Using the LM3909 this circuit was found in the January 1992 issue of Radio Electronics magazine. Resistor R1 should be chosen according to the table given next to the diagram.
This circuit tests crystals up to a few megahertz with ease. The circuit is from a 1977...
In the figure we have the way to connect 6 solar cells in order to obtain higher voltage and...
This circuit can be used both as a beat oscillator and for testing and adjusting AM receivers for...