[cctalk] Re: Repairing an Olivetti M24 PSU

On 9/3/25 11:18, Rob Jarratt wrote: Switching power supplies generally radiate a ton of electrical fields at their switching frequency.  If you see insanely high frequencies in these measurements, you can usually assume they are radiated interference.  You can also turn on the scope's bandwidth filter.  I did see REAL ripple in one of the traces, there were long straight lines with slight tilt between the noise pulses, those are the real ripple. Improving the ground connection at the scope probe also helps. The power supply injects currents into the ground terminal due to capacitance between output transformer windings, and these current flowing in the probe's ground braid contaminates the measurement. Possibly running a HEAVY copper braid between the scope's ground terminal and the power supply ground will reduce the effect. Jon