> When I used a variable load on the 12V both the amplitude and the period > varied. More load less amplitude.
More load _reduces_ the ripple? That's very unusual. > Added the AVO option. Then I have perfect picture. So the extra loading > makes a difference. But that mostly loads the +5V line. I am wondering what on earth can generate a waveform of around 390Hz in that supply. Have you checked that the +12V Startup supply is nice and smooth. I doubt that's the problem, but it is worth eliminating it. -tony
