This circuit for communications receivers was found in the January 1974 issue of Radio Electronics magazine. The transistors are Japanese types of the time, as the circuit was part of equipment of that origin.
This circuit is from a 1957 Raytheon transistor manual. The diode can be of general-purpose...
The circuit shown in the figure shuts off a load when the voltage drops below the value determined...
This circuit was obtained from an English magazine from 1976. The signal from the circuit should be...