The Franklin Oscillator

The Franklin oscillator is a little strange and not immediately obvious how it works:

The following helps a lot:

(source: www.radiosparks.com/images_d/Franklin Oscillator.png)

So positive feedback at parallel resonance (0 degrees phase shift).

The next image is a transistor version:

(Source: www.uploadarchief.net/files/download/franklinoscillator.gif)

Here is a rationalised (long tail pair) FET version:

(source: www.uploadarchief.net/files/download/osci.png)

Still it takes a leap of faith to get to here:

(Source: i178.photobucket.com/albums/w269/notxyl97/DL7MWNQ-Multiplier.png)

But at low voltages most of the biasing components can go!

AlanX