METRIX OX8050 oscilloscope - spikes on square wave signal

[tuchap]

Hello,

I've a Metrix OX8050 oscilloscope that displays a spike on square wave transitions. This is on both channels and the same with AC and DC input. The probe is correctly compensated and it's the same when injecting an external 1kHz square wave through a coaxial cable. Any ideas? Thanks

 

[danadak]

You have a short ground clip lead ?

Probing Techniques for Accurate Voltage Measurements on Power Supplies with Oscilloscopes

This application note describes considerations and techniques for making accurate voltage measurements on power converters with an oscilloscope, especially as they relate to probe

www.tek.com

Regards, Dana.

 

[tuchap]

You have a short ground clip lead ?

Probing Techniques for Accurate Voltage Measurements on Power Supplies with Oscilloscopes

This application note describes considerations and techniques for making accurate voltage measurements on power converters with an oscilloscope, especially as they relate to probe

www.tek.com

Regards, Dana.

The issue is with internal probe adjust signal (then internal ground of the scope), and also when feeding through a coaxial cable, then not ground related.

 

[Nigel Goodwin]

Hello,

I've a Metrix OX8050 oscilloscope that displays a spike on square wave transitions. This is on both channels and the same with AC and DC input. The probe is correctly compensated and it's the same when injecting an external 1kHz square wave through a coaxial cable. Any ideas? Thanks

If the calibration signal looks like that, how can you know the probe is correctly compensated? - it looks very much like it isn't, perhaps the probe is faulty?.

Is the probe just x10, or is it switchable x1/x10?.

 

[tuchap]

If the calibration signal looks like that, how can you know the probe is correctly compensated? - it looks very much like it isn't, perhaps the probe is faulty?.

Is the probe just x10, or is it switchable x1/x10?.

Because I've tried with several different probes (10x and switchable) and by direct connection to a generator. It's possible to see that the compensation is correct because this overshoot is much shorter than the slope induced by wrong compensation.

 

[rjenkinsgb]

The probe compensation only works in x10 and that must be only adjusted with the probe switched to the x10 setting.
(And only using the insulated tool supplied with the probe kit).

Direct connections are not reliable with fast edges.