We found this circuit in an old publication. The components used are rare today. Accuracy depends on the resistors in the input selection network. The circuit operates from 10 to 500 kHz.
We found this oscillator in a documentation for radio amateurs from the 1970s. The circuit can use...
Many oscilloscopes have high impedance inputs that make it difficult to observe high frequency signals...
This is the receiver for the previous circuit we found in the December 1992 Radio Electronics...