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 was obtained in an Electronics World of 1969. It is a crystal oscillator with a 100...
This circuit, shown in the figure, consists of a variable gain amplifier with differential input...
This circuit was found in the July 1992 Radio Electronics magazine. Sensitivity adjustment is made...