Seventy-five years ago this month, the October 1946 issue of Popular Science showed how to put together this one-tube 80 meter CW transmitter. In the picture above, the transmitter is at the left. Not shown is an antenna matching unit. The two chasses are shown at left. Both the transmitter and matching unit have identical sets of coils and capacitors, and are connected by twisted lamp cord.
According to the article, the set can be put together for a few dollars, and fewer hours. It requires a power supply capable of supplying 250-300 volts. The set was said to be capable of real performance, despite its size. But the article noted that the 80 meter band was crowded with high power stations, so there would be a better chance of getting through during the relatively quiet hours.