Shown here is a one-tube transmitter for 80 or 40 meters from the May 1951 issue of Radio News.

The 12-watt set’s main feature was its compact size. The author, Leon Wortman, W2LJU, noted that he knew at least one ham who had stayed off the air “because of the apartment shortage.” Whenever that ham expressed a desire to get back on the air from his cramped apartment, he wife protested that there was no room for equipment, nor even room to hang her nylons. The transmitter itself measured only 3 by 5 inches, although it also called for a similarly compact power supply which could be tucked away. The transmitter itself was crystal controlled using a 6V6GT.

Voltage doubler. Wikipedia image.

The power supply employed a 117 volt isolation transformer, but used a voltage doubler circuit to supply the B+. The author noted that the circuit was by no means new, and was employed in many receivers. However, it was rarely used in ham gear, and it was intriguing to think that you could take a voltage and double it without the use of inductors or transformers. It does this by charging a capacitor on each half of the cycle, and then placing those in series. In this case, the unit employed selenium rectifiers.