When l was a kid, l built a one tube transmitter. l had a Halicrafters S38 receiver. l went on to buy an "ARC 5" transmitter from government surplus for $4.95. They were used on airplanes at one time. Anyway l removed the dynamo power supply and install an AC transformer/5U4G and filter. l was on the air! let my General Class HAM Lisc expire a few years back.