Actually John, that's not so daft ! Years ago when i first got interested in radio while still at school, i remember that a friend's father had a homebrew 160 metre station in which every bottle in the Tx, Rx and power supply used govt.surplus 807. And, Yes I do mean "in the power supply as well ! Even the rectfier was an 807. I think all the components came from ex-military WW2 kit. I certainly remember the Rx tuning mech. was one of those Muirhead slow-motion drives approx 3 inches dia.