Intro:

This is a modern take on the original Garner oscillator, unlike other versions this one won’t lock up in full conduction and is guaranteed to always oscillate using modern parts, whereas the original -after a few modifications- would only seem to work with germanium transistors.

Mods:

The modifications are clear, we basically introduced a series resistor to limit inrush current during the low period, the low impedance side formed by the 10 Ohm resistor in Q2’s path was also adjusted, originally a higher resistance was found. We therefore achieved a safe balance which allows us to revive one of Garner’s proudest moments (Hey why else would anyone patent it otherwise, right?)

Another take:

Taking this oscillator as a baseline we can introduce other forms such as a sawtooth oscillator (It’s not perfect though!) with the help of our friend, capacitance.

How to:

To visualize the output waveform you could use a soundcard or a proper oscilloscope. Since the oscillating frequencies on both circuits are within the audible range you could also use a piezo speaker to hear it.

Fun isn’t it?, feel free to experiment and let me know if you find anything intersesting!.

Cheers.

This is the first oscillator I ever built. I remember looking at books and magazines, schematics on the net, etc. They were all either colpitt or hartley oscillators. Generally speaking while they’re simple enough, they require the use of proper inductors which is something that usually you don’t have when you’re just starting out or you can’t measure them because you don’t yet own the proper equipment (unless you’re lucky).

As to avoid frustration, you should ignore them for now and take a look at simpler oscillators like the one that follows:

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