This tone control was obtained in the Audio Handbook of the National Semiconductor of 1977. The circuit controls the signals of medium frequencies in a wide dynamic range as shown in the diagram.
This sample and hold circuit configuration was found in a manual from the 70s. The operational amplifiers...
This small MW transmitter emits its signals at a distance of a few tens of meters, depending on the...
Found in American documentation from the 90s, this circuit uses common FETs. It has a range drift...