Seventy-five years ago this month, the January 1948 issue of QST showed this one-tube one-watt transmitter using a 1S4 tube.  A flashlight battery supplied the filament voltage, and 30-90 volts of B+ was required.  Coil data was shown for 80 meters, but the circuit could easily be used on other bands.

A balanced antenna could be connected to L2, or that coil could be dispensed with and the antenna connected to the point marked X, worked against ground.  From Connecticut, the set made 22 contacts with 10 states over the course of 10 hours.  It was sent to the magazine by Ernest Lindsey, W4BIW.