This ham sixty years ago, probably the article author, Clare Green, W3IKI, at the key of a QRP rig described in the September 1965 issue of Electronics Illustrated.

He notes that anyone can turn on a couple hundred watts and make some contacts. But you could also use the telephone or the U.S. Mail. He discovered the challenge of QRP (low-power operation), and came up with this 1/2 watt transmitter for 80 meters. It was notable for having a stable VFO, meaning that you weren’t stuck on a single frequency.

He notes that the contacts have to be clean on your key, because the low voltages wouldn’t be forgiving of the added resistance.