This circuit can be used to test crystals from 1 to 20 MHz and also has an output to measure their frequency. We found it in the November 1998 Electronics Now magazine.
With the values of the components indicated, the circuit generates a 1 kHz signal. The power...
This circuit for measuring very low currents was found in an American documentation from the...
This circuit for the two-meter band of radio amateurs was found in 1980s documentation....