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Looking into a 465 S/N B260137 and trying to determine what seems to be causing the additional trace in background of triggered wave forms. Power supplies all look good for voltage and ripple. Suspecting trigger board but exactly unsure. Any thoughts would be welcome
Added photos to album : 465 Scope with Ghost trace

Craig

On Fri, Feb 21, 2025 at 09:43 AM, Craig Cramb wrote:

Looking into a 465 S/N B260137 and trying to determine what seems to be
causing the additional trace in background of triggered wave forms. Power
supplies all look good for voltage and ripple. Suspecting trigger board but
exactly unsure. Any thoughts would be welcome
Added photos to album : 465 Scope with Ghost trace

Most likely blanking is not working, you are seeing the trace travel back from end of sweep (right side) to beginning of sweep which should have been blanked. Since retrace happens faster than the regular sweep it looks like a slower waveform. Could be DC restorer diodes or something else in the blanking circuit.
Ozan

Could be DC restorer diodes or something else in the blanking circuit.
Ozan

Thanks for your quick response, I will start looking into that area.

Craig