Self-biasing JFET circuit (CB25563E)

This JFET amplification stage was found in the April 1993 issue of Electronics Now. The input impedance is 10 Megohms.

Wien Bridge Oscillator (CB8089E)
This circuit generates sinusoidal signals between 300 and 3000 Hz. We find a 303 Circuits from the 90's....
Line Amplifier (CB19052E)
This amplifier for audio transmission lines was found in a 1961 American publication. The critical...
Intercom with telephone (CB7829E)
Old phones with dials can be used in a simple home intercom system, as this circuit from Popular...