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 circuit found in a 1988 documentation consists of a timer or sequential timer controller. The...
This resistance meter circuit was found in the February 1984 issue of Radio Electronics magazine. It is...
We found this circuit on the internet. The components are current, and the time depends on C1...