This high input impedance circuit is suggested by Motorola's 1993 Linear Interface ICs. The power supply must be symmetrical. The circuit has a differential input.
This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time...
This circuit is from 1971 American documentation. Transistors are still common except for 2N2060...
The frequency of this CMOS oscillator depends on the capacitor C and the 4051 output that goes to the...