A wacky looking build. It's a simple Twin T Audio Frequency Oscillator used to help setup home brew or kit transmitters. Produces a tone and saves having to whistle down the microphone whilst setting radio. The circuit includes a preset so the peak to peak of the sine wave can be set to match that of the microphone that is going to be used with the radio.

I built this with components recycled from old junk box CB radios and surplus leftover components that I have gathered over the years.

Seems to be producing 800Hz tone at about 40mV peak to peak.

Circuit design is from S.Hartley and can be found here.