This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit equivalents although the indicated types can still be found with some ease.
This circuit uses an oscillator that generates a signal of approximately 1450 kHz to test...
Light falling on the transistor changes both the mark and the space of the generated signal thanks to the...
This basic configuration can be found in a lot of articles on this site. In this case, the relay...