Crystal test (CB7538E)

Found in the American 73 magazine for radio amateurs, this circuit can test common quartz crystals. The circuit includes the power supply.

| Clique na imagem para ampliar |

26 V switching regulator (CB8688E)
Found in a 1964 Electronic Design, this circuit makes use of period components. The components are from...
Digital inverter with transistor (CB25625E)
In the figure we have the simple way to obtain a digital inverter using a general-purpose...
Christmas light (CB7591E)
Found in a RE Experimenter Handbook from the 90s, this circuit is intended for the use of LEDs in...