This well-designed bistable configuration is for educational purposes. We found it in the September 19873 Radio Electronics magazine. The transistors are types from that time.
This line protector circuit was found in a 2002 documentation, but it is totally current and...
This antenna for the frequencies 146 or 440 MHz was found in a magazine 73 for Amateur Radio of...
With this circuit it is possible to increase the output voltage of a 7812 regulator. The circuit...