This receiver is from a 1924 Gernsback publication. The receiver has good efficiency when powered by the indicated voltages. Listening is through a high-impedance phone.
This circuit appears several times in this section and on this site, obtained from different...
This circuit was found in a General Electric documentation from 1970. Equivalent transistors can be...
The circuit shown consists of a NO and NC sensor system for alarms. The output must be connected to a...