Hell Ziko, 1°) repeat trigger instead of auto trigger : it doesn't change anything : signal : 1,7kHz, sinus, 3v p to p (from my Marconi generator) acquisition with repeat trigger, both channels at +-10V Spectrum : Hann, average,... both channels at +-10V Marconi 1,7kHz 3V Ch A B +-10V.jpg 2°) OK for...