This circuit was obtained in the 1990 Motorola Linear Databook. The circuit uses a 139 series comparator, but other series can be used. The power source need not be symmetric.
This powerful FM transmitter with FET can reach more than 1 km in favorable conditions. L1...
Found in Popular Electronics from the 90s, this circuit generates two tones that are selected by a...
Found in a 73 magazine for radio amateurs of the 90s, this circuit provides a 2 kV voltage with 7.5...