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.
One 40108 Schmitt inverter or one 4093 gate can be used as a half monostable to be triggered by...
This signal generator found in Japanese documentation of 1973 uses an unusual integrated circuit...
This is the basic configuration of an operational amplifier as a current regulator. We found it in...