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, found in a 1964 US documentation, consists of a selective amplifier that lets only...
We found this circuit in an old documentation from the 70s. Its purpose is to indicate the...
We found this circuit in the April 1996 issue of Electronics Now magazine. The circuit uses a...