It’s been a long time since vacuum tubes were cutting-edge technology ... as well as how continuous wave (CW) modulation really optimizes QRP setups like this. Thanks to [Stephen Walters ...

[Pete Juliano, N6QW] built a 20 M QRP CW transmitter using just a handful of parts. That in itself will not raise any eyebrows, until you find that he built it using one of the very first RF ...