I have wound two toroids and one E-core and they all work in the circuit with varying frequency of oscillation, from 50kHz to 80 kHz.
However the output is not sinusoidal, there is like a ringing on one side of the waveform. I can get 200v when rectified.
I have tried to attach a photo from the oscilloscope but this site won't let me attach it until I have posted ten times!!
Any ideas what's wrong despite no photo?
Thanks