This circuit is used in transceivers, enabling input selection by diode switching through polarity reversal. The circuit is from an old American documentation on telecommunications.
This interesting circuit is nothing more than a joke. Of course it can be used for other purposes....
This powerful high-fidelity amplifier was described in an article in Radio Electronics magazine in...
The power of this germanium transistor audio output stage is a few tens of milliwatts. The circuit is...