Cathode follower oscillator

The amplifier is a long-tail pair of two triodes, two bipolar transistors or two junction FETs.

A capacitor at the anode resistor of the right triode couples the amplified signal back to the LC-circuit.

The emitter follower is coupled to the common-base amplifier through the long-tail resistor R1, providing net gain necessary for oscillation.

[4] The voltage across the tuned circuit is approximately ±Vbe peak relative to ground.

The source-coupled oscillator uses two junction FET and a LC-circuit to produce a sine wave signal.