Found in a 90s R-E Experimenters Handbook, this circuit amplifies signals from 100 Hz to 3 MHz. The circuit has a gain of approximately 30 dB. Bipolar transistors are general-purpose types.
This circuit provides just over ½ W to a small speaker. We found this configuration in an old...
This circuit was found in Philips documentation from 1969. The components are from the time...
We found this simple alarm circuit in a 1981 documentation. As we can see, it is a car alarm...