Freeze Alarm (CB14454E)

The circuit of a 1968 publication can be implemented with more modern transistors such as BC548 for NPN and BC558 for PNP.

UHF amplifier (CB10063E)
This amplifier was found in a 70s documentation. The product gain x bandwidth is 350 MHz. The...
Trill Generator (CB21241E)
This circuit mimics the trill of a bird. We found it in an American documentation from the 90s. It is...
Pulsator (CB14824E)
With the values indicated for this circuit, the lamp will flash 60 times per minute (1 per...