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.
Found in a 1990 Hobbyst Handbook this circuit has an output power of a few tens of watts and...
Two NAND gates are used in the configuration shown here to perform as a monostable triggered by...
Found in a 1980s American documentation, this circuit is based on the common CMOS series...