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 that also serves to control LEDs and other loads is from a 1960 publication. The...
This circuit was found in a documentation from the 70s. The FET admits current equivalents and the...
The operating range of this circuit is 10 kHz 30 MHz. Equivalent transistors can be used. The...