Found in a 1966 publication, this circuit is a simple version of a field strength meter. The diode is a general-purpose germanium type.
This circuit can be tuned in a 100 kHz band around the frequency of the crystal. The transistor can be...
The figure shows how to obtain a digitally programmed resistance using the 4066. The circuit is...
This audio oscillator has its frequency determined by C1, C2 and the inductor. The inductor can be...