This 1924 receiver uses a battery for the tube filaments and a high voltage battery for the amplifier and detector circuit. The speaker is kind of high impedance era.
This circuit is from the 80's, using an integrated of the time. The circuit serves as a reference,...
This circuit was obtained from an American 80's documentation. The operational ones can be...
This logarithmic gain operating configuration was found in the June 1994 Electronics Now magazine. The...