Found in a QST magazine from the 90s, this circuit broadcasts on different amateur radio bands depending on the coil. Data for the coil and crystal are provided next to the diagram.
Found in an English Maplin documentation from 1983, this circuit generates separate frequency...
This powerful inverter provides a high-quality sine wave signal. I found it in a Radio Electronics issue...
Circuits and devices can be tested using the tester. The visual indication of the state of the...