RE: Part 2 – RoadTest Rohde & Schwarz NGL201 Power Supply

DAB — Tue, 30 Aug 2022 19:17:41 GMT

Good interim test report.

RE: Part 2 – RoadTest Rohde & Schwarz NGL201 Power Supply

michaelkellett — Sun, 28 Aug 2022 09:11:18 GMT

Hello Cosmin,

There is a problem with many of your pictures, which are very small even when clicked on.

I can't read most of the screen writing on the scope or psu. I find the best way to get pics onto E14 is to take a photo at around a 2.5Mbyte type compression setting and then post it as .jpg or .png

Your review is interesting.

Using the sourcemeter as a load may not work out well, sourcemeters and electronic loads use their own internal feedback loops which may clash with the feedback loop of the device you are testing. I would use a MOSFET switching a fixed power resistor in and out of ciruit.

Although I have two electronic loads (one cheap, one mid range (Rigol) I found I needed to build a box with relay switched fixed loads and a MOSFET pulser able to witch in a selection of additional loads. I just couldn't get truly reliable test results any other way.

Noise can be very hard to measure with a mains powered digital scope. Many squirt large amounts of RF energy back into the mains via the transformer interwinding capacitance and RF suppression filter. Removing the earth connection may or may not help (but is always unsafe). The only really reliable technique is to use an optically isolated or battery powered scope with a low noise pre-amp and filter.

I keep an ancient 20MHz analogue scope for this purpose but currently it's out of action (having gone noisy itself with mains hum !)