We found this tube receiver in a 1950s Japanese publication. The circuit uses 5 tubes and has an RF amplifier stage for greater sensitivity. The power supply is not shown on the circuit.
This current meter with many scales was found in a 80s American documentation. The operational amplifier...
This circuit was found in the February 1971 issue of Radio Electronics magazine. It is designed to power...
This circuit is old, causing LEDs to be lit sequentially. Several types of games can be programmed using...