This amplifier was found in a tube equipment manual from 1947. The high-fidelity circuit has pentode tubes at the output and a source with transformer.
This car battery power supply was found in the June 1990 issue of Radio Electronics magazine....
This toy musical instrument has the notes given by the capacitors on the keyboard. The circuit can be...
Originally designed for an incandescent lamp, this flasher or pulser can be adapted to operate with...