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Why is there a difference in trace width between 1x and 10x probe?

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tautech:
Never discount it's a SMPS somewhere close by, maybe even in the next room as walls aren't made of lead and RF doesn't obey walls.
Keep switching things OFF until you find the culprit which then should be given flying lessons.  >:D

wasedadoc:

--- Quote from: tautech on April 15, 2023, 07:18:44 am ---Never discount it's a SMPS somewhere close by, maybe even in the next room as walls aren't made of lead and RF doesn't obey walls.
Keep switching things OFF until you find the culprit which then should be given flying lessons.  >:D

--- End quote ---
Even the SMPS in the 'scope.

Wallace Gasiewicz:
Here is what I would do, you probably have done most of this.
Plug in both of your probes and let them lie on the bench, get traces with 1X and 10X settings.Connect the ground lead on probes to the tip and get readings on 1X and 10X. This makes a RF "sniffer".
Then put them near the SG with the SG ON and repeat.
I think you have already done this with the probes attached to the SG,Just to be complete:  are your probes matched to your scope input impedance.

This might help locating the point of interference.If you see interference with the probes not attached to the SG the interference is in the ether.
If you see interference with the probes near the turned on SG then you have a culprit.You can also move the probes near to the scope.

Ethernet cables can also produce RF. I have observed this at about 14.2 MHz.If you see interference off the air, with the probes used as a sniffer, you might wish to characterize this interference using the FFT.
I think you are using 1X-10X switched probes. They can have bad characteristics and IMHO, not usually as good as "straight" 10X or straight 1X probesI am far from an expert on probes, but I have had problems similar to this with probes that switch from 1X to 10X.

2N3055:
What you see is difference in BW of probes mostly, with some little more noise of the scope...
But sharp peaks are really there. Enabling BW limit is hiding what crap PSU really sprays...

BW limit at 20MHz is used when you do measurements to compare with other PSU that are measured at 20MHz BW.

You also need to NOT use ground clip but a very short ground spring (or something of that sort).
That will make sure that your probe is not an antenna but really measures at certain point.

sonpul:
Do not use clamps or long conductors to measure weak signals. You can put a special spring on the probe, perhaps it is included with the oscilloscope. If not, then you can do it.
Look at the last two waveforms. The second one is with a spring. The latter with a clamp and a grounding conductor with a crocodile. Generator with high output impedance.

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