This very high input impedance JFET circuit was found in the 1995 Encyclopedia of Electronic Circuits Volume 5. The JFET is a general-purpose transistor as is the output transistor.
This is a circuit with a period component that consisted of a voltage reference. The circuit is...
The critical components of this 1978 circuit are transformers, which, hopefully, can be obtained from...
We found this circuit in the March 1991 issue of Radio Electronics magazine. The integrated...