This old circuit from the 80's generates logic signals with 50% active cycle (squares). The integrated circuit used is not common today, but equivalent logic functions can be used in a modern version.
This powerful amplifier with 2N3055 transistors at the output provides a few tens of watts rms on a...
With this circuit it is possible to receive and send audio signals simultaneously over the same...
This circuit generates 100 MHz signals from a 20 kHz crystal. The circuit is from an 80's...