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 moisture-activated relay was obtained from an American documentation from the 1980s,...
Found in an old American publication, this circuit indicates the direction the antenna is pointing in...
We found this circuit in Radio Electronics magazine from August 1984. The circuit aims to control the...