This circuit was found in the magazine of radio amateurs 73 in a 90's edition. The components are current and the transistor is of general use.
This small receiver for the medium wave range was found in a Japanese documentation from 1961. The...
We can either supply this circuit with 12 V if we use a relay for this voltage as well as 6 V if...
This circuit is from an English publication of 1991. With it you can use a common multimeter on...