This amplifier with the EL84 tube is a European commercial type from Corpim mounted on a printed circuit board. The diagram appeared in a September 1958 Radio Electronics magazine.
This oscillator with FET was found in Popular Electronics from the 90s. This traditional...
This low-power circuit was found in the March 1990 issue of Radio Electronics magazine. It...
This circuit found in a 1964 US publication reverses the signal level by providing 9 to 0 V...