This circuit tunes MW radios to apply the signal to a good audio amplifier. The circuit is from an old documentation. Transistors are general purpose types.
Found in a 90’s HAM Radio, this circuit is used for an optical communications system or even audio...
This circuit is from a 60's documentation. The capacitance C1 can be between 20 pF and 0.01 uF...
This circuit is from an old French documentation from the 70s. The coupler admits equivalents and...