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 sensitive medium wave (MW) radio pick up the local station without the need of an external...
This audio circuit was published in a Rado Electronics issue from October 1963. The transistors are from...
Using a V/F converter this circuit was found in the June 1991 issue of Radio Electronics magazine. The...