lots of wires and resistors and capacitors. Some even worked, but the most fun was building a tiny wee transmitting device, that allowed me to jam radio signals on my little transistor radio a few feet away. Mind you I used to live in mortal terror that a man from the GPO would turn up at the house and drag me away for the crime of having an unlicensed radio transmitter.
The Post Office had real power in those days you know.