Found in American documentation from the 1980s, this circuit makes use of components of the time, which are uncommon today. The circuit detects the approach using a sensor formed by metal plates.
This circuit connected to the input of a good amplifier, with suitable coils can tune stations of medium...
This circuit was obtained in an American documentation of 1975. The transistor can be the BC548, and...
The values of the components of this Mullard (Philips) circuit depend on the desired voltages. The...