Eighty-five years ago this month, the October 1941 issue of Radio News showed how to build this compact transmitter for 10-160 meters. Band switching was accomplished with plug-in coils, and input power was about 8 watts, and it operated AM phone as well as CW. The large component in the center was the modulation transformer. A voltage-doubler circuit was used, eliminating the need for a power transformer. The 6J5 served as Pierce oscillator, with the 25B6G as amplifier. The other two tubes handled the modulation.

Since it was an AC-DC circuit, the article warned that the chassis should not be grounded.