Found in a 90s Electronics Engineering, this circuit makes use of components of the time. The critical component is the microwave sensor diode.
This circuit is a variation of the common grid dip meter, having been found in a 1975 publication on FETs....
This circuit was found in old documentation, but the setting applies to any operational. Resistors...
This circuit was found in an Electronics World magazine from 1990. The circuit can be mounted...