The radio already had its electrolytics replaced — a topic of hot contention lately. If you want to build your own tube-based AM transmitter, you might want to have soup for lunch.

An AM transmitter is simple enough, in this case an oscillator and buffer driving a class C power amplifier. The modulation is applied by a transistor in series with the power amp, driven from an ...

WJLX(AM) in Jasper, Ala., which made national headlines last year after the disappearance of its broadcast facilities, has ...