This circuit is from an old American documentation and its use in motorcycles with 12 V is suggested to power 6V radios. The transistor can be the BD136 and BC548.
This circuit was found in an American publication called Ham Radio. The circuit uses still current...
From an audio signal, this circuit gets two signals of the same amplitude and opposite phases....
Found in an Electronic Design from 1968 this circuit generates a linear sawtooth signal modulated...