9V power source (CB21164E)

This simple circuit with a 5V regulator was found in an American documentation from the 90's. The output voltage is adjusted in a trimpot.

| Clique na imagem para ampliar |

Side Tone for SSB (CB19978E)
This circuit was found in a documentation for radio amateurs from the year 70. Its purpose is to...
Flame Alarm (CB13715E)
We got this circuit in an old publication from 1978. The circuit uses a phototransistor and an...
2-Transistors MW Radio (CB18842E)
This simple transistor radio with only two germanium transistors was found in a Japanese magazine from...